DRAFT
DEVELOPMENT DOCUMENT FOR
EFFLUENT LIMITATIONS GUIDELINES
AND NEW SOURCE PERFORMANCE STANDARDS
TIMBER PRODUCTS INDUSTRY
VENEER/PLYWOOD AND HARDBOARD, WOOD PRESERVING
VENEER/PLYWOOD AND HARDBOARD
PREPARED BY
ENVIRONMENTAL SCIENCE AND ENGINEERING, INC.
GAINESVILLE, FLORIDA
JUNE, 1973
WOOD PRESERVING
PREPARED BY
MISSISSIPPI FOREST PRODUCTS LABORATORY
MISSISSIPPI STATE UNIVERSITY
MAY, 1973
FOR:
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
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NOTICE
The attached document is a DRAFT CONTRACTOR'S REPORT. It includes tech-
nical information and recommendations submitted by the Contractor to the
United States Environmental Protection Agency ("EPA") regarding the sub-
ject industry. It is being distributed for review and comment only. The
report is not an official EPA publication and it has not been reviewed by
the Agency.
The report, including the recommendations, will be undergoing extensive
review by EPA, Federal and State agencies, public interest organizations
and other interested groups and persons during the coming weeks. The
report and in particular the contractor's recommended effluent guidelines
and standards of performance is subject to change in any and all respects.
The regulations to be published by EPA under Sections 304(b) and 306 of
the Federal Water Pollution Control Act, as amended, will be based to a
large extent on the report and the comments received on it. However,
pursuant to Sections 304(b) and 306 of the Act, EPA will also consider
additional pertinent technical and economic information which is developed
in the course of review of this report by the public and within EPA. EPA
is currently performing an economic impact analysis regarding the subject
industry, which will be taken into account as part of the review of the
report. Upon completion of the review process, and prior to final pro-
mulgation of regulations, an EPA report will be issued setting forth EPA's
conclusions regarding the subject industry, effluent limitations guide-
lines and standards of performance applicable to such industry. Judgments
necessary to promulgation of regulations under Sections 304(b) and 306 of
the Act, of course, remain the responsibility of EPA. Subject to these
limitations, EPA is making this draft contractor's report available in
order to encourage the widest possible participation of interested per-
sons in the decision making process at the earliest possible time.
The report shall have standing in any EPA proceeding or court proceeding
only to the extent that it represents the views of the Contractor who
studied the subject industry and prepared the information and recommenda-
tions. It cannot be cited, referenced, or represented in any respect in
any such proceedings as a statement of EPA's views regarding the subject
industry.
U. S. Environmental Protection Agency
Office of Air and Water Programs
Effluent Guidelines Division
Washington, D. C. 20460
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DRAFT-
DEVELOPMENT DOCUMENT FOR
EFFLUENT LIMITATIONS GUIDELINES
AND STANDARDS OF PERFORMANCE
TIMBER PRODUCTS INDUSTRY:
VENEER/PLYWOOD AND HARDBOARD
Prepared by:
Environmental Science and Engineering, Inc
2324 Southwest 34th Street
Gainesville, Florida 32601
Under Contract No. 68-01-1506
June, 1973
WOOD PRESERVING
Prepared by
Dr. Warren S. Thompson
Mississippi Forest Products Laboratory
Mississippi State University
Post Office Drawer FP
Mississippi State, Mississippi 39762
Under EPA Project No. R801308
May, 1973
FOR:
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
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DRAFT
ABSTRACT
This document presents the findings of an extensive study of
the timber products industry by Environmental Science and
Engineering, Inc., (Veneer/Plywood and Hardboard) and Missi-
ssippi Forest Products Laboratory (Wood Preserving), for the
purpose of recommending to the Environmental Protection Agency,
Effluent Limitations Guidelines, Federal Standards of Perfor-
mance, and Pretreatment Standards for the industry, to imple-
ment Sections 304, 306, and 307 of the "Act."
Effluent limitations guidelines contained herein set forth
the degree of effluent reduction attainable through the ap-
plication of the best practicable control technology currently
available and the degree of effluent reduction attainable
through the application of the best available technology eco-
nomically achievable which must be achieved by existing point
sources by July 1, 1977 and July 1, 1983, respectively. The
Standards of Performance for new sources contained herein set
forth the degree of effluent reduction which is achievable
through the application of the best available demonstrated
control technology, processes, operating methods, or other
alternatives.
The hardboard industry has been divided into two subcategor-
ies; dry process hardboard and wet process hardboard. The
proposed regulations for the dry process hardboard industry
for all three levels of technology set forth above establish
the requirement of no discharge of wastewaters to navigable
water. The proposed regulations for the wet process hard-
board industry for July 1, 1977 are a discharge of BODs and
suspended solids of 1.6 kilograms per ton (3.2 pounds per ton)
and 2.8 kilograms per ton (5.6 pounds per ton), respectively.
The recommended discharge limitations for July 1, 1983 for
BODs and suspended solids are 0.2 kilograms per ton (0.4
pounds per ton) and 1.1 kilograms per ton (2.1 pounds per ton),
respectively. The recommended Standards of Performance for
new sources are the same as those for July 1, 1983.
The veneer and plywood industry is considered as one category
of the timber products industry without further subcategoriza-
tion. The proposed regulations for all three levels of tech-
nology set forth above establish the requirement of no dis-
charge of wastewaters to navigable waters, with special
considerations for plants with existing steam vats.
The best practicable treatment and control technology currently
available and the best available treatment and control
111
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW-BY 'EPA.
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DRAFT
technology economically achievable are defined for the wood
preserving industry, along with technology applicable to new
sources. Effluent limitations commensurate with these levels
of technology are recommended for each of four industry sub-
categories.
An evaluation of the results has shown that the most serious
waste problem in terms both of volume and quality of effluent
is at plants that steam condition stock prior to treatment
with oily preservatives. Among plants that condition stock
by other means, treat with water-soluble chemicals, or use
non-pressure processes for preservative treatment, a zero
discharge of process water is currently practical.
Supportive data and rationale for development of the proposed
Effluent Limitations Guidelines and Standards of Performance
are contained in this document.
iv
NOTICE. THESE ARE TENTATIVE RECCMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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CONTENTS
Section Page
I Conclusions 1
II Recommendations 5
III Introduction 9
Purpose and Authority 9
Summary of Methods 10
General Description of the Industry 11
Inventory of the Industry 17
IV Process Description and Industry
Categorization 41
Process Description-Veneer and Plywood 41
Process Description-Hardboard 52
Process Description-Wood Preserving 65
Industry Categorization 68
Veneer and Plywood-Subcategorization 68
Hardboard Industry-Subcategorization 72
Wood Preserving-Subcategorization 75
V Water Use and Waste Characterization 79
Part A: Veneer and Plywood 79
Part B: Hardboard 107
Dry Process Hardboard 107
Wet Process Hardboard 115
Part C: Wood Preserving 137
Wastewaters Containing
Entrained Oils 137
Salt-Type Preservatives and
Fire Retardants 144
Raw Waste Loading Data 144
Sources of Wastewater 153
VI Selection of Pollutant Parameters 159
Wastewater Parameters of Pollutional
Significance 159
Discussion of Pollutant Parameters 160
v
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CONTENTS (Continued)
Section
VII Control and Treatment Technology 163
Part A: Control and Treatment
Technology in the Veneer
and Plywood Industry 163
Part B: Control and Treatment
Technology in the
Hardboard Industry 170
Dry Process Hardboard 170
Wet Process Hardboard 170
Part C: Control and Treatment
Technology in the Wood
Preserving Industry 191
Status of Technology in
Industry 191
Status of Pollution Control
in Industry 191
Treatment and Control
Technology 196
VIII Cost, Energy, and Non-Water
Quality Aspects 245
Part A: Veneer and Plywood 245
Part B: Hardboard 251
Cost and Reduction Benefits
of Alternative Treatment and
Control Technologies for Dry
Process Hardboard 251
Cost and Reduction Benefits
of Alternative Treatment and
Control Technologies for Wet
Process Hardboard 252
Part C: Wood Preserving 257
Alternate Treatment and
Control Technologies 257
Engineering Estimates for
a Hypothetical Subcategory
1 Plant 257
Engineering Estimates for
a Hypothetical Subcategory
2 Plant 258
Non-Water Quality Aspects 259
VI
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CONTENTS (Continued)
Section
IX Effluent Reduction Attainable Through
the Application of the Best Practicable
Control Technology Currently Available -
Effluent Limitations Guidelines 261
Introduction 261
Veneer and Plywood Industry 262
Dry Process Hardboard Industry 264
Wet Process Hardboard Industry 266
Wood Preserving Industry 268
X Effluent Reduction Attainable Through
the Application of the Best Available
Technology Economically Achievable -
Effluent Limitations Guidelines 279
Introduction 279
Veneer and Plywood Industry 280
Dry Process Hardboard Industry 280
Wet Process Hardboard Industry 280
Wood Preserving Industry 282
XI New Source Performance Standards 291
Introduction 291
Veneer and Plywood Industry 291
Dry Process Hardboard Industry 292
Wet Process Hardboard Industry 292
Wood Preserving Industry 292
XII Acknowledgements 299
XIII References 301
XIV Glossary 315
Appendix A 331
Appendix B 357
VII
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TABLES
Number Title Page
1 Consumption of Principle Preservatives and
Fire Retardants of Reporting Plants in the
United States 16
2 Summary of Veneer and Plywood Plants in the
United States 18
3 Forest Industries 1968 Plywood Statistics 26
4 Softwood Plywood Production for 1972 28
5 Hardwood Plywood Production in the
United States 29
6 Softwood Plywood Production in the
United States 29
7 Inventory of Hardboard Manufacturing
Facilities 31
8 Wood Preserving Plants in the United States
by State and Type 36
9 Materials Treated in the United States by
Product and Preservatives, 1967-1971 38
10 Ingredients of Typical Protein, Phenolic
and Urea Glue Mixes 49
11 Current and Projected Adhesive Consumption
in the Plywood Industry 50
12 Classification of Hardboard by Surface,
Finish, Thickness and Physical Properties 66
13 Some Properties of United States Woods 81
14 Winter Characteristics of Oregon Log Ponds
Part A: Chemical Characteristics 83
Part B: Physical Characteristics 84
15 Summer Characteristics of Oregon Log Ponds
Part A: Chemical Characteristics 85
Part B: Physical Characteristics 86
IX
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TABLES (Continued)
Number Title Page
16 Winter Wasteload from Oregon Log Ponds 87
17 Ponderosa Pine Wet Deck Data 88
18 Analysis of Sample Taken from a Wet Decking
Recycle Pond 88
19 Characteristics of Debarking Effluents 91
20 Characteristics of Steam Vat Discharges 92
21 Characteristics of Hot Water Steam
Vat Discharges 94
22a Analysis of Drier Washwater 95
22° Waste Loads from Veneer Driers 96
23-A Average Chemical Analysis of Plywood Glue 98
23-B Average Chemical Analysis of Plywood
Glue Washwater 100
23-C Characteristics of Glue Washwater 101
23-D Amount of Adhesive Washwater Generated in
Southern Pine Plywood Plants 102
23-E Glue Waste Discharge Measurements 103
24 Wastewater Flow and Source 108
25 Average Chemical Analysis of Plywood Resin 110
26 Analyses of Some Common Species of Wood 124
27 Wastewater Discharges from Wet Process
Hardboard 132
28 Raw Wastewater Characteristics from Wet
Process Hardboard 133
29 Progressive Changes in Selected Character-
istics of Water Recycled in Closed
Steaming Operations 140
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TABLES (Continued)
Number Title Page
30 Phenol and COD Values for Effluents from
Thirteen Wood Preserving Plants 143
31 Ratio Between COD and BOD for Vapor Drying
and Creosote Effluent Wastewaters 146
32 Range of Pollutant Concentrations in
Wastewater from a Plant Treating with CCA-
and FCAP-Type Preservatives and a Fire
Retardant 146
33 Raw Waste Loadings for Plant No. 1 147
34 Raw Waste Loadings for Plant No. 2 148
35 Raw Waste Loadings for Plant No. 3 149
36 Raw Waste Loadings for Plant No. 4 150
37 Raw Waste Loadings for Plant No. 5 151
38 Average JRaw Waste Loadings for Five Wood-
Preserving Plants 152
39 Source and Volume of Water Discharged and
Recycled per Da) by a Typical Wood-
Preserving Plant 156
40 The Adhesive Mixes Used (Cascophen 3566C) 169
41 Representative Process Water Filter
Efficiencies 177
42 Primary Settling Tank Efficiency 181
43 Treatment Efficiency of Biological Systems 184
44 Example of an ASB System Performance
Related to Temperature 189
45 Method of Disposal of Wastewater by Wood
Preserving Plants in the United States 192
XI
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TABLES (Continued)
Number Title Pag<
46 Method of Disposal of Wood Preserving
Wastewater by Region 192
47 Compliance with State and Federal Water
Standards Among Wood Preserving Plants
in the United States 193
48 Plans of Wood Preserving Plants not in
Compliance with Water Standards in the
United States 193
49 Type of Secondary Wastewater Treating
Facilities Installed or Planned by Wood
Preserving Plants in the United States 194
50 Type of Secondary Wastewater Treating
Facilities Installed or Planned by Wood
Preserving Plants by Region 195
51 Efficiencies of Oil Separation Process 198
52 Effect of Lime Flocculation on COD and
Phenol Content of Treating Plant Effluent 202
53 Toxic Constituents in the Principal Salt-
Type Preservatives and Fire Retardant
Chemicals Used in the United States 204
54 Concentrations of Pollutants Before and
After Laboratory Treatment of Wastewater
from Two Sources 206
55 Concentration of Pollutants in Plant
Wastewater Containing Salt-Type Preserv-
atives and Fire Retardants Before and
After Field Treatment 207
56 BOD, COD and Phenol Loading and Removal
Rates for Pilot Trickling Filter Processing
a Creosote Wastewater 211
57 Relationship Between BOD Loading and Treat-
ability for Pilot Trickling Filter Process-
ing a Creosote Wastewater 212
XII
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TABLES (Continued)
Number Title Pag(
58 Sizing of Trickling Filter for a Wood
Preserving Plant 213
59 Substrate Removal at Steady-State Con-
ditions in Activated Sludge Units Contain-
ing Creosote Wastewater 217
60 Reduction in Pentachlorophenol and COD in
Wastewater Treated in Activated Sludge
Units 218
61 Results of Laboratory Tests of Soil
Irrigation Method of Wastewater Treatment 220
62 Reduction of COD and Phenol Content in
Wastewater Treated by Soil Irrigation 221
63 Average Monthly Phenol and BOD Concentra-
tions in Effluent from Oxidation Pond at
Weyerhaeuser"s DeQueen, Arkansas Operation:
1968 and 1970 225
64 Effect of Chlorination on the COD and
Phenolic Content of Pentachlorophenol and
Creosote Wastewaters 226
65 Effect of Chlorination with Calcium Hypo-
chlorite on the Pentachlorophenol Content
of Wastewater 228
66 Effect of Chlorination with Chlorine Gas
on the Pentachlorophenol Content of
Wastewater 228
67 Effect of Chlorination of Pentachlolophenol
Waste on COD 229
68 Chlorine Required to Eliminate Taste in
Aqueous Solutions of Various Phenolic
Compounds 231
69 Chlorine Demand of M-Cresol After Various
Contact Times 232
Xlll
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TABLES (Continued)
Number Title Pagt
70 Chlorophenol Concentration in Creosote
Wastewater Treated with Chlorine 234
71 Summary of Wastewater Characteristics
for 17 Exemplary Wood Preserving Plants 241
72 Summary of Waste Loads from Treatment
Alternatives 245
73 Effluent Limitations Based on Best
Practicable Control Technology Currently
Available: Wood Preserving Industry 272
74 Effluent Limitations Based on Best
Practicable Control Technology Currently
Available: Wood Preserving Industry 272
75 Recommended Premissible Discharge of
Specific Pollutants in Non-Process Waste-
water from Wood Preserving Plants in
Subcategories 2, 3, and 4. 274
76 Recommended Permissible Discharges of
Metals from Wood Preserving Plants in
Subcategory 1 That Employ the Same Retort
for Both Oil-Type and Salt-Type Preserv-
atives 276
77 Effluent Limitations Based on Best Avail-
able Technology Economically Achievable 288
78 Effluent Limitations Based on Best Avail-
able Technology Economically Achievable 288
79 Recommended Premissible Discharge of Metals
from Plants in Subcategory 1 That Employ
One Retort to Apply Preservative Treatment
with Oil-Type and Salt-Type Preservatives 290
80 Standards of Performance for New Sources 295
xiv
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TABLES (Continued)
Number Title
81 Standards of Performance for New Sources
82 Recommended Permissible Discharge of Metals:
Plants Applying Dual Treatment of Salt-
Type and Oil-Type Preservatives, and Plants
Using a Single Retort to Apply Both Preserv-
atives 297
xv
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FIGURES
Number Title Page
1 Simplified Process Flow Diagram for
Veneer and Plywood Production 13
2 Distribution of Softwood Veneer and
Plywood Mills Throughout the United
States 21
3 Distribution of Hardwood Veneer and
Plywood Mills Throughout the United
States 22
4 Distribution of Veneer and Plywood Mills
in the State of Oregon 23
5 Distribution of Veneer and Plywood Mills
in the State of North Carolina 24
6 United States Forest Areas 25
7 Growth of the Plywood Industry in the
United States 30
8 Geographical Distribution of Hardboard
Manufacturing Facilities in the United
States 33
9 Detailed Process Flow Diagram for Veneer
and Plywood 43
10 Wet Barking Process Diagram 45
11 Raw Material Handling in the Hardboard
Industry 53
12 Typical Dry Process Hardboard Mill 54
13 Typical Wet Process Hardboard Mill 55
14 Process Flow Diagram for a Typical
Wood Preserving Plant 69
15 Water Balance for a Plywood Mill Pro-
ducing 9.3 Million Square Meters per
Year on a 9.53 Millimeter Basis 104
xvi i
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FIGURES (Continued)
Number Title Page
16 Water Balance for a Typical Dry Process
Hardboard Mill 114
17 Water Usage in Raw Materials Handling
in the Hardboard Industry 116
18 Water Use in the Explosion Process 118
19 - Effect of Preheating Time and Tempera-
ture on Yield 122
20 The Chemical Components of Wood 125
21 Relation Between Dissolved Lignin and
Wood 126
22 Process Water Recycle in a Typical
Wet Process Hardboard Mill 128
23 Process Water Recycle in a Hardboard
Mill Using the Explosion Process 129
24 Water Balance for a Typical Wet
Process Hardboard Mill 135
25 Variation in Oil Content of Effluent
with Time Before and After Initiating
Closed Steaming 138
26 Variation in COD of Effluent with Time
Before and After Closed Steaming 139
27 Variation in COD Content and Waste-
water Flow Rate with Time 142
28 Relationship Between BOD and COD
for Wastewater from a Creosote
Treating Operation 145
29 Source and Volume of Daily Waste Use
and Recycling and Wastewater Source
at a Typical Wood-Preserving Plant 155
30 Plywood Plant Wash Water Reuse
System 168
XVlll
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FIGURES (Continued)
Number Title Page
31 Inplant Treatment and Control Techniques
at Mill No. 7 175
32 Typical Wet Process Hardboard Mill with
Pre-Press 176
33 Inplant Treatment and Control Techniques
at Mill No. 3 178
34 Typical Wet Process Hardboard Mill with
Savo System 180
35 Variation of Effluent BOD and Suspended
Solids as a Function of Time for Mill
No. 2 186
36 Variation of Effluent BOD and Suspended
Solids as a Function of Time for Mill
No. 3 187
37 Variation of Effluent BOD and Suspended
Solids as a Function of Time for Mill
No. 4 188
38 Effect of Detention Time on Oil Re-
moval by Gravity Separation 199
39 Determination of Reaction Rate Constant
for a Creosote Wastewater 215
40 COD Removal from a Creosote Wastewater
by Aerated Lagoon without Sludge 216
Return
41 Phenol Content in Weyerhaeuser's
Oxidation Pond Effluent Before and
After Installation in June, 1966 of
Aerator 224
42 Relationship Between Weight of Activated
Carbon Added, and Removal of COD and
Phenols from a Creosote Wastewater 236
xix
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FIGURES (Continued)
Number Title Pag<
43 Wastewater Flow Diagram for Wood
Preserving Plant Employing an Ex-
tended Aeration Waste Treatment
System in Conjunction with Holding
Lagoons and Soil Irrigation 242
44 Wastewater Flow Diagram for Wood
Preserving Plant Employing Chemical
Flocculation, Sand Filtration, and
Soil Irrigation 243
45 Wastewater Flow Diagram for a Wood
Preserving Plant Employing an
Oxidation Pond in Conjunction with
an Aerated Raceway 244
xx
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DRAFT
SECTION I
CONCLUSIONS
VENEER AND PLYWOOD INDUSTRY
For the purpose of establishing Effluent Limitations Guidelines
and Standards of Performance, the veneer and plywood industry
as a whole serves as a single logical category. Factors such
as age, size of plant, process employed, climate, and waste con
trol technologies do not justify the segmentation of the indus-
try into any subcategories. Similarities in waste loads and
available treatment and control technologies further substan-
tiate this.
It is concluded that by July 1, 1977 all veneer and plywood
mills except those with existing steam vats can achieve zero
discharge of wastewaters to navigable water. This can be
achieved by the application of existing technology. Plants
with existing steam vats may be able to do likewise, but the
technology is not yet established. It is, therefore, believed
that mills with existing steam vats should be given special
consideration, keeping in mind that with biological treatment
BOD loads can be reduced to about 80 kilograms (180 pounds)
per day for the typical mill producing 9.3 million square
meters (100 million square feet) per year on a 9.53 millimeter
(three-eights inch) basis.
HARDBOARD INDUSTRY
For the purpose of further establishing Effluent Limitations
Guidelines and Standards of Performance, the hardboard manu-
facturing industry (which is a category of the timber products
industry) has been broken down into two subcategories--dry
process hardboard and wet process hardboard--because of their
wide variation in process and wastewater flow. Factors such
as age, size of plant, climate and waste control technologies
do not justify the segmentation of the industry into further
subcategories. Similarities within the two subcategories in
waste loads and available treatment and control technologies
further substantiate this.
It is concluded that the dry process hardboard mills can
achieve the requirement of no discharge of wastewater by
July 1, 1977 as 25 percent of the mills presently have no
discharge.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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DRAFT
It is concluded that the wet process hardboard mills can
achieve the requirements of 1.7 kilograms per ton (3.4 pounds
per ton) and 2.8 kilograms per ton (5.6 pounds per ton) of
BODs and suspended solids, respectively, by July 1, 1977, as
22 percent of the mills are presently meeting this limitation.
WOOD PRESERVING INDUSTRY
For the purpose of further establishing Effluent Limitations
Guidelines and Standards of Performance, the wood preserving
industry (which is a category of the timber products industry)
has been divided into four subcategories as follows:
Plant
Subcategory Description
1 Pressure process employing oily preser-
vatives in which the predominant method
of conditioning green stock is by
steaming and/or vapor drying
2 Pressure processes employing oily pre-
servatives in which the predominant
method of conditioning green stock is
by water-borne salts
3 Pressure processes employing water-
borne salts
4 Non-pressure processes
The basis for the subcategorization was the variation both in
volume and composition of discharges, the method of condition-
ing wood preparatory to treatment, and whether a pressure or
non-pressure process is used.
The volume of wastewater originating from non-pressure preser-
vative processes is small and consists principally of precipi-
tation that enters the open tanks employed. Modification of
existing facilities to prevent the entry of rain and snow
and/or dehydration of oil to maintain water content an an
acceptable level can be used to eliminate discharges from this
segment of the industry.
Plants that employ pressure retorts and treat unseasoned stock
with oily preservatives have a more serious pollution problem.
Their effluents are normally characterized by a high phenol
content and a high oxygen demand, the latter due primarily to
2
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COWENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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DRAFT
entrained oils and various extractives, principally carbo-
hydrates, that are removed from wood during conditioning.
This process may be accomplished by either one of two tech-
niques, depending primarily upon species of wood. Boultoni-
zing is the predominant conditioning method used at plants
that treat Douglas-fir and other West-Coast species, while
open steaming is the predominant method used with the pines
and other species native to the East. Wastewater from the
Boulton process consists of water removed from the wood. Be-
cause the volume is relatively small, amounting to less than
9,500 liters per day (2,500 gallons per day) at most plants,
it is practicable to reuse it for cooling water and dispose
of the surplus by evaporation. A zero discharge of process
water has already been achieved by many plants that employ
the Boulton method of conditioning.
The waste stream from plants employing open steaming is com-
posed both of the water removed from the wood and the steam
condensate that forms in the retort during the steaming opera-
tion. The volume is large relative to that for the Boulton
process, and the waste usually has a much higher oxygen demand
because of emulsified oils and dissolved solids. Elimination
of discharges from plants in this group is not practicable.
The waste is amenable to conventional wastewater treating
methods, and the volume of discharge can be reduced substan-
tially by in-plant process changes and control techniques.
Wastewaters from pressure processes in which water-soluble
preservatives and fire retardants are employed contain trace
amounts of the chemicals used. These are primarily salts of
copper, chromium, arsenic, and zinc, as well as fluorides,
phosphates, and borates. A zero discharge is practicable
for such plants because of the small volume of wastewater
involved, and the feasibility of reusing it as makeup water
in preparing fresh batches of treating solution.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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DRAFT
SECTION II
RECOMMENDATIONS
VENEER AND PLYWOOD INDUSTRY
For the veneer and plywood industry, the recommended effluent
limitations for the best practicable control technology cur-
rently available (July 1, 1977) are no discharge of wastewaters
to navigable water with special consideration for mills with
existing steam vats. No discharge of wastewaters to navigable
water is recommended as the Effluent ^im.itations Guidelines and
Standards of Performance for the' bes't'available technology eco-
nomically achievable (July 1, 1983) and for new sources.
HARDBOARD INDUSTRY
No discharge of wastewater to navigable water is also recom-
mended as the Effluent Limitations Guidelines and Standards of
Performance for the dry process hardboard industry. This re-
presents the degree of effluent reduction obtainable by exist-
ing point sources through the application of the best practicable
control technology currently available, and the best available
technology economically achievable. This also represents, for
new sources, a standard of performance providing for the control
of the discharge of pollutants which reflects the greatest degree
of effluent reduction achievable through application of the best
available demonstrated control technology, processes, operating
methods or other alternatives.
For the wet process hardboard industry, the recommended effluent
limitations for the best practicable control technology currently
available (July 1, 1977) are a BOD and suspended solids of 1.7
kilograms per metric ton (3.4 pounds per ton) and 2.8 kilograms
per metric ton (5.6 pounds per ton), respectively. The recom-
memded effluent limitations for the best available technology
economically achievable (July 1, 1983) are a BOD and suspended
solids of 0.2 kilograms per metric ton (0.4 pounds per ton) and
1.1 kilograms per metric ton (2.1 pounds per ton), respectively.
The recommended standards of performance for new sources are a
BOD and suspended solids of 0.2 kilograms per metric ton (0.4
pounds per ton) and 1.1 kilograms per metric ton (2.1 pounds
per ton), respectively.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COWENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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DRAFT
WOOD PRESERVING INDUSTRY
A high degree of pollution abatement is practicable in the wood
preserving industry through the application of conventional
wastewater treatment methods and in-plant process changes and
controls. Recommendations pertaining to effluent guidelines
for the four subcategories into which the industry was divided
are summarized below:
(1) A zero discharge requirement for all levels of treat-
ment and control technologies is recommended for: (a) all non-
pressure processes; (b) plants employing only water-soluble
preservatives and fire retardants, and that portion of the
production facilities used to apply salt-type chemicals at
plants that also treat with other types of preservatives; and
(c) plants that employ the Boulton process as the predominant
method of conditioning.
(2) The following effluent limitations are recommended
for plants that use steaming and vapor drying as the pre-
dominant methods of conditioning stock for preservative
treatment:
Oil
and Suspended
Phenols COD BOD Grease Solids
Best Practicable
Control Technology
Currently Available 0.658 109.236 69.272 11.987 33.304
(Kg/1000M3) (0.041) (6.806) (4.316 (0.747) (2.075)
Best Available
Technology Economi-
cally Achievable
and New Sources 0.064 41.301 6.662 3.338 13.323
(Kg/1000M3) (0.004) (2.573) (0.415) (0.208) (0.830)
NOTE: Values in parentheses are discharge equivalents in
pounds per 1,000 cubic feet)
A variance to the effluent guidelines is recommended for certain
plants for which circumstances make unrealistic a uniform ap-
plication of effluent limitations. Specifically, it is recom-
mended that:
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
-------
DRAFT
A discharge of trace quantities of pollutants in
non-process water be permitted at older plants in subcate-
gories for which a zero discharge requirement is proposed.
(2) The discharge of copper, chromium, arsenic, and
other ions used in salt-type treatments be permitted in
specified amounts for subcategory 1 plants, the oils waste-
water from which becomes contaminated with salt-type pre-
servatives due to: (a) use of a single retort for both types
of preservatives, or (b) dual treatment of certain products
with both creosote and inorganic salts.
(3) In applying the best practicable control technology
currently available guidelines, special consideration be
given to plants that: (a) have already invested in wastewater
treating facilities, the performance of which is adequate to
protect receiving waters and to remove 95 percent or more of
the major pollutants from the discharge, but which fails to
meet the best practicable control technology currently avail-
able effluent limitation; or (b) have inadequate land area
available to provide lagoon space for long-term detention
time following biological treatment.
(4) A discharge equivalent to 25 percent of that allowed
for subcategory 1 plants be permitted under best practicable
control technology currently available for subcategory 4
plants that are unable to keep water out of open tanks during
winter months because of ice formation on stock prior to
treatment.
Wastewater from preservative treatments employing oil -type
preservatives contains no constituent that is incompatible
with a well-designed and operated publicly owned wastewater
treatment plant. Wastewater from salt- type treatments con-
taining arsenic, copper, zinc, and chromium potentially is
incompatible with a biological treatment system, and it is
recommended that such waste receive an appropriate pretreat-
ment prior to discharge to the sewer.
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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DRAFT
SECTION III
INTRODUCTION
PURPOSE AND AUTHORITY
Section 301 (b) of the Act requires the achievement by not
later than July 1, 1977, of effluent limitations for point
sources, other than publicly owned treatment works, which
are based on the application of the best practicable con-
trol technology currently available as defined by the Ad-
ministrator pursuant to Section 304 (b) of the'Act. Section
301 (b) also requires the achievement by not later than
July 1, 1983,of effluent limitations for point sources,
other than publicly owned treatment works, which are based
on the application of the best available technology econom-
ically achievable which will result in reasonable further
progress toward the national goal of eliminating the dis-
charge of all pollutants, as determined in accordance with
regulations issued by the Administrator pursuant to Sec-
tion 304(b) of the Act. Section 306 of the Act requires
the achievement by new sources of a Federal standard of per-
formance providing for the control of the discharge of pol-
lutants which reflects the greatest degree of effluent
reduction which the Administrator determines to be achievable
through the application of the best available demonstrated
control technology processes, operating methods, or other
alternatives, including, where practicable, a standard per-
mitting no discharge of pollutants.
Section 304(b) of the Act requires the Administrator to pub-
lish within one year of enactment of the Act, regulations
providing guidelines for effluent limitations setting forth
the degree of effluent reduction attainable" through the ap-
plication of the best control measures and practices achiev-
able including treatment techniques, process and procedure
innovations, operation methods and other alternatives. The
regulations proposed herein set forth effluent limitations
guidelines pursuant to Section 304(b) of the Act for the
plywood/#eneer, hardboard, and wood preserving-categories
of-the titnber products processing industry.
Section 306 of the Act requires the Administrator, within one
year after a category of sources is included in a list published
pursuanrt to Section 306(b) (1) (A) of the Act, to propose regu-
lations establishing Federal standards of performance for new
-------
DRAFT
sources within such categories. The Administrator published
in the Federal Register of January 16, 1973-(38 F.R. 1624),
a list of 27 source categories. Publication'of the list
constituted announcement of the Administrator's intention of
establishing, under Section 306, standards of performance ap-
plicable to new sources within the plywood/veneer, hardboard,
and wood preserving categories of the timber products processing
industry.
SUMMARY OF METHODS USED FOR DEVELOPMENT'OF THE EFFLUENT
LIMITATIONS GUIDELINES AND STANDARDS'' OF PERFORMANCE
Those effluent limitations guidelines and standards of per-
formance proposed herein were developed in the following
manner. The point source category was first categorized for
the purpose of determining whether separate limitations and
standards are appropriate for different segments within a
point source category. Such subcategorization was based upon
raw materials used, product produced, manufacturing process
employed, and other factors. The raw waste characteristics
for each subcategory were then identified. This included an
analysis of (1) the source and volume of water used in the
process employed and the source of waste and wastewaters in
the plant; and (2) the constituents (including thermal) of
all wastewaters including toxic constituents and other con-
stituents which result in taste, odor, and color in water or
aquatic organisms. The constituents of wastewaters which
should be subject to effluent limitations guidelines and
standards of performance were identified.
The full range of control and treatment technologies existing
within each subcategory was identified. This included an iden-
tification of each distinct control and treatment technology,
including both inplant and end-of-process technologies, which
are existent or capable of being designed for each subcategory.
It also included an identification in terms of the amount of
constituents (including thermal) and the chemical, physical,
and biological characteristics of pollutants;- of the effluent
level resulting from the application of each of the treatment
and control technologies. The problems, limitations and reli-
ability of each treatment and control technology and the re-
quired implementation time was also identified. In addition,
the non-water quality environmental impact, such as the effects
of the application of such technologies upon other pollution
problems, including air, solid waste, noise and radiation were
10
-------
DRAFT
also identified. The'energy*requirements of- each of the
control and treatment technologies'were identified, as well
as the cost of the application of such technologies.
The information, as outlined.above, was then evaluated in
order to determine what levels of technology constituted the
"best practicable control technology currently available,"
"best available technology economically achievable" and the
"best available demonstrated control technology, processes,
operation methods or other alternatives." In identifying
such technologies, various factors were considered. These
included the total cost of application of technology in rela-
tion to the effluent reduction benefits to be achieved from
such application, the age of equipment and facilities involved,
the process employed, the engineering aspects of the applica-
tion of various types of control techniques'process changes,
non-water quality environmental impact (including energy re-
quirements) and other factors. Consideration of the technol-
ogies was not limited to those presently employed in the in-
dustry, but included also those processes in pilot plant or
laboratory research stage and those used by-other industries.
The alternative of combined industrial/municipal treatment,
including the compatibility and economic ramifications, was
also examined.
The data for identification and analysis were derived from a
number of sources. These sources included Environmental
Protection Agency research information, published literature,
internal reports furnished by the industry and equipment
manufacturers, qualified technical consultation, on-site
visits and interviews at exemplary plants throughout the
United States, and evaluation of permit application data
provided under Permit Programs of the Rivers and Harbors
Act of 1899 (Refuse Act) All references used in this study
are included in Section XIII.
GENERAL DESCRIPTION OF THE INDUSTRY
The timber products processing industry includes a broad
spectrum of operations ranging from cutting and removing
the timber from the forest to the productive utilization
of wood wastes. The greatest water pollution potential in
the industry exists in the case of plywood/veneer mills,
hardboard mills, and wood preserving plants, and although a
greater total volume of wastes may be discharged from other
liquid waste generating factories of the industry, the strength
is lower and total flow is distributed over a substantially
11
-------
DRAFT
larger number of installations. At any given location the
environmental impact of the relatively higher strength wastes
from an installation of the three categories mentioned above
will be considerably greater, Therefore, Phase I of this study
includes plywood/veneer mills, hardboard mills, and wood preserv-
ing plants.'
Veneer and Plywood
Plywood is an assembly of numbers of layers of wood joined to-
gether by means of an adhesive. It is a multi-use material
characterized by its ability to be designed and engineered for
construction purposes, decorative purposes, flat shapes, curves,
and bent shapes. Hardwood plywood is distinguished from softwood
plywood in that the former is generally used for decorative pur-
po-ses and has a face ply of wood from deciduous or broad leaf
trees. Softwood plywood, on the other hand, is generally used
for construction and structural purposes, and the veneers typically
are of wood from evergreen or needle bearing trees. Hardwoods in-
clude such species as oak, walnut, lauan, elm, cherry, hickory,
pecan, maple, birch, gum, cativo, teak, rosewood, .and mahogany.
The principal raw material in the veneer and plywood industry is
roundwood, with species varying according to-geographical loca-
tion.
The various operations for converting roundwood into veneer and
finally into plywood are relatively simple and'chiefly mechanical.
A Simplified process flow diagram for the production of veneer
and plywood from roundwood is shown in Figure 1.
The most important operation in this process is the cutting of
the veneer. The appearance of a plywood panel is greatly de-
pendent upon the manner in which the veneer is cut. This is the
chief reason for cutting veneers in different ways. Prior to
the cutting of veneer, most logs are heated to make cutting easier
and to help insure smooth-cut veneer.
Veneer can be cut in four ways: (1) rotary lathing;-(2) slicing;
(3) stay log cutting; and (4) sawing veneer.
After rotary veneers are cut, they may go directly to a clipper
or may be stored temporarily on a series of horizontal storage
decks or on reels. The green clipper clips the veneers to various
widths and also may remove defects. From the clippers the veneers
are conveyed to the dryers, large chambers which are equipped with
heating elements and fans and which have automatic conveying systems
on which the veneer moves. Some mills now use high speed drivers
12
-------
LOG
STORAGE
DEBARKER
LOG
CONDITIONER
VENEER
CUTTER
VENEER
DRIER
VENEER OPERATION
VENEER
PREPARATION
GLUE
LINE
PRESS
FINISHING
PLYWOOD OPERATION
FIGURE 1 - SIMPLIFIED PROCESS FLOW DIAGRAM FOR
VENEER AND PLYWOOD PRODUCTION
13
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DRAFT
located behind the rotary lathe which allow the veneer to be
dried in a continuous sheet after it is cut. Veneers are gen-
erally dried to moisture contents of below ten percent, which
is a level compatible with gluing and consistent with the mois-
ture content to which hardwood plywood products will be exposed
while in service.
After drying, less than full-size sheets are dry-clipped and
joined together to form full-size sheets in preparation for
gluing. Taping machines and tapeless splicers are used in this
joining process. Patching and repairing are then accomplished.
After pressing, the panels are stacked for conditioning, sawed
to dimension, and sanded. They are then ready for inspection,
grading, strapping, and shipping. Grading and inspection usually
are done at intermediate steps in the manufacturing process.
Hardboard
The industry refers to panel products reconstituted from wood
fibers and chips as "board." To a great extent, the board is
manufactured from chips or fibers which are by-products of lum-
ber or plywood production. Particle board, insulation board,
and hardboard make up this group of products.
There are two major subcategories of hardboard manufacturing
based upon the manner in which the board is formed. In the
wet process, water is used as the medium for carrying the
fibers and distributing them in the forming machine. In
the dry process air serves that function. The present
hardboard industry in the United States developed from a
defiberization process invented by William H. Mason during
the 1920's. It was the prototype of wet process hardboard.
Other methods of fiber preparation were later developed.
All are intended basically to provide ultimate bonding in
the hardboard. The resulting fibers may be washed, screened,
and refined before being carried in a liquid slurry to a
board-forming machine similar to that used in making paper,
a cylindrical former, or a batch unit. After forming, the
wet mat may be pressed either wet or dry. If the mat is
to be pressed dry, then all of the moisture must be removed
by evaporation after wet-forming. All but one of the wet-
dry hardboard mills discussed later are associated with an
insulation board mill.
14
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DRAFT
Fiber preparation in the dry process is similar to that
in the wet process. After fiber preparation, existing
water is reduced in a dryer. The fibers are then trans-
ported by an air stream to a dry-felting machine for mat
formation. After formation of the dry mat, the mat is
pressed in a dry state by all but two of the dry press
hardboard mills to be discussed later. Two mills add
water to the mat after dry formation; however, in one
mill any water added is evaporated in the pressing opera-
tion. Virtually all new hardboard installations since
the 1950's have utilized the dry process.
Wood Preserving
The wood preserving industry applies treatment to round
and sawn wood products by injecting into them chemicals
that have fungistatic and insecticidal properties, or
that impart fire resistance.
The most common preservatives used in wood preserving are
creosote, pentachlorophenol, and various formulations of
water-soluble, inorganic chemicals, the most common of
which are salts of copper, chromium, and arsenic. Fire
retardants are formulations of salts, the principal ones
of which are borates, phosphates, and ammonium compounds.
Eighty percent of the plants in the United States use at
least two of the three types of preservatives. Many
treat with one or two preservatives plus a fire re-
tardant (1) .
Consumption data for the principle preservatives for the
five-year period between 1967 and 1971 are given in
Table I. In terms of amount used, creosote in its various
forms is the most important, followed in order by penta-
chlorophenol and salt-type preservatives. Among the
latter, the CCA (copper-chromium-arsenic) formulations
account for most of that used.
The general trend in presevative use is a decrease in
creosote consumption and an increase in the use of penta-
chlorophenol and salt-type preservatives. This trend is
expected to continue. Consumption of fire retardants has
been relatively stable for the past five years, but it is
anticipated that it will increase significantly as exist-
ing building codes are modified to permit the use of
fire retardant treated wood in lieu of other flameproof
construction materials.
15
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DRAFT
TABLE I
CONSUMPTION OF PRINCIPLE PRESERVATIVES AND FIRE RETARDANTS
OF REPORTING PLANTS IN THE UNITED STATES. 1967-1971 (2)
Year
Material
Creosote
Creosote-
Coal Tar
Creosote-
Petroleum
Total
Creosote
Total
Petroleum
Penta-
chlorophenol
Chromated
Zinc Chloride
(Units)
Million
Liters
Million
Liters
Million
Liters
Million
Liters
Million
Liters
Million
Kilograms
Million
Kilograms
1967
329
216
135
559
279
11.2
0.8
1968
293
219
121
518
279
12.0
0.7
1969
274
206
115
485
258
11. b
0.6
1970
256
229
125
475
286
12.9
0.7
1971
242
218
118
441
307
14
0
.5
.6
CCA
ACC
Pyresote
Non-Com
FCAP
Osmose Flame
Proof
Other
Solids
Million
Kilograms 1.0 1.4 2.1 2.7
Million
Kilograms 0.6
0.5
0.4 0.4
Million
Kilograms 1.3 1.7 1.1 1.2
Million
Kilograms 2.4 2.7
Million
Kilograms 2.4
3.9
0.5
1.2
3.4 3.1 2.8
1.8 2.0 1.2 1.0
Million
Kilograms 2.0
1.8 1.8 2.0 2.4
Million
Kilograms 2.7 2.8 2.3 1.7 1.7
Note: Data are based on information supplied by approximately
357 plants for each year.
16
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DRAFT
INVENTORY OF INDUSTRY
Veneer and Plywood
Today there are approximately 501 veneer and plywood mills
in the United States, 248 of which use softwood, 253 use
hardwood, and 27 use a combination of softwood and hardwood.
As shown in Table 2, the largest concentrations of mills
are in Oregon, Washington, and North Carolina. Figures 2
through 5 show the distribution of mills throughout the
United States. Hardwood and softwood mills are located ac-
cording to availability of raw materials, and their distri-
bution, therefore, follows the timber distribution as shown
in Figure 6. A detailed inventory of the mills in the United
States is included in Appendix A of this document. A sum-
mary is presented in Table 2.
In 1968, a Forest Industry survey resulted in the most com-
plete statistics available for the plywood industry. At
that time there were 175 softwood and 242 hardwood plywood
mills. Although hardwood plywood mills were more numerous,
individual installations were smaller. In 1968, the pro-
duction of softwood plywood in the United States was about
1.4 billion square meters on a 9.53 millimeter basis (15
billion square feet on a three-eights inch basis) , while
that of hardwood plywood was slightly more than 186 million
square meters on a 6.35 millimeter basis (2 billion square
feet on a one-fourth inch basis). Included in Table 3 are
statistics from the 1968 survey. More recent data collected
as a result of correspondence with the industry association
shows that in 1972, softwood plywood production was 1.71
billion square meters on a 9.53 millimeter basis (18.3 bil-
lion square feet on a three-eights inch basis), while that
of hardwood plywood was estimated as 205 million square
meters on a 6.35 millimeter basis (2.2 billion square feet
on a one-fourth inch basis).
During the decade 1950-1960, the world's production of
plywood rose by 150 percent. The United States accounted
for about 50 percent of the world's plywood production.
More important, however, is that the United States along
with Canada was the major source of softwood timber. As
the demand for construction materials continues to increase
so does the demand for softwood plywood. Twenty years ago
practically all of the softwood plywood in the United States
was produced in the Pacific Northwest from Douglas fir. In
the past ten years, however, the industry has expanded into
the southeastern United States where the use of southern
17
-------
DRAFT
TABLE 2
SUMMARY OF VENEER AND PLYWOOD PLANTS IN THE UNITED STATES
SOFTWOOD PLYWOOD
Alabama 6
Arizona 1
Arkansas 8
California 15
Colorado 1
Florida 2
Georgia 5
Idaho 5
Louisiana 12
Maryland 1
Michigan 2
Mississippi 6
Montana 4
New Hampshire 1
North Carolina 6
Oklahoma 1
Oregon 81
South Carolina 3
Texas 9
Virginia 1
Washington 29
TOTAL 199
SOFTWOOD VENEER
Arkansas 1
California 8
Florida 1
Georgia 1
Maryland 1
Minnesota 1
New Jersey 1
North Carolina 6
Oregon 31
South Carolina 1
Texas 1
Virginia 1
Washington 9
Wisconsin 2_
TOTAL 65
18
-------
DRAFT
HARDWOOD PLYWOOD
TABLE 2 CONTINUED
HARDWOOD VENEER
Alabama
Arkansas
California
Florida
Georgia
Illinois
Indiana
Louisiana
Maine
Michigan
Minnesota
Mississippi
New Hampshire
New York
9
4
6
3
6
1
6
2
3
4
2
6
2
2
Alabama
Florida
Georgia
Illinois
Indiana
Iowa
Kentucky
Maine
Maryland
Michigan
Minnesota
Mississippi
Missouri
New Jersey
4
4
5
1
13
2
4
1
1
3
2
3
2
1
North Carolina 26
Oregon 9
Pennsylvania 4
South Carolina 16
Tennessee 4
Texas 3
Vermont 5
Virginia 11
Washington 5
West Virginia 1
Wisconsin 16
TOTAL 157
19
New York 5
North Carolina 19
Ohio 2
Oregon 5
Pennsylvania 5
South Carolina 6
Tennessee 2
Vermont 1
Virginia 7
West Virginia 2
Wisconsin 4_
TOTAL 107
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DRAFT
TABLE 2 CONTINUED
SOFTWOOD 5 HARDWOOD PLYWOOD
Alabama 2
Florida 1
Michigan 1
New Hampshire 1
North Carolina 1
Oregon 3
South Carolina 1
Texas 1
Washington 4
TOTAL 16
SOFTWOOD § HARDWOOD VENEER
Florida 1
Georgia 1
Minnesota 1
North Carolina 3
Oregon 3
Virginia 1
TOTAL 11
TOTAL PLYWOOD PLANTS - 340
TOTAL VENEER PLANTS - 161
20
-------
oribou
SOFTWOOD - PLYWOOD
6 VENEER
SOFTWOOD 8 HARDWOOD
PLYWOOD & VENEER
NOTE :
OREGON AND NORTH CAROLINA ARE HIGH
DENSITY AREAS AND ARE SHOWN ON SEPARATE
MAPS
FIGURE 2 - DISTRIBUTION OF SOFTWOOD VENEER AND PLYWOOD RILLS THROUGHOUT THE UNITED STATES
-------
Francis
k Angeles
oBoise
Phoe
J= E G E N
A HARDWOOD - PLYWOOD
8 VENEER
• SOFTWOOD a HARDWOOD-
PLYWOOD a VENEER
^urango
NOTE :
OREGON AND NORTH CAROLINA ARE HIGH DENSITY
AREAS AND ARE SHOWN ON SEPARATE MAPS.
Minneapoli
frl
\
AA
Chicago1
Detroit / Jamestow
Rochester
A *»
lew York
I Philadelphia
IPIMsbu
Dayton
Clarksburg ,
Joseph
pKansas City
Richmond
St. Louis
0 Nashville
-, Dallas
Little ROCK
<|Shr.v.port
(Baton Rouge
i Atlanta
Birmingham \A
Montgomery
o A
Mobile
New Orleans
Orlandoi
San Antonio
Miami
FIGURE 3 - DISTRIBUTION OF HARDWOOD VENEER AND PLYWOOD MILLS THROUGHOUT THE UNITED STATES
-------
L E G E N D
• SOFTWOOD
A HARDWOOD
• SOFT AND HARDWOOD
FIGURE 4 - DISTRIBUTION OF VENEER AND PLYWOOD HILLS IN THE STATE OF OREGON
-------
• SOFTWOOD
A HARDWOOD
• SOFT AND HARDWOOD
WILMINGTON
FIGURE 5 - DISTRIBUTION OF VENEER AND PLYWOOD hILLS IN THE STATE OF NORTH CAROLINA
-------
UNITED STATES FOREST AREAS
[SJ
en
Softwood timber is indicated by grey,
hardwood by black areas.
FIGURE 6 (3) - UNITED STATES FOREST AREAS
-------
DRAFT
TABLE 3
FOREST INDUSTRIES 1968 PLYWOOD STATISTICS C4)
Number of
Softwood
Plywood
Region Plants
New
England
Middle
Atlantic
East North
Central
West North
Central
South
Atlantic 10
East South
Central 7
West South
Central 17
Mountain 11
Pacific 130
Total
U.S.A. 175
Softwood Ply-
wood Production
In Square meters
(9 . 53 mm Basis)
54,730,000
49,500,000
142,500,000
101,720,000
1,063,000,000
1,411,500,000 -
Number of
Hardwood
Plywood
Plants
15
7
41
4
72
24
11
31
205
Hardwood Ply-
wood Production
In Square meters
(6.35 mm - Sur-
face Measure)
7,175,000
1,675,000
29,950,000
4,200,000
42,660,000
30,625,000
4,100,000
77,375,000
197,750,000
26
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DRAFT
pine has catapulted this area into the plywood scene (See
Table 4). In 1968, the southeast accounted for 20 percent
of the nation's softwood plywood production.
As a result of demand, hardwood plywood production has re-
mained fairly constant over the past 20 years (Tables 5 and
6, and Figure 7) .
Hardboard
In 1973, there were 27 manufacturing facilities which pro-
duced hardboard by some variation of the two basic processes.
As shown in Table 7, 17 of these were variations of the
dry process and 10 were variations of the wet process. In
addition, some hardboard is produced at six insulation board
plants, but the wastewater aspects of these will be considered
in Phase II of the study. It has been estimated that in 1972,
the total production of hardboard in the United States, on a
3.2 millimeter (one-eighth inch) basis, was 0.54 billion square
meters (518 billion square feet). The geographical distri-
bution of the hardboard industry is shown more graphically
in Figure 8.
From the viewpoint of total utilization of the forest resource,
those categories of the timber products processing industry
which are relatively indiscriminate in terms of the properties
of the wood raw material used are of increasing importance.
High quality lumber and plywood are prized for certain struc-
tural characteristics which are inherent in the structure of
the harvested tree. As the timber products industry becomes
more dependent on smaller, second-growth timber and as the
demands for timber products increase, it becomes more important
to develop those categories of the industry which can use wood
and wood wastes in a variety of forms and in large quantities.
In general, the categories of this type include those which
can use wood reduced to small particles or fibers and then
reconstitute them into useful form. Essentially, these opera-
tions are represented by the "board" category of the industry
as described previously. In its entirety, this is one of the
most rapidly expanding industrial operations in the United
States. Hardboard production contributes to that growth. It
has been reported that 16 times as much hardboard was used in
1953 as compared with 1929. The Forest Products Research
Society reported that hardboard production on a 3.2 millimeter
(one-eighth inch) basis increased from 0.09 billion square
meters (0.96 billion square feet) in 1948 to 0.14 billion
square meters (1.5 billion square feet) in 1953 (5). In 1968,
-27
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DRAFT
TABLE 4
SOFTWOOD PLYWOOD PRODUCTION FOR 1972
State Sq. Meters-9.55 mm Basis
California 140,543,000
Oregon 803,700,000
Washington 210,443,000
Idaho 156,366,000
Others 495,066,000
CMostly South)
Note: Data obtained from APA.
28
-------
DRAFT
TABLE 5
HARDWOOD PLYWOOD PRODUCTION IN THE UNITED STATES
Year
1947
1955
1960
1965
1970
1972
Square Meters Surface Area
68,700,000
87,000,000
82,500,000
170,500,000
146,600,000
204,765,000
Note: Data obtained from Hardwood Manufacturing
Association - April 1, 1973.
TABLE 6
SOFTWOOD PLYWOOD PRODUCTION IN THE UNITED STATES
Year
1925
1940
1950
1960
1970
1972
Sq. Meters-9.53 mm Basis
14,240,000
111,690,000
237,700,000
727,500,000
1,334,700,000
1,707,400,000
No. of Plants
12
25
68
152
179
Note: Data obtained from APA.
29
-------
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3
CO
1.500 -
1,000 -|
500 -
250 -
50 -
1930
1970
YEAR
FIGURE 7 - GROWTH OF THE PLYWOOD INDUSTRY IN THE UNITED STATES
A - SOFTWOOD PLYWOOD PRODUCTION ON A 9.53mm (3/8") BASIS
- HARDWOOD PLYWOOD PRODUCTION ON A 6.35mm (1/4") BASIS
30
-------
DRAFT
TABLE 7
INVENTORY OF HARDBOARD"MANUFACTURING" FACILITIES
DRY PROCESS
Anacortes Veneer
Anacortes, Washington
Celotex Corporation
Deposit, New York
Celotex Corporation
Marion, South Carolina
Celotex Corporation
Paris, Tennessee
Evans Products
Doswell, Virginia
Evans Products
Moncure, North Carolina
Evans Products
Phillips, Wisconsin
Georgia-Pacific Corporation
Coos Bay, Oregon
DRY-WET PROCESS
Weyerhaeuser Company*
Klamath Falls, Oregon
Georgia Pacific Corporation
Conway, North Carolina
Masonite Corporation
Spring Hope, North Carolina
Masonite Corporation
Towanda, Pennsylvania
Pope and Talbot
Oakridge, Oregon
Superwood (Nu-Ply)
Bemidji, Minnesota
U.S. Plywood
Champion International
Catawba, South Carolina
U.S. Plywood
Champion International
Lebanon, Oregon
Weyerhaeuser Company
Craig, Oklahoma
WET PROCESS
Abitibi Corporation
Roaring River, North Carolina
Evans Products
Corvallis, Oregon
Forest Fibre
Stimpson Lumber Company
Forest Grove, Oregon
31
-------
DRAFT
TABLE' 7 CONTINUED
[INVENTORY OF HARDBOARD MANUFACTURING FACILITIES)
Masonite Corporation
Laurel, Mississippi
Masonite Corporation
Ukiah, California
Superior Fibre
Superior, Wisconsin
Superwood
Duluth, Minnesota
Superwood
North Little Rock, Arkansas
U.S. Plywood
Champion International
Dee (Hood River), Oregon
WET-DRY PROCESS
Abitibi Corporation*
Alpena, Michigan
WET-DRY HARDBOARD PLANTS
OPERATED IN CONJUNCTION~
WITH INSULATION BOARD PLANTS
Boise Cascade
International Falls, Minnesota
Temple Industries
Diboll, Texas
U.S. Gypsum
Danville, Virginia
U.S. Gypsum
Greenville, Mississippi
U.S. Gypsum
Pilot Rock, Oregon
Weyerhaeuser Company
Craig, Oklahoma
* To be given special consideration
32
-------
: G i N D
WET
A DRY PROCESS
• DRY-WET PROCESS
• WET- DRY PROCESS
WET-DRY/INSULATION
FIGURE 8 - GEOGRAPHICAL DISTRIBUTION OF HARDBOARD MANUFACTURING
FACILITIES IN THE UNITED STATES
-------
DRAFT
27 hardboard plants in the United States produced approxi-
mately 0.39 billion square meters (4.2 billion square feet)
of product. For 1972, hardboard production was estimated
to be 0.54 billion square meters (5.8 billion square feet)(6).
During the first part of 1973, pia«g -for three new dry-process
plants were completed, and const.ructd.en: has "already begun. .
A United States Forest Service survey published in 196~4', based
on information collected in 1962, established that the amount
of timber consumed in the United States has increased to 0.37
billion cubic meters (13 billion cubic feet) annually. It
projected a demand of 0.79 billion'Cubic meters (28 billion
cubic feet) by the year 2000 - more than twice the 1962
],evel - based on a population of 325 million. The increased
?opulation must also be sheltered, and experts predict 1QD mil-
ion homes must be built in the next 30 years. If hardboard
manufacture increases at the same rate during the next decade
as in the last two decades, annual production is projected to
be 0.93 billion square meters (10 billion square feet) by 1980
(6). This means that ten plants with annual capacity-of 39 mil-
lion square meters (420 million square feet) each would have to
b.e completed during the next seven years.
Somewhat akin to the saw mill part of the forest products in-
dustry, the board portion is spread nationally with some pro-
duction of each kind in each forest region of the United States.
The hardboard and particle board industries utilize the resi-
dues from other wood working plants in large measure and accord-
ingly provide opportunities to reduce the cost of other products
and expand the development of completely integrated wood indus-
tries.
It is anticipated that there will be two'major factors .which
will influence the location trend of future hardboard plant
additions. The trend toward integrated forest product com-
plexes, which involves pulp• and paper, plywood, particle board
and hardboard operations, all contained at one location is ex-
pected to increase. Installations such as these will be predi-
cated upon the benefits derived from logistics and economics.
Currently, 33 percent of the hardboard plants are owned by one
of the major.forest industry companies, and this percentage is
expected to increase moderately in the near future, which will
no doubt have some impact on the location trend.
The other major factor influencing' growth trend is that
associated with supply and demand, with new plants being
located where there is demand predicted on the dynamic
growth and expansion areas. Raw material availability
and price may have some impact on the development of this
particular growth trend.
34
-------
DRAFT
By far the most dynamic growth areas are the South Atlantic,
South Central, and Pacific Coast regions. It is anticipated
that the growth trend will intensify in these two areas during
the next decade and probably on into the 1990's.
Due to the anticipated demand for hardboard production, it
is not expected that any operations will be phased out prior
to 1980. After this time, however, wet process plants in
the capacity range of 4.6 to 9.3 million square meters (50 to
100 million square feet) will become economically marginal
due to operating performance and environmental capital
expenditures.
Wood Preserving
The wood preserving industry^ in the United States is composed
of approximately 390 treating plants, 315 of which use pres-
sure retorts. Most of the plants are concentrated in two
distinct regions. The larger region extends from East Texas
to Maryland and corresponds roughly to the natural range of
the southern pines, the major species utilized. The second
concentration of plants is located along the Pacific Coast,
where Douglas fir and western red cedar are the species of
primary interest to the industry. Only 23 percent of the
United States' plants are located outside these two regions.
The distribution of plants by type and location is given in
Table 8.
The production of treated wood is very responsive to the
general state of the national economy, particularly the health
of the construction industry. Production overall decreased
from 1967 to 1971 (Table 9), but is expected to show a sharp
increase for 1972.
The volume of wood treated with creosote showed the largest
decrease during the 1967 to 1971 period, and accounted for
most of the decrease in total production. Wood treated with
pentachlorophenol registered a slight increase during the
period, while that treated with CCA-type preservatives in-
creased almost four-fold. Production of fire-retardant
treated wood remained essentially constant. These trends
are expected to continue, except that an increase in the
production of fire-retardant treated wood is anticipated.
35
-------
DRAFT
TABLE 8
WOOD PRESERVING PLANTS IN THE UNITED STATES BY STATE AND TYPE
(1971)
Commercial
Pressure
NORTHEAST
Connecticut
Delaware
0
1
Dist. of Columbia 0
Maine
Maryland
Massachusetts
New Hampshire
New Jersey
New York
Pennsylvania
Rhode Island
Vermont
West Virginia
TOTAL
NORTH CENTRAL
Illinois
Indiana
Iowa
Kansas
Kentucky
Michigan
Minnesota
Missouri
Nebraska
North Dakota
Ohio
Wisconsin
TOTAL
SOUTHEAST
Florida
Georgia
North Carolina
South Carolina
Virginia
TOTAL
0
6
1
1
4
5
6
1
0
3
28
6
6
0
0
6
4
3
7
0
0
7
3
42
23
24
18
11
15
91
Non-
Pressure
0
0
0
0
0
0
0
2
0
0
0
0
0
2
0
0
0
0
0
2
5
5
0
0
0
0
12
1
1
0
0
1
3
Pressure
and Non-
Pressure
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
2
0
1
0
0
1
4
1
2
0
0
1
4
Railroad
Pressure
0
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
0
0
1
0
0
0
0
1
2
0
0
0
0
0
0
and Other
Non- Total
Pressure Plants
0
0
0
0
0
0
0
0
0
1
2
1
0
1
0
0
0
0
0
0
3
0
0
1
0
0
1
0
1
0
0
1
1
34
6
11
i *"*
12
£. 7
63
2p
5
1 T
27
19
11
17
99
36
-------
DRAFT
TABLE 8 CONTINUED
Commercial
Railroad and Other
Pressure
Non- and Non- Non- Total
Pressure Pressure Pressure Pressure Pressure Plants
SOUTH CENTRAL
Alabama
Arkansas
Louisiana
Mississippi
Oklahoma
Tennessee
Texas
TOTAL
ROCKY MOUNTAIN
Arizona
Colorado
Idaho
Montana
Nevada
New Mexico
South Dakota
Utah
Wyoming
TOTAL
PACIFIC
Alaska
California
Hawaii
Oregon
Washington
TOTAL
UNITED STATES
TOTAL
22
11
21
18
6
6
27
111
1
2
3
2
0
1
0
0
1
10
0
8
3
6
7
24
306
1
0
0
1
0
1
3
6
0
0
3
3
0
0
0
1
0
7
0
0
0
0
5
5
35
0
1
1
3
0
0
2
7
0
0
0
1
0
0
1
1
1
4
0
2
0
4
4
10
30
0
0
0
0
0
1
2
3
0
0
0
2
0
1
0
0
0
3
0
0
0
0
0
0
9
0
0
0
0
0
0
0
. 0
0
0
1
0
0
0
0
0
0
1
0
2
0
0
1
3
10
23
12
22
22
6
8
34
127
1
2
7
8
0
2
1
2
2
A |-
25
0
12
3
10
1 *7
17
A 1
42
390
37
-------
(si
oo
DRAFT
TABLE 9
MATERIALS TREATED'IN THE UNITED STATES. BY PRODUCT AND PRESERVATIVE. 1967-1971 (2)
(Note: Components may not add to totals due to rounding.)
Thousand Cubic Meters
Preservative
Creosote and
Cresoste-Coal
Tar
Creosote-
Petroleum
Petroleum-
Pentachloro-
phenol
Chromated
Copper
Arsenate
Year
1967
1968
1969
1970
1971
1967
1968
1969
1970
1971
1967
1968
1969
1970
1971
1967
1968
1969
1970
Poles
and Railroad
Piling Ties
1,636
1,456
1,330
1,315
1,172
30
27
18
18
15
950
927
919
1,074
1,157
5
11
35
42
1,683
1,712
1,497
1,650
1,856
808
125
694
806
775
7
6
5
10
4
1
0.2
1
1
Lumber
and
Timbers
504
528
451
357
342
82
97
81
62
45
446
54
450
436
430
146
197
254
366
Fence
Posts
184
184
175
181
193
68
45
42
32
27
290
224
212
194
233
3
4
7
9
Other
100
100
93
78
70
12
11
7
9
9
186
168
142
146
143
0.5
4
8
10
Total
4,146
3,980
3,545
3,587
3,6326
1,000
905
849
926
871
1,879
1,846
1,729
1,864
1,967
217
306
306
4287
-------
DRAFT
TABLE 9 CONTINUED
Thousand-Cubic Meters
OJ
-------
DRAFT
TABLE 9 CONTINUED
Thousand Cubic Meters
Preservative
Fire
Retardants
All
Others
All
Preservatives
Year
1967
1968
1969
1970
1971
1967
1968
1969
1970
1971
1967
1968
1969
1970
1971
Poles
and
Piling
...
—
—
—
12
15
13
12
4
2,857
2,649
2,522
2,600
2,492
Railroad
Ties
3
2
0.3
2
0.1
0.1
2,508
2,447
2,199
2,469
2,639
Lumber
and
Timbers
99
94
104
100
47
18
72
3
19
1,716
1,772
1,687
1,576
1,694
Fence
Posts
_ _ _
—
—
—
6
4
3
62
3
595
466
443
428
472
Other
32
42
30
37
7
6
13
6
2
382
360
323
292
305
Total
134
138
134
138
71
43
102
83
28
7,538
7,695
7,175
7,366
7,602
-------
DRAFT
SECTION IV
PROCESS DESCRIPTION AND INDUSTRY CATEGORIZATION
PROCESS DESCRIPTION-VENEER AND PLYWOOD
Raw Materials
A large variety of wood is utilized in the manufacture of
veneers. A high percentage of veneer produced in the
United States is manufactured from Douglas fir, in particu-
lar that manufactured in the Northwest, with lesser quanti-
ties of veneer made from ponderosa pine and hemlock also in
the Northwest, and southern pine in the Southeast. In general,
veneer is classified as softwood or hardwood due to the marked
differences in the utilization of the respective products.
Softwood veneer is manufactured on the west coast, the Rocky
Mountain region, and the southeastern United States. The
species that are used in the western United States include
Douglas fir, sitka spruce, western hemlock, balsam fir,
western larch, ponderosa pine, sugar pine, western white
pine, and redwood. In the southeastern states bald cypress
and southern pine are most commo'n. The hardwood species com-
monly used in the United States are beech, birch, maple, bass-
wood, red gum, yellow poplar, cottonwood, tupelo, sycamore,
and oak.
Softwood veneer is almost exclusively used in the manufactur-
ing of softwood plywood; however, small quantities are also
used as center stock and cross-banding for panels made with
hardwood faces. Hardwood veneer, on the other hand, has
several important uses that can be categorized as (1) face
veneer, (2) commercial veneers, and (3) veneers for containers.
Face veneers are of the highest quality and are used to make
plywood panels employed in the manufacturing of furniture and
interior decorative panels. There are more than 50 such manu-
facturers throughout the eastern United States. Commercial
veneers are those used for cross bands, cores, and backs of
plywood panels and concealed parts of furniture. Container
veneers consist of a large variety of inexpensive veneers used
in the manufacturing of crates, hampers, fruit and vegetable
baskets and kits, boxes and similar container items.
Manufacturing
Plywood is manufactured in practically every state in the Union
The majority of softwood plywood is produced on the Pacific
Coast while the bulk of the hardwood plywood is manufactured in
41
-------
DRAFT
the southeastern states. The hardwood plywood industry is
made up of a large number of small factories distributed
widely over the eastern United States.
The detailed process description will be restricted to factors
of the process which affect wastewater characteristics. A
detailed flow diagram of the veneer and plywood manufacturing
process is shown in Figure 9. This will also be the outline
followed in the process description.
Log Storage
Veneer mills throughout the country, like many other mills
within the Timber Products Industry, find it necessary to re-
tain large inventories of logs to maintain a continuous supply
throughout the year. There are three'common methods of storing
logs in the industry: (1) dry-decking, (2) wet-decking, and
(3) log ponding.
Dry-decking is simply the practice of stacking- logs on land.
When logs are stored in this manner there exists a'tendency for
them to dry out rapidly at the ends which in turn.causes cracks
to be formed in the wood. This phenomenon is known'as "end
checking" and it greatly increases the amount of product wastage
End-checking can be minimized by sprinkling the land.^decked logs
with water and this method of storing logs is'referred to as wet-
decking. Land-decking, whether wet or dry, requires large
machinery to handle the logs.
The third method of storing logs is by floating them in a body
of water. End-checking is not a problem with this form of
storage and logs can be handled more easily. Logs'may be
floated in lakes, rivers, estuaries, or man-made ponds', with
the last being the most common receptacle for .this-purpose.
Log ponding, when feasible, has been accepted as'the most con-
venient and economical form of log storage. Some-logs, such
as southern pine, sink in water and land-decking-"is 'therefore
a necessity. Many veneer and plywood mills use a combination
of log ponds and land-decking for log storage with1 the land-
decking being used for short periods of detention and log ponds
for long term log storage.
42
-------
LIQUID WASTE
"GREEN END" < ST£AM DRIER WASH'
OVERFLOW FROM CONDENSATE AND DELUGE
LOG POND WATER
LOG STORAGE
( LOG POND. _ LOG . LOG VENEER VEH
COLO DECK UbBAHKING *" SI LAMING * LAIHt " OH
4
I
1
EXHAUST
GASES
IEER
HER
OR BOTH)
GASES
SOLIDS
BARK
LIQUIDS
I
\
GLUE V
PREPARATION)*
v /'
VENEER
PREPARATION
^
GLUE
^
GLUE
LI
NE
1
UNUSABLE
VENEER AND
TRIMMINGS
i ___ __ _L
GLUE WASH
WATER
RECYCLE
RESSING! FINISHING
TRIM AND
SANDER
DUST
j
SOLID WASTE IS BURNED IN BOILER
CHIPPED FOR REUSE OR SOLD
FIGURE 9 - DETAILED PROCESS FLOW DIAGRAM FOR VENEER AND PLYWOOD
-------
DRAFT
Barkers
From storage the logs are first taken to'a barker where
the bark is removed before' the logs are cut into smaller
sections, usually about two and four-tenths meters (eight
feet) long. The bark can be removed in either a dry or
wet process.
Logs are debarked by several different'types of machines (7),
including: (1) drum barkers, (2) ring barkers, (3) bag
barkers, (4) hydraulic barkers, or (5) cutterhead barkers.
Drum barkers are made in a wide variety of sizes, generally
two and four-tenths to four and nine-tenths meters (eight
to sixteen feet) in diameter and up to 22.8 meters (75 feet)
in length. A drum barker consists of a cylindrical shell
rotating on its horizontal longitudinal axis. Logs are fed
into one end and the tumbling and rolling action removes the
bark. Water sprays may be used to reduce dust., promote the
thawing of wood in cold climates, or reduce the bond between
the bark and wood.
Ring barkers or rotary barkers consist of a rotating ring on
which several radial arms are pivoted. On the end- of each arm
is a tool which abrades or scrapes off the bark. A ring bar-
ker handles only one log at a time, but can handle logs up
to 213.4 centimeters (84 inches) in diameter.
Bag barkers or pocket barkers are simple stationary .containers
in which the logs are rotated to remove bark by abrasion.
Water may also be used in this process for the same purposes
as were described for the drum barkers.
The hydraulic barker uses a high pressure water .jet to blast
bark from a log. Pressures from 56.25 to 112.4 kilograms of
force per square centimeter (800 to 1600 psi) are used with
flow rates varying from 25.2 to 101 liters per. second (400 to
1600 gallons per minute). Due to the large volumes-of ultra-
clean water required, the inability to recycle wa-ter and the
resulting wastewater flow, hydraulic barkers are slowly being
phased out. In the cutterhead barker, logs are fed through
the barker one at a time and a cylindrical cutterhead removes
bark by a milling action as it rotates parallel to the axis
of the log. No water is employed.
All of the wet barkers use large amounts of water-and require
a fairly complex operation (Figure 10) to separate the bark
from the water and dry it so that it can be used'as fuel in
the boiler. In spite of the recovery operations, the effluent
from wet barkers have high solids concentrations. It is
44
-------
cn
LOG
STORAGE
PROCESS
WATER
1
PROCESS
BACK WATER
1
t
LOG
WASHER
_,
Jr«
COARSE
SCREENING
i<^
f
FINE
SCREENING
1
i
DIVERSION
BOX
1
i
EFFLUENT
4-4-J.1.4**
J
' 1
WET DRUM
POCKET OR
HYDRAULIC BAR
1
BARK PRESS
fc DEB
LOG
1
OFF
tKER
CYC
*-*^
ARKED
S
GASES
t
LONE +•-+-+-.
+ | 1+ + +^ BARK BOILER ^-4-t-l
4
ASH TO LAND . ._
DISPOSAL
BJ
PR
BA
GA
BA
RE
EF
ODUCT AND
W MATERIAL
OCESS WATER —
CK WATER
SES
RK ASH ^
SIDUE
FLUENT -
4 4
L™i
—
h++-
FIGURE 10 (8) - WET BARKING PROCESS DIAGRAM
-------
DRAFT
expected that wet barkers will disappear in the near
future since at the present time their main use is for
debarking oversized logs, which are diminishing in supply.
Log Conditioning
Heating of logs prior to veneering serves to improve the
cutting properties of wood, particularly hardwood. His-
torically, both hardboard and softwood mills have prac-
ticed log heating. There has been in recent years a trend
away from log heating in the softwood industry, but the
current trend is again toward this practice.
Wken the heating of logs occurs not only prior to veneer-
ing, but also prior to debarking, it also facilitates the
debarking operation, and this has been the common practice
in the past. With the increasing use of ring and cutterhead
barkers whose operations are not aided by prior heating to
the same degree as other debarking methods, heating commonly
occurs between the debarking and veneering operations.
There are basically two methods of heating logs: (1) by direc-
ting steam onto the logs in a "steam vat" (steam tunnel), and
(2) by heating the logs in a "hot water vat" full of water
which is heated either directly with live steam or indirectly
with steam coils.
Heating in steam vats is generally more violent than in hot
water vats. Steam vats are therefore more applicable to species
of wood that do not rupture under rapid and sudden thermal in-
creases. The times and temperatures of these conditioning
processes vary with species, age, size, and character of veneer
to be cut. The experience has been that the harder (more
dense) the species and the more difficult to cut, the longer
the conditioning period and the lower the temperature required.
Some of the softer woods can be cut satisfactorily without
such conditioning. Among these are poplar, bass wood, cotton-
wood, and certain conifers.
Veneer Cutting
The principal process unit in the manufacturing of veneers is
the cutting of the veneer. There are four methods used to cut
veneer: (1) rotary lathing, (2) slicing, (3) stay log cutting,
and (4) sawn veneering.
Currently more than 90 percent of all veneer is rotary cut (9).
In this method of cutting, a bolt of wood is centered between
two chucks on a lathe. The bolt is turned against a knife
extending across the length of the lathe, and, as the log
turns, a thin sheet of veneer is peeled from it. Lathes
46
-------
DRAFT
capable of peeling logs from 3.66 to-4.88 meters (12 to 16
feet) in length are not uncommon. More commonly, however,
veneer is cut in lengths ranging from 0.610 to 2.44 meters
(two to eight feet). The bolts that are to be veneered are
usually cut from 10 to 15 centimeters (four to six inches)
longer than the width of veneer to be cut from them.
Most slicers consist of a stationary knife. The flitch to be
cut is attached to a log bed which moves up and down. On
each downward stroke a slice of veneer is cut by the knite.
Slicers are used primarily for cutting decorative face veneers
from woods such as walnut, mahogany, cherry, and oak.
Stay log cutting produces veneers which are intermediate be-
tween rotary cut and sliced veneers. A flitch is attached to
a stay log or metal beam, mounted off center to a rotary lathe.
The stay log method produces half-round veneer which is generally
used for faces.
A very small quantity of veneer is cut by sawn veneering. A
circular type saw,called a segment saw,with a thin, segmented
blade turns on an arbor. The thin blade reduces saw kert.
This method generally is used only for certain species such as
oak, red cedar, and Spanish cedar in order to achieve special
effects. Veneers are cut to thicknesses ranging from .0.0231 to
9.53 millimeters (one-one hundred and tenth to three-eighths of an
inch). Most of the rotary cut veneers are either-3'.63, 3.18, -3.b4,
1.69, or 1.27 millimeters (one-seventh, one-eighth, one-tenth,, one-
fifteenth, or one-twentieth of an inch) thick.' Sliced-veneer usu-
ally ranges from 1.27 to 0.635 millimeters (one-twentieth to one-
fortieth of an inch). Sawed veneers vary from 6.35 to 0.795 milli-
meters (one-fourth to one-thirty second of an inch)-in.thickness.
The veneer coming from the lathe is cut to rough green size,
and defects are removed at the green clipper.
Veneer Drying
Freshly cut veneers are ordinarily unsuited for gluing because
of their wetness. In the undried (green) state, veneers are
also susceptible to attack by molds, blue-stain, and-wood-destroy-
ing fungi. It is therefore necessary to remove the-excess moisture
as rapidly as possible. Veneers are usually dried to a moisture
content of less than ten percent.
Several methods for drying veneers are in common use. The
most common dryers are long chambers equipped with rollers on
belts which advance the veneer longitudinally through the
47
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DRAFT
chamber. Fans and heating coils are located on the sides of
the chamber to control temperature and humidity.
The majority of high-temperature (above 100°C:212°F) veneer
dryers depend upon steam as a heat source. The heat is trans-
ferred to the air by heat exchangers. However, direct-fired
oil and gas dryers are becoming increasingly common in the
industry.
The conventional progressive type and compartment type lum-
ber kilns are also used in drying veneers. Air drying is
practiced but is quite rare except in the production of low
grade veneer such as that used in crate manufacturing. Air
drying is accomplished by simply placing the veneer in stacks
open to the atmosphere, but in such a way as to allow good
circulation of air.
Veneer Preparation
Between the drying and gluing operations are a series of minor
operations that prepare and/or salvage veneer. These opera-
tions may include grading and matching, redrying, dry-clipping,
jointing, taping and splicing, and inspecting and repairing.
These operations are self-descriptive and completely mechanical
or manual except for jointing and splicing which may use some
sort of adhesive; however, the bonding does not have to be as
strong as that in the gluing of plywood, and the amount of
adhesive used is kept to a minimum. Most of these gluing
operations do not require washing.
Gluing Operations
A number of adhesives can be used in the manufacture of ply-
wood. For the purpose of this discussion, distinction is
made between (1) protein, (2) phenol-formaldehyde, and (3)
urea-formaldeJjyde glues, since these are the classes of glue
most often used in the industry. Protein glue is extracted
from plants and animals, while the other two are synthetic
and thermosetting glues. Table 10 lists ingredients of typi-
cal protein, phenolic, and urea glue mixes.
Both protein and urea-formaldehyde glues are chiefly interior
glues, while phenol-formaldehyde is an exterior glue. Urea-
formaldehyde is used almost exclusively in the hardwood plywood
industry when the panels are used for furniture 'and indoor
panelling. Phenol-formaldehyde is a thermosetting resin like
48
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DRAFT
TABLE 10
INGREDIENTS OF TYPICAL PROTEIN, PHENOLIC AND UREA GLUE MIXES (lO)
Protein Glue For Interior Grade Plywood:
Water
Dried Blood
Soya Flour
Lime
Sodium Silicate
Caustic Soda
Formaldehyde Doner for Thickening
Phenolic Glue For Exterior Grade Plywood
Water
Furafil
Wheat Flour
Phenolic Formaldehyde Resin
Caustic Soda
Soda Ash
Urea Glue For Hardwood Plywood
Water
Defoamer
Extender (Wheat Flour)
Urea Formaldehyde Resin
49
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DRAFT
urea- formaldehyde, but it is waterproof and is practically
the only glue used to make exterior plywood. Exterior glue,
however, is being increasingly used to produce interior ply-
wood as well as exterior, so that the use of phenol-formalde-
hyde is increasing rapidly. Table 11 shows the break-down of
glue usage in 1965 and the projected usage for 1975. At present,
phenolic glues comprise about 50 percent of all glue consumed
while by 1975 it is projected that about 80 percent of all the
glue used in plywood manufacturing will be phenolic based.
Historically, protein glues had been the only adhesive used
in the plywood industry. However, as a result of synthetic
resins becoming less expensive and their versatility becoming
more recognized, the use of protein glues is disappearing. At
the present time, the main advantage of some protein glues is
that they can be cold pressed. But while cold pressing is a
simpler and cheaper operation, it is usually only satisfactory
for interior plywood.
TABLE 11
CURRENT AND PROJECTED ADHESIVE CONSUMPTION IN
THE PLYWOOD INDUSTRY
1965
(Millions of Kilograms
s)
197
Plywood Type Phenolic Urea Protein Phenolic Urea Protein
Western
Exterior 37 -- -- 88
Western
Interior 6.4 -- 47 62
Southern
Exterior -- -- -- 41
Southern
Interior 4.5 -- -- 39
Hardwood -- 25 -- -- 54 --
TOTALS 48 25 47 230 54 Nil
50
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DRAFT
Most plywood manufacturers mix their own glue'in'large dough
type mixers. The glue is then applied to the veneer by means
of a spreader, the most common of which consists'of two power
driven rollers supplied with the adhesive. Protein glues are
usually applied with steel rollers, while other glues are
usually applied with rubber-covered rollers. More recently
the practice of applying glue by means of sprays and curtain-
coaters has emerged. Since all glues harden with time, the
glue system must be cleaned regularly to avoid build-up of
dried glue. Some of the most recent spray curtain-coater glue
applicators require less washing than the conventional rollers.
Pressing
The gluing operations in the plywood industry are finished by
subjecting the sheets to pressure for the purpose"of insuring
proper alignment and an intimate contact between the wood and
the glue. The adhesive is allowed to partially cure under pres-
sure. Pressing may be accomplished at room temperature (cold-
pressing) or at high temperature (hot-pressing). Cold-pressing
is used with casein, some protein, and some urea-formaldehyde
adhesives. Hot-pressing equipment is used to cure some protein,
some urea-formaldehyde, and all of the phenol-formaldehyde ad-
hesives.
Most presses are hydraulic and apply pressures from 6.1 to 17
atmospheres (75 to 250 psig). Presses can be hot or cold de-
pending upon operating temperatures. Cold presses are operated
at room temperatures, while hot presses are operated at temp-
eratures of up to around 177°C (350°F) with heat being trans-
ferred by means of steam, hot water, or hofoil. Plywood pres-
sing time ranges from two minutes to 24 hours, depending upon
the temperature of the press and the type of glue used. The
hotter the press, the shorter the pressing time.
In recent years, radio-frequency heat has been*used to cure
synthetic resin adhesives. This works on'the principle that
when an alternating electric current oscillating in the radio
frequency range is applied to a dielectric material, the ma-
terial will be heated. It is still questionable whether this
method of heating is economically worthwhile; however, it is
technically applicable for pressing plywood as well as edge-
gluing.
Finishing
After the pressing operation, any number of a series of
finishing steps, depending upon the operation and the pro-
duct desired, can be taken. These operations include:
(1) redrying, (2) trimming, (3) sanding, (4) sorting,
(5) molding, and (6) storing.
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DRAFT
PROCESS DESCRIPTION-HARDBOARD
The raw material for hardboard- production like the pulp
and paper industry is essentially all wood. This wood
may be in the form of round wood, wood chips made from
waste products from saw mills and plywood mills, or other
sources of wood fiber'. Raw material handling for both
wet and dry process hardboard mills is shown in Figure 11.
Figure 12 shows a typical inplant process diagram of a
dry process hardboard mill and Figure 13 shows a typical
inplant process diagram of a wet process hardboard mill.
All phases of the raw materials handling for both dry and
wet hardboard mills are essentially the same. The prin-
ciple difference between the two processes is the manner
in which the fibers are carried and formed into a mat.
Raw materials, such as logs, chips, or other forms of wood,
are transported to the hardboard mill site for storage and
processing. Logs may be stored in a log deck or log pond
upon arrival at the mill. Chips arriving by rail car,
truck, or simply by conveyer from an adjoining mill are
stored in bins or piles. Logs may or may not be debarked
before being chipped. There are no general standards for
bark removal as each mill has its own standards for the
quantity of bark allowed in its finished product. In some
mills logs are washed before debarking to remove dirt and
other abrasive material that would be'detrimental to ma-
chinery or to the final product.
Log Barkers
Logs are debarked by several different types of machines (7) ,
including: (1) drum barkers; (2) ring barkers; (3) bag
barkers; (4) hydraulic barkers; and (5) cutterhead barkers.
Drum barkers are made in a wide-variety of sizes, generally
2.4 to 4.9 meters (8 to 16 feet) in diameter and up to
22.9 meters (75 feet) in length. A drum barker consists
of a cylindrical shell rotating on its horizontal longi-
tudinal axis. Logs are fed into-one end and the tumbling
and rolling action removes the bark. Water sprays may be
used to reduce dust, promote the thawing of wood in cold
climates, or reduce the bond between the bark and wood.
Ring barkers or rotary barkers consist of a rotating ring
on which several radial arms are pivoted. On the end of
each arm is a tool which abrades or scrapes off the bark.
52
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LOGS
o
LOG
STOR AGE
LOG WASH
DEBARKER
CHIPPER
CHIP
'STORAGE^
O
TO PROCESS
CHIP
WASH
FIGURE 11 - RAW MATERIAL HANDLING IN THE HARDBOARD INDUSTRY
53
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CHI PS
en
**W" " I ' IF! HER l^rEL
^JPREHEATERJZJ REFINER | .BRYER 1^1
(50) (60)pI3 Hi; ^ (7.5)
CHIPS
FIBER
rERSl V, J \ P R F S <
Vj to)
PREPRESS
MAT
-^ - p-
. «— r^X TO
* r^-vT FINISHING
BOARD
(XX) APPROXIMATE PERCENT MOISTURE
FIGURE 12 - TYPICAL DRY PROCESS HARDBOARD MILL
-------
CH I PS
FIBER
DILUTION
WATER
in
en
PREHEATER REFINER
M AT
BOARD
TO ATMOSPHERE
AT
CHIPS
SCREW
-FEED
WET FORMING
MACHIN E
(1.5)
TO
FINISHING
WATER IN
WATER OUT
(XX) APPROXIMATE PERCENT FIBER
(CONSISTENCY IN PROCESS)
FIGURE 13 - TYPICAL WET PROCESS HARDBOARD MILL
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DRAFT
A ring barker handles only one log at a time but can handle
logs up to 2.1 meters (7 feet) in diameter. Bag barkers
or pocket barkers are simple stationary containers in which
the logs are rotated to remove bark by abrasion. Water may
also be used in this process.
The hydraulic barker uses a high pressure water jet to blast
bark from a log. Pressures from 56 to 112 kilograms per
square centimeter (800 to 1600 psi) are used with flow rates
varying from 1,514 to 6,057 liters per minute (400 to 1600
gallons per minute). Due to the large volumes of ultra clean
water required, the inability to recycle water because of
nozzle plugging, and the resulting wastewater flow, hydraulic
barkers are slowly being phased out. The last general type
of barker is a cutterhead barker. Logs are fed through this
barker one at a time, and a cylindrical cutterhead removes
bark by a milling action as it rotates parallel to the axis
of the log.
Logs or wood scraps must be either processed to chips on-site
or converted to chips off-site and hauled to the mill. There
are several types of chippers utilized in the industry with
disc chippers being the most common. After chipping, chips
are screened to segregate them into various sizes. Screens
may be of the rotating, shaking, vibrating, or gyrating types,
with vibrating and gyrating screens being the most prevalent.
Chips are stockpiled in the open, under a roof, or totally
enclosed in chip silos. Some mills presently wash chips to
remove dirt and other trash which would cause high maintenance
in the fiber preparation stages. The quantity of dirt in
chips depends upon many factors. For the future, hardboard
manufacturers project the utilization of complete trees, in-
cluding bark, limbs, and leaves. This will cause additional
dirt to be brought to the mill. Weather conditions during
logging operations also have a significant effect on the
quantity of dirt as logs must be stored on the ground. Chip
washing is also important for thawing frozen chips in more
northern climates. There is a general industrial trend to-
ward use of lower quality fiber because of the increased
demand for timber products, high cost of logs, and their
general scarcity. With the use of lower quality fiber, such
as tree limbs and bark, it will become more and more desirable
to wash chips.
Fiber Preparation
Fiber preparation is one of the most important process operations
in the production of hardboard. There are two basic methods of
56
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DRAFT
fiber preparation, but a wide range of variations exists
within each basic method. These two basic methods are:
(1) Thermal plus mechanical refining
(2) Explosion process.
In the explosion process, wood chips are subjected to high
temperature steam in a "gun," or high pressure vessel, and
ejected through a quick opening valve (7). Upon ejection,
the softened chips burst into a mass of fiber or fiber bun-
dles. The process is essentially a high temperature acid
hydrolysis and lignin softening procedure, and is adaptable
to almost any ligno-cellulosic material. Chips approxi-
mately 19 millimeters (three-fourths inch) square, prepared
in conventional chippers and screened, are fed into a bat-
tery of 50.8 centimeter [20 inch) calibre guns or high
pressure vessels. Each gun is filled and closed. The chips
are then ^teamed to 42 kilograms per square centimeter (600
psi) for about one minute after which the pressure is quickly
raised to about 70 kilograms per square centimeter (1,000 psi
equivalent to about 285°C [550°FJ) and held for about five
seconds. The time of treatment at this high pressure is very
critical, and depends on the species and the-desired quality
of the product. The pressure is suddenly released into a
brown, fluffy mass of fiber. Entering a cyclone the steam
is condensed and the exploded fiber falls into a stock chest
where it is mixed with water and pumped through washers, re-
finers, and screens. The yields of fiber from pulping by
the explosion method are lower than those for other coarse
pulping procedures, due largely to the hydrolysis of hemi-
cellulosic material under conditions of steaming at high
pressure. The explosion process is used in only two hard-
board mills in the United States, both owned-by the Masonite
Corporation.
By far the most widely used fiber preparation consists of
both thermal and mechanical pulping (11). Thermal plus
mechanical refining, as its name implies, involves a pre-
liminary treatment of the raw material with heat in addition
to mechanical action in order to reduce the raw material to
pulp. The mechanical reduction is carried out in disc re-
finers or attrition mills after the pulp-type chips or
shredded raw materials have first been softened by steaming.
One of the advantages of this attrition mill method of pulping
over conventional grinding lies in the fact that a greater
variety of species and forms of raw material may be processed,
including materials from roundwood, slabs, edgings and veneer
residues, as well as materials such as pulp screenings,
shavings, and sawdust. Furthermore, with the possibilities
57
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DRAFT
of variation in pre-steaming, of plate pattern, of plate
clearances, and of number of refiners, there is considerable
latitude for the production of pulps possessing a wide range
of properties. In general, attrition mills such as disc
pulpers produce a good quality of pulp. A fast draining
pulp can be readily produced, having few abraded fibers and
coarse fiber bundles.
In the dry process, similar equipment can be used. However,
the wood can also be subjected to lower steam pressures of-
2.1 to 8.5 kilograms per square centimeter (30 to 120 psi)
for somewhat longer periods (one to two minutes) and then
passed through a disc refiner. In some cases the resin is
added to the chips while they are being refined by pumping
it through a hole drilled through the refiner shaft.
Prior to passing wood chips or other fibrous raw materials
through disc pulpers or refiners, it is often expedient to
give the material some form of pre-treatment in order to
reduce subsequent power consumption and improve pulp quali-
ties. However, the extent of the treatment will again depend
upon the nature of the raw material and the end product desired,
Steaming softens the wood to produce a pulp with fewer broken
fibers and coarse fiber bundles. The fibers of pulp so made
are more flexible and felt together more readily to form a
stronger board than pulp from wood that has not been steamed.
However, with some species, steaming may increase the tough-
ness of the chips and thereby increase the energy required
for defibering. The operation is carried out in digesters
under a variety of conditions of time and temperature.
In one process the chips are brought to a temperature of 170°
to 190°C (340° to 375°F) in a period of 20 to 60 seconds by
means of steam pressure between 7 and- 11.5 kilograms per
square centimeter (100 and 165 psi) and at this temperature
are passed through a disc refiner. It is claimed that due
to the short steaming period little hydrolysis takes place
and there is little loss of wood substance, the yield ranging
from 90 to 93 percent.
Attrition mills of the disc type have two discs, one sta-
tionary and one rotating, or both rotating, for defibering
and refining. Various disc patterns are available and
choice depends on species, pre~-treatment, and the type of
pulp desired. In most cases, the discs are made of special
alloys. The discs are usually 600 to 1,000 millimeters
(23 to 40 inches) in diameter and operate at 400 to 1,200
revolutions per minute.
58
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DRAFT
Double disc attrition mills, with the discs rotated in
opposite directions, do more work on the fiber and conse-
quently produce a higher stock temperature. Such equip-
ment, when operating on wood chips, produces well fiberized
material which may have all the strength required for
board manufacture. However, where further development or
strength is desired,further refining may be useful.
The single rotating disc mill has certain advantages. The
feed opening is more accessible and can be made very large
to accomodate bulky materials. It has fewer moving parts
and fewer bearings than the double disc mill.
Factors which determine the pulp quality produced by attri-
tion mills are properties of the raw material, pre-treatment,
the physical shape of material to be refined, plate design,
plate clearance, rate of feed, consistency, temperature,
speed of rotation, and rate of energy consumption. Many of
these factors can only be determined by experiment. Plate
clearances usually vary from 1.30 millimeters (0.05 inches)
for an initial breakdown of chips to a very low clearance
for the final refining. As the clearance between the plates
is reduced the strength of the pulp is increased, but because
of the production of more fines, the rate of drainage is re-
duced. An improved quality of stock may be obtained by using
a plate clearance of about 0.25 millimeters (0.01 inch),
screening out the acceptable stock,and recycling the coarse
material. This procedure reduces the power consumption and
the pulp will have a higher percentage of intermediate length
fibers and fewer fines. A certain amount of fines, however,^
is desirable as they improve board properties, such as rigidity,
and provide a smoother surface.
The power requirements for refiner stock from woods commonly
used vary from about 200 to 800 kilowatt" hours per ton (10 to
40 horsepower per ton) depending on species and pre-treatment.
The consistency of pulp leaving the attrition mill in a wet
process hardboard mill may vary over wide limits, but in
general is between 30 and 40 percent fiber. Lower consis-
tencies are used with certain material to prevent'feed chokes.
High consistencies tend to produce better pulps by raising the
temperature.
After conversion of the raw material to a fibrous pulp in the
attrition mills, it may be screened to remove coarse fiber
bundles, knots, and slivers. Some of the coarse material
can be returned to the system for further breakdown. Modern
equipment can produce a pulp which does not require screening.
59
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DRAFT
There are various attrition mills on the market for the
preparation of pulp. Some of the better known ones are des-
cribed in some detail in references (12) and (13). However,
brief reference is made here to the Asplund method (12) which
has been used extensively for preparation of stock for hardboard
mills. This involves the use of a single rotating disc and
has the feature of combining the steaming and defibering in
one unit in a continuous operation. The entire operation is
carried out under pressure and has"the advantage that no
cooling of the steamed chips takes place prior-to defibering,
and foaming difficulties are substantially reduced. A unit
may be expected to process 9 to 45 metric tons (10 to 50 tons)
of dry wood per day, depending on the type of wood and the
degree of defibering required. For hardboard stock, slight
refining may be desirable, especially for the removal of
slivers. When using modern refining equipment subsequent
screening may be unnecessary. However, when screening is
considered necessary a vibratory or rotary-type screen
may be used.
The American Hardboard Association (14) describes the remain-
ing processes in the following way.
Forming Hardboard
The manufacture of hardboard consists basically of reducing
trees to fibers and putting them1 back together'in the form
of sheets or boards having properties and characteristics
not formerly attainable in the natural wood. Before board
formation is started, it is often desirable to introduce
certain chemical additives to pulp which increases the
strength, water resistance, and other desirable properties
of hardboard. The additives to be used and the amounts
depend on the species of wood, degree of refining, and the
final properties desired. After the inclusion of additives
to the refined pulp, which may be in the form of either a
wet slurry or a dry fluff, the pulp is ready for delivery
to the board former.to begin the process of reassembling
fibers into hardboard. The formation or felting of fibers
to form a mat may be done by either the wet-felting process
or the dry-felting (air-felting) process.
Wet-Felting: In the wet process the mat is usually formed
on a fourdrinier type machine such as those used in making
paper. Refined pulp is pumped to the head box of the machine
and diluted with large quantities of water, until the mixture,
called "stock," contains only about one and one-half percent
pulp. The stock flows rapidly and smoothly from the bottom
of the head box onto an endless traveling wire screen. Special
60
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DRAFT
devices control the flow of stock allowing it'to-spread evenly
on the screen as an interlaced fibrous'blanket which may be
several inches thick depending upon the desired thickness of
the finished hardboard. The screen, kept level by tension,
and a number of rollers carry stock onward for about 9 meters
(30 feet) while water is withdrawn through the wire screen.
The water is first removed by gravity and as the screen advances
additional water is removed when the screen passes over one
or more suction boxes. At this point, stock has felted to-
gether into a continuous fibrous1 sheet called "wetlap."
The forming screen extends between a number of pairs of press
rollers which also have an endless screen travelling around
a series of the paired rollers. Here more water is removed
as the press rollers gradually apply pressure to the wetlap,
a process which is similar to the wringing action of a wash-
ing machine.
When the wet mat emerges from press rollers it is still
quite wet (50 to 75 percent moisture) but yet strong enough
to support its weight over a small span. At this point, it
leaves the forming screen and- continues its travel over a
conveyor. The wet mat is then trimmed to width and cut ojrf
to length by a travelling saw which moves across the travelling
mat on a bias making a square cut without the necessity of
stopping the continuous wetlap sheet. The thickness of wet
mat is normally three or four- times the finished thickness of
the hardboard to be produced. It still contains a great
deal of water which must be removed before the hardboard
manufacturing process is complete. The wet mat may be de-
livered directly to a platen press where water is removed
by a combination of pressing and heating or it may be con-
veyed to a heated roll dryer where water is evaporated by
heating alone. The direct pressing method is used to pro-
duce smooth one-side hardboard (SIS). The evaporative
drying method is used in the production of smooth two-side
hardboard (S2S). These operations will be described later.
Dry-Felting: The main difference'between- the dry, or air-
felting process, and the wet-felting process is that in the
dry process fibers are suspended in air rather than in water
as is the case in the wet-felting process. The unit developed
for laying down a continuous mat'of dry fibers is called the
felter. The prepared fibers are fed by volumetric feeders to
the felting unit at a controlled rate. A nozzle in the unit
distributes fibers to the top of the felter chamber and the
fibers fall to the floor of the felter similar to a heavy
snow storm. The effects of this snowing action produce an
interwoven mat of fibers. The floor of the felter is a moving
screen which is synchronized with the volumetric feeders.
61
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DRAFT
Air is sucked through the screen to aid'in the felting. As
the mat emerges from the felting chamber', • it has attained the
height necessary for the thickness of the board desired.
When a finished board of 3.2 millimeters (one-eighth inch) is
desired, the height of the mat as it emerges from the felting
chamber may be as much as 10 to 15 centimeters (4 to 6 inches).
Once the mat is formed, the procedure of compressing, trim-
ming, and sawing of the mat is similar to that for the wet
process. However, air-formed mats prior to pressing are
always thicker and softer than wet-formed mats and usually
require more care in loading the hardboard press.
Hardboard Press
The heart of every hardboard process is the press. Here
the reassembly of wood particles is completed and fibers
are welded together into a tough, durable grainless board.
Hardboard presses are massive, consisting of heavy steel
heads and bases, each of which may weigh 45 metric tons
(50 tons) or more, held together by steel columns 25 to
30 centimeters (10 or 12 inches) in diameter and as long
as 9 to 12 meters (30 to 40 feet). Between the head and
the base of the press are suspended a number of steel platens
which are drilled internally to provide circulating passages
for high pressure steam or water which is used to provide
heat necessary to help weld the fibers together. Several
hydraulic rams with a movable head are placed below the
platens and on top of the base to apply pressure upwards
toward the head of the press. When open, the hydraulic
rams are at their lowest position. Each'platen; except the
top and bottom platens which are fastened firmly to the press
head and moving base respectively, is individually suspended,
allowing an air space of 8 to 25 centimeters (3 to 10 inches)
between platens. The unpressed mats are placed one on top of
each platen so that there is an equivalent of a multi-deck
sandwich with the mat located between the steel platens.
When the press is loaded, hydraulic pressure is applied to
the rams. This operation forces the platens up against the
head of the press, squeezing the mats down to a fraction of
their former thickness. Pressures exerted may vary from 35 to
100 kilograms per square centimeter (500 to 1,500 psi) depend-
ing on the process and density desired in the finished board.
Most hardboard presses have 20 openings and 21 platens, so
that 20 boards may be pressed at the same time. Some presses
have as few as ten openings and some as many as 30. Press
sizes vary, but include 1.2 meters by 4.9 meters (four feet by
16 feet), 1.2 meters by 2.4 meters (four feet by eight feet),
1.2 meters by 5.5 meters (four feet by 18 feet), and 1.5 meters
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DRAFT
by 4.9 meters (five feet by 16 feet). The 1.2 meters by 4.9
meters (four feet by 16 feet)-is the most common production
size. The combination of heat and pressure applied to mats
in the press welds the fibers back together and produces
properties which are unattainable in natural wood. The amount
of time required for pressing and the details of temperature
and pressure vary widely, depending upon the process and
physical properties in the particular hardboard being produced.
To facilitate loading and unloading the board in the press,
most presses are equipped with loading and unloading racks,
which usually take the form of multi-deck elevators, with
one deck for each opening in the hardboard press. Mats are
loaded on all decks of a loading rack. When the hardboard
press is open, unpressed mats are fed into the press at the
same time pressed mats are removed at the other end of the
press and placed into an unloading rack. Then, while the
new boards are under pressure, unpressed mats are placed
into the loading rack and pressed mats are discharged one at
a time from the loading rack and conveyed to subsequent opera-
tions.
Pressing Operation: There are two basic-types'of hardboard,
smooth one-side (SIS) and smooth two-sides (S2S). In making
SIS hardboard, the cut-to-size mat is delivered from the
board former onto a piece of screen wire slightly larger in
overall dimensions than the piece of wet mat. The wires carry-
ing wet mats are loaded into the decks of the press loading
racks and are loaded into the press openings. When the press
is closed and pressure applied, a large portion of water is
removed. The remaining water must be evaporated by the heat
of the press platens. Temperatures used in the production of
SIS board are around 190°C (380°F). The entire process of
pressing the board is carefully controlled by automatic elec-
trical equipment.
When a wet-formed mat is to be used to produce S2S hardboard,
it is delivered from the forming machine into a hot air dryer
where surplus moisture is evaporated. This may require from
one to four hours depending upon the weight of board being
produced. At this stage the mat is in large pieces, usually
two or three times as wide as the hardboard which will ulti-
mately be pressed. The mat is trimmed to the desired length
and width (usually slightly larger than 1.2 meters by 4.9
meters [four feet by 16 feet]) and delivered to the S2S hard-
board press. At this point, the board may have less than one
percent moisture content, and it is strong and rigid enough
to support its own weight. Thus, board can be delivered
63
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DRAFT
directly into the press openings and*pressed'with smooth pla-
tens, or caul plates, directly against both sides. Since
moisture does not have to be squeezed and evaporated, the
press cycle, which is from one to four minutes for common
thickness, is much shorter than for comparable thicknesses of
SIS board, which requires a 4 to 12 minute pressing time. The
dried board is much harder to compress than the soft, wet SIS;
consequently, hydraulic pressures three times greater
must be applied. Press temperatures in excess of 288°C
(550°F) must also be attained.
Dry-formed mat may also be used to produce S2S hardboard.
When this is done, the fibers must be reduced to a desired
low moisture content prior to the board formation. Most
dry air-formed mats are deposited-directly on traveling
caul plates and delivered into the press. These traveling
caul plates are necessary because the air-formed mat is
too fragile to support its own weight before pressing.
However, once in the press the combination of heat, pres-
sure, and time consolidates the soft, fluffy material into
a tough, durable piece of hardboard.
Oil Tempering
After being discharged from the press, a certain amount of
hardboard is selected to receive a special treatment called
tempering. Tempering consists of impregnating the sheets
of hardboard by dipping or roller-coating them in a bath
composed of drying oils and various drying resins derived
from petroleum.
As sheets are removed from the oil bath, they are passed
through a series of pressure rollers which aid in permeating
the oils and removing any excess. The oil is then stabilized
by baking the sheet from one to four hours at temperatures
ranging from 143° to 171°C (290° to 340°F) . Tempering hard-
board increases the hardness, strength, and water resistance,
thus making the board more resistant to abrasion and weathering.
Humidification
When sheets of hardboard are removed from the press, or the
tempering oven, they are very hot and dry. The boards must
be subjected to a seasoning operation called "humidification,"
otherwise they may tend to warp and change dimensions. Humidi-
fication is carried out by conveying boards through a long
tunnel humidifier, or charging them in racks which enter a
chamber where a high relative humidity is maintained. The
boards are retained in the humidifier until they reach the
proper moisture content. Although hardboards are humidified,
they should be allowed to adjust to local atmospheric condi-
tions before being installed.
64
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DRAFT
Further Processing
The final operation includes trimming the board to length
and width. Sheets of hardboard may be cut into any size a
customer desires. Also, hardboard may be fabricated in a
variety of ways. Some of the finishing processes include
simulating wood grain finishes, applying paint for a variety
of uses, embossing, and scoring.
After all operations have been completed and the sheets of
hardboard pass their final rigid inspection, they are wrapped
or packaged and sent to the warehouse for shipment to cus-
tomers.
Table 12 shows the proposed voluntary classification of hard-
board by surface finish, thickness, and physical properties.
PROCESS DESCRIPTION-WOOD PRESERVING
Treatments are applied by the industry to round and sawn wood
products by injecting into them chemicals previously described
that have fungistatic and insecticidal properties, or that im-
part fire resistance. Treatment is accomplished by either pres-
sure or non-pressure processes. Pressure processes for treating
wood with preservatives employ a combination of air and/or hydro-
static pressure and vacuum. Differences among the various pres-
sure treating processes used are based mainly on the sequence of
application of vacuum and pressure. The particular process used
does not significantly affect either the quantity or the quality
of wastewater discharged by a plant. Non-pressure processes uti-
lize open tanks and either hot or cold preservatives in which the
stock to be treated is immersed. Employment of this process on a
commercial scale to treat timbers and poles is largely confined
to the Rocky Mountain and Pacific regions, particularly the latter,
It is used to treat lumber and posts in the East.
The effect of species of wood on the waste stream is significant
only to the extent that it determines the conditioning method that
must be employed to prepare stock for preservative treatment.
Some species, such as the southern pines, are conditioned by a
process in which the stock is steamed at approximately 118°C
(245°F) for periods of from 1 to 16 hours preparatory to preserva-
tive treatment. This process, which is normally carried out in
the same retort in which the actual injection of preservative is
subsequently performed, has as its purpose to reduce the moisture
content of green wood and to render the wood more penetrable,
thus improving the quality of the preservative treatment. Other
species, i.e., Douglas fir, are conditioned for the same purposes
65
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DRAFT
TABLE 12
CLASSIFICATION OF HARDBOARD BY SURFACE FINISH, THICKNESS, AND PHYSICAL PROPERTIES (15)
Water Resistance
(max av per panel)
Class
1
2
3
Surface
SIS
SIS
and
S2S
SIS
and
S2S
SIS
and
S2S
Water
Nominal Absorption based
Thickness on Weight
mm-
2.1
2.5
3.2
4.8
6.4
7.9
9.5
2.1
2.5
3.2
4.8
6.4
7.9
9.5
3.2
4.8
6.4
9.5
SIS
percent-
1
30
20
15
12
10
8
8
40
25
20
18
16
14
12
20
18
15
14
S2S
percent1
25
20
18
12
11
10
40
20
25
25
20
15
12
25
20
20
18
Tensile Strength
Modulus of (min av per panel)
Rupture Parallel Perpendic-
Thickness • (min av per to ular to
Swelling panel) Surface Surface
SIS
percent
25
16
11
10
8
8
8
30
22
16
14
12
10
10
15
13
13
11
S2S
percent -Kilo-Newton per square meter-
20
16
15 1015 507.5 21.75
11
10
9
30
25
18
18 725 362.5 14.5
14
12
10
22
18
14 625.5 290 14.5
14
Note: 1: Tempered
2: Standard
3: Service-Tempered
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DRAFT
TABLE 12 CONTINUED
Water Resistance
Cmax av per panel)
Class Surface
SIS
and
S2S
4
S2S
SIS
and
S2S
5
S2S
Water
Nominal Absorption based
Thickness on Weight- •
mm
3.2
4.8
6.4
11.1
12.7
IS. 9
17.5
19.1
20.6
22.2
25.4
9.5
11.1
12.7
15.9
17.5
19.1
20.6
22.2
25.4
SIS
percent
30
25
25
25
25
— _
25
25
25
S2S
percent
30
27
27
27
18
15
15
12
12
12
12
25
25
25
22
22
20
20
20
20
Tensile btrengtn
Modulus of (min av per panel)
Rupture Parallel Perpendic-
Thickness (min av per to ular to
Swelling panel) Surface Surface
SIS
percent
25
15
15
15
15
—
20
20
20
S2S
percent --Kilo-Newton per square meter-
25
22
22
22
14
12
12
9
9
9
9
20
20
20
18
18
16
16
16
16
435 217.5 10.875
290 145 5.075
Note: 4: Service
5: Industrialite
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DRAFT
by a process called Boultonizing in tvhich the wood is heated
under vacuum in the preservative at 82° to 104°C (180° to 220°F)
prior to preservative injection. Boultonizing is not used where
the preservative is of the water-borne type.
Wastewater generated in steam conditioning is composed of both
steam condensate and water removed from the wood. Wastewater
from the Boultonizing process is composed only of water removed
from the wood. Both waste streams are contaminated by the pre-
servative used, and, where the same preservative is used, the
difference between them is primarily a quantitative one.
A process flow diagram for a typical plant using steam condition-
ing is shown in Figure 14.
INDUSTRY CATEGORIZATION
The general objective of industry categorization is to subdivide
the industry in order that separate effluent limitations and stan-
dards may be developed for such categories, if it is determined
that separate regulation is necessary. A further necessary con-
sideration, however, has to be based on whether differences in
segments of the industry require separate technical analyses,
even if the results of the analyses should lead to the same regu-
lations .
The Environmental Protection Agency preliminarily categorized the
timber products industry according to Standard Industrial Classifi-
cation (SIC) codes. In Phase I of this study, veneer and plywood,
hardboard, and wood preserving are covered. Due to the extreme
differences among the three industries, the categorization is main-
tained.
VENEER AND PLYWOOD-SUBCATEGORIZATION
The veneer and plywood industry has been assigned two SIC codes:
SIC 2435 includes hardwood veneer and plywood, and SIC 2436 in-
cludes softwood U6) . It has been concluded that due to the
applicability of treatment and control technology to the indus-
try and due to other factors, hardwood and softwood veneer and
plywood mills can be treated as one category without further sub-
categorization. Representatives of the industry have concurred
with this conclusion.
Raw Materials
Numerous species of wood are used to cut veneer and produce ply-
wood. Wastewater characteristics vary widely with raw material.
For example, it is known that softwoods in contact with water,
particularly hot water, release more wood sugars than do hardwoods
68
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o
10
O £?-
FIGURE 14 - PROCESS FLOW DIAGRAM FOR A TYPICAL WOOD-PRESERVING PLANT
(COURTESY OF ALBERT H. HALFF ASSOCIATES, INC., DALLAS, TEXAS)
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DRAFT
Within the broad categories of softwood and hardwood there are
also many species with varying leaching characteristics. In
addition, it is known that variations in process are often dic-
tated by the raw materials. For example, hardwoods require log
conditioning while some species of softwood do not.
While it would be expected that different wastewater charac-
teristics result from different raw materials, it is observed
that volumes of wastewaters vary only with process variations.
In addition, the control and treatment technology applied to
the industry consists almost exclusively of recycle and con-
tainment and is more a function of wastewater volume than of
pollutant concentration. Differences according to species do
not significantly affect the degree to which wastewaters can
be treated or controlled and, therefore, are rejected as pos-
sible elements for subcategorization.
Type Of Product
The type of product manufactured is not directly related to
wastewater volumes or concentrations and is, therefore, con-
sidered ineffective as a basis for subcategorization.
Size And Age Of Facility
The veneer and plywood industry is an old industry and contains
a number of old mills. The softwood plywood industry, however,
has been experiencing substantial growth for the past 20 years,
and numerous new facilities have been constructed. The south-
eastern United States, the main area for new development, con-
tains many of the newer plywood plants. Even though the ages of
plants vary, the ages of various components of a plant are not
necessarily reflected in total installation age; equipment is
constantly being replaced. Plant age is therefore'rejected as
a possible element for subcategorization.
The size of mills can also vary drastically from a backyard
operation producing 200,000 square meters (two million square
feet) of plywood per year to a large plywood mill producing
50 million square meters (600 million square feet) per year.
Since the volume of wastewater produced by a mill is largely
proportional to the size of the mill, control and treatment
are similarly proportional. While some special considerations
based on economics may be necessary for extreme cases, plant
size is rejected as a possible element for subcategorization.
70
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DRAFT
Process Variation
As suggested above, there are many process variations in the
veneer and plywood industry. These variations can.-be due to
a number of factors, including: raw materials, climate, type
of product, and personal preference.
Earlier in this section, process variations were described
in detail. A mill may or may not condition logs; it may have
wet or dry decking; it may remove the bark with or without^
water; it may or may not dry the veneer. Also, log condition-
ing may be accomplished in steam vats or hot water vats;
dryers may have to be cleaned weekly, bi-weekly, or not at
all. Most of these differences are dictated by the factors
previously listed, while in some cases it is merely a matter
of personal preference.
Even though there are a number of variations, particular unit
processes are basically similar from plant to plant. It was
therefore concluded that a feasible approach would be to charac-
terize each- unit operation rather than entire mills, and then
to assemble these unit operations accordingly to determine the
characteristics of a particular plant.
The variations in process are quite numerous, as might be expec-
ted in an industry composed of about 500 installations; however,
with few exceptions, all variations can comply with regulations
based on a single category encompassing all veneer, plywood,
and veneer-plywood installations.
Land Availability
Since most treatment technology requires some amount'of land,
and since one of the more economically attractive1 treatment
alternatives considered is containment of the wastes, land
availability must be considered. Most veneer and. plywood
mills have sufficient land availability. However, there are
certain plants located in urban areas which have a decisive
lack of available land. While it is likely that most of these
will have the opportunity to use municipal sewers-, they will
require specific consideration. With this stipulation, land
availability is rejected as a parameter for subcategorization.
71
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DRAFT
HARDBOARD INDUSTRY- SUBCATEGORIZATION
In developing Effluent Limitations Guidelines and Standards
of Performance for new sources for a given industry, a judg-
ment must be made as to whether effluent limitations and
standards are appropriate for different segments (subcategories)
within the industry. The factors considered in determining
whether such subcategories are justified are:
Raw materials
(2) Manufacturing process
(3) Plant size
(4) Plant age
(5) Product
(6) Plant location
(7) Air pollution control equipment
(8) Waste generated
Treatability of wastewaters
After extensive review of the above factors, involving plant
inspections, discussions with industry representatives, and
review of literature, it was concluded that the hardboard
industry should be broken into two subcategories which are
(1) dry process hardboard and (2) wet process hardboard.
Raw Material
Raw materials in the hardboard industry consist mainly of
wood fiber and quantities of additives such as phenolic
formaldehyde, urea formaldehyde, alum, ferric chloride and
petroleum waxes. The type of wood fiber utilized will
depend upon many variables including plant location, avail-
ability of raw material, and product to be made. The species
of wood and even the season of harvest will have an effect on
wastewater characteristics.
Composition changes in the binders are being made at different
times by the industry to reduce raw materials cost, to improve
the final product, and to reduce wastewater concentrations.
Each mill has its own characteristics; however, in general, the
waste characteristics for dry process hardboard mills and wet
process hardboard mills are similar. Therefore, raw materials
is not a basis for subcategorization.
Manufacturing Process
There are two different manufacturing processes in the hardboard
industry which affect wastewater flow and composition. These
are the dry-felting process and the wet-felting process. In
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DRAFT
the dry-felting process the fibers are suspended in air as
compared with the wet-felting process where the fibers are
suspended in water. There is little or no process wastewater
discharge from the dry-felting process, while there is a
continuous and substantial wastewater discharge from the
wet-felting process. One of the dry process mills which
adds water to the mat after dry forming has a discharge
from the press. This mill should be considered a special
case and be given special consideration.
Wet-felting (wet process) hardboard mills may press board either
dry or wet. If the board is to be pressed dry it is oven dried
before pressing. Since there is only one existing hardboard
mill which produces hardboard alone by wet-felting, dry pres-
sing, it is not sufficient cause for a separate category. The
wastewater from this particular mill is somewhat higher than a
typical wet process mill; therefore, it should be considered a
special case and given individual consideration.
There are several insulation board mills which produce hardboard
by the wet process followed by dry pressing. Because insulation
board mills will be considered in Phase II and because of the
unknown interrelationship between the manufacture of insulation
board and hardboard, these mills will also be surveyed in
Phase II.
In the wet process hardboard mills, fiber preparation is a
major factor affecting wastewater characteristics. Two mills
utilize the explosion process for fiber preparation which
causes substantially more BOD to be released. However, both
of these mills have installed evaporators to handle this high
BOD process wastewater and their overall waste discharge is
as low or lower than other wet process mills. The degree of
fiber preparation will depend upon many factors including
wood species, inplant processes, and final product. There
are even separate fiber preparation lines for boards that
are made up in layers with the degree of fiber preparation
for each layer dependent upon the product to be produced.
The effect of fiber preparation on wastewater flow and
composition is not sufficient in itself to be used as
grounds for subcategorizing the industry.
Plant Size
It has been determined from existing data and from on-site
inspections that, other than in volumes of water, plant size
has no effect upon the wastewater characteristics and, there-
fore, should not be taken into consideration. Plant size
will only affect costs of treatment as treatment cost for
73
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DRAFT
larger plants will generally be less per unit basis than for
small plants.
Plant Age
A review of the data shows that plant age has no significant
effect on wastewater discharge. The major effects of plant
age are the higher maintenance cost and difficulty involved
in installing recycle systems, not in wastewater flow or con-
centration. Therefore, plant age is not an appropriate basis
for subcategorization.
Product
The type of hardboard produced in any one mill does not neces-
sarily determine the inplant processes used to make that pro-
duct. In the hardboard industry the product itself is not
sufficient justification for subcategorizing the industry, as
similar products can be produced by a combination of different
inplant processes. It is the inplant processes which affect
the wastewater characteristics rather than the product resulting
from the processes.
Plant Location
Geographical location of hardboard mills affects wastewater
characteristics mainly due to the type of available raw materials.
Variation in raw materials has already been rejected as grounds
for subcategorizing the industry. Plant location will affect
the weather conditions experienced and the effect of low temp-
eratures on biological treatment systems should be given special
consideration. Plant location in itself is not sufficient
grounds for subcategorization.
Air Pollution Control Equipment
Air pollution control is a major problem in the dry process hard-
board industry and the industry is just beginning to take steps
to control the problem. Air pollution control equipment is not
a major factor affecting wastewater discharge in the hardboard
industry, therefore, the industry subcategorization should not
be affected by air pollution equipment.
Wastes Generated
Variation in waste generated in the hardboard industry is directly
related to the two different manufacturing processes utilized in
making hardboard, the wet-felting process and the dr.y-felting pro-
cess. The wastewater flow, excluding cooling water, from a typi-
cal dry process hardboard mill will consist of a discharge of less
than 1,890 liters per day (500 gallons per day). This compares
74
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DRAFT
with a wastewater flow of 1,430,000 liters per day (378,000 gal-
lons per day) from a typical wet'process hardboard mill. There-
fore, there is justification for subcategorizing"the industry
into the wet process and dry process hardboard mills.
Treatability of Wastewaters
Treatability of wastewaters is not a justified basis for subcate-
gorization. Wastewaters from all wet process hardboard mills
are difficult to treat; however, there is not sufficient varia-
tion to subcategorize the hardboard industry base on treatability
of wastewater alone.
WOOD PRESERVING INDUSTRY-SUBCATEGORIZATION
The wood preserving industry is defined as the treatment of round
and sawn wood products by injecting them with chemicals which pro-
tect the wood from insect of microorganism attack or provide fire
resistance.
.Factors Considered
With respect to identifying any relevant, discrete categories
for the wood preserving industry, the following factors or
elements were considered in determining whether the industry
should be subdivided into subcategories for the purpose of
the application of effluent limitations guidelines and standards
of performance:
(1) Raw materials
(2) Products produced
(3) Production processes or methods
(4) Size and age of production facilities
(5) Wastewater constituents
(6) Treatability of wastes.
After considering all of these factors, it was concluded that
the wood preserving industry should be subcategorized based on
the method of conditioning the stock, type of preservative em-
ployed, and type of process involved. The wood preserving in-
dustry may be divided into four subcategories as follows:
Subcategory Description
1 Pressure processes employing oily
preservatives in which the predomi-
nant method of conditioning green
stock is by steaming or vapor
drying
75
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DRAFT
(Subcategory) (Description)
2 Pressure processes employing oily
preservatives in which the predomi-
nant method of conditioning green
stock is by Boultonizing
3 Pressure processes employing water-
borne salts
4 Non-pressure sources.
These categories subdivide the industry by major process, either
pressure or non-pressure, and by type of preservative used,
either oil-type or water-borne. It further subdivides pressure
processes that employ oil-type preservatives into two groups
based on the method of conditioning green wood preparatory to
preservative treatment.
Categorization based on treatment process, preservative used,
and method of conditioning is necessary because "of the effect
of these variables on wastewater volume and on the opportunity
for recycling waste, thus limiting or, in some instances, cur-
tailing discharges. The specific considerations that dictated
the selection of the categories shown are summarized below:
(a) Because of the processing methods used,
pressure treatments require the use of
water, some of which comes into contact
with the product. Non-pressure treat-
ments generate no process water. Con-
tamination of water which occurs in the
latter process is due directly or indi-
rectly to precipitation, and can generally
be avoided.
(b) Technology is currently available that makes
practical the recycling of wastewater from
salt-type treatments. This is not neces-
sarily the case for wastewater from treat-
ments which employ oily preservatives.
(c) The volume of wastewater generated during
conditioning of green stock preparatory to
preserva-tive treatment is several times
greater by steaming than by Boultonizing.
76
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DRAFT
Subcategories 1 and 2 will apply principally to plants which
treat southern pine and Douglas fir, respectively, with creosote
and/or pentachlorophenol in the various forms in which they are
used. As such, they will cover the majority of the plants in
the industry.
Subcategory 3 will apply both to plants which treat only with
water-borne preservatives and fire-retardants and to that por-
tion of the production equipment used to apply salt-type treat-
ments at plants which also treat with oily preservatives.
Subcategory 4 will ajppl_y to all 'non^ressure processes regardless
of type, preservative used, and "the products treated.
77
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DRAFT
SECTION V
WATER USE AND WASTE CHARACTERIZATION
PART A: VENEER AND PLYWOOD
Water usage varies widely in the veneer and plywood industry
depending on types of unit operations employed and the degree
of recycle and reuse of water practiced. In general, total
water usage is less than 3.15 liters per second (50 gallons
per minute). There are some veneer and plywood plants that
do not discharge wastewater into navigable streams, but all
use fresh water to some extent. While there are plants pre-
sently being designed to recycle all wastewater, none are now
in operation and the practicability of doing so has not been
established. It is observed, however, that considerable ef-
fort can be made to reduce the amount of wastewater to be
discharged or contained. The amount of information available
on volumes and characteristics of wastewaters from the industry
is minimal; however, its problems are also dwarfed when com-
pared to that of most other industries. Data used in waste-
water characterization is based mostly on data from the litera-
ture, information supplied by individual mills, and sampling
and analyses conducted for the purposes of this study. Since
the volumes that are involved are small, attention has been
directed to finding methods for reducing the volumes and ways
of handling in such a way as to eliminate discharges.
When wood comes in contact with water, there can occur various
chemical effects which cause leaching and dissolution of vari-
ous compounds into the water. Wood is exceedingly difficult to
define chemically because it is a complex heterogeneous product
of nature composed of interpenetrating components, largely of
high molecular weight. The principal components generally are
classified as cellulose, lignin, hemicellulose, and solvent-
soluble substances (extractives). The paper industry (7)
reports the amounts present to be in the range of 40 to 50
percent, 15 to 35 percent, 20 to 35 percent, and 3 to 10 percent,
respectively.
The yield, composition, purity, and extent of degradation of
these isolated components depend on the exact conditions of
the empirical procedures employed for their isolation. By far
the most important factor relative to the values obtained in
chemical analysis for wood components is the tree species.
79
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DRAFT
At normal temperatures wood has remarkable resistance to
degradation by chemicals and solvents. This may be attri-
buted to the penetrating network structure of wood comprised
of polymers with widely differing properties. Also, the high
crystallinity of the carbohydrate system reduces the acces-
sibility of the wood components to reagents.
Water at room temperature has little chemical effect on wood,
but as temperature rises and pH decreases because of the
splitting off of acetyl groups, wood becomes subject to rapid
acid hydrolysis with the dissolution of carbohydrate material
and some lignin. At temperatures above 140°C (220°F) con-
siderable and rapid removal of hemicellulose occurs (7).
Fortunately, cellulose resists hydrolysis better than hemi-
cellulose fractions. Table 13 relates properties and
composition of many common woods used in tnis country.
In veneer and plywood mills, water is used in the following
operations:
(1) Log storage
(2) Log debarking
(3) Log conditioning
(4) Cleaning of veneer dryers
(5) Washing of the glue line
and glue tanks
(6) Cooling
Figure 9 (Section IV), presented a detailed process flow
diagram. The water use and waste characteristics for each
operation are discussed below.
LOG STORAGE
As described in Section IV, Process Description and Industry
Categorization, there are three methods of storing logs,and
two of these, log ponds and wet-decking, depend on the use of
water.
Log Ponds
There are hundreds of log ponds throughout the country. Some
of these are in conjunction with veneer and plywood operations,
but many more are part of logging operations, saw mills, hard-
board plants, paper mills, and other operations in the timber
products industry. Log ponds can take a number of forms. As
discussed in Section IV, they can be in an estuary, river, lake,
80
-------
TABLE 13 (17)
SOME PROPERTIES OF CERTAIN UNITED STATES WOODS
Spiucc
Iji^clmann
li.il
Silka
\\ lute
Kir
Alpine
Dakim
Crand
Nohle
Silver
\\lute
Douglas fir, coast t)pc
Pine"
Jack
Lol.lolly
Lodgepnle
Ixinglcaf'
1'ondcrosa
Red
Shortleaf
Shsh
Sugai
\Vlntc eastern
White western
Hemlock
1'astcrii
Western
Inarch
Tainarjck
Western
Cypress, l-alil
Ash, white
H.isswocxl
Beech
Ilirch
Taper
Yellow
Riittcmut
Chestnut
Cuuimln'r lice
Dm, AniiiK.ni
Cum
Hl.ick
Sttlll
Maple
Hed
Sil»er
Sti»ar
1'opl.ir
Qu.iknr.; asprii
Hakim
('..IslLIII inllllllUIKxl
I..IIL;» ln.illi aspen
SxiMllUllt
Ullm, poplar
grin ilij
SftrinA-
tiff.
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380
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81
-------
DRAFT
or they can be in the form of man-made impoundment. The data
available in the literature along with that obtained by sam-
pling are based on man-made impoundments which are the most
common in the veneer and plywood industry. All of these are
based on the state of Oregon where log ponds abound.
In order to characterize the quality of water leaving a log
pond, there are many factors that must be considered. These
include:
(1) Type of logs in pond
(2) Number of logs in pond
(3) Age of logs
(4) Detention time of logs
(5) Size of pond
(6) Hydraulic detention time
(7) Quality of water entering pond
While the first five factors can usually be approximated with
sufficient accuracy, the last two can be elusive. Both the
hydraulic detention time and the quality of water entering the
pond are a function of the quantity and frequency of rain as
well as drainage area and runoff characteristics. In western
Oregon, for example, the average yearly rainfall is approxi-
mately 137 centimeters (54 inches), but almost all of the
rain occurs in the winter months of November through April.
In general, in western Oregon log ponds do not discharge dur-
ing the summer, and the concentrations accumulate until the
winter rainy season when the ponds begin to overflow. At the
end of the rainy season the quality of water in the log ponds
is usually at its best. A variable discharge, as is common in
Oregon, makes the task of characterization an exceedingly dif-
ficult one. In fact, in order to accomplish a reasonable
characterization, it would be necessary to monitor several log
ponds over at least a one-year period.
The data used to characterize log ponds in this study are
based on samples collected in the winter of 1973 and on addi-
tional samples collected under Environmental Protection Agency
Project Number NP01320, by Doctor Frank D. Schaumburg (18),
in the summer of 1972. From this data it is possible to for-
mulate an approximation of the characteristics of man-made log
ponds in Oregon and to obtain some idea of the waste loads
that these might represent.
Tables 14 and 15 characterize the water from various log ponds
in terms of concentration. From this data it can be seen that
there are significant differences in concentration from summer
to winter.
82
-------
TABLE 14
WINTER CHARACTERISTICS OF OREGON LOG PONDS*
PART A: CHEMICAL CHARACTERISTICS
oo
Pond BOD5 COD DS SS TS Turb. Phenols Color Kjld-N T-P04~P
A-l
A- 2
A- 3
A- 4
A- 5
A- 6
5
10
2
3
7
3
57
64
47
67
46
78
81
90
69
130
120
271
31
579
11
21
42
26
112
669
80
151
162
297
12
40
8
6
28
4
0
0
0
0
0
0
.03
.03
.03
.01
.08
.06
18
9
14
9
12
13
2.30
0.34
1.40
1.33
2.82
0.45
0.02
0.02
0.02
0.02
0.025
0.02
Note: Turbidity in JTU; color in Pt.-Cobalt units; all others in mg/1.
-------
TABLE 14 (CONTINUED)
WINTER CHARACTERISTICS OF OREGON LOG PONDS*
PART B: PHYSICAL CHARACTERISTICS
Surface Average
Area Depth Volume Log Water Remarks and
Pond (Hectares) (Meters) (Cu.M) Type of Log Detention Source Approximate Eff.
00
A-l
A-2
A-3
A-4
23
1.2
23
17
1.5 345,192 651 Doug.fir 44 Days
351 Hemlock
1.8 22,937 40% Doug.fir 3 Hours
601 Hemlock
1.4 314,912 90% Doug.fir 60 Days
1.2 207,039 100% Doug.fir 126 Days
Reservoir
Creek
Another
Pond
Overflow in Nov.
to Mar.=about
1,635 Cu.M/Day
Impounded creek
Overflowing Nov.
to Mar.=about
489,400 Cu.M/Day
Overflow in Nov.
to Mar.=about
1,635 Cu.M/Day
Overflow in Nov.
to Mar.=about
1,643 Cu.M/Day
*Based on Environmental Science and Engineering, Inc. sampling from
March 2 to March 6, 1973.
-------
TABLE 15
oo
tn
Pond
TS
SUMMER CHARACTERISTICS OF OREGON LOG PONDS (18)
PART A: CHEMICAL CHARACTERISTICS
SS
BOD5
DO Temp. pH COD BOD2Q BOD5 CT5U Kjld-N N03-N P04
B-l
B-2
B-3
B-4
254
747
356
606
43
180
4
122
0.1
0.3
1.5
0.7
22
21.5
23
21.5
6.9
7.1
7.5
7.4
116
504
23
353
48
167
10
116
29
54
6
68
0.25
0.11
0.25
0.19
2
10
1
4
.4
.4
.0
.9
0.6
1.5
0.1
0.7
0.5
1.2
0.1
2.0
Note: All concentrations in mg/1 except temperature in degrees Centigrade and pH
-------
TABLE 15 (CONTINUED)
00
en
SUMMER CHARACTERISTICS OF OREGON LOG PONDS (18)
PART B: PHYSICAL CHARACTERISTICS
Area Depth Pond Age
Pond (Hectares) (Meters) (Years)
Type
Logs Length of
Stored- Storage
Water
Source Remarks
B-l
B-2
B-3
B-4
10.5
8.09
1.01
1.21
2,44
1.85
to
2.44
3.66
1.22
to
1.52
11 Doug.fir 1-3 years stream
14
19
Doug.fir 80% of
logs about
1 week
85% Pond- 2 weeks
erosa pine
15% Doug.fir
Over 90% 1 week
Ponderosa
pine
wells
stream
Non-everflowing
except during high
runoff periods;
Sanitary wastes
dumped into pond.
Non-overflowing
except during high
runoff periods;
Sanitary wastes
from plywood dump-
ed into pond.
Overflowing at
about 25.2 liters
per second
spring; Overflowing at
irriga- about 1.01 liters
tion per second.
-------
DRAFT
In the winter, BOD values range from two to ten milligrams per
liter and in the summer from six to 68 milligrams per liter.
COD values are from six to 26 times larger than BOD values in
the winter and from four to ten times larger in the summer.
Log ponds with higher hydraulic loads also have higher solids
concentration. Total solid concentrations vary from about 80
to 700 mg/1.
All of the log ponds have a distinct brown coloration which
has been credited by Schaumburg (18) to leached tannins from
the bark of the logs. The Pearl Benson Index has often been
used as a measure of color producing substances, but COD has
also been found by Schaumburg to correlate satisfactorily.
Table 16, below, presents approximate waste loads from ponds
sampled during this study. Three of the four ponds presented
in this table show good correlation; however, the other carries
much greater loads. The greater loads may be partly due to the
greater hydraulic loads and partly to the shorter detention
time of the logs - factors favoring greater leaching.
Wet-Decking
Since wet-decking is the most acceptable alternative to tra-
ditional log-ponding, it is necessary to determine the waste
characteristics from such operations. Schaumburgfs study (18)
on log handling includes the results of field work conducted
to obtain leaching data from wet-decking. This data is shown
in Table 17. It appears that the amount of waste transferred
from the logs to the water is about the same regardless of
whether the logs are stored in ponds or wet-decked.
TABLE 16
WINTER WASTELOAD FROM OREGON LOG PONDS
Pond BODs COD PS SS TS Phenols Kjld'N T-POa
A-l 23 262 367 144 516 0.138 10.6 <0.092
A-2 2027 13600 -912 121000 120000 6.587 74.3 <4.36
A-3 20 477 701 112 814 0.306 14.2 <0.202
A-4 12 258 502 81 583 -0.039 -0.277
Note: Units are in kilograms per million cubic meters
87
-------
DRAFT
TABLE 17
PONDEROSA PINE WET DECK DATA (18)
Parameter Sampled Value
Mean log diameter 49 cm
Mean log length 9.9 m
Estimated number of logs 24,400
Estimated surface area 371,600 sq.m
Mean BOD of runoff 19 mg/1
Flow 1,612 cu.m/day
BOD per day 30.6 kg/day
TABLE 18
ANALYSIS OF SAMPLE TAKEN FROM A WET DECKING RECYCLE POND
BOD 16 mg/1
COD 323 mg/1
Total Solids 544 mg/1
Suspended Solids 104 mg/1
Dissolved Solids 440 mg/1
Total Phosphorus 2.0 mg/1
Kjeldahl Nitrogen 2.7 mg/1
Turbidity 80 JTU
pH 8.16
88
-------
DRAFT
However, collection and recycling of sprinkling water makes
zero discharge from wet-decking more feasible than from log
ponds. The main advantage of wet-decking is that the volume
of wastewater produced is more easily controlled due both to
the operation and to the fact that sprinkling enhances evapo-
ration. The increased evaporation partially offsets the effect
of rainfall runoff on wastewater volume.
A small hardwood and veneer plywood plant with a wet-decking
operation recycles the sprinkled water by collecting it into
two small ponds of less than two hectares (one acre) where
solids are allowed to settle. The effluent from these ponds
is pumped back to the sprinklers through a coarse screen. One
of these ponds was sampled and the results of analyses are pre-
sented in Table 18. No significant accumulation of BOD and
COD is observed when this data is compared with the data in
Table 17. The major concern of such a recycling system is the
accumulation of solids and particularly of colloidal solids.
While there are problems associated with recycling, these are
operational problems that vary from plant to plant and also
vary with location, soil conditions, and other such factors.
These problems can be solved in most cases. There are now
several plants within the industry that recycle sprinkling
water successfully.
LOG BARKING
Logs can be barked with or without water. A typical mill
barks logs without water and it appears that the trend will
be for all barking to be accomplished without water (mech-
anically). A very small amount of water may be used to
control dust and small wood particles; however, no discharge
is necessary. Nevertheless, there are still some applications,
such as with very large logs, which make wet barking necessary.
Since wet barkers are being phased out in the veneer and ply-
wood industry, no effort is being made to verify the charac-
terization of the wastewaters associated with it. The
following is based on results of Environmental Protection
Agency Contract Number 68-01-0022 and 68-01-0012 (8).
As discussed in Section IV, Process Description and Industry
Categorization, there are three types of wet barkers:TH
drum barkers;(2) pocket barkers; and (3) hydraulic barkers.
Drum and hydraulic barkers are the most common. In any
case, a wet barking operation requires a number of steps
to separate the bark from the water. The bark is usually
pressed to remove water and then sent to a boiler where it
89
-------
DRAFT
is used as a source of fuel. Figure 10 in Section IV presented
a typical process flow diagram for wet barking.
Results of an analysis of the effluent from a hydraulic barking
process are shown in Table 19. The water employed in hydraulic
barking must be free of suspended solids to avoid clogging noz-
zles. It can be concluded that the total suspended solids
content in the discharge from hydraulic barking ranges from 521
to 2,362 mg/1, while BOD values range between 56 and 250 mg/1.
Results of an analysis of the effluent from a drum barker is
also given in Table 19. Total suspended solids concentrations
are only slightly higher in a drum barker than in a hydraulic
barker, but BOD values are significantly higher. Drum barking
often involves recycling, which accounts for'part of the in-
crease. The high BOD values are also due to a longer contact
between the bark and the water and to the grinding action which
is absent in hydraulic barking.
BOD values are also affected by the species of wood barked and
by the time of the year in which the log in cut.
LOG CONDITIONING [STEAMING)
The industry uses two distinct types of log steaming systems.
These are discussed in Section IV; Process Description and
Industry Categorization, and are referred to as steam vats
and hot water vats. In the South about 50 percent of the
plants use steam vats and 50 percent use hot water vats. In
the West, however, only about 30 percent of the plants use
any kind of conditioning and these use steam vats almost
exclusively.
The only wastewater from a steam vat is condensed steam.
This water carries leachates from the logs as well as wood
particles. Table 20 presents the results of analyses of
wastewaters from steam vats. The magnitudes of these flows
vary according to the size and number of vats. A plant pro-
ducing 9.31 million square meters (100 million square feet)
of plywood on a 9.53 millimeter (three-eights inch) basis
has an effluent of about 1.58 to 3.15 liters per second (25
to 50 gallons per minute). A southern plywood mill produces
a BOD load of 2,500 kilograms per million square meters
(51.5 pounds per million square feet) of board on a 9.53 mil-
limeter (three-eights inch) basis, and a total solids load
of 29,200 kilograms per million square meters on a 9.53
millimeter basis (6,000 pounds per million square feet on
a three-eights inch basis) of board.
90
-------
DRAFT
TABLE 19
CHARACTERISTICS OF DEBARKING EFFLUENTS (8)
Total
Suspended Non-Set.
Mill
1
2
3
4
5
6
7
/
8
9
10
11
Type of
Debarking
Hydraulic
Hydraulic
Hydraulic
Hydraulic
Hydraulic
Hydraulic
LI » r f\ ^» rt 1 1 1 \ f
ny QI au -L i c
Hydraulic
Drum
Drum
Drum
Solids
(mg/1)
2,362
889
1,391
550
521
2,017
2nnn
, uuu
600
2,017
3,171
2,875
Solids
(mg/1)
141
101
180
66
53
69
^ 9 no
<£U(J
41
69
57
80
BOD5
(mg/1)
85
101
64
99
121
56
97
1
250
480
605
987
Color
Less
Less
Less
Less
Less
Less
35
20
Less
Less
Units
than 50
than 50
than 50
than 50
than 50
than 50
than 50
than 50
91
-------
10
fo
TABLE 20
CHARACTERISTICS OF STEAM VAT DISCHARGES
Concentrations
Plant
A
B
C
D
E
F
BOD
470
3,117
2,940
1,499
1,298
476
COD
8,
4,
8,
3,
3,
1,
310
005
670
435
312
668
DS
2,430
5,080
2,202
2,429
917
SS
2,940
86
370
389
107
74
TS
5,370
5,450
2,591
2,536
991
Turb, Phenols
450 0.69
245 0.57
249
30 0.30
28 0.20
Kjld-N
56.
16.
39.
1.
4.
8
5
3
87
73
T-P04-P pH
5,70 4.12
14 4.1-6.1
5.38
5.3
.173
1.93
Note: All units are in mg/1 except Turbidity, which is in JTU's and pH,
-------
DRAFT
A hot water vat conditions the log with hot water heated
either directly with steam or by means of heating coils with
steam, oil or other heat sources. When the vat is heated in-
directly, there is no reason for a constant discharge. Steam
vats regardless of heating method are usually emptied periodi-
cally, and the water is discharged and replaced with clean
water. Some plants settle spent wastewater and pump it back
into the vats. Chemical characteristics for hot water vats
for a series of veneer and plywood plants are given in Table
21.
DRYER WASHWATER
Veneer dryers accumulate wood particles. Volatile hydrocar-
bons will also condense on the surface of dryers to form an
organic deposit which is called "pitch." In order to avoid
excessive buildup of these substances, dryers must be cleaned
periodically. Wood particles can be removed either by flush-
ing with water or by blowing with air. While some of the
pitch can be scraped off, generally a high pH detergent must
be applied to dissolve most of the pitch and then it must be
rinsed off with water.
The nature of the dryer wash water varies according to the
amount of water used, the amount of scraping prior to appli-
cation of water, condition of the dryer, operation of dryer,
and, to some extent, the species of wood that is being dried.
The amount of water used varies from plant to plant and from
operator to operator. One drying operation was observed to
use about 23,000 liters (6,000 gallons) of water per dryer
over a period of 80 hours. At this plant there were six
dryers and they were washed every three weeks. The washing
operation consisted of removing the bulk of the wood residue
by blowing it out with air and hauling it away, and then
washing the dryer with water for about three-quarters of an
hour to remove more wood particles. After this water clean-
ing, the caustic detergent was applied. Finally, the deter-
gent was rinsed off with water for another three-quarters of
an hour. Samples of spent water were taken during both
applications of water, and the analyses of these samples are
shown in Table 22-A. The effluent from this washing operation
was averaged over a seven-day period and expressed in terms
of a unit of production basis as shown in Table 22-B.
One thing that is emphasized by various experts in the veneer
and plywood industry is that pitch build-up can be minimized
by proper maintenance of the dryers. In addition, the volume
93
-------
TABLE 21
CHARACTERISTICS OF HOT WATER STEAM VAT DISCHARGES
Concentrations
vo
Plant
A
B
C
D*
E*
BOD
4,740
3,100
326
1,000
1,900
14
9
1
4
COD
,600
,080
,492
,000
DS
3,950
1,570
1,948
319
SS
2,520
460
72
160
1,462
6
2
2
1
1
TS Turb. Phenols
,470 -- 0.40
,030
,020 800 <1.0
,000
,781
Kjld-N T-P04-P pH
26.4 -- 5
23.4 -- 3
16.2 <1.0 6
4
4
.4
.8
.9
.5
.4
Note: All units are in mg/1 except Turbidity, which is in JTU, and pH
*Analyses for plants 'D1 and 'E1 were provided by the respective plants, and
figures for plant 'E' represent an average for several mills owned by one company
-------
vo
in
TABLE 22a
ANALYSIS OF DRIER WASHWATER
Plant BOD COD DS SS TS Turb. Phenols Color Kjld-N T-P04-P
A
Part I 210 1,131 643 113 756 19 1.31 32 17.7 1.93
Part II 840 6,703 1,095 5,372 6,467 50 0.20 43 211 11.0
B 60 1,568 1,346 80 1,426 6 4.68 51 2.91 0.495
Note: All units are concentrations in mg/1 except for Turbidity in JTU's and
Color in Pt-Cobalt units.
-------
TABLE 22b
WASTE LOADS FROM VENEER DRIERS
Plant BOD COD DS SS TS Phenols Kjld-N T-P04-P
«o A 60.94 412 99.7 319 418 0.018 13.2 0.18
B 2.33 60.6 52.3 3.09 55.2 0.014 0.112 0.019
Note: all units are in kilograms per million square meters.
-------
DRAFT
of water necessary to wash the dryers can be greatly reduced.
For example, one Oregon plant of about one-half the size of
the one described previously was observed to use one-twelfth
as much water per week to clean its dryers. Wastewater charac-
teristics from this plant are also given in Tables 22-Aand22-B.
It must be noted, however, that this plant provides settling
and screening for the spent wash water before discharge, and
samples were taken at the discharge.
Most dryers are equipped with deluge systems to extinguish
fires that might be generated inside the dryer. Fires in
dryers are actually quite common, especially in those that
are poorly maintained. This water is usually handled in a
similar manner to dryer wash water, and many plants actually
take advantage of fires to clean the dryers. Fire deluge
water can add significantly to the wastewater problems in
some cases.
In addition to the two wastewater sources from veneer dryers
that have been mentioned, water is occasionally used for flood-
ing the bottom of the dryers. Many operators question the
logic behind this practice, while some claim that it prevents
fires and reduces air pollution problems. In any event, this
water does not have to add to the wastewater problems of a
mill. Several plants recycle all flood, wash, and fire water,
and because the flooding results in substantial evaporation of
water, these plants have found that fresh water can be used to
clean the dryers and still keep the system closed.
GLUE SYSTEM
Presently there are three types of glues in use in the veneer
and plywood industry: (1) phenolic formaldehyde resin; (2)
urea formaldehyde; and (3) protein glue. Protein glues are
slowly being phased out of the industry, while phenolic glues
are becoming more widely used. The main source of wastewater
from a glue system results from the washing of the glue
spreaders and mixing tanks.
The most extensive study of wastewater from glue systems in
the veneer and plywood industry was made by the Environmental
Protection Agency and carried out by Bodien (10). Table 10,
found in Section IV, shows a list of the typical ingredients
of the three categories of glues already established. The
specific quantities of these ingredients may vary slightly.
Table 23-A lists the results of chemical analyses of typical
mixtures of the different glues. The wastewaters from the
washing operations are diluted at a ratio of about twenty
97
-------
10
00
TABLE 23-A
AVERAGE CHEMICAL ANALYSIS OF PLYWOOD GLUE (10)
Analysis and Units Phenolic Gluea Protein Glueb Urea Gluec
COD, mg/kg
BOD, mg/kg
TOC, mg/kg
Total Phosphate, mg/kg as P
Total Kjeldahl Nitrogen, mg/kg as N
Phenols, pg/kg
Suspended Solids, mg/kg
Dissolved Solids, mg/kg
Total Solids, mg/kg
Total Volatile Suspended Solids, mg/kg
Total Volatile Solids, mg/kg
653,000
—
176,000
120
1,200
514,000
92,000
305,000
397,000
84,000
172,000
177,000
88,000
52,000
260
12,000
1,810
59,000
118,000
177,000
34,000
137,000
421,000
195,000
90,000
756
21,300
346,000
240,000
550,000
346,000
550,000
aBorden's Cascophen 31 which is similar to Borden's Cascophen 382
bfiorden's Casco S-230
cBorden's Casco Resin 5H
-------
DRAFT
to one with water to yield concentrations shown in Table 23-B.
Samples of two phenolic and one urea formaldehyde wastewater
were collected and are shown in Table 23-C. These are in the
same range as those in Table 23-B, so it is reasonable to as-
sume a twenty to one dilution with water. This ratio varies
considerably, however, according to frequency of cleaning and
amount of water used.
Wastewaters from glue systems are presently being handled by:
(1) direct discharge; (2) lagooning and discharge; (3) eva-
porators; (4) partial incineration; and (5) reusing the wash
water.
Several studies have been made of wastewater flow and reuse in
gluing operations to determine the possibility of complete
wastewater recycling. Most plywood mills add about 20 percent
water by weight, and the use of some wash water in the glue
mix is, therefore, possible. Table 23-D shows a list of south-
ern plywood mills along with the wastewater generated and the
water needed in glue makeup. Table 23-E shows measurement of
wastewaters generated by four Oregon plywood plants. It is
obvious from this data that in order to use all of the wash
water as glue makeup,significant reductions must be made in the
wastewater generated. These reductions, however, are feasible
and many plants currently operate with complete recycle.
Cooling Requirements
A veneer and plywood mill requires a certain amount of cooling
water to dissipate heat from the air compressor as well as
from machines such as the press and the lathe. A mill pro-
ducing 9.3 million square meters (100 million square feet) of
plywood per year on a 9.53 millimeter (three-eights inch) basis
needs to dissipate about 55,000 kilo-calories (217,000 BTU)
(20) per hour from the compressor and 101,000 kilo-calories
(400,000 BTU) (20) per hour from the rest of the plant, for a
total of 156,000 kilo-calories (617,000 BTU) per hour.
Mass Water Balance in a Veneer and Plywood Mill
An account of water gains and losses that occur in a typical
mill is given in this section. A schematic diagram of water
balance is given in Figure 15.
A veneer and plywood mill with an annual production of 9.3
million square meters (100 million square feet) of plywood on
a 9.53 millimeter (three-eights inch) basis is used as a basis
for the development of the water balance. Such a mill would
99
-------
o
o
TABLE 23-B
AVERAGE CHEMICAL ANALYSIS OF PLYWOOD GLUE WASHWATER (10)
(assuming a 20:1 dilution with water)
Analysis and Units Phenolic Gluea Protein Glueb Urea Gluec
COD, mg/kg
BOD, mg/kg
TOG, mg/kg
Total Phosphate, mg/kg as P
Total Kjeldahl Nitrogen, mg/kg as N
Phenols, ug/kg
Suspended Solids, mg/kg
Dissolved Solids, mg/kg
Total Solids, mg/kg
Total Volatile Suspended Solids, mg/kg
Total Volatile Solids, mg/kg
32,650
-25,000
8,800
6.00
60
25,700
4,600
15,250
19,850
84,000
172,000
8,850
440
2,600
13
600
90.5
2,950
5,900
8,850
1,700
6,850
21,050
9,750
4,500
37.8
1,065
173,000
10,300
27,500
17,300
27,500
aBorden's Cascophen 31 which is similar to Borden's Cascophen 382
bBorden's Casco S-230
cBorden's Casco Resin 5H
-------
TABLE 23-C
CHARACTERISTICS OF GLUE WASHWATER
Plant
A
B
C
BOD COD TS
15,900 16,700 7,910
8,880
710 5,670 5,890
DS SS Kjld-N
6,850 21.8
6,310 1,640
3,360 2,530
T-P04-P Phenols pH
2.46 4.16 9.77
20.2 0.14 5.25
10.8
Note: Plants A and C utilize phenolic glue and Plant C uses urea glue.
-------
o
Is)
TABLE 2 3-D
AMOUNT OF ADHESIVE WASHWATER GENERATED IN SOUTHERN PINE PLYWOOD PLANTS (19)
Plywood Plant
Production
(million sq.
meters/year)
9 .53mm basis
2.7
3.6
4.5
5.4
6.3
7.2
8.1
9.0
Weekly
Adhesive
Use
38,590
51,454
64,316
77,180
90,044
102,906
115,770
128,634
Amount
Glue
Mixers
9,286
9,286
9,286
11,939
23,877
23,877
23,877
23,877
of Washwater
Glue
Hold Tanks
948
1,895
1,895
1,895
1,895
2,843
2,843
2,843
Produced (
Glue
Spreaders
6,633
13,265
13,265
13,265
19,898
19,898
26,530
26,530
liters)
Total
16,866
24,446
24,446
27,099
45,670
45,670
53,250
53,250
Amount of
Adhesive
per week
7,364
9,820
2,276
14,732
17,188
19,640
22,096
24,552
-------
TABLE 23-E
GLUE WASTE DISCHARGE MEASUREMENTS
o
OJ
Average Discharge
Plant
1
2
3
4
Days
Measured
212
49
42
42
for Days
Measured (I/sec)
0.814
1.54
1.13
3.36
1966 Production
(sq.M - 9.53mm basis)
9,000,000
12,150,000
9,000,000
6,300,000
Number of
Spreaders
4
3
4
2
-------
47,034(1)
WATER
IN
LOGS
(50)
163,440(s)
163,440(1)
LOG
CONDITIONING
(50)
44,220(s)
VAPORS
OFF
DRYERS
(3)
1,634(1)
1,634(1)
DRYER
WASHING
(3)
WATER
IN
PLYWOOD
6,583(1)
(7)
VAPORS
OFF
PRESS
454(s)
(7.5)
GLUE
WASHUP
4,222(1)
4,222(1)
(7.5)
GLUE
4,222(1)
(1) - liquid water
(2) - steam
(XX) - I of moisture by weight
based on dry wood
Water in = 485,800
Water out= 485,800
All units in Kg of water per Day
iS_
Lb.
(Ib. of water per Day)
FIGURE 15 - WATER BALANCE FOR A PLYWOOD MILL PRODUCING
9.3 MILLION SQUARE METERS PER YEAR
ON A 9.53mm BASIS
104
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DRAFT
be producing plywood equivalent to 93,980 kilograms (207,000
pounds) per day or 95 metric tons (104 tons) per day on a dry
wood basis.
Water Gains
Water gains from a typical mill include water from the logs
and glue from various freshwater intakes that are used
throughout the process without the water becoming incorpo-
rated into the wood.
The moisture content of incoming logs varies according to
species. For the purpose of these calculations, 50 percent
moisture is assumed. Water from incoming logs is thus 47,000
kilograms per day or 500 kilograms per metric ton (1,000 pounds
per ton). The amount of water that is applied to plywood glue
is estimated to be 4,200 kilograms per day or 43 kilograms per
metric ton (85 pounds per ton) of dry plywood.
The freshwater sources of water vary with operation. Based
on data previously given, the following quantities can be
estimated: about 163,000 kilograms (360,000 pounds) per day
or 1,750 kilograms per metric ton (3,500 pounds per ton) of
steam is used in log conditioning; about 1,620 kilograms
(3,570 pounds) per day or 17.5 kilograms per metric ton (35
pounds per ton) of water is used to wash veneer dryers; and
about 4,200 kilograms (9,300 pounds) per day or 45 kilograms
per metric ton (90 pounds per ton) of water is used to wash
the glue system.
Water Losses
Water losses from a typical mill include the water in the
finished plywood, vapor losses from the pressing, and spent
water from log conditioning and washing operations.
The amount of water that is in the finished plywood can be
calculated to be 6,600 kilograms per day (14,500 pounds per
day or 140 pounds per ton) based on a seven percent moisture
content.
Vapor losses occur in the dryers and in the press. Based on
three percent moisture content in dried veneer, approximately
44,000 kilograms per day (97,400 pounds per day or 940 pounds
per ton) of steam must be released. Similar calculations
indicate a steam discharge of 450 kilograms per day (1,000
pounds per day or 10 pounds per ton) from the press.
105
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DRAFT
Wastewater discharged from log conditioning equals the amount
of steam applied, if coils are not used. This would be equi-
valent to a discharge of 163,000 kilograms per day (360,000
pounds per day or 3,500 pounds per ton).
Wastewater discharges from the washing operations are equal to
the respective water usage. Dryer wash water is approximately
163,000 kilograms per day (3,600 pounds per day or 35 pounds
per ton), and glue wash water is approximately 4,200 kilograms
per day (9,300 pounds per day or 90 pounds per ton).
106
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DRAFT
PART B: HARDBOARD
DRY PROCESS HARDBOARD
Specific Water Uses
There are several processes in the dry process hardboard
industry where water might be used. However, due to a wide
variety of raw material handling techniques and inplant
processes and housekeeping practices, no single dry process
hardboard mill uses water in all of the following processes:
Log Washing
Chip Washing
Resin System
Caul Washing
Housekeeping
Humidification
Fire Fighting
Cooling
The quantity of water utilized in any dry process hardboard
mill depends upon water uses in raw material handling and
inplant processes, recycle system utilized, housekeeping prac-
tices, and many other factors. Table 24 shows wastewater flows
from 11 of the 16 existing dry process hardboard mills. The
quantity of process water utilized in a typical mill would be
approximately 18,925 liters (5,000 gallons) per day. Most of
this water is either evaporated in the press or becomes a part
of the final product. A typical wastewater flow from a dry
process mill should be less than 1,900 liters (500 gallons)
per day. Cooling water usage varies widely from mill to mill
but rarely exceeds 280,000 liters (75,000 gallons) per day.
Therefore, it can be seen that the water usage in a dry pro-
cess hardboard mill is exceedingly low and wastewater dischar-
ges minimal.
Log Washing
Log washing is practiced by a minority of mills and not neces-
sarily on a continuous basis. Log washing is used to remove
dirt and sand from the log surface, the quantity of which
varies according to harvesting and storage techniques. Weather
conditions are a factor in the need for log washing as wet con-
ditions may cause excessive quantities of mud to adhere to the
logs when harvested. Since mills store both whole logs and
107
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o
00
TABLE 24
WASTEWATER FLOW AND SOURCE
MILL
A
B
C
D**
E
F
G
H
I
J**
K
LOG
WASH
0
0
0
YES
81,650
0
0
0
0
0
0
CHIP
WASH
0
0
0
0
0
0
0
0
0
0
0
RESIN*
WASH
0
0
38
0
0
0
5,670
3
0
570
0
CAUL*
WASH
0
570
110
300
0
380
0
750
0
0
0
HOUSEKEEPING*
20,000
380
0
YES
—
0
0
0
0
0
—
COOLING
WATER
320,000
81,650
227,000
YES
YES
—
189,000
125,000
160,650
283,500
Ot
HUMIDIFICATION
0
11,340
0
0
0
0
0
0
0
0
0
Note - All flows given in liters per day
* Actual Intermittant Flow Averaged Daily
** Total Waste Contained on Site
t Cooling Water Used for Boiler Makeup
-------
DRAFT
chips on site and the ratios of logs purchased as compared
with chips vary, the quantity of water utilized will vary ac-
cordingly. Fresh water can be utilized for log washing.
•Cooling water from the inplant processes may also be used.
Quantities of water utilized for log washing can be expected
to vary from 400 liters per metric ton (100 gallons per ton)
to 1,250 liters per metric ton (less than 300 gallons per
ton) (8). Typical chemical analyses would include a BOD of
200 mg/1 and a suspended solids of 500 mg/1.
Chip Washing
The purpose of chip washing is similar to that of washing logs.
Chips that are brought in from outside sources can contain dirt
and sand which cause excessive equipment wear. Chip washing
serves not only to remove this unwanted matter, but also gives
the chips a uniform moisture content and, in northern climates,
helps thaw frozen chips. There were no dry process hardboard
mills reporting the use of chip washing, but the trend is toward
mills having to wash chips. As prime sources of fiber become
increasingly scarce such as from whole logs, the future trend
is toward whole tree utilization. This means that whole trees,
or just limbs and branches, would be chipped in the forest and
shipped to the mill. Due to the increased extraneous material,
chip washing will become a necessity.
Fresh water may be used for chip washing or cooling water from
inplant equipment might also be used. As there are presently
no chip washing systems reportedly in use, there are no water
usage figures or waste characteristics available in the dry
process hardboard industry.
Resin System
Water is used to make up the resins which are added as binders
for hardboard. The water used for making resin is not a waste-
water but becomes part of the hardboard as it is evaporated in
the press. Some mills claim it is necessary to clean the resin
system,and available data,as shown in Table 24, indicates that
there is no standard procedure for cleanup as water usage varies
widely.
There are two types of resins used in the hardboard industry,
phenolic formaldehyde and urea formaldehyde. These resins are
essentially the same as those utilized in the plywood industry
where most mills have already gone to a completely closed resin
system. Table 25 shows typical chemical analysis of plywood
glue.
109
-------
TABLE 25 (10)
AVERAGE CHEMICAL ANALYSIS OF PLYWOOD RESIN
Analysis and Units Phenolic Resin (a) Urea Resin (b)
COD, mg/kg
BOD, mg/kg
TOG, mg/kg
Total Phosphate, mg/kg as P
Total Kjeldahl Nitrogen, mg/kg as N
Phenols, Wg/kg
Suspended Solids, mg/kg
Dissolved Solids, mg/kg
Total Solids, mg/kg
Total Volatile Suspended Solids, mg/kg
Total Volatile Solids, mg/kg
(a) Borden's Cascophen 31 which is similar
(b) Borden's Casco Resin 5H
653,000
--
176,000
120
1,200
514,000
92,000
305,000
397,000
84,000
172,000
to Borden's
421,000
195,000
90,000
756
21,300
346,000
204,000
550,000
346,000
550,000
Cascophen 382
-------
DRAFT
The chemical analysis of resin washwater will be those
concentrations shown in Table 25 diluted by a factor depending
upon the quantity of water used for wash up. Several hardboard
mills are presently recycling this wash water as resin makeup
water or simply do not wash at all, therefore, they have no dis-
charge. Due to the small quantity of water and ease of reuse,
there should be no discharge from the resin system in any hard-
board mill.
Caul and Press Plate Wash Water
Another minor water usage and wastewater source for some mills
is for caul and press plate wash water. After a period of use.
cauls and press plates acquire a buildup of resin and organics
on their surfaces. This results in sticking in the presses and
blemishes on the hardboard surface. The cauls or press plates
must then be cleaned to remove this buildup. The cleaning op-
eration consists of submerging the cauls in a caustic cleaning
solution for a period of time to loosen the organic matter.
Press plates are also cleaned with a caustic solution inplace.
After soaking,cauls are removed, rinsed with fresh water, then
put back in use. The tanks used for soaking the cauls are
emptied as needed, normally only a few times each year. The soak-
ing water and rinse water used in a typical dry process hard-
board mill ranges from 380 to 950 liters (100 to 250 gallons)
per day or approximately 4 liters per metric ton (1.0 gallons
per ton) of hardboard production.
Miscellaneous Housekeeping Water
Water may be used in small quantities for various cleaning pro-
cedures. The frequency and quantity of water used for clean-
ing purposes is highly variable as there are generally no
scheduled cleanup procedures. Information gathered from sev-
eral dry process hardboard mills indicates that this water usage
can be expected to range from zero to less than 1,500 liters
(400 gallons) per day in a typical mill. This source of waste-
water is of such a minor volume that it can easily be disposed
of onsite. Several mills utilize no water for cleaning as all
house cleaning is done by sweeping and vacuum cleaning.
Humidification
All dry process hardboard mills humidify their board after
pressing. This consists simply of passing the boards through
a room with a high humidity and temperature to bring the mois-
ture content to a more stable level. Approximately 45 liters
111
-------
DRAFT
(12 gallons) of water per ton of product are used for this
purpose. Most mills report no wastewater discharge from this
process.
Fire Water
A major problem with the dry process for manufacturing hard-
board is the problem of fires. The inside of a dry process
hardboard mill can easily become coated with dry fibers and
an electrical spark or excessively hot press or other piece
of equipment can easily start a fire. More frequently, a
fire starts in a refiner and quickly spreads through the fiber
conveying system. Mills have elaborate fire fighting systems
which use large quantities of water to put fires out quickly.
Fires are certainly not scheduled and their frequency varies
from mill to mill. Depending upon the duration and extent of
the fire, the water used to control a fire will vary accor-
dingly. Fire water should not be considered as a continuous
wastewater flow because a typical mill will have a fire only
a few times each year.
Cooling Water
The largest water usage in a dry process hardboard mill is for
cooling water. This water is used for cooling various inplant
equipment such as refiners and air compressors, and is normally
not changed in quality except for the addition of heat. Al-
though this usage is the largest volume used in a dry process
hardboard mill, it is relatively small when compared with other
industries. The volume of cooling water varies widely from
mill to mill depending upon temperature of freshwater source
and the equipment within a mill. Cooling water can be expected
to range from 18,900 to 280,000 liters (5,000 to 75,000 gallons)
per day with a typical mill utilizing 190,000 liters (50,000
gallons) per day. There is a potential for cooling water to
become contaminated with lubricating oil and in this event the
oil must be removed before the cooling water is discharged.
Scrubber Water
Air pollution from dry process hardboard mills is a major con-
cern. One method of air pollution control is the use of wet
scrubbers. Although only two hardboard mills report using a
wet scrubber, the future trend is toward the use of wet scrub-
bers in many dry process hardboard mills. The water usage for
wet scrubbing in a dry process hardboard mill will vary depen-
ding on the individual scrubber design. Since there are only
112
-------
DRAFT
two wet scrubbers in operation, representative data for the
industry is unavailable. One of the mills using a wet scrubber
reportedly achieves zero discharge by settling and filtering
the scrubber water before recycle. In fact, there is need for
water makeup.
Mass Water Balance in a Dry Process Hardboard Mill
An account of water gains and losses in a typical dry process
hardboard mill is given in this section. A schematic diagram
of the water balance (net gains and losses) for a typical dry
process hardboard mill is shown in Figure 16. Water gains or
losses are shown as liters of water per metric ton of dry pro-
duct produced in a typical 225 metric ton per day mill.
Water Gains. Water gains in a typical dry process hardboard
mill result from incoming raw materials and fresh water intake.
Incoming wood normally has approximately 50 percent moisture
which represents 100 percent of the final product weight.
Water from incoming wood
(50 percent moisture)
= 1,000 liters per metric ton
(240 gallons per ton)
The water usage within a dry process hardboard mill is highly
variable depending upon water usage within an individual pro-
cess and plant operation. A typical dry process mill uses
water only for glue preparation, caul wash, humidification
and cooling.
Water in glue
(3.5 percent of product)
35 liters per metric ton of
product (8.4 gallons per ton)
Caul wash (950 liters per day) = 4.2 liters per metric ton of
(250 gallons) product (1 gallon per ton)
Humidification =
(5.0 percent of product)
Cooling water (284,000 liters
per day)
(75,000 gallons)
50 liters per metric ton of
product (12 gallons per ton)
= 1,250 liters per ton of
product (300 gallons per
ton)
Water Losses . Water losses in a dry process hardboard mill
result from:
Fiber drying to 7.5 = 960 liters per metric ton of product
percent moisture (230.4 gallons per ton)
113
-------
GAIN = IOOO
RAW
MATERIALS
HANDLING
COOLING WATER
GAIN = I250 RES|N LOSS =
SYSTEM 4
I GAIN=35 L
FIBER
PREPARATION
COOLING WATER
LOSS=I250
FIBER
DRYER
FELTER
CAUL WASH
GAIN=4.2-»
LOSS = 4.2
PRESS
FRESH WATER
LOSS=75
HUMIDIFICATION
FINISHING
PRODUCT
TOTAL GAIN =23392
TOTAL LOS 8=2339.2
•••GAINS AND LOSSES SHOWN IN LITERS/TON DRY PRODUCT
FIGURE 16 - WATER BALANCE FOR TYPICAL DRY PROCESS HARDBOARD MILL*
-------
DRAFT
Press evaporation = 75 liters per metric ton of product
(0.0 percent moisture) (18 gallons per ton)
Water in product
(5.0 percent moisture) = 50 liters per metric ton of product
(12 gallons per ton)
Caul wash (950 liters per day) =4.2 liters per metric ton
(250 gallons) (1.0 gallons)
Cooling water = 1,250 liters per metric ton of pro-
(284,000 liters per day) duct (300 gallons per day)
WET PROCESS HARDBOARD
Specific Water Uses
There are several processes in the wet process hardboard in-
dustry where water is used. Wet process mills have similar
overall water uses and wastewater sources, however, due to
variations from mill to mill there will be variations in water
use in the following processes:
Raw Materials Handling
Fiber Preparation
Mat Formation and Pressing
Finishing
Miscellaneous
Raw Materials Handling
There are two potential sources of water usage and waste
discharge in the raw materials handling process; 1) log wash-
ing, 2) chip washing (see Figure 17 for schematic diagram of
the raw materials handling processes).
Log Washing. Log washing is practiced by a minority of mills
ana not necessarily on a continuous basis. Log washing is
used to remove dirt and sand from the log surface, the quan-
tity of which varies according to harvesting and storage
techniques. Weather conditions are a factor in the need for
log washing as wet conditions may cause excessive quantities
of mud to adhere to the logs when harvested. Since mills
store both whole logs and chips on site and the ratios of logs
purchased as compared with chips vary, the quantity of water
utilized will vary accordingly. Fresh water can be utilized
for log washing;or cooling water from the inplant processes
115
-------
LOGS
o
LOG
STORAGE
CHIPS
LOG WASH
DEBARKER
CHIPPER
WATER IN
WATER OUT
o
TO PROCESS
FIGURE 17 - WATER USAGE IN RAW MATERIALS HANDLING
IN THE HARDBOARD INDUSTRY
116
-------
DRAFT
may also be used. Quantities of water utilized for log washing
can be expected to vary from 417 liters per ton (100 gallons per
ton) to less than 1,250 liters per ton (300 gallons per ton) (8).
Typical chemical analyses would include a BOD of 200 mg/1 and
a suspended solids of 500 mg/1.
Chip Washing. The purpose of chip washing is similar to that of
washing logs. Chips that are brought in from outside sources
can contain dirt and sand which cause excessive equipment wear.
Chip washing serves not only to remove this unwanted matter, but
also gives the chips a uniform moisture content and, in northern
climates, helps thaw frozen chips. There is only one wet pro-
cess hardboard mill reportedly using chip washing, but the trend
is toward mills having to wash chips. As prime sources of fiber
become increasingly scarce such as from whole logs, the future
trend is toward whole tree utilization. This means that whole
trees, or just limbs and branches, would be chipped in the for-
est and shipped to the mills. Due to the increased extraneous
material, chip washing will become a necessity.
Fresh water may be used for chip washing; and cooling
water from inplant equipment might also be used. There is
presently only one chip washing system reportedly in use
with a water usage of approximately 330 liters per ton (96
gallons per ton).
Fiber Preparation
As previously discussed, there are two principal fiber prepara-
tion processes: 1) thermal plus mechanical refining, and 2)
the explosion process. Figure 13 (Section IV) shows a sche-
matic diagram of a typical wet process hardboard mill where
thermal plus mechanical refining is used for fiber prepara-
tion. All but two wet process mills utilize some variation
of this process. Two mills owned by the Masonite Corporation
utilize the explosion process as shown in Figure 18.
The actual water used in fiber preparation in the wet process
is relatively small as compared to overall water use in a wet
process mill. In general, the only water used in fiber pre-
paration is the addition of steam into the cooker. This quan-
tity of steam can be expected to equal one half the weight of
dry chips processed or approximately 0.5 cubic meters per 1.0
ton (120 gallons per short ton).
The principal reason for significant wastewater flows and
concentrations from the wet process as compared with the dry
117
-------
CHI
oo
MAKE-UP
WATER
WATER IN
WATER OUT
TO ATMOSPHERE
STOCK
TO
FINISHING
V
FIGURE 18 - WATER USE IN THE EXPLOSION PROCESS
-------
DRAFT
process is the fact that the fiber is diluted from approximately
40 percent consistency to 1.5 percent consistency with sig-
nificant quantities of water prior to forming on a wet felting
machine. There are limitations on the concentrations of or-
ganics in the process water which means that most of the soluble
organics released into solution during fiber preparation must
be disposed of in some manner (usually discharged as wastewater)
as only a portion of the solubles may be retained in the hard-
board. In the dry process all solubles released during fiber
preparation are retained in the board.
The interrelation between fiber preparation processes, varia-
tions of cooking time, and temperature and wood chemistry on
wastewater discharge is extremely important. The following
information was derived from a number of sources, the most
important of which are reference numbers (7) and (17) . Wood
is exceedingly difficult to define chemically because it is a
complex heterogeneous product of nature made up of interpene-
trating components, largely of high molecular weight. The
principal components generally are classified as cellulose,
lignin, hemicellulose, and solvent-soluble substances (ex-
tractives). The amounts present are in the range of 40 to 50
percent, 15 to 35 percent, 20 to 35 percent, and 3 to 10 per-
cent, respectively.
The yield, composition, purity, and extent of degradation of
these isolated components depend on the exact conditions of
the emperical procedures employed for their isolation. By far
the most important factor relative to the values obtained in
chemical analysis for wood components is the tree species. The
variation in chemical composition of wood greatly influences
the quantities and kinds of chemicals released during fiber pre-
paration.
At normal temperatures wood has remarkable resistance to degra-
dation by chemicals and solvents. This may be attributed to
the interpenetrating network structure of wood comprised of
polymers with widely differing properties. Also, the high
crystallinity of the carbohydrate system reduces the accessi-
bility of the wood components to reagents.
Water at room temperature has little chemical effect on wood,
but as temperature rises and pH decreases because of the
splitting off of acetyl groups, wood becomes subject to rapid
acid hydrolysis with the dissolution of carbohydrate material
and some lignin. At temperatures above 140°C considerable and
rapid removal of hemicelluloses occurs. Fortunately, cellulose
resists hydrolysis better than the hemicellulose fractions.
119
-------
DRAFT
The thermal and explosion pupling processes such as the Asplund
and Masonite processes make use of the effect of water on wood
at high temperatures to prepare fiber for mechanical refining
prior to being pressed into hardboard. The high temperatures
soften the lignin-hemicellulose matrix to permit the separation
of fibers with reduced power cost and fiber damage. Also, car-
bohydrate and lignin degradation products and the lignin softened
by high temperatures facilitate bonding of the fibrous structure
upon drying of the board.
Cooking wood with steam at temperatures of about 180°C causes
a rapid loss in weight. Part of the loss is due to thermal de-
composition and simple solution, but the acids released by the
wood hydrolyze appreciable amounts of carbohydrates as well. In
commercial operations, yields of pulp fall to between 75 and 90
percent, therefore, potential wastewater problems increase sig-
nificantly. Wood species high in water-solubles will obviously
give lower yields of pulp.
In the well-known explosion process wood chips are exposed to
high-pressure steam in a "gun" or small digester fitted with a
quick-opening valve that allows the chips to disintegrate when
the pressure is abruptly released. In the gun the chips are
steamed at 41.8 ATM (600 psi) for 1 minute, and the pressure
is then increased to 69 ATM (1,000 psi) for an additional 5
seconds before the valve is opened. Differences in wood species,
condition, and size of chips modify the cycle. The high tempera-
ture, high pressure treatment does not remove the lignin but
makes it sufficiently plastic for the chips to burst apart on
release. Hemicellulose is hydrolyzed, becoming pentose sugars,
some of which are dehydrated and polymerized to form furfural
resins as a result of the steaming and the subsequent high-
temperature pressing and tempering involved in manufacturing
boards. This process causes the release of significant quan-
tities of organics which must be disposed of as a waste stream.
Another representative and more commonly used process uses a
screw press to force compressed chips into one end of a hori-
zontal stainless-steel tube, typically 3 meters (10 feet) long
and 1 meter (3 feet) in diameter, which the chips traverse in
about 30 seconds while exposed to steam at 182°C and 12.9 ATM
(175 psi) . At the far end they are fiberized in a single-rotating-
disk mill while still hot and under pressure. From the disk mill
the pulp is discharged to a cyclone, from which it goes to a surge
bin followed by a second refiner for further processing. Other
types of continuous or quick-cycle digesters may be substituted
and give similar results. Due to the lower temperatures and
120
-------
DRAFT
pressures the quantity of released organics is considerably less
than in the explosion process, resulting in less potential waste.
The yield, chemical composition, and physical properties of the
pulps prepared by any method are dependent upon two sets of
variables, i.e.:
Variables associated with the wood,
1. Species
2. Density
3. Growth factors
4. Moisture content
5. Length of storage
6. Particle size
Variables associated with the fiber preparation system,
7. Concentration of pH or liquor (water solution)
8. Temperature of digestion
9. Time of digestion
The dissolution of the wood substances takes place mainly during
pre-heating and defibration process and is closely related to the
kind of raw material used. It is also a function of the pre-
heating temperature and the pre-heating time used.
It is rather difficult to make determinations of the yield of
pulp from wood as a function of the pre-heating conditions as,
in general, the pre-heating periods used in practice are fairly
short in comparison to the time it takes for the chips to reach
the final temperature in the pre-heater. Some attempts have
been made, however, and in Figure 19 a graph for beechwood is
shown, where the pre-heating period was extended to 16 minutes.
These determinations were made with water as "cooking liquor,"
and it is clearly shown that the dissolution proceeds much
faster as the pre-heating temperature is increased (21).
During the pre-heating mainly two reactions take place. One of
them is the hydrolysis of hemicellulose molecules, whereby oli-
gosaccharides are formed. These short-chain molecules are small
enough to dissolve in water. The other reaction is the hydroly-
sis of acetyl groups, whereby acetic acid is formed, causing an
increase in the hydrogen ion concentration in the raw material.
The higher acidity causes the hydrolytic reactions to proceed
still faster. Thus the reactions can be said to be autocatalytic,
For that reason it is very difficult to calculate rates of
121
-------
YIELD %
100
90
80
I58°C
I72°C
I83°C
70
5 10 15
PREHEATING TIME MINUTES
20
FIGURE 19 (21) -
EFFECT OF PREHEATING TIME AND
TEMPERATURE ON YIELD
122
-------
DRAFT
reaction for the dissolution of wood substances during the
pre-heating stage. As a rough estimation, however, the rate
of reaction seems to double with an increase in temperature
of about 8°C (50°F), which is normal for most chemical
reactions (21).
So far no exhaustive investigations seem to have been made on
the composition of the substances dissolved during the pre-
heating and defibration steps. An examination of the com-
position of the substances dissolved in the Masonite process
was made by Edhborg some fifteen years ago. The temperature
in the Asplund-Defibrator process is normally about 180°C and
the pre-heating time is usually from one up to a few minutes. The
temperature in the explosion process, on the other hand, is in-
creased to between 250 and 300°C, even if it is only for a few
seconds. This leads to larger amounts of substances being dis-
solved in the latter process and also to more acidic conditions--
a pH value of about 3 was obtained in an extract from an explo-
sion pulp whereas the pH values in extracts from defibrator
pulps are usually close to 4. The acidity depends partly on
volatile acids like acetic and formic acid and partly on non-
volatile ones, among which uronic acid is the most frequent (21)
The investigation on dissolved substances in the explosion
process was based on coniferous wood as raw material. The
dissolved substances in this case consisted of about 70 percent
carbohydrates, 10 percent lignin - partly modified - and 20
percent "organic resins." The carbohydrates consisted of 35
percent pentosans - mostly xylans - and 65 percent hexosans (21)
Corresponding investigations on dissolved substances in the
Asplund-Defibrator process were made with beech as raw material.
In this case 75 percent of the dissolved substances were carbo-
hydrates and a few percent were lignin type substances. In
addition about 10 percent acetic acid - partly free and partly
bound as acetyl groups - were found. In this case about 80
percent of the carbohydrates were pentosans -- mainly xylans --
and 20 percent hexosans.
Tables 13 and 26 relate properties and composition of many
common woods used in this country, and Figure 20 indicates the
effects various treatments have on these components. Figure
21 depicts a general relationship of lignin dissolution ver-
sus percent of wood dissolved.
123
-------
to
TABLE 26 (7)
ANALYSES OF SOME COMMON SPECIES OF WOOD
(Extractive-free basis, percent of dry wood)
Constituent
Ash
Acetyl
Lignin
a-Cellulose
Hemicellulose
Total3
-------
ts)
l/l
1
TOTAL
WOOD
SUBSTANCE
Neutral
Solvents
and/or
Steam
i
2
EXTRACTIVE
FREE WOOD
95%
|
Soluble
or
Volatile
*
3
EXTRACTIVES
5%
I
INORGANIC
<.05%
Mild
Oxidation
and ~~
Extraction
Degraded
Soluble
t
4
SOLOCELLULOSE
(TOTAL
POLYSACCHARIDE
FRACTION)
70%
5
LIGNIN
25%
6
Dilute WOOD
Aqueous CELLULOSE
Alkali 60%
Ac
Soluble Hydrc
1
GLUCOSI
TRACES
OTHER
CARBOH'
AND IMF
id
>lysis
E +
OF
fDRATES
HJRITIES
MANNOSE
XYLOSE
GALACTOSE
ARABINOSE
URONIC ACIDS
Acid
Hydrolysis
HEMICELLULOSE
20%
FIGURE 20 (7) - THE CHEMICAL COMPONENTS OF WOOD
-------
100
o
LJ
o
V)
CO
o
80
60
<
I 40
E
o
o
£ 20
a.
20
w
40
60
80
100
PERCENT WOOD DISSOLVED
FIGURE 21 (7) - RELATION BETWEEN DISSOLVED LIGNINS AND WOOD
126
-------
DRAFT
Mat Formation and Pressing
Figure 13 shows that from the refiner,fiber is discharged into
a cyclone where the fiber is diluted with process water. Figure
22 shows a typical schematic diagram of the process water flow
in the wet process. From the refiner,fiber is diluted to ap-
proximately 5.0 percent through the cyclone then diluted still
further to approximately 1.5 percent fiber in the stock chest.
A mat is then formed on the wet forming machine where the fiber
concentration is increased to approximately 35 percent prior
to wet pressing. Water removed from the mat formation flows to
a process water chest where it is recycled as process water.
Water released upon pressing either evaporates to the atmosphere
or flows back to the process water chest or is discharged directly
as a wastewater. Process water may be recycled until the tem-
perature, soluble organics or suspended solids become too high.
Normally, fresh makeup water is added at a constant rate to con-
trol these parameters and the overflow is discharged to waste.
In the explosion process considerably more soluble organics are
released. All of these plants (two) use recycle process water
for fiber washing. Fiber wash water from the explosion process
is a major source of wastewater. A waste load from this process
alone of 40 kilograms per metric ton (80 pounds per ton) into a
flow of 2.5 cubic meters per ton (600 gallons per ton) is re-
ported. Typical wastewater characteristics of this fiber wash
are shown below:
BOD = 22,620 mg/1
COD = 51,100 mg/1
TS = 32,000 mg/1
Volume = 2.5 cubic meters per metric ton (600 gallons
per ton)
Because of these high waste concentrations it has been found
that it is practical to evaporate this waste stream. The re-
sulting liquor is sold as cattle feed or incinerated (Figure
231. This is the normal procedure in both of the plants
that use an explosion process.
Two other wet process mills which use the more conventional
cooking processes wash fiber prior to mat formation. These
mills do not evaporate this wash water separately as is done
by the Masonite mills, but simply discharge it directly to
waste.
127
-------
Isj
oo
STEAM
CHIPS
PREHEATER ^_ REFINER
SCREW
FEED
WATER IN
WATER OUT
r^T*> ALTERNATE ROUTE
TO
ATMOSPHERE
STOCK L-1 WET FORMING
CHESTS J™| MACHINE
A 05)
WET I—r-\
PRESS f^V
J
I
DILUTION
WATER
*
PROCES
WATER
CHEST
t
5
f
X
/
/
/
<**-"
',
/
t
r
r ,
TO
FINISHING
MAKE-UP
WATER
>
TO
TREATMENT
(XX) APPROXIMATE PERCENT FIBER
(CONSISTENCY IN PROCESS)
FIGURE 22 - PROCESS WATER RECYCLE IN A TYPICAL WET PROCESS HARDBOARD MILL
-------
TO ATMOSPHERE
10
CHIPS
GUN
w
CYCLONE
WATER IN
WATER OUT
CONCENTRATED
BY-PRODUCT
STOCK ==WETFORMING
/!=> i=r
f
MASHER
^
1—, j—J CHEST | JMACH
it
1
PROCESS
WATER
CHEST
TO
FINISHING
' i f
'(//tii/fr/if/iiiiffil
<£=-MAKE-UP WATER
TO TREATMENT
CONCENTRATE TO
CATTLE FEED
FIGURE 23 - PROCESS WATER RECYCLE IN A HARDBOARD MILL
USING THE EXPLOSION PROCESS
-------
DRAFT
The moisture in the chips entering the wet process is
approximately 50 percent. Assuming that the mat is formed from
a 1.5 percent fiber concentration and that the board coming from
the press has a 0.0 percent moisture, and that there is no re-
cycle, approximately 66.8 cubic meters per ton (16,000 gallons
per ton) of process water must be disposed of in some form.
While a portion of this water will be disposed of as steam, the
majority will be discharged as a waste stream. The actual vol-
ume discharged is a function of the amount of recycle practiced.
There are three principal factors which limit recycling of pro-
cess water: temperature, suspended solids, and soluble solids.
Usually a process water temperature of a certain minimum is
required to avoid excessive use of resin. At lower temperatures
the naturally occurring resins in the fiber will set, thereby
becoming ineffective for bonding. Furthermore, when the board
is formed at low temperature, longer pressing times are required
which can significantly reduce production rates. Most hardboard
mills operate with a process water temperature between 30°C
(100°F) and 63°C (145°F). The more the process system is closed,
the higher its temperature becomes. It has been found that as
temperatures increase outside of this range, certain corrosion
problems are experienced. Furthermore, conditions near forming
machines become very humid, making working conditions unpleasant.
A certain critical temperature seems to exist after which spots
will appear on the board, thereby lowering the aesthetic quality
of the board. This critical temperature varies with raw material,
process and product produced.
Increased recycling of process water increases the concentration
of soluble organics. This increased concentration raises the
risk of spot formation on the board and the chance of sticking
in the hot press. This is partly due to build-up of volatilized
organics on press plates. The critical concentration of soluble
organics, above which process problems are encountered, is pri-
marily a function of wood species.
The effect of suspended solids concentrations relates to the
dewatering characteristics of the board. It has been reported
that as suspended solids concentrations increase with recycling,
a certain concentration is reached after which the board will
not exhibit proper water drainage during mat formation (22).
This can be attributed to a buildup of fines which cause the
mat to dewater slowly. As suspended solids become too numerous
in the process water they must be removed either by blowing
down this highly concentrated water and diluting it with fresh
water, or by removing the solids from the process water by some
other means.
130
-------
DRAFT
Miscellaneous Wastewater Sources
By far the major wastewater discharge from a wet process
hardboard mill is process water from mat formation, pressing,
and fiber washing where used. Other wastewater sources which
may be classified as miscellaneous streams include resin system
wash water, caul wash water, housekeeping water, and cooling
water.
Resin Wash Water. Water is used to make up the resins which are
added as binders for hardboard. The water used for making re-
sin is not a wastewater, but is evaporated in the press. Some
mills claim it is necessary to clean the glue system; and indications
are that there is no standard procedure for cleanup. Several
hardboard mills are presently recycling this wash water as re-
sin makeup water or simply are not washing at all, therefore,
they have no discharge.
Caul, Press Plate or Screen Wash Water. Another minor water
usage and wastewater source is for caul and press plate (screen)
wash water. After a period of use cauls and press plates acquire
a buildup of resin and organics on their surface. This results
in sticking in the presses and blemishes on the hardboard sur-
face. The cauls or press plates must then be cleaned to remove
this buildup. The cleaning operation consists of submerging the
cauls in a caustic cleaning solution for a period of time to
loosen the organic matter. Press plates are also cleaned with
a caustic solution inplace. The cauls are removed, rinsed with
fresh water, then put back in use. The tanks used for soaking
the cauls are emptied as needed, normally only a few times each
year. The soaking water used may amount to about 4 liters per
metric ton (1.0 gallons per ton) of hardboard production. Rinse
water volume varies with frequency of washing of cauls or plates
(approximately 1.0 gallons per ton).
Water can be used in small quantities for various cleaning pro-
cedures. The frequency and quantities of water used for clean-
ing purposes is highly variable as there are generally no
scheduled cleanup procedures. Information gathered indicates
that the volume of wastewater from this amounts to less than
8 liters per ton (2.0 gallons per ton) of board.
Total Wastewater Flow
Table 27 is a summary of the total wastewater flow from eight
wet process hardboard mills. Table 28 gives a summary of the
average wastewater concentrations from these same mills.
131
-------
DRAFT
TABLE 27
WASTEWATER DISCHARGES FROM WET PROCESS HARDBOARD
Plant
Production
metric tons
(t) Chip Wash Included
* Projected Figures
Wastewater
m3/day
Wastewater
mVmetric ton
1
2
3
4(t)
5
6
7
8*
91
77
1,356
136
82
127
356
327
4,164
2,952
16,578
1,590
757
908
1,628
833
45.9
38.2
12.2
11.7
9.3
7.1
4.6
2.6
132
-------
OJ
TABLE 28
RAW WASTEWATER CHARACTERISTICS FROM WET PROCESS HARDBOARD
Discharge Flow
BODt;
S.S.
Plant
1
2
3°*
4
5
6*
7*
8
m-i/D iiH/metric ton mg/1 kg/metric ton
4,164
2,945
16,578
1,589
757
897
1,635
840
45.9
38.2
12.2
11.7
9.3
7.1
4.6
2.6
720
1,130
1,800
3,000
3,500
3,900
--
3,350
33
50
23
28
32
28
8.5
mg/1 kg/metric ton
220
540
1,650
430
450
48
10
6.5
19
4
3.21
0.125
pH
5.0
4.5
4.4
4.0
* After Primary Treatment
° Masonite Explosion Process
-------
DRAFT
Wastewater flows vary from about 4.2 to 45.8 cubic meters per
metric ton (1,000 to 11,000 gallons per ton), depending largely
upon the amount of process water recycled. BOD concentrations
vary from 720 mg/1 to 4,000 mg/1 and suspended solids from 48
to 1,650 mg/1. A comparison of data reported as raw wastewater
concentrations from mill to mill should be done with caution.
Several mills report raw wastewater concentrations after primary
sedimentation while others do not. These mills utilize primary
clarifiers as part of their recycle systems while other mills
consider primary clarifiers as part of their waste treatment
system. The average discharge of BODs in kilograms per metric
ton (pounds per ton) ranges from 8.5 to 50 (17 to 100), while
average discharge of suspended solids ranges from 0.13 to 19
kilograms per metric ton (0.25 to 38 pounds per ton).
Other representative analyses of raw wastewater discharged from
a typical wet process hardboard mill are shown below:
Concentrations
Parameter mg/1
BOD 1,300 - 4,000
COD 2,600 - 12,000
SS 400 - 1,100
TDS 500 - 4,000
Kjld'N 017 - 4.0
P04~P 0.3 - 3.0
Turbidity 80 - 700
pH 4.0-5.0
Phenols 0.7 - 1.0
Water Balance for a Typical Wet Process Hardboard Mill
A schematic diagram of the water balance (net gains and losses)
for a typical mill is shown in Figure 24. Water gains or los-
ses are shown as liters of water per metric ton of product
produced in a typical 127 metric tons (1401 tons) per day mill.
Water Gains. Water gains in a typical wet process hardboard
mill result from incoming raw materials and freshwater makeup.
Incoming wood has approximately 50 percent moisture content
which represents 100 percent of the final product weight.
The volume of miscellaneous housekeeping water, used for such
things as floor and caul washing, is highly variable. There
is little data as this stream is normally discharged to the
treatment system with the process water without monitoring.
134
-------
Ul
LOSS: 83.5
STEAM GAIN=835 LOSS: 188 GAIN= 50
GAIN = 29,840 A WATER FROM TO STEAM OR
COOLING a 4> ADDITIONS ATMOSPHERE WATER
GAIN =500 SEAL WATER A 11
STEAM II JL ll &
2-TONS Jl V V 1 — — 1 | — 1
CMII'S , , V T^h . 1C L_" STOCK UWET FORMING WET 1 LiMiniFiFB ^
— ^> ^PREHEATER1-1 REFINER ' Yr r~lCHESTSn MACHINE PRFSS "UW'""-'t« /
—if* 1 ^ iiri r oE n& M i c«ir-^ n t r i in t n M*^^^ ^ 11 iimMvnii^b rft 11 do 1 }/
(soi \ (401 p-^ t — i 1 o /is) /
NSCREW FEED ^ \_V
GAINS = I,000 Jl Afc 17,590
LOSS: 29,6 17
COOLING AND 1 1
SEAL WATER D|LUT1Q
WATER
MAKE-U
WATER
GAIN = 9,1
\ (15) W (35)»—
46,655 V 63,911
PROCESS
WATER
-------
DRAFT
Water from incoming chips
(50 percent moisture)
Steam to preheater
Cooling and seal water
Additive dilution water
Process water makeup
Humidifier
Miscellaneous housekeeping =
1,000 liters per ton (240 gallons
per ton)
500 liters per ton (120 gallons
per ton)
29,840 liters per ton (7,150 gal-
lons per ton)
83.5 liters per ton (20 gallons
per ton)
9,890 liters per ton (2,370 gal-
lons per ton)
50 liters per ton (12 gallons per
ton)
42 liters per ton (10 gallons per
tonj
Total water gain
= 41,405 liters per ton (9,922 gal-
lons per ton)
Water Losses. Water losses in a wet process mill result from:
Steam off of press
Cooling and seal water
discharge
Steam from cyclone
= 188 liters per ton (45 gallons
per ton)
= 29,817 liters per ton (7,145
gallons per ton)
= 83.5 liters per ton (20 gallons
per ton)
Discharge of excess pro-
cess water (includes
miscellaneous housekeeping = 11,267 liters per ton (2,700
water discharge) gallons per ton)
Water in product
= 50 liters per ton (12 gallons
per ton)
Total water losses
= 41,405 liters per ton (9,922
gallons per ton)
136
-------
"DRAFT" "DRAFT--
PART C: WOOD PRESERVING
WASTEWATERS CONTAINING ENTRAINED OILS
Wastewater characteristics vary with the particular preservative used,
the volume of stock that is conditioned prior to treatment, the con-
ditioning method used, and the extent to which effluents from the re-
torts are diluted with water from other sources. Typically, wastewaters
from creosote and pentachlorophenol treatments have high phenolic, COD,
and oil contents and may have a turbid appearance that results from emul-
sified oils. They are always acid in reaction, the pH values usually
falling within the range of 4.1 to 6.0. The COD for such wastes fre-
quently exceeds 30,000 mg/liter, most of which is attributable to en-
trained oils and to wood extractives, principally simple sugars, that
are removed from wood during steam conditioning.
Effect of Closed Steaming
The characteristics of wood preserving wastewater are different for plants
that practice modified-closed or closed steaming. In the former process
steam condensate is allowed to accumulate in the retort during the steam-
ing operation until it covers the heating coils. At that point, direct
steaming is stopped and the remaining steam required for the cycle is
generated within the retort by utilizing the heating coils. Upon com-
pletion of the steaming cycle, the water in the cylinder is discarded
after recovery of oils. In closed steaming, the water in the retort at
the end of a steaming cycle is returned to a reservoir, after recovery of
free oils, and is reused instead of being discarded.
The principal advantage of modified-closed steaming, aside from reducing
the volume of waste released by a plant, is that effluents from the re-
torts are less likely to contain emulsified oils than when open steaming
is used. Free oils are readily separated from the wastewater; and as a
result of the reduction of the oily content, the oxygen demand and the
solids content of the waste are reduced significantly relative to efflu-
ents from plants using conventional open steaming. Typical oil and COD
values for wastewater from a single plant before and after the plant com-
menced modified-closed steaming are shown in Figures 25 and 26 (23) *
respectively. The COD of the wastewater was reduced by about two-thirds
when this steaming method was initiated. Oil content was reduced by a
factor of ten.
Water used in closed steaming operations increases in oxygen demand,
solids content, and phenol concentration with each reuse. The high oxy-
gen demand of this waste is attributable primarily to wood extracts, prin-
cipally simple sugars, the concentration of which increases with the use of
the water. Because practically all of the solids content of this waste
are dissolved solids, only insignificant reductions in oxygen demand and
137
-------
Avg. oil content
before closed
steaming-1360mg/1
(si
CO
Avg.oil content
after closed
steaming—136 nig/ I
8 12
TIME ( weeks)
16
20
FIGURE 25 - VARIATION IN OIL CONTENT OF EFFLUENT WITH TIME
BEFORE AND AFTER INITIATING CLOSED STEAMING (23)
-------
65-
IO
30 40 50
TIME (days)
FIGURE 26 - VARIATION IN COD OF EFFLUENT WITH TIME BEFORE AND
AFTER CLOSED STEAMING: DAYS 0-35 OPEN STEAMING;
DAYS 35-130 CLOSED STEAMING (23)
-------
"DRAFT"
Improvement in color result from primary treatments involving floccula-
tion. The progressive changes in the parameters for water used in a
closed steaming operation are shown in Table29 (24). Although suchwastes
are perhaps more difficult to treat, this disadvantage is counterbalanced
in part by the fact that substantial reductions in the volume of waste-
water and total kilograms of pollutants released can be achieved by using
closed steaming.
Table 29 Progressive Changes In Selected Characteristics Of
Water Recycled In Closed Steaming Operations (24)
Charge
No.
1
2
3
4
5
7
8
12
13
14
20
Effect of
Phenol
46
169
200
215
231
254
315
208
230
223
323
NOTE:
Time
COD
15,516
22,208
22,412
49,552
54,824
75,856
99,992
129,914
121,367
110,541
123,429
Values expressed
Total
Solids
10,156
17,956
22,204
37,668
66,284
66,968
67,604
99,276
104,960
92,092
114,924
as mg/liter.
Dissolved
Solids
8,176
15,176
20,676
31 ,832
37,048
40,424
41 ,608
91 ,848
101,676
91 ,028
88,796
Because many plants use the same preservatives and follow essentially the
same treating practices, the wastewaters they release are qualitatively
similar with respect to a number of chemical and biochemical properties.
Quantitatively, however, they differ widely from plant to plant — and
even from hour to hour at the same plant, depending upon the time during
a treating cycle that samples for analysis are collected.
140
-------
"DRAFT"
Data on the effect of time of sampling during a treating cycle on the
flow rate and COD content of effluent from a plant operating a single
retort are shown in Figure 27. Flow rate was measured and samples for
analysis collected at 30-minute intervals, beginning during a steaming
cycle and continuing through the treating cycle and part of the succeed-
ing steaming cycle. The COD of the effluent varied inversely with flow
rate and ranged from 400 mg/liter to 43,000 mg/liter during the 24-hour
sampling period, a 100-fold variation. Flow rate varied from 7570 Ipd
to 151,400 Ipd (2000 gpd to 40,000 gpd). The pattern of variation for
phenol and solids content was similar to that for COD.
Variation in effluent characteristics among plants is illustrated by
the data in Table 30, which show the phenol and COD values of raw waste
for 13 plants. Also shown in the table are the COD values following a
treatment consisting of flocculation and sedimentation. The phenol and
COD values for the raw waste vary over a wide range, as does the effic-
iency of the treatment, as judged by the percent reduction in COD occa-
sioned by flocculation (23).
Biological Characteristics
Wastewater from the wood preserving industry is usually relatively treat-
able. Limited experience with bench-scale and pilot plant activated
sludge, trickling filter, and soil irrigation systems indicate that bio-
logical treating methods are generally effective in reducing the oxygen
demand and phenolic compounds to acceptable levels. Because these waste
waters have a very low nutrient content, the addition of nitrogen and
phosphorus prior to biological treatment is necessary to maintain a vi-
able bacterial population.
Because of its prolonged exposure to temperatures in the range of 110°
to 121°C (230° to 250°F) and its relatively high content of phenolic
compounds, process water is sterile upon its discharge from retorts.
Its successful biological treatment requires the employment of strains
of bacteria that have been acclimated to concentrations of phenolic com-
pounds of 300 mg/liter or higher. On a laboratory scale, this require-
ment renders BOD determinations difficult to make and almost impossible
to interpret, especially as regards comparisons of results obtained by
different analysts. It is not possible to ascertain whether the differ-
ences obtained are due to the characteristics of the waste samples or to
differences in the bacterial cultures employed and their degree of accli-
mation to the waste. Dust and Thompson (25;obtained differences in BOD
values for creosote wastewater of 200 percent among several acclimated
cultures of bacteria.
Fortunately, the correlation between BOD and COD for wood preserving
wastewater is high. Using creosote wastewater with BOD values larger
than 150 mg/liter, the above authors found that the equation BOD = 0.497
COD x 60, for which r = 0.985, accounted for practically all of the
141
-------
rsj
8 12 16
TIME ( hours)
20
24
FIGURE 27 - VARIATION IN COD CONTENT AND WASTEWATER FLOW RATE WITH TIME (23)
-------
DRAFT
TABLE 30 PHENOL AND COD VALUES FOR EFFLUENTS
FROM THIRTEEN WOOD PRESERVING PLANTS (23)
Plant
Location
Mississippi
Mississippi
Mississippi
Mississippi
Mississippi
Mississippi
Virginia
VI rgi ni a
Georgia
Georgia
Georgia
Tennessee
Louisiana
Phenol
(mg/1 )
162
109
—
168
83
50
192
508
119
331
123
953
104
Raw
6,290
11,490
48,000
42,000
12,300
1.000
9,330
32,300
7,440
3,370
17,100
1,990
10,500
COD (mg/1)
After
Flocculation
3,700
5,025
2,040
31 ,500
4,500
--
3,180
8,575
2,360
1,880
3,830
1,990
6,070
Percent
Reduction
41
56
96
25
63
—
66
73
68
44
78
0
42
143
-------
"DRAFT"
variation between the two parameters (Figure28), The general applica-
bility of this equation was indicated by spot checks of the COD:BOD
ratio for similar wastes from several plants.
The COD:BOD ratio increases rapidly for BOD values smaller than 150
mg/liter (Table31), and averages 6.2 for values in the range of 20 to
40 mg/liter. This ratio is in line with the value of 6.1 reported for
the petroleum industry for effluents similar in composition to those of
the wood preserving industry.
SALT-TYPE PRESERVATIVES AND FIRE RETARDANTS
Wastewaters resulting from treatments with inorganic salt formulations
are low in organic content, but contain traces of heavy metals used in
the preservatives and fire retardants employed. Average analytical data
based on weekly sampling for a year of the effluent from a plant treat-
ing with both preservatives and a fire retardant are given in Table 32.
The presence and concentration of a specific ion in wastewater from such
treatments depend upon the particular formulation employed and the ex-
tent to which the waste is diluted by washwater and storm water.
RAW HASTE LOADING DATA
Average analytical data for five typical wood preserving plants treating
with pentachlorophenol-petroleum solutions and/or creosote are given in
Tab!es 33-37.. Data for plants 1 through 4 (Tables 33-36) were obtained
from 24 samples collected at hourly intervals at the outfall from each
plant and analyzed separately to obtain information on short-term varia-
tion in effluent quality. These data were later supplemented by analysis
of several grab samples collected over a period of several months. Data
for Plant 5 are based on a series of grab samples collected during 1972.
Information on volume of discharge of process water was obtained either
from 24-hour measurements (Plants 1-4) or estimated based on number of
retorts, processing operations used, and other considerations (Plant 5).
Waste volume flow data do not include cooling water, which was recycled
at all plants, coil condensate, or boiler blow-down water. Production
figures for 1971 were estimated from the void volume of the retorts oper-
ated by the plants.
Raw waste loadings for each pollutant are expressed in terms of concentra-
tions (mg/liter) and kilograms per 1000 m3 of product treated for each of
the five plants. Maximum, minimum, and average raw waste loadings per day
based on analytical data and volume of discharge are also given. A com-
posite of these data, representing the average raw waste loadings given
in Tables33-37 is shown in Table 38.. The effluent characteristics repre-
sented by these data are assumed to be representative of the raw waste
streams of plants treating with creosote and pentachlorophenol-petroleum
solutions. Since each of the five plants involved are typical of the in-
dustry, data for the hypothetical plant given in Table 38 will be the basis
for an analysis of effluent treatment cost presented later in this report.
144
-------
en
10-
O)
CO
O
X
Q
O
GQ
I4
"" 1 1 1 II 1 1 1 1 1 1 1 1 1 T
0
Y=0.497X+60
"-
! — '«''' A i i i — L
6 8 10 12
Influent C 0 D x io3 mg/|
14
16
FIGURE 28 - RELATIONSHIP BETWEEN BOD AND COD FOR WASTEWATER
FROM A CREOSOTE TREATING OPERATION (23)
-------
DRAFT
TABLE 31 RATIO BETWEEN COD AND BOD FOR VAPOR DRYING
AND CREOSOTE EFFLUENT WASTEWATERS*
(NOTE: Data provided by the Research Department, Koppers Company, Inc.)
(mg/liter)
Range of BOD
40 - 75
20 - 35
10 - 15
Average
*Ana lysis revealed these
not included in average,
COD
150
160
300
300
320
450
160
210
180
120
100
210
180
70
--
values to
»
BOD
45
40
45
75
45
60
25
35
30
20
10
15
10
10
—
be statistical
Ratio
COD/BOD
3.3
4.0
6.7
4.0
7.1
7.5
6.4
6.0
6.0
6.0
10.0
14.0*
18.0*
7.0
6.2
aber rants. They were
TABLE 32 RANGE OF POLLUTANT CONCENTRATIONS IN WASTEWATER FROM
A PLANT TREATING WITH CCA- AND FCAP-TYPE
PRESERVATIVES AND A FIRE RETARDANT
(mg/liter)
Parameter
COD
As
Phenols
Cu
Cr+6
Cr+3
F
P04
NH3-N
Range of
Concentrations
10
13
0.05
0.05
0.23
0
4
15
80
- 50
- 50
- 0.16
- 1.1
- 1.5
- 0.8
- 20
- 150
- 200
PH
5.0 - 6.8
146
-------
DRAFT
TABLE 33 RAW WASTE LOADINGS FOR PLANT NO. 1
Parameter
COD
Phenols
Oil and
Grease
Total
Solids
Dissolved
Solids
Suspended
Solids
pH 4.6
Raw Waste
(mg/1 )
28,600
134
530
11,963
11,963
1,844
Loadings*
(Kg/ 1000
m3 Prod)
13,723.0
(854.8)
48.2
(3.0)
188.3
(11.7)
4,251.6
(264.9)
3,596.8
(224.1)
654.8
(40.8)
Raw Waste
Max.
2,705.5
(5,952.0)
6.7
(14.8)
84.5
(186.0)
836.6
(1,840.5)
673.0
(1,480.6)
163.6
(359.9)
Loadings/day
Min.
317.0
(697.5)
0.1
(0.2)
4.2
(9.3)
5.0
(11.1)
2.3
(5.1)
3.3
(7.2)
(Kg)**
Avg.
1,631.8
(3,590.0)
5.6
(12.4)
22.4
(49.3)
505.7
(1,112.6)
427.8
(941.1)
78.0
(171.5)
Average flow - 42,494 Ipd (11.227 gpd)
Void vol.of cylinders - 293 m3 (10,337 ft3)
1971 production (est.) - 26,760 m3 (945,000 ft3)
Average work days/year - 225
Average daily production - 119 m3 (4,200 ft3)
Preservatives - Creosote
*Parenthetical values in pounds/1000 ft3
**Parenthetical values in pounds.
147
-------
DRAFT
TABLE 34 RAW WASTE LOADINGS FOR PLANT NO. 2
Raw Waste Loadings*
Parameter (Kg/ 1000
(mg/1 ) nr Prod)
COD 22
Phenols
Oil and
Grease
Total 3
Solids
Dissolved 3
Solids
Suspended
Solids
pH 4.9
,685 7
258
55
,504 1
,044 1
460
Average flow - 68,471 Ipd
Void vol. of cylinders -
1971 production (est.) -
Average work
Average daily
Preservatives
days/year -
production
- Creosote,
,712.
(480.
88.
(5.
19.
(1.
,190.
(74.
,035.
(64.
155.
(9.
0
5)
3
5)
3
2)
9
2)
2
5)
7
7)
(18,090
427 m3 (1
60,163 m3
300
- 201
,„
Raw
Waste Loadinqs/day (Kg)**
Max.
5
(13
(1
(1
,988.
,175.
54.
(120.
4.
(10.
728.
,603.
645.
,419.
95.
(210.
9
6) 0
7
3)
6
2)
8
4)
3
6)
7
6)
Min.
794
,746
9
(19
2
(4
118
(206
106
(234
16
(35
.0
.8)
.0
.9)
.0
.4)
.2
.0)
.5
.4)
.1
.4)
Avg.
1,546
(3,402
17
(38
3
(8
238
(525
207
(456
31
(69
.7
.8)
.6
.7)
.7
• 2)
.9
.6)
.5
.6)
.4
.0)
gpd)
5,068 ft3)
(2,124,588 ft3)
n
(7,082 ft0)
Pentachlorophenol
*Parenthetical values in pounds/1000 ft3
**Parenthetical values in pounds
148
-------
DRAFT
TABLE 35 RAW WASTE LOADINGS FOR PLANT NO. 3
Raw Waste Loadings* Raw Waste Loadings/day (Kg)**
Parameter (Kg/1000
(mg/1) m3 Prod) Max.
COD 12,467 3
Phenols 82
Oil 150
Total 1,724
Solids
Dissolved 1,528
Solids
Suspended 196
pH 4.5
,295.1 943.2
(205.3) (2,075.0) (1
25.7 5.9
(1.6) (12.9)
40.1 25.0
(2.5) (55.0)
455.8 130.3
(28.4) (286.6)
404.5 115.5
(25.2) (254.0)
51.4 14.8
(3.2) (32.6)
Min.
500.0
,100.0)
3.5
(7.8)
69.5
(153.0)
61.6
(135.6)
7.9
(17.4)
Avg.
708.4
(1,558.4)
5.6
(12.3)
8.5
(18.8)
98.0
(215.5)
86.8
(191.0)
11.1
(24.5)
Average flow (est.) - 56,
Void vol. of cylinders -
1971 production (est.) -
Average work days/year -
Average daily production
Preservatives - Creosote,
775 Ipd (15,000 gpd)
457m3 (16,152-ft3)
64,491 m3 (2,277,432 ft3)
300
- 215 m3 (7,591 ft3)
Pentachlorophenol
*Parenthetical values in pounds/1000 ft3
**Parenthetical values in pounds
149
-------
DRAFT
TABLE 36 RAW WASTE LOADINGS FOR PLANT NO. 4
Raw Waste Loadings*
Parameter
Raw
Waste Loadings/day (Kg)**
(Kg/ 1000
(mg/1) m3 Prod)
COD
Phenols
Oil
Total
Solids
Dissolved
Solids
Suspended
Solids
pH 5.
8
9,318
312
580
3,432
2,748
684
2,291.
(142.
77.
(4.
142.
(8.
844.
(52.
675.
(42.
168.
(10.
9
8)
0
8)
8
9)
2
6)
7
1)
5
5)
1
(2
(1
Max.
,131.
,489.
21.
(46.
45.
(100.
530.
,166.
383.
(842.
147.
(324.
Min.
7
8)
2
6)
8
8)
3
7)
1
4)
4
2)
373
(822
14
(32
24
(53
99
(219
93
(206
6
(13
.1
• 6)
.6
.2)
.5
.9)
.9
.7)
.8
.4)
.0
.3)
Avg.
563
(1,239
18
(41
35
(77
207
(456
166
(365
41
(90
.3
.3)
.9
.5)
.0
.1)
.5
.5)
.1
.5)
.3
.9)
Average
Void vol
flow
. of
(est.) - 60
cylinders -
1971 production (est.) -
Average
Average
work
daily
Preservatives
days/year -
production
- Creosote
,560 1
523 m
pd (16,000 gp
3
(18,470 ft3
d)
73,746 m3 (2,604,270
300
- 246
m
3 (8,681 ft
«5
3)
ft3)
, Pentachlorophenol
*Parenthetical values in pounds/1000 ft3
**Parenthetical values in pounds
150
-------
DRAFT
TABLE 37 RAW WASTE LOADINGS FOR PLANT NO. 5
Raw Waste Loadings*
Parameter (Kg/1000
(mg/1) m3 Prod)
COD
Phenol
Oil and
Grease
Total
Solids
13,273 3
Dissolved
Solids
Suspended
Solids
pH 4.
5
126
172
5,780 1
5,416 1
364
Average flow (est.) - 34,
Void vol. of cylinders -
1971 production (est.) -
Average work days/year -
Average daily production
Preservatives - Creosote,
,072.
(191.
28.
(1.
40.
(2.
,338.
(83.
,253.
(78.
83.
(5.
0
4)
9
8)
1
5)
6
4)
5
1)
5
2)
Raw
Max.
593
(1,305
5
(11
9
(21
259
(570
241
(532
--
Waste Loadings/day (Kg)**
Win.
.2
.0)
.1
.2)
.9
.8)
.5
.9)
.8
.0)
317
(699
3
(7
1
(2
168
(370
137
(303
—
.8
.1)
.4
.4)
.0
.3)
.3
.2)
.9
.4)
Avg
452
(995
4
(9
5
(12
197
(433
184
(406
12
(27
•
.5
.5)
.3
.4)
.9
.9)
.0
.5)
.6
.2)
.4
.s)
444 Ipd (9,100 gpd)
356 m3 (12,557 ft3)
44,175 m3 (1,560,000 ft3)
300
- 147 m3 (5,200 ft3)
Pentachlorophenol
*Parenthetical values in pounds/1000 ft3
**Parenthetical values in pounds
151
-------
DRAFT
TABLE 38 AVERAGE RAW WASTE LOADINGS FOR
FIVE WOOD-PRESERVING PLANTS
Raw Waste Loadings*
Parameter (kg/1000
(mg/1) m3 Prod)
COD 19,269 5,378.4
(335.1)
Phenols
Oil and
Grease
Total
Solids
Dissolved
Solids
Suspended
Solids
pH 4.9
182
297
5,280 1
4,571 1
710
Average flow - 52,990 Ipd
Void vol. of cylinders -
1971 production (est.) -
Average work days/year -
Average daily production
Preservatives - Creosote,
51.4
(3.2)
83.5
(5.2)
,463.8
(91.2)
,276.0
(79.5)
199.0
(12.4)
Raw
Max.
1,651.
(3,634.
12.
(28.
37.
(82.
470.
(1,035.
387.
(852.
87.
(191.
Waste Loadings/day (Kg)**
9
2)
8
2)
5
5)
7
5)
4
2)
2
9)
(14.000 gpd)
411 m3 (14,517 ft3)
53,867 m3 (1,902, 258
285
- 189 m3 (6,674 ft3)
Pentachlorophenol
Min
502.
(1,106.
6.
(13.
7.
(16.
109.
(240.
93.
(205.
12.
(26.
ft3)
•
9
3)
3
8)
5
4)
5
9)
5
8)
2
8)
Avg.
1,016
(2,235
9
(21
15
(34
278
(612
241
(530
37
(82
.0
.2)
.6
.1)
.6
.4)
.4
.5)
.0
.2)
.5
.4)
*Parenthetical values in pounds/1000 ft3
**Parenthetical values in pounds
152
-------
"DRAFT"
SOURCES OF WASTEWATER
Wastewaters from wood preserving operations are of the following types
and contain the contaminants indicated:
a. Condensate from conditioning by steaming and Boulton-
izing - This is the most heavily contaminated waste-
water, since it comes into direct contact with the
preservative being used. Condensates from penta-
chlorophenol and creosote treatments contain entrained
oils, phenolic compounds, and carbohydrates leached
from the wood. Those from salt-type treatments contain
traces of the chemicals present in the preservative
formulation used. The oxygen demand of this waste is
high because of dissolved wood extractives and, in the
case of creosote and pentachlorophenol treatments, en-
trained oils.
b. Cooling water - Cooling water is used to cool condensers,
air compressors, and vacuum pumps and, in the case of
plants that use it on a once-through basis, accounts for
approximately 80 percent of the total discharge. Water
used with surface condensers, air compressors, and dry-
type vacuum pumps is unchanged in quality. That used
with barometric condensers and wet-type vacuum pumps is
contaminated with the preservative used, unless the pre-
servative is of the water-borne type. In the latter
case, the cooling water is unchanged in quality.
c. Steam condensate from heating coils - Water from this
source is uncontaminated, unless a coil develops a leak
through which preservative can enter.
d. Boiler blow-down water - is contaminated with chemicals,
principally chromates and phosphates, used as boiler
compounds.
e. Vacuum water - Water extracted from the wood during the
vacuum cycle following steam conditioning is contami-
nated with the preservative employed. In the Boulton
process, the cylinder condensate is largely composed
of water from this source.
f. Wash water - Water used to clean equipment is contami-
nated with the preservative used, with oil and grease,
and may also contain detergents.
g. Water softener brine - Water used for this purpose is
contaminated with various dissolved inorganic materials
including salts of calcium and magnesium.
153
-------
"DRAFT"
The source and volume of water used, including recycled water, and the
amount of wastewater discharged by a hypothetical wood preserving plant
(Table 38 ) that employs steam conditioning are shown in the flow dia-
gram that is Figure 29 . A more complete breakdown of these data is
given in Table 39 .
This plant has a daily intake of approximately 121,120 liters (32,000
gal.), gross water usage of 567,750 liters (150,000 gal.), and a dis-
charge of 104,100 liters per day (27,500 gpd). An estimated 13,250
liters (3,500 gal.) of cooling waterarelost by evaporation. Roughly
446,650 liters (118,000 gal.) are recycled as cooling water, including
6,400 liters (1,700 gal.) of water extracted during the conditioning
process (vacuum water). The amount of vacuum water recovered averages
about 1.9 kilograms per cubic meter (4.3 pounds per cubic foot) of green
wood that is steam conditioned. Approximately two times this amount is
removed from Boultorn*zed stock.
The actual volume of water used at a plant of this size and type is not
static, but rather varies depending upon the condition of the stock
(either green or seasoned) being treated and the size of the individual
items. For illustrative purposes only, the data in Table 39 were com-
puted based on the assumption that the plant treated stock one-half of
which was green and one-half of which was seasoned. It all green mater-
ial were treated, the volume of boiler water and cooling water used would
approximately double.
Both the gross water used in a plant and the volume discharged depends
primarily upon whether a plant uses cooling water on a once-through basis
or recycles it. To a lesser extent, the disposition of coil condensate —
either reused for boiler make-up water or discharged — is also important
in determining the volume of wastewater. Nationwide, approximately 75 per-
cent of the plants recycle their cooling water; only 33 percent reuse their
coil condensate.
Gross water usage is also influenced by cool ing water requirements. Among
plants of the same size and type of operation, the volume used varies by
as much as fourfold. Such variation is attributable to the operating pro-
cedures used. Important variables in this regard are the length of the
vacuum period, during which cooling water is required for both the con-
denser and the vacuum pump, and whether or not the rate of flow to the
condenser is reduced after the initial period of operation when a high
flow rate is needed.
Volume of cooling water used also varies with the conditioning process
used—either steaming or Boul torn'zing. In the former process, the con-
denser is operated only about three hours following a conditioning cycle.
In the Boultonizing process, the condenser is operated for the entire
period, which often exceeds 30 hours. Gross cooling water usageata larger
plant employing the Boulton process may amount to 3.8 million liters (1 mil-
lion gallons) per day.
154
-------
Intake
122,256,
(32,300)
gal.
11,166
(2,950)^-
(Evaporation) 102,
113
(30
550
000)
STEAM
(To retorts Icoils)
10?
(27
384
050)
o6:
440,952
016,500)
454,
[120
813
800)
6,434
(1,700)
200
000)
O
z
o
o
o
Vacuum Water
i,
(5
892
00)
CO
CO
111
0
O
CC
Q.
13^248 l,
(3,| 500) (Evaporation) (s
892
00)
104,277
Waste (27,550)
FIGURE 29 - SOURCE AND VOLUME OF DAILY WATER USE AND RECYCLING AND
WASTEWATER SOURCE AT A TYPICAL WOOD-PRESERVING PLANT
155
-------
DRAFT
TABLE 39 SOURCE AND VOLUME OF WATER DISCHARGED AND
RECYCLED PER DAY BY A TYPICAL WOOD-PRESERVING PLANT
(Note: Based on hypothetical plant,
data for which are given in TABLE 38)
Source
Cylinder condensate
Coil condensate
Boiler blowdown
Vacuum Water
Cooling water
Other
TOTAL
Volume
Used
51 ,096
(13,500)
55,640
(14,700)
6,813
(1,800)
-
454,200
(120,000)
1,892
(500)
567,500
(150,500)
Volume
Discharged
51 ,098
(13,500)
44,474b
(11,750)
6,813
(1,800)
-
13,248C
(3,500)b
1,892
(500)
104,277
(27,550)
Volume
Recycled
-
-
-
6,434a
(1,700)
440,952
(116,500)
-
447,387
(118,200)
Open values are in liters.
Parenthetical values values are in gallons.
sWater extracted from wood and recycled as cooling water.
bApproximately 15 percent loss due to flash evaporation.
cLoss of cooling water by drift and evaporation.
156
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"DRAFT"
Assuming recycling of cooling and coil condensate water, the most impor-
tant source of wastewater in terms of volume and level of contamination
is cylinder condensate. The amount of wastewater from this source varies
with the volume of stock that is green and must be conditioned prior to
preservative treatment. For plants operating on similar steaming or
Boultonizing schedules the volume of waste does not vary widely among
plants of comparable size and generally is less than 75,700 liters (20,000
gallons) per day.
157
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DRAFT
SECTION VI
SELECTION OF POLLUTANT PARAMETERS
WASTEWATER PARAMETERS OF POLLUTIONAL SIGNIFICANCE
Veneer and Plywood Industry and Hardboard Industry
Major wastewater parameters of significance for the veneer and
plywood industry and the hardboard industry include:
BOD
COD
Phenols
Oils and grease
pH
Temperature
Dissolved Solids
Suspended solids
In addition, parameters of lesser importance include:
Phosphorus
Nitrogen
The above parameters have been selected as representing those
chemical constituents which might be present in wastewater from
a veneer or plywood mill or a hardboard mill and which might
have a detrimental effect on a receiving water.
Wood Preserving Industry
Chemical and biological constituents of wood preserving waste-
waters that should be subject to effluent limitations because
of potential deleterious effects on receiving waters are listed
below. The selection of these parameters was based on data
obtained from various sources, including industry sources, and
on observations made at the exemplary plants inspected during the
field phase of this study.
Phenols Copper
BODS Chromium
COD Arsenic
Dissolved solids Zinc
Suspended solids Fluorides
Oil and grease Ammonia
pH Phosphorus
159
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DRAFT
All parameters are not present in the raw waste streams of all
wood preserving plants, the inorganics listed in the second
column occurring only in wastewater from plants treating with
salt-type preservatives. The particular ions present in the
discharges from these plants depend upon the preservative and/or
fire retardant formulation used.
DISCUSSION OF POLLUTANT PARAMETERS
BODS: Biochemical Oxygen Demand, 5 day at 20°C
This parameter is the widely used measure for determining degrad-
able organic matter in a wastewater. It is a standard criterion
utilized in pollution control regulations. BOD concentrations
are an indication of soluble and suspended organics. These organics
are composed of simple wood sugars as well as long chain and cyclic
hydrocarbons, and, if discharged to a receiving body of water or
into groundwater, pollution problems can result.
COD: Chemical Oxygen Demand
The COD of a wastewater is another measure for organic matter con-
centration. It is a chemical analys-is used to augment the BOD
analysis, and, in certain cases where a definite ratio between
BOD and COD has been established, it can substitute for the BOD
analysis. Furthermore, COD can often serve as an indicator of
organics that are not readily biodegradable.
Phenols
Phenols area natural constituent found in wood; therefore, water
contacting wood can be expected to obtain some concentration of
phenols. Resin, another potential source of phenols, might also
be found in wastewater discharges. It is a cyclic hydrocarbon
which can be degraded biochemically by the BOD test but not chemi-
cally by standard COD analysis.
Phenol concentrations in receiving waters offer the potential of
taste and odor problems in drinking water supplies as well as the
potential of toxicity to biota.
Oil and Grease
Oil and grease (hexane extractables) are standard lubricating
chemicals in a variety of inplant machinery. These lubricating
chemicals can find their way into cooling water, washwater, and
other miscellaneous waste streams. Creosote is an oil, and
various petroleum products are used as carriers for pentachloro-
phenol. These oils invariably are present in wastewater from
160
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DRAFT
treatments employing oily preservatives and they create a
serious pollution problem. Values for raw wastewater range
from less than 50 to over 1000 milligrams per liter.
The pH of a liquid is by definition the negative log of the
hydrogen ion concentration. It is an important parameter in
that most reactions in water are a function of hydrogen ion
concentrations from an equilibrium as well as from a kinetic
standpoint.
Wastewaters from creosote and pentachlorophenol treatments are
invariably acid in reaction, the pH ranging between 3.8 and 6.0.
Those from salt- type treatments may be either acid or basic, de-
pending upon the particular formulation used.
Temperature
Temperature is also an important parameter in reaction kinetics
and equilibria. Large heat loads on a receiving stream can
cause significant temperature increases which in turn can re-
sult in serious imbalance in micro-ecesystems .
Dissolved Solids
Total dissolved solids is a chemical analysis which, when added
to the total suspended solids concentrations, gives the total
solids in a waste stream. It is also a measure of the soluble
organics that are leached from wood. In the case of salt-type
treatments in wood preserving plants, inorganic preservatives
contribute to the dissolved solids content of wastewaters. In
any recycle system dissolved solids accumulate even though sus-
pended solids are removed. Sufficient blowdown must be maintained
to prevent deposition on heating and cooling surfaces.
Suspended Solids
Wastewaters can carry substantial suspended solids concentrations
due to wood fibers, fiber fragments, and other residue. Sus-
pended solids is an important factor in determining the quality
of wastewater since it affects light penetration and 'the aesthetic
properties of the receiving waters.
Phosphorus
The only source of phosphorus from the veneer and plywood industry
is the wood itself. Phosphorus is an important nutrient and can
have significant effect on the eutrophication of receiving waters.
However, the wastewaters from this industry are nutrient deficient,
and phosphorus is not considered a problem.
161
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DRAFT
Nitrogen
The main forms of nitrogen in water are organic nitrogen, ammonia,
nitrites, and nitrates. Nitrate is the lowest oxidation level
of these. Biochemical reactions will oxidize ammonia to nitrite
and finally to nitrate. This oxidation necessitates oxygen,
thereby exerting an oxygen demaad_ in water. Furthermore, nitrates
have been found to be toxic .at high levels to infants and to
interfere with disinfection by halogens. Nitrogen is an important
nutrient and can affect eutrophication in receiving waters. Urea
formaldehyde glue and protein glues introduce organic nitrogen.
Assuming no discharge from glue waste, the wastewaters from a
veneer and plywood mill are nitrogen deficient and nitrogen
concentrations are not a problem.
Inorganics
All of the inorganics listed for the wood preserving industry
occur in one or more salt-type-preservatives and fire retardants.
As indicated previously, the particular ions present depend upon
the salt formulation used. Concentrations in raw wastewater range
from five to 100 milligrams per liter.
162
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DRAFT
SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
PART A: CONTROL AND TREATMENT TECHNOLOGY IN THE VENEER
AND PLYWOOD INDUSTRY
Introduction
Treatment and control technology in the veneer and plywood
industry is not extensive. This is due in large part to
the fact that the water pollution problems in the industry
are relatively minor when compared to other industries. _The
major effort made by the industry to reduce wastewater dis-
charge has been to reduce the amount of wastewater produced
by reuse and conservation of water and to contain wastewaters
that cannot be reused. Each source of potential wastewater
and methods of treatment is discussed below.
Log Storage
As discussed in Section IV, Process Description and Industry
Categorization, log storage may consist of log ponds, wet
decking, or dry decking. Water quality and discharge
volumes of log ponds cannot be characterized with available
data; therefore, development of documentation for effluent
limitations guidelines for this waste source will be accom-
plished in Phase II of the Timber Products study. Wet deck-
ing, on the other hand, allows for greater control of water
usage to such an extent that zero discharge to navigable
waters is feasible. There is no wastewater discharge from
dry decking. Therefore, in this document, control and treat-
ment technology for waste streams from log storage will be
concerned with the wet decking method.
Several plywood mills presently recycle the water that has
been used to sprinkle logs in wet decking. Such a recycle
system generally consists of a settling pond or sump to
catch the drainage from the log sprinkling area and of
screening facilities prior to reuse. Sprinkling enhances
evaporation of water, thereby balancing out runoff from
rain in most areas of the country. Solids which tend to
slowly fill the settling pond can be removed and disposed
of as landfill. While there are operational problems
associated with such a recycle system, in most instances
the problems can be solved. It is felt that with few
exceptions this technology is applicable to the industry
in general.
163
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DRAFT
Dry decking of logs is also practiced in a number of mills,
although it is mostly applicable to mills producing low
quality veneer and to mills that have a fairly constant
supply of logs and do not require large log storage. If
deterioration of logs becomes a-problem, then wet-decking
must be practiced.
Log Conditioning
Wastewater from log conditioning has become the largest and
most difficult source to handle in a plywood mill since it
has been demonstrated that glue washwater can be eliminated
as a pollution source.
Although seldom used, biological treatment of the effluent
from hot water vats and steam vats is practicable and effec-
tive. It has been reported that 85 to 90 percent reduction
of BOD and COD is attainable by using lagoons or aerated
lagoons (20). Other types of biological treatment have not
been reported, but it is obvious that conventional biological
processes such as the activated sludge process are also tech-
nically feasible.
Hot water vats when heated indirectly through coils will not
have a continuous discharge caused by steam condensate. Any
discharge results from spillage when logs are either placed
into or taken out of the vat. Plants operating in this manner
need only to settle the water in small settling tanks or ponds
and reuse the water for any makeup that might be required.
There are several plants designed to operate in this manner;
however, the tendency has generally been to operate this sys-
tem by injecting live steam into the vats to heat the water
to the desired level and then to use the steam to maintain
the temperature. The reason for the use of steam injection
rather than heating coils is to raise the temperature as
quickly as possible. Quicker heating-may also be accomplished
by adding more heating surface to the vats. Plants that use
steam coils in their hot water vats and then settle and reuse
the water have experienced a decreased pH in the vats with
time. Addition of lime or sodium hydroxide may be necessary
to reduce resulting corrosion problems. The resulting sludge
may be trucked to landfill.
Wastewater discharge from steam vats is more difficult to
eliminate. By design, condensate from the vats must be
discharged because of the difficulty of reusing the con-
taminated condensate as boiler makeup water. Various modi-
fications have been made to steam vats which allow them to
be converted to totally closed systems. Several plants have
164
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DRAFT
converted steam vats to hot water spray tunnels which would
have conditioning effects similar to hot water vats (20).
Hot water does not heat the logs as rapidly or as violently
as direct steam; however, it is a practical alternative for
most plants. While many mills cannot use hot water vats due
to the fact that some species of logs do not sink, hot water
sprays can be used as an alternative. Hot water spray systems
can be placed in existing steam vats with only minor modifi-
cations. These systems work on the principle of heating
water through heat exchange coils and then spraying the hot
water over the logs. The hot water can then be collected and
reheated after settling and screening.
The other possible modification is a technology from the wood
preserving industry called "modified steaming" (20). Modi-
fied steaming works on principles similar"to hot water sprays
with the exception that no sprays are used. Coils in the
bottom of the vat are used to produce steam from the water.
The steam conditions the log in much the same manner as in
conventional steam vats. As the steam condenses, it falls
to the bottom of the vat where it is revaporized.
Either the use of hot water sprays or the employment of modi-
fied steaming would allow mills that now use steam vats to
operate similarly to mills that now use hot water vats without
direct steam impingement. All of these methods are closed
systems and, therefore, require some type of solids removal
and "flush-outs" a few times each year. They may also require
pH adjustment. The relatively small volumes of wastewater
produced during the "flush-outs" could then be contained or
used for irrigation.
Veneer Dryers
The practice of cleaning veneer dryers with water is one that
will necessarily continue; however, the frequency of cleaning
and the volume of washwater can be significantly reduced.
Plywood mills producing 9.3 million square meters (100 mil-
lion square feet) on a 9.53 mm (three-eights inch) basis per
year presently use approximately 57,000 liters (15,000 gal-
lons) of water per week to clean dryers. There are many modi-
fications to cleaning procedures which can reduce this vol-
ume. A plywood mill in Oregon has already reduced its veneer
dryer washwater to 8,000 liters (2,000 gallons) per week by
manually scraping the dryer and blowing it out with air prior
to the application of water. Close supervision of operators
and the installation of water meters on water hoses also
encourages water conservation. Most mills can reduce the
165
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DRAFT
volume of water to about 12,000 liters (3,000 gallons)
per week, and this small volume can be handled without
discharge by containment, land irrigation-, or evapora-
tion.
Glue Lines
Current technology in the handling of glue washwater
allows zero discharge to navigable waters to be achiev-
able throughout the industry. Recycle systems which
eliminate discharge from the glue lines are now in op-
eration in about 60 percent of all mills visited and
are practicable with all three major types of glue. In
1968, only one plywood mill had a glue washwater recycle
system CIO), Currently the system is accepted technol-
ogy in the industry. Nevertheless, there are still a
number of plywood mills that discharge wastewater from
their glue operations.
A plywood mill using phenolic glue can reduce the waste-
water flow from its glue operation to about 7,570 liters
(about 2,000 gallons) per day, without altering the pro-
cess, by conserving water (10), Urea formaldehyde glues
do not require any more frequent washing than do phenolic
glues and, therefore, can be similarly controlled. Pro-
tein glues, however, normally necessitate more frequent
cleaning because of shorter glue pot life. In order to
reduce the flows from a mill phat uses protein glue, in-
plant modifications in addition to water conservation
are necessary.
Phenolic glues usually require about 227 kilograms (500
pounds) of water per batch (4.5 cubic meters [1,200 gal-
lons] per day), Further reduction of wastewater is
then necessary for all of the wastewater to be used in
the makeup of glue. Table 26, found in Section V, indi-
cates that most southern plywood mills produce about
twice as much wastewater from glue washing than can be
used for glue mixing.
Various inplant operational and equipment modifications
can be used to reduce glue washwater; for example:
(1) Some plants wash glue spreaders several
times a day, and some wash only once a
week. The less frequent washings can
reduce the amount of water to between
10 and 30 percent of the original volume.
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DRAFT
(2) The use of steam to clean the spreaders also
reduces the water usage considerably. While
steam cannot be used for some types of rub-
ber coated roller spreaders commonly used with
phenolic and urea glues, steam would be a
practical modification for protein glue opera-
tions which use steel rollers. This is quite
significant since the frequency of washing for
protein glue lines cannot be reduced to the
same extent as when synthetic resins are used.
(3) The use of high pressure water lines and noz-
zles can reduce the amount of water used to
30 percent of .the original volume.
(4) The use of glue applicators which spray the glue
rather than roll it onto the wood can reduce
the volume of washwater, since these do not
require washing as frequently as do the glue
spreaders.
(5) The use of washwater for glue preparation and
the reuse of remaining washwater for washing
the glue system is a simpl-e method of reducing
wastewater flows. Since a fraction of the
washwater is used to prepare glue, a volume
of fresh water can be added as final rinse in
the washing of the glue spreaders.
Any number of these modifications in combination wi.th each other
can be used to completely recycle the washwater and eliminate
discharge from the glue system. A typical recycle system is
shown in Figure 30.
There has been no difference in the quality of glue made with
fresh water and that made with washwater (19). An economic
benefit has been established by using glue wastewater, due to
the fact that it contains glue and other chemicals such as
sodium hydroxide, as shown in Table 40. Substantial savings
in raw materials can be realized.
Complete recycle systems are now in operation for phenolic, urea,
and protein glues. Mills that use several types of glues must
have separate recycle systems to segregate the different wash'--
waters. Attempts at mixing washwater from different types of
glues have been unsuccessful.
In addition to washwater recycle, there are plants that contain
and evaporate glue washwater, spray the glue water on the bark
that goes into the boiler, or use a combination of these techniques
167
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PLYWOOD PLANT BUILDING
00
7-1/2 H.R MOTOR
PROVIDING CONTINUOUS
AGITATION
TRASH
REMOVAL
CONVEYOR
BELT
CONCRETE
SETTLING
TANK
GROUND
LEVEL
2000 GAL|
COLLECTION
TANK
|WATER
METERING
TANK
GLUE
MIXER
MIX
HOLD
TANK
PUMP
PUMP
GLUING AREA
GLUE
SPREADERS
CONCRETE DRAINAGE TROUGH IN FLOOR
FIGURE 30 (19) - PLYWOOD PLANT WASH WATER REUSE SYSTEM
-------
<£>
TABLE 40 (19)
THE ADHESIVE MIXES USED (CASCOPHEN 3566C)
Ingredients Mix la Mix 2b Mix 3C
Water
Phenofil
Wheat Flour
Mix 5 minutes
W-156V Resin
Mix 2 minutes
501 Caustic Soda
Mix 15 minutes
W-156V Resin
Mix 5 minutes
TOTAL
Resin Solids in Mix
700
350
140
220
131
2,178
3,719
25.7%
701
350
140
220
75
2,156.5
3,642.5
25.7%
700
350
140
220
100
2,163.
3,673.
25.
5
5
7%
^Control mix - clean water used for mix.
"D20:l dilution of Mix 1 used for mix water - pH 11.5
C30:l dilution of Mix 1 used for mix water - pH 11.4
-------
DRAFT
PART B: CONTROL AND TREATMENT TECHNOLOGY IN THE HARDBOARD
INDUSTRY
DRY PROCESS HARDBOARD
Introduction
The small volumes of water discharged from dry process hard-
board mills and the variation of waste sources from mill to
mill have resulted in little new waste treatment technology
being developed. In general, due to the small volumes of
wastewater generated, the major treatment processes have been
limited to oil-water separation, waste retention ponds, or
perhaps spray irrigation.
The major wastewater source in one particular mill may be a
zero discharge source in another mill. Inplant modifications
to reduce, eliminate, or reuse wastewater flow can.greatly
affect total wastewater discharge from any mill. By inplant
modifications and containment on site, zero discharge can be
achieved in the dry process hardboard industry.
Inplant Control Measures and Technology
Log Wash: Only two mills out of 16 existing mills reported
washing logs. One mill which washes logs has' zero-discharge
of all its waste through impounding and land irrigation. The
second mill uses approximately 82 cubic meters (21,600-gallons)
per day for log washing which is discharged directly to a
stream without treatment. Log washwater can be successfully
reused by settling with only a small percentage of-blowdown
to remove accumulated solids. The blowdown from log'wash-
water recycle systems can be disposed of by impounding or
land spreading.
Chip Wash: At the present time, there are no dry .process
hardboard mills which report washing chips, however, several
indicate plans to install chip washing in the future. Until
such time as chip washers are installed and experience gained,
no technology is available in the dry process hardboard indus-
try for treatment of this waste stream. Predicted-wastewater
discharges from a chip wash system are 18.9 to 37.8 cubic
meters (5,000 to 10,000 gallons) per day which could be dis-
posed of by impounding or land spreading.
170
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DRAFT
Six mills out of the total of 16 dry process hard-
board mills report zero discharge from their resin systems.
Several other mills report a waste discharge of less than
750 liters (200 gallons) per day. All hardboard mills use
essentially the same types of resin (phenolic or urea for-
maldehyde) . Taking into consideration that several mills
already have zero discharge and that many plywood mills using
the same resin have zero discharge, there is no reason all
dry process hardboard mills cannot have zero discharge from
their resin systems.
Caul Wash: Five mills report no caul washwater discharge for
one of several reasons; the two most commonly given are:
they do not use cauls or the water usage is so small that
it is insignificant. Those mills reporting discharges of
caul washwater average only some 750 liters (200 gallons/day).
This low quantity of water can be neutralized as needed,
then disposed of by impounding or land spreading.
Housekeeping: Housekeeping washwater is a miscellaneous waste-
water flow which varies from mill to mill. Several mills re-
port no housekeeping washwater as all cleaning inplant is done
by sweeping and vacuum cleaning. At least two mills have waste
flow from their press pit which usually contains oil. This
wastewater can be eliminated by preventing condensate water
from entering the press pit and by reducing hydraulic fluid leaks
Housekeeping wastewater can be either totally eliminated or,
if water is used, held on site by impounding and spray irriga-
tion.
Cooling Water: Cooling water is by far the major wastewater
flow from dry process hardboard mills. Cooling water is used
in such unit processes as refiner seal water cooling systems,
air compressor cooling systems, and resonance frequency gen-
erator cooling systems. Use of cooling water varies widely
but is consistently less than 380 cubic meters (100,000 gal-
lons) per day. Cooling water can be recycled through cooling
towers or cooling ponds. Blowdown from these areas could be
used for log washing or chip washing.
Humidifier: Hardboard must be brought to a standard moisture
content after dry pressing. This is done in a humidifier unit
in which a high moisture and temperature is maintained. Nine
mills report no water discharge from humidification units,
while one mill reports a volume of less than 11 cubic meters
(3,000 gallons) per day. It has been proven that humidifiers
can be operated with zero discharge, therefore, all dry pro-
cess hardboard mills should achieve zero discharge from this
source.
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Finishing: All dry process hardboard- mills report zero
discharge from finishing operations.- Concern-was indicated
by industry with the potential of new technology causing
wastewater flow from the finishing operation. For example,
air pollution control regulations may make it necessary to
switch from oil based paints to water based paints, in which
case a potential wastewater source could exist. At the pre-
sent time there is zero discharge from finishing operations.
Until such time as technology changes create wastewater dis-
charges from this source,there should be zero discharge.
Identification of Water Pollution Related Operation and
Maintenance Problems At Dry Process Hardboard Mills
The water pollution resulting from dry process hardboard
mills is directly related to wastewater flow and concentra-
tion, which, in turn, is influenced by operation and main-
tenance problems in each mill. The decision to wash logs or
chips by a mill is a result of the effect of dirt and sand
on inplant machinery. High maintenance cost resulting from
abrasion of refiner plates, etc., make it desirable to wash
logs and chips. Quantities of extraneous material on logs
depend upon harvesting and storage operations, and therefore
directly affect wastewater flow composition.
The operation and maintenance of the resin system affects
wastewater flow. Most hardboard mills and numerous plywood
mills using similar resins are able to operate with zero
discharge from their resin systems. Simple modification of
inplant equipment or maintenance procedures should eliminate
the resin system as a source of wastewater flow.
Caul washing, a minor wastewater source, is an inplant process
that is affected by operation. Cauls are soaked in tanks con-
taining sodium hydroxide and other cleaning agents. After
soaking they are rinsed and put back into use. The method
of operation of this cleaning system can greatly reduce the
water usage and therefore the quantities of water to be dis-
charged. The resulting low volumes of water (less than 750
liters [200 gallons] per day) can be easily discharged onsite.
Housekeeping practices vary widely from mill to mill with
resulting effects on wastewater discharge. Several mills
are able to perform clean up operations without having waste-
water being discharged. Other mills use water for clean up
operations because of the ease and efficiency of water clean-
ing. Modification of inplant housekeeping procedures can
172
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DRAFT
minimize water usage with resulting zero discharge from
this source.
The press pit (a sump under the press) can collect oil, fiber,
and condensate water. The method-of-clean up of the'-.press pit
can significantly reduce waste from this process. Modifica-
tions can be made to reduce or eliminate condensate water so
that an oil/water emulsion will not be formed.
WET PROCESS HARDBOARD
Introduction
There is no single scheme currently being used to treat waste-
water discharges from wet process hardboard mills. The major
treatment and control methods presently being used include
water recycle, filtration, sedimentation, coagulation, evapor-
ation and biological oxidation processes such as lagoons,
aerated lagoons, and activated sludge processes.
The treatment and control methods presently utilized in.any
one mill have been influenced by pressure from regulatory
agencies, land availability, access to city sewer, and indi-
vidual company approach to wastewater control.
Inplant Control Measures and Technology
Raw Materials Handling: There were no mills reporting washing
logs; however, it logs were washed, a simple recirculation sys-
tem could be installed to eliminate discharge from-.this _ source.
This recirculation system would consist of a sedimentation
basin or pond to catch the washwater and allow the-removal of
suspended solids. Pumps preceeded by screens would"recirculate
the water for log washing. Accumulated deposits in the sedi-
mentation basin or pond would be removed as needed and-disposed
of as landfill. Chip washing, if practiced, could be eliminated
as a wastewater source in a similar manner.
Process Water: The major source of wastewater flow-,and concen-
tration comes from discharging the process water. This includes
fiber preparation, mat formation, and pressing. As has been
previously discussed, the source of organric material in the
process water is from the solution of wood chemicals. The quan-
tity of organics released is directly dependent upon wood
species, cooking time, and temperature.
It has been suggested that a decrease in BOD load can-.be made
by reducing the cooking or preheating temperature at the expense
of higher energy consumption in the refiners. Little research
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has been done in this area, but it should be-stated'that only a
portion of the BOD can be eliminated in this manner.
Assuming that chips contain 50 percent fiber andMnus±rbe diluted
to 1.5 percent fiber prior to mat formation, for every ton of dry
fiber processed, 60.5 cubic meters (16,000- gallons)•of water is
needed for dilution. The obvious procedure to obtain'this quantity
of water and prevent discharge of organic material is to recycle
all of the process water.
There are several limiting factors preventing total recycle of pro-
cess water, including temperature, soluble organics, and build up
of fines. Temperature of-process water can be controlled by the
installation of a heat exchanger. At least two mills report the
use of shell and tube heat exchangers to control process water
temperature.
Soluble organics are the most difficult to control in the wet pro-
cess. The explosion process utilized by two Masonite mills pro-
duce greater quantities of soluble organics than other, processes
because of the higher temperature and pressure. Due to the large
quantities of organic material released from the wood, Masonite
has installed evaporation systems to reduce the quantities of
organics discharged in their wastewater. Figure 31 shows a
schematic diagram of one of these systems. In this system counter-
current washers are used to remove a major portion of the organics
from the fiber prior to dilution and mat formation. This waste
stream passes through a clarifier and is evaporated. The concen-
trated organic stream from the evaporator is sold as cattle feed
or it can be incinerated, and the condensate is either reused as
process makeup water or discharged as a wastewater stream. Process
water from the felter and the press passes through a clarifier to
remove settleable solids. All solids are reused to make board,
while the overflow is used for fiber wash or dilution water. The
total discharge from this mill without biological treatment is
only 3.25 kilograms per metric ton (6.5 pounds per ton).
The more conventional cooking .processes release less organics and
it is questionable whether or not process water soluble concentra-
tions can be increased to a high enough level to make evaporation
economical without inplant modifications. However, at least one
mill in Sweden is presently evaporating excess process water (26).
One possibility to decrease the volume of wastewater without in-
creasing the concentration of soluble substances in the process
water system at the same time is to arrange some kind of pre-
pressing of the pulp to remove the concentrated organics before
they enter the main process water stream. An arrangement of this
type is shown in Figure 32, where a pre-press has been inserted
174
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TO ATMOSPHERE
CHI
REFINER ~ FIBER
,-J WASHER
STOCK Jz^ WET FORMING
CHEST j | MACHINE
TO
FINISHING
-j
in
CLARIFIER
WATER IN
WATER OUT
CONCENTRATED
BY-PRODUCTS
If
1
.BERL
I
1
1
\
rn\i\i
\
',
rrrr*i
r
1
EVAPORATOR
CLARIFIER
^. 1
SLUDGE (FIBER)
TO PROCESS
CONDENSATE
FIGURE 31 - INPLANT TREATMENT AND CONTROL TECHNIQUES AT MILL NO. 7
-------
STEAM
cr>
WET FORMING
MACHINE
PROCESS
WATER
CHEST
WATER IN
WATER OUT
(XX) ?r«P£?XIMATE pE«CENT FIBER
(CONSISTENCY IN PROCESS)
(35)
WET
PRESS
TO TREATMENT
FIGURE 32 - TYPICAL WET-PROCESS HARDBOARD MILL WITH PRE-PRESS
-------
TO ATMOSPHERE
CHIPS
WATER IN
WATER OUT
CONCENTRATED
BY-PRODUCTS
IPROCE5
J>
J
- L
|
SLUDGE TO
LANDFILL
FIGURE 33 - INPLANT TREATMENT AND CONTROL TECHNIQUES AT MILL NO. 3
-------
DRAFT
after the cyclone. If the process water system is completely
closed all soluble substances with the exception of those de-
posited in the hardboard would be contained in the wastewater
leaving the pre-press. The concentration of soluble substances
in this wastewater depends on the amount of substances dissolved
during the pre-heating, on the volume of wastewater leaving the
pre-press, and finally on the efficiency of the pre-press,
i.e., the consistency of the pulp leaving the press. The effi-
ciency of such a system can be increased by installing two or
three presses in series. A system of this type can signifi-
cantly reduce the concentration of soluble organics in the
process water, allowing increased recirculation rates.
Suspended Solids: Suspended solids within the process stream
should be controlled to limit the build up of fines which re-
duce water drainage during .mat formation and to limit the sus-
pended solids discharged in the raw wastewater. If inplant
treatment methods such as evaporation are used, the suspended
solids concentrations entering these processes must be con-
trolled. Suspended solids removal systems consist primarily
of gravity settling, screening, filtration, and flotation.
Only two mills utilize sedimentation tanks for removal of sus-
pended solids in process water prior to recycle. Both of these
mills utilize the explosion process. These systems are shown
in Figures 31 and 33. Process water from both mat formation
and final pressing is passed through a clarifier and reused in
the process. Other mills utilize gravity separators in their
final wastewater treatment scheme, but do not recycle back to
process. In one of the two mills utilizing sedimentation to
remove solids from the process water, the settled solids are
returned to the process and become part of the board. The
other mill has not been able to do this due to a different
species of raw material.
Filters can accomplish the same liquid solid separation as
gravity separation. The efficiency of such filters varies
widely depending upon flow rates, suspended solids concentra-
tions, and types and sizes of solids. Representative data for
filter efficiency may be found in Table 41, below.
TABLE 41
REPRESENTATIVE PROCESS WATER FILTER EFFICIENCIES
Suspended Solids (mg/1)
Mill Before Filter
0
p
Q
R
1000
170
1000
230
- 3500
- 1000
- 1300
- 620
80 -
30 -
280 -
90 -
250
150
330
145
178
-------
DRAFT
One of the most interesting systems utilized for controlling
suspended solids is a patented process developed in Finland
at the Savo Oy.Mill. This system is a chemical treatment
system followed by sedimentation and/or flotation. The chemi
cal treatment includes adjustment of the pH value, addition
of chemicals for coagulation, followed by removal of sus-
pended solids and some dissolved and colloidal solids.
There are two mills in the United States presently using this
system to some degree. Typical data from the Savo system
from one of these mills is shown below:
Influent Effluent Percent Reduction
(mg/1)
COD
SS
TDS
Soluble
Organics
Volatile Sus-
pended solids
7775
750
5525
4285
740
4745
48
4788
3362
46
39
94
13
22
94
An advantage reported from the use of the Savo system is that
all sludge from the system can be reused in the board. One
mill has been able to reduce its wastewater flow to 2.3 cubic
meters (611 gallons) per ton and BOD discharge to 8.5 kilo-
grams per metric ton (17 pounds per ton). This low discharge
rate and concentration is the result of inplant modifications
and does not include any end of line treatment. Figure 34
shows a schematic diagram of this process.
End Of Line Wastewater Treatment
The existing end of line waste treatment facilities consist
primarily of screening followed by primary and biological
treatment. All of the existing nine wet process hardboard
mills utilize primary settling basins either within the pro-
cess or as part of their final waste treatment facilities.
In order to protect the primary settling units from sludge
loading and to remove as much fiber as possible, screens are
generally placed ahead of the primary units. Fiber removed
be screening is disposed of by landfill or returned to pro-
cess.
Three of the nine wet process mills were either sampled by
Environmental Science and Engineering, Inc., or the mill
reported treatment efficiencies across their primary clari-
fiers. This data is shown in Table 42. Although this data
179
-------
00
o
STEAM
CHIPS
WATER IN
WATER OUT
WET FORMING
MACHINE
FIBER
TO
PROCESS
PROCESS
WATER
CHEST
TO
ATMOSPHERE
TO
FINISHING
i
i
SAVO
1
1
DISCHARGE
FIGURE 34 - TYPICAL WET-PROCESS HARDBOARD MILL WITH SAVO SYSTEM
-------
DRAFT
TABLE 42
PRIMARY SETTLING TANK-EFFICIENCY
Mill
4
5
6
BOD
mg/1
2400
3500
6000
In
k/kTg
28.
32
42.
5
2
BOD
mg/1
2400
3300
3900
Out
"\f / "\f tf fT
/ n
28.5
30'.5
28
Percent
Removal
0
5
35
SS In
mg/1 k/kkg
1650 19
430 4
1440 10
SS
Out
mI7l k/fcTg
178
154
450
2
1.
3.
4
25
Percent
Removal
89
69
68
oo
-------
DRAFT
may be typical of the treatment efficiency that existing
facilities are achieving, it is not representative of the
efficiency, that can be obtained through, proper design and
operation. The three mills listed in Table 42 utilized
settling.ponds as primary clarifiers. These ponds are
allowed to fill with solids before being dredged for solids
removal. Accumulated solids undergo anaerobic decomposi-
tion causing an increase in BOD and suspended solids (SSI
in the effluent.
A properly designed clarifier with a mechanical sludge
collector and continuous sludge removal can be expected
to obtain approximately 75 to 90 percent SS removal and
10 to 30 percent BOD removal.
The pH of wet process wastewater varies from 4.0 to 5.0.
The pH must be adjusted to near 7.0 to obtain satisfactory
biological degradation. The pH may be adjusted by either
the addition of lime or sodium hydroxide.
Wet process hardboard mill wastewater is deficient in nitro-
gen and phosphorus. These chemicals must be added in some
form to obtain rapid biological degradation of the waste.
The most commonly used source of nitrogen is anhydrous
ammonia, and the most commonly used source of phosphorus is
phosphoric acid.
Existing biological treatment systems consist of lagoons,
aerated lagoons, activated sludge, or a combination of
these. T-he type of system presently used at each mill is
shown below:
Mill No.
End Of Line Treatment System
1
2
3
4
5
6
7
8
9
Primary settling pond - aerated lagoon -
secondary settling pond.
Primary settling pond - aerated lagoon -
secondary settling pond.
Primary clarifier - activated sludge -
aerated lagoon.
Primary settling pond - activated sludge
aerated lagoon.
Primary settling pond - activated sludge
lagoon or spray irrigation.
Primary settling pond.
No treatment.
No treatment.
Aerated lagoon.
182
-------
DRAFT
Table 43 shows the treatment efficiency of the five-mills which
presently have biological treatment systems in operation._ The
values shown are average values and do not define the variations
in effluent that can be expected from biological systems. It
should be noted that the values shown for mills No. 1, 2, and 5
include the efficiency of the primary settling units while for
mills No. 3 and 4 the efficiency is across the biological unit
alone.
Mills No. 1 and 2 utilize aerated lagoons. Their treatment
efficiencies for BOD removal have averaged 70 and 79 percent,
respectively. Mills 3, 4, and 5 utilize some variation of the
acitvated sludge process and their average efficiencies for BOD
removal are 97,77, and 95 percent, respectively. Mill No. 4,
whose activated sludge system averages only 77 percent efficiency
for BOD removal,is actually not operated as an activated sludge
system as there is no sludge waste'from the system. Therefore,
the system is more representative of an aerated lagoon system.
The efficiency of solids removal across the biological system
for all mills is essentially zero. There are several reasons
for this. Biological solids produced in waste treatment systems
treating hardboard wastewater are difficult to settle and dewater.
There is presently no economical method that is satisfactory for
handling waste activated sludge from these biological systems.
One mill attempts to utilize a centrifuge for sludge thickening
prior to incineration, however, the system is highly variable
in its efficiency and frequently excess sludge has to be hauled
by tank trucks to a land spreading area.
Several mills in the United States and Europe have put excess
sludge back into the process water to become part of the board
(21). The quantity of sludge which can be reclaimed in this
manner is variable from mill to mill depending upon a variety of
factors. It is known that the addition of sludge to the board
increases the water absorption, reduces the drainage rates, and
make it necessary to add additional chemicals to compensate for
the sludge addition (27).
At least one mill (mill No. 5) is disposing of its waste sludge
by spray irrigation. Waste sludge is pumped to an aerobic di-
gester, then the digested sludge is pumped to a nearby spray
irrigation field. Land irrigation or sludge lagooning has the
advantage of making it unnecessary to dewater the sludge prior
to disposal.
The difficulty in handling waste activated sludge from the acti-
vated sludge treatment of wet process hardboard wastewater leads
to a build up of solids within the system with a resulting dis-
charge of solids in the effluent. Weather conditions (temperature)
183
-------
DRAFT
00
TABLE 43
TREATMENT EFFICIENCY OF BIOLOGICAL SYSTEMS
BOD. ke/kkp
Mill No.
* + l
* + 2
*3
*4
*+5
** + !
** + 2
*3
*4
*5
Influent
33
50
23
28.5
32
BOD
720
1310
1800
2400
3500
Effluent
7
15
0.6
6.45
1.55
, me/1
151
393
54
552
175
Percent
Removal
79
70
97
77
95
79
70
97
77
95
Influent
10
1.4
0.7
1.4
220
—
114
60
151
SS, kg/kkg
Effluent
9
_ _
3.6
4.2
3.6
ss, mg/1
198
_ m
295
360
38!!
Percent
Removal
10
0
0
0
10
0
0
0
+ Includes efficiency of primary settling
** Aerated lagoons
* Activated sludge
-------
DRAFT
are also reported to have an effect on the settling rate of
biological solids in both aerated lagoon systems and the acti-
vated sludge system (28).
Figures 35, 36, and 37 show the variations in effluent BOD and
suspended solids for mills No. 2, 3,.. and 4, respectively. Values
shown are monthly averages and do not necessarily indicate a di-
rect relationship between suspended solids and season (tempera-
ture) . The main information presented by these graphs is that
for either the aerated lagoon or activated sludge average, sus-
pended solids in the effluent can be expected to be 250 milli-
grams per liter.
Table 44 shows an example of an aerated stabilization basin (ASB)
or aerated lagoon performance related to temperature. This table
is for a biological system treating paperboard waste; however,
similar effects are experienced in the wet process hardboard in-
dustry. The main difference, however, is that the quantity of
solids can be expected to be several times greater.
Summary of Waste Treatment Control Technology
Water Reuse: The existing nine wet process hardboard mills
presently practice considerable recycle of wastewater. These
systems include:
(1) Process water recycle with blowdown to con-
trol suspended and dissolved organics. This
blowdown may occur in a pre-press, from the
wet or hot press, or from the process water
chest.
(2) Process water recycle through a primary clari-
fier with blowdown of some clarifier effluent
and recycle of some or all sludge to the stock,
chest.
(3) Process water recycle through a primary clari-
fier with blowdown being evaporated and some
evaporator condensate being utilized for make-
up. In the explosion process all fiber wash-
water is discharged through a primary clari-
fier prior to evaporation.
(4) Process water recycle with blowdown passing
through a chemical coagulation, system. Plant
of coagulated waste recycled back to process
and all sludge returned to stock chest.
185
-------
00
1/72 2/72 3/72 4/72 5/72 6/72 7/72 8/72 9/72
1 T
10/72 11/72 12/72
1/73
FIGURE 35 - VARIATION OF EFFLUENT BOD AND SUSPENDED SOLIDS
AS A FUNCTION OF TIME FOR MILL NO. 2
-------
z
o
OO
BOD
1/72 2/72 3/72 4/72 5/72 6/72 7/72 8/72 9/72 10/72 11/72
12/72
FIGURE 36 - VARIATION OF EFFLUENT BOD AND SUSPENDED SOLIDS
AS A FUNCTION OF TIME FOR MILL NO. 3
-------
30-
25 •£, -
00
CO
CD
10-
5-
1/72
2/72
3/72
4/72
5/72
6/72
7/72
8/72
9/72
10/72
11/72
FIGURE 37 -
VARIATION OF EFFLUENT BOD AND SUSPENDED SOLIDS
AS A FUNCTION OF TIME FOR MILL NO. 4
-------
DRAFT
TABLE 44 (28)
EXAMPLE OF AN ASB SYSTEM PERFORMANCE RELATED TO TEMPERATURE
PAPE REGARD*
Average
Monthly
Temperature
(°C)
21
21
19
17
17
11
7
5
5
3
Effluent
BODS
Cmg/1)
11
17
22
17
11
20
40
i
29
38
42
Cone.
SS
Cmg/1)
22
21
23
17
16
29
56
61
31
42
* Includes long-term
settling
189
-------
DRAFT
Wastewater Treatment: End of pipeline treatment technol-
ogy presently consists of:
(1) Screening
(2) Primary clarification
a. settling ponds
b. mechanical clarifiers
(3) pH control
(4) Nutrient addition
(5) Aerated lagoons
(6) Activated sludge process
(7) Oxidation lagoons
Sludge Handling: Systems utilized for disposal of waste
sludge include:
(1) Reuse in manufacture of hardboard
(2) Landfill
(3) Spray irrigation
(4) Incineration
190
-------
DRAFT
PART C: CONTROL AND TREATMENT TECHNOLOGY IN THE WOOD PRESERVING INDUSTRY
STATUS OF TECHNOLOGY IN INDUSTRY
The technological base of the wood preserving industry is generally quite
weak by comparison with most other industrial categories. Relatively few
companies have employees with the engineering and other technical skills
needed to utilize effectively current or potential developments in waste
treatment and management, or to adopt processing methods that would min-
imize waste loads. Engineering services required by individual plants
are most commonly performed by consulting firms. This situation is ameli-
orated somewhat by the American Wood-Preservers' Association through the
activities of its technical committees and publication of its Proceedings,
both of which serve to keep its members advised of current developments.
Membership in the Association represents plants that account for an esti-
mated 90 percent of the total production of the industry.
STATUS OF POLLUTION CONTROL IN INDUSTRY
The comments and data which follow summarize the status of pollution con-
trol activities in the wood preserving industry, as revealed by a recent
survey of 377 plants (1). The data are based on results obtained from
207 plants.
Disposition Of Wastewater
The approach to the pollution problem taken by many treating plants is
to store their wastewater on company property (Table 45). This is by
far the most popular method of handling wastewater, accounting for 42
percent of the plants reporting. Seventeen percent are still releasing
their wastewater with no treatment, while 14 percent of the plants are
discharging to sanitary sewer systems. Of the latter group, 63 percent
are discharging raw waste to sewers, while 37 percent are giving the
waste a partial treatment before releasing it. Only 9 percent of the
207 plants responding to the survey presently are giving their waste the
equivalent of a secondary treatment before releasing it. Eighteen per-
cent either have no wastewater or are disposing of it by special methods
such as evaporation or incineration.
There were no unusual trends when the data on methods of disposal of
wastewater were broken down by region (Table 46). However, it is of in-
terest to note that a high proportion of the plants in the West dispose
of their waste by special methods, or have no waste stream.
Compliance With Standards
Sixty percent of the plants surveyed indicated that they currently meet
state and federal water pollution standards (Table 47). Twenty-five per-
cent stated that they do not meet these standards and 15 percent do not
know whether they do or not. A higher portion of plants in the West
191
-------
DRAFT
TABLE 45 METHOD OF DISPOSAL OF WASTEWATER BY WOOD
PRESERVING PLANTS IN THE UNITED STATES
Disposal Method
Release - No Treatment
Store In Ponds
To Sewer - Untreated
To Sewer - Partial Treatment
Secondary Treatment
Other*
*No wastewater, Incineration,
Number
of
Plants
35
86
19
11
18
38
etc.
Percent
of
Plants
17
42
9
5
9
18
TABLE 46 METHOD OF DISPOSAL OF WOOD PRESERVING
WASTEWATER BY REGION
Region
Southeast
Southwest
Atlantic Coast
Lake and Northeast
Release
Untreated
13
5
9
2
Store
29
20
10
17
Sewer
12
6
4
6
Treat
5
4
4
5
Other
17
5
4
2
and Southwest currently meet standards than In other regions of the
country,, However, the differences among regions are not great, ranging
from 57 percent of the plants In the Atlantic Coast region to 73 percent
in the West.
There was considerable evidence of confusion on the part of some respond-
ents regarding the question of compliance or non-compliance. A number of
plants that are currently releasing their wastewater with no treatment
stated that they meet federal and state standards. Conversely, a number
192
-------
DRAFT
of plants that retain their waste on company property or release it into
sanitary sewer systems stated that they do not meet standards, or do not
know whether they do or not,
TABLE 47 COMPLIANCE WITH STATE AND FEDERAL WATER STANDARDS
AMONG WOOD PRESERVING PLANTS IN THE UNITED STATES
Compliance
Yes
Don't Know
No
Number
of
Plants
126
29*
52
Percent
of
Plants
60
15
25
*Includes Non-Responses
Table 48 gives a breakdown of what the plants that do not now meet the
standards plan to do with their wastewater. Nationally, roughly one-
third of the plants have made no plans. Most of the remainder plan
either to construct on-site treating facilities for their wastewater
(31 percent) or discharge it to sewer systems (19 percent). Twelve of
the 81 plants involved indicated that they would dispose of their waste
by other means. Incineration and evaporation were two of the "other"
methods mentioned.
TABLE 48 PLANS OF WOOD PRESERVING PLANTS NOT IN COMPLIANCE
WITH WATER STANDARDS -- UNITED STATES
Number
Plan of
Plants
None 29
Discharge To Sewer - Raw 5
Discharge to Sewer - Oil Removal 6
Discharge To Sewer - Oil + Phenol Removal 4
Construct On-Site Treating System 25
Other 12
TOTAL 81
193
-------
DRAFT
Over a third of the plants not meeting standards are located in the South-
east. Most of these plants are planning to treat their waste on site or
discharge it to a sewer system. Half of the plants in the West and Lake
and Northeast states indicated that they have made no plans to meet ap-
plicable standards.
Of the plants that have installed or plan to install secondary treating
facilities, 70 percent will use either oxidation ponds or soil percolation
(Table 49). Only 14 plants (about 16 percent) have elected to use trick-
ling filters or activated sludge. The choices of the various methods of
treatment were generally uniform among regions, with no single region
showing a strong preference of one method over another (Table 50).
TABLE 49 TYPE OF SECONDARY WASTEWATER TREATING FACILITIES
INSTALLED OR PLANNED BY WOOD PRESERVING PLANTS IN U.S.
of
Plants
Oxidation Pond 31
Trickling Filter 8
Activated Sludge 6
Soil Percolation 31
Chemical Oxidation 3
Other (incineration) 1_0_
TOTAL 89
PLANT SANITATION
By plant sanitation is meant those aspects of plant housekeeping which re-
duce or eliminate the incidence of water contamination resulting from equip-
ment and plumbing leaks, spillage of preservative, and other similar sources.
Lack of attention to these sources of pollution is a serious problem at many
plants that will require remedial action. Its origin lies in the lack of
appreciation of the fact that even small losses of preservative can largely
negate waste management practices directed toward collecting and treating
process water.
194
-------
DRAFT
TABLE 50 TYPE OF SECONDARY WASTEWATER TREATING FACILITIES INSTALLED
OR PLANNED BY WOOD PRESERVING PLANTS BY REGION
Treatment
Oxidation Pond
Trickling Filter
Activated Sludge
Soil Percolation
Chemical Oxidation
Other
SE
12
3
1
12
1
0
sw
9
3
2
2
0
4
Region
AC
3
0
1
9
1
0
w
2
1
1
2
1
6
L&NE
5
1
1
6
0
0
Preservative Loss From Retorts
Areas under and in the immediate vicinity of retorts are the most import-
ant from the standpoint of plant sanitation. The camber in some retorts
prevents the complete drainage of preservative from the retort upon com-
pletion of a charge. Consequently, when the retort door is opened to re-
move the charge, a quantity of preservative drains into pipe trenches or
sumps under the retort where it becomes contaminated with dirt, storm
water, and other types of preservatives. Most plants process the preserva-
tive through oil separators and thereby recover most of it. The better
managed and equipped plants collect it in troughs as it drains from the
retorts and transfer it to underground storage tanks.
Losses of preservative in the vicinity of the retort are of particular
importance in salt-type treatments because they represent the major source
of pollution. Many such plants are equipped to collect preservative spill-
age and wash water and reuse it as make-up water for fresh treating solu-
tions.
Storm Water
Storm water becomes contaminated as it flows over areas saturated with pre-
servative from spills and leaks. Areas of particular concern are those
around and in the vicinity of treating cylinders, storage tanks, and sepa-
rators. Because these areas are usually not large, it is practical to re-
duce the volume of storm water that must be treated by constructing dikes
and drainage ditches around the areas to prevent uncontaminated water from
flowing across them.
195
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DRAFT
Preservative accumulation in the soil where treated stock is stored.
although unavoidable, is another potential source of contaminated storm
water. Storage yards frequently encompass large areas. Depending upon
their topography, the problem of collecting all storm water from these
yards for treatment may be a formidable one indeed, especially in regions
of heavy rainfall. It is probable that no significant contamination of
water occurs from this source. Thompson (29) analyzed storm water samples
collected at various locations in storage yards of two commercial treat-
ing plants and found insignificant phenol and COD contents.
Equipment Leaks
Preservative losses from pipes and pumps contribute to the pollution prob-
lem at many plants. The early detection of leaks from these sources can
best be accomplished by periodic and systematic checks of all pumps and
plumbing employed in the transfer of preservatives.
TREATMENT AND CONTROL TECHNOLOGY
Wastewater treating facilities have been installed and are in operation
at only about 9 percent of the estimated 390 plants in the United States
(Table 45). Most of these facilities have been in operation for only a
relatively short period of time. It follows that both experience in the
treatment of wastewater from the wood preserving industry and the backlog
of data on such operations is limited. This problem is lessened some-
what by studies and field experience in the treatment of petroleum wastes.
Data from this industry are frequently directly applicable to the wood
preserving industry because of the similarity of the effluents involved,
particularly as regards phenol content, oil content and other parameters.
Likewise, within the past three years laboratory and pilot-plant studies
have supplied useful information on the treatment of effluents from wood
preserving operations. Perusal of these sources, as well as information
obtained from visits to and analyses of effluent samples from wood pre-
serving plants that have effective waste treatment and management programs,
provided the data on which this section is based.
Primary Treatments
Primary treatments for creosote and pentachlorophenol-petroleum waste-
waters usually include flocculation and sedimentation. This process, as
currently practiced at a number of plants, is normally carried out for
one of two purposes: (1) to remove emulsified oils and other oxygen-
demanding substances preparatory to secondary treatment, and (2) to render
wastewaters acceptable to municipal authorities prior to releasing it into
sanitary sewers. A few plants discharging their waste into city sewers
apply primary treatments to reduce sewer charges levied by municipal
authorities, rather than to meet specific influent limitations.
196
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DRAFT
One of the principal benefits of primary treatments of oily wastewater
is the reduction of the oil content of the wastewater to a level compat-
ible with the secondary treating process that is employed. This is par-
ticularly important with those wastewaters containing emulsified oils,
which normally cannot be removed by mechanical means. Flocculation treat-
ments employing a suitable polyelectrolyte are quite effective in breaking
emulsions and precipitating the oil. Reductions in oil content on the
order of 95 percent are not unusual. Where the oil content of wastewater
is not a serious problem, however, flocculation treatments preparatory
to secondary treatment may not be necessary. The decision in this regard
must be based on the relative cost of such treatments and that of provid-
ing sufficient secondary treating capacity to accomodate the additional
COD loading that would normally be removed during primary treatment of
the wastewater.
Primary treatments of wastewaters containing salt-type preservatives and
fire retardants serve to precipitate heavy metals and thus make the waste
amenable to biological treatment. The contractor is not aware of any
plant that is currently applying a secondary treatment to this type of
wastewater.
Wastewaters Containing Entrained Oils - It is the intermingling of the
oils and water from the treating cycle and the condensate from condition-
ing operations that is responsible for most of the pollution problem in
the industry. Oils account for most of the oxygen demand of the waste-
water, serve as carriers for concentrations of pentachlorophenol far in
excess of those attainable in oil-free water, and create emulsion problems.
In a very real sense, control of oils is the key to pollution control in
the wood preserving industry.
Recovery Of Free Oils - Most wood preserving plants have oil-recovery sys-
tems for reclaiming a high percentage of the oil that becomes entrained
in water during treating operations. Apart from environmental consider-
ations, this practice is and always has been done for economic reasons:
it is less expensive to recover and reuse this oil than to buy new oil.
With the passage of the Federal Water Pollution Control Act of 1965 and
subsequent amendments, the contribution of non-recovered oils to the cost
of treating wastewater has become an important consideration. Within the
past five years many plants have added new oil-recovery systems or re-
vamped existing ones.
Free oils are recovered from wastewater by gravity-type separators. Vari-
ous designs are used. The most common ones are patterned after the API
separator developed by the American Petroleum Institute (30). These are
equipped to recover oils both lighter and heavier than water. Basically
they consist of a horizontal tank divided into three or more compartments
by strategically placed baffles which decrease turbulence. Heavy oils
sink to the bottom where they are removed by a pump to a dehydrator, and
197
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thence transferred to storage. Floating oils are removed by a skimmer.
For pentachlorophenol-petroleum solutions, a simple tank or series of
tanks with provisions for drawing off the oil that collects at the top
and the water from the bottom is all that is required (31). Good prac-
tice dictates that separate effluent handling systems be installed for
each preservative. However, many plants are not so equipped.
A few plants have installed air-flotation equipment to effect oil-water
separation. In these units, all oil is brought to the surface of the
water by bubbles created by saturating a portion of the wastewater with
air under pressure and releasing it at the bottom of the flotation cham-
ber. The oil is removed at the surface by a skimming device. Mechani-
cal oil scavengers are also sometimes used to remove surface oils.
The percentage of entrained oils removed by oil-water separation equip-
ment varies widely, depending in part upon whether or not the oil is in
a free or emulsified form. Data on the percent efficiencies of several
oil-separation processes, including the API separator, are given in
Table 51. These data are based upon the treatment of petroleum refinery
wastewater, but are probably applicable to other oily wastes. Separator
efficiency is of course a function of detention time. The effect of
this variable on oil removal is shown in Figure 38.
TABLE 51 EFFICIENCIES OF OIL SEPARATION PROCESSES (32)
Source OfPercent Removal
Influent Free Oils Emulsified Oils
API Separator Raw Waste 60 - 99 Not applicable
Air Flotation without
Chemicals
Air Flotation with
Chemicals
Chemical Coagulation and
Sedimentation
API
Effluent
API
Effluent
API
Effluent
70 -
75 -
60 -
95
95
95
10 -
50 -
50 -
40
90
90
Only free oils are removed in conventional oil-water separators. However,
emulsions are broken by rotary vacuum filters and by centrifugation, both
of which have been tested on wood preserving wastewater at a few plants in
the South. Wastewaters containing emulsified oils frequently have oil con-
tents in excess of 1000 mg/liter after passing through gravity-type separa-
tors (24). Oils in this form normally must be removed by primary treat-
ments involving flocculation.
198
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AVERAGE TEMPERATURE- 38°C
INITIAL OIL CONCENTRATION -45P.P.M. ±4 P. P.M.
0 40 80 120 160 200
SEPARATION TIME IN MINUTES
FIGURE 38 C33) -
EFFECT OF DETENTION TIME ON OIL
REMOVAL BY GRAVITY SEPARATION
199
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DRAFT
The formation of oil-water emulsions is a particular problem where con-
ventional steam conditioning is used and apparently results from agita-
tion of retort condensate as it is expelled from the retort through a
steam trap. Thompson (34) analyzed condensate samples collected alter-
nately from a hole drilled near the bottom of a retort and from a pipe
leading from the trap and found that only those samples that had passed
through the trap contained emulsified oils. Some plants treating with
pentachlorophenol-petroleum solutions have greatly reduced the problems
of emulsion by replacing high-speed pumps involved in preservative trans-
fer with low-speed, high-volume models.
Breaking Of Oil-Water Emulsions - Emulsions may be broken chemically,
physically, or electrically. Chemical methods involving flocculation
and sedimentation are the most widely used, generally are the least ex-
pensive, and are effective with effluents from wood preserving plants.
For these reasons, the remarks which follow are confined to processes
which are based on the use of chemicals.
Chemicals that have been used to break oil-water emulsions, either in
the laboratory or field, include metallic hydroxides, principally lime,
ferric chloride and other salts of iron, alum, bentonite clay, and vari-
ous types of polyelectrolytes. The same material or combination of ma-
terials does not work equally well with with wastewaters from all plants
(Table 30, Section V). Jones and Frank (35) achieved COD and BOD reduc-
tions of 83 and 73 percent, respectively, in creosote wastewater by using
a single cationic polymer at a rate of 40 mg/liter. Similar results were
observed by Thompson at a Chicago-based plant treating with both creosote
and pentachlorophenol that flocculated its waste prior to routing it to a
sanitary sewer.
Oil reductions in refinery wastewater of more than 95 percent were ob-
tained by Simonsen (36) who used both anionic and cationic polyelectro-
lytes in combination with bentonite clay. There was no difference be-
tween the two types of polymers in the results obtained. However, only
cationic polyelectrolytes broke oil-water emulsions from wood preserving
plants in work reported by Jones and Frank (35). Aluminum chloride, alum,
activated-silica, clay and lime were employed by Weston and Merman (37)
with refinery wastes. Reductions in BOD, COD, and oil content on the
order of 50 percent were reported.
Ferric chloride was found by Thompson and Dust (23) to be an effective
flocculating agent for both creosote and pentachlorophenol wastewaters.
However, floe formation occurred only within very narrow pH limits. This
feature would pose serious problems in field applications of this chemical.
Much of the research work on flocculating wood preserving wastewaters has
involved the use of lime either singly or in combination with a polyelectro-
lyte. Thompson and Dust (23) reported that the optimum dosage of lime, as
judged from COD reductions, varied from 0.75 to 2.0 g/liter, depending upon
200
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DRAFT
wastewater characteristics. Percent reduction in this parameter increased
with increasing dosage up to a maximum, and then was unaffected by further
lime additions (Table 52). Phenol content, exclusive of pentachlorophenol,
was not decreased by flocculation of the wastewater. However, pentachloro-
phenol was regularly reduced to a concentration of about 15 mg/liter in
wastewaters containing this chemical. It was surmised from this result
that pentachlorophenol, unlike other phenolic compounds, is primarily as-
sociated with the oil phase in oil-water emulsions and is precipitated
with the oils when the emulsion is broken. The residual concentration of
pentachlorophenol remaining in the filtrate was reported by Thompson and
Dust (23) to correspond approximately to the solubility of this chemical
in water. Typical data showing the reduction of pentachlorophenol result-
ing from lime additions to a wastewater are shown below:
Lime Dosage Residual PCP
(gm/liter) Concentration (mg/liter)
0 150
1.0 45
1.5 25
2.0 17
Middlebrook (38) also used lime, in dosages of 2 g/liter, to obtain re-
ductions in COD of up to 70 percent in a creosote wastewater. Similar
results were achieved with alum. Both chemicals were used successfully
by Gaskin (39) to treat creosote and vapor-drying wastewater previously
de-emulsified with sulfuric acid. Lime and caustic soda were reported
by van Frank and Eck (40) to be effective in flocculating oily wastewater
after polyelectrolytes alone failed to produce a floe.
Among numerous polyelectrolytes tested by Thompson and Dust (23) rela-
tively few were found that were effective with wood preserving wastewater
in the absence of lime. The primary contributions that many of the test
materials made to the flocculation process were the agglomeration of
minute floe particles, which promoted rapid settling, and reduction in
sludge volume. Only a few of them were effective in initiating floe forma-
tion in samples of wastewater from 20 plants, and none increased COD re-
moval beyond that obtained with lime alone. The few that were effective
in initiating floe formation in the absence of lime are relatively new
products currently marketed by a large chemical company. Reductions in
COD for individual polyelectrolytes in this group ranged from 50 to 74
percent and averaged 62 percent (24). Several wood preserving plants
currently use them in primary treatments of their wastewater. Lime in
combination with polyelectrolytes is used by other plants.
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TABLE 52 EFFECT OF LIME FLOCCULATION ON COD AND PHENOL
CONTENT OF TREATING-PLANT EFFLUENT
COD
Lime
(gm/1)
0.0
0.25
0.50
0,75
1.00
1.25
1.50
PH
5.3
6.8
7.9
9.7
10.5
11.4
11.8
Cone.
(mg/1 )
1 1 ,800
9,700
7,060
5,230
5,270
5,210
5,210
Percent
Removal
—
23
39
56
55
56
56
Phenol
(mg/1)
83
81
72
78
80
84
83
Vacuum and pressure filtration has also been used to break oil-water emul-
sions, permitting the recovery of the oil (41). Halff (42), in commenting
on work with vacuum filtration through diatomaceous earth, reported that
a precoated rotary vacuum filter efficiently broke oil-water emulsions
from wood preserving operations. The same author tested sand filtration
of composited wastewater from several wood preserving plants and concluded
that the method was not practical, although a 99 percent reduction in tur-
bidity was achieved by the process.
Methods of breaking oil-water emulsions in the petro-chemical industry
have been reviewed by Halladay and Crosby (43). The theory of floccula-
tion has been covered by Powell (121).
Sludge Dewatering - The availability of effective polyelectrolytes for
flocculation treatments lessens considerably the problem of sludge handling
and disposal. Using lime alone, a volume of sludge equal to 30 percent of
the wastewater is produced by flocculation. This value is reduced to about
7 percent when lime is used in combination with a suitable polyelectrolyte,
and is reduced still further when one of the newer polyelectrolytes is used
alone.
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DRAFT
Sludge drying beds similar to those employed with domestic sewage have
been used successfully to dewater sludge resulting from primary treat-
ments of wood preserving wastewater (39). Recent tests conducted by
Oust (44) have shown that the dewataring characteristics of beds of this
type are unaffected by adding a total of 41 centimeters (16 inches) of
sludge from creosote wastewater to them in two applications during a
24-hour period. Upon drying, the sludge can be easily removed from the
beds using a garden rake. Drying beds are currently in use at a number
of plants in the southern states.
Sludge dewatering can also be accomplished mechanically with equipment
currently available (45). Results of tests of the effectiveness of one
machine in processing sludge from creosote wastewater were promising (44).
The sludge was dewatered to a solids content of 25 percent.
Wastewaters Containing Heavy Metals - Because heavy metals contained in
wastewater from plants that treat with salt-type preservatives and fire
retardants are toxic to microorganisms in low concentrations (46), they
must be removed before subjecting the wastewater to secondary treatments
involving biological oxidation. Unlike primary treatments of oily waste-
waters in which recovery of oil is primarily a physical problem, the re-
moval of preservative salts from solution is a chemical problem and is
related to the properties of the specific ions present. A listing of
the principal water-soluble preservatives and fire retardants currently
marketed in the United States, and the toxic constituents in each, is given
in Table 53.
The procedure used to precipitate heavy metals from wood preserving ef-
fluents was adopted from the electroplating industry. Dodge and Reams (47)
compiled a bibliography of over 700 references dealing with the processing
and disposal of waste from this industry, and it has been estimated that
50 additional articles on the subject have been published annually since
this bibliography first appeared (48). A detailed treatment of the sub-
ject has been prepared by Bliss (49). The basic procedure followed, while
modified somewhat, depending upon the specific preservative salts involved,
is described below.
With the exception of boron, hexavalent chromium is the only ion shown in
Table 53 which will not precipitate from solution when the pH of the waste-
water is raised to 7 or 8 with lime. Since trivalent chromium will pre-
cipitate from neutral or slightly alkaline solutions, the first step in
treating wastewaters containing this metal is to reduce it from the
hexavalent to the trivalent form. The use of sulfur dioxide for this
purpose has been reported on in detail by Chamber!in and Day (28). Chrom-
ium reduction proceeds most rapidly in acid solution. Therefore, the
wastewater is acidified with sulfuric acid to a pH of 4 or less before
introducing the sulfur dioxide. The latter chemical will itself lower the
pH to the desired level, but it is less expensive to use the acid.
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DRAFT
TABLE 53 TOXIC CONSTITUENTS IN THE PRINCIPAL SALT-TYPE PRESERVATIVES
AND FIRE RETARDANT CHEMICALS USED IN THE UNITED STATES
Dinitro
Cu Zn Cr B As F phenol
Fluor-Chrome Arsenate Phenol X XX X
Chromated Zinc Chloride X X
Copper!zed Chromated Zinc
Chloride XXX
Chromated Copper Arsenate XXX
Chromated Zinc Arsenate XX X
Acid Copper Chromate X X
Ammoniacal Copper Arsenite X X
Fire Retardant
Type A XX
Type B XXX
Type D XXX
When the chromium has been reduced, the pH of the wastewater is increased
to 8.5 or 9.0 to precipitate not only the trivalent chromium, but also the
copper and zinc. If lime is used for the pH adjustment, fluorides and
most of the arsenic will also be precipitated. Care must be taken not to
raise the pH beyond 9.5, since trivalent chromium is slightly soluble at
higher values. Additional arsenic and most of any residual copper and
chromium in solution can be precipitated by treating the waste with hydro-
gen sulfide gas, or by adding sodium sulfide. Ammonium and phosphate com-
pounds are also reduced by this process.
This procedure is based on the well-known fact that most heavy metals are
precipitated as relatively insoluble metal hydroxides at alkaline pH. The
theoretical solubilities of some of the hydroxides are quite low, ranging
down to less than 0.01 mg/liter. However, theoretical levels are seldom
achieved because of unfavorable settling properties of the precipitates,
204
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DRAFT
slow reaction rates, interference of other ions in solution, and other
factors. Among the ions shown in Table 53, copper and zinc (51 and 52),
and chromium (53 and 54) can be reduced to levels substantially lower
than loO mg/liter by the above procedure,, Fluorides have a theoretical
solubility at pH's of 8,5 to 9.0 of 8.5 mg/liter, but residual concen-
trations on the order of 10 to 20 mg/liter are more usual because of slow
settling of calcium fluoride. The use of additional lime, alum coagula-
tion (56) and filtration through bone char (57) are reported to reduce
fluoride concentrations to 1.0 mg/liter or less.
The most difficult ion to reduce to acceptable concentration levels is
arsenic. Treatment of water containing arsenic with lime generally re-
moves only about 85 percent of the metal (58). Removal rates in the
range of 94 to 98 percent have been reported for filtration through fer-
ric sulfide beds (59), coagulation with ferric chloride (60), and pre-
cipitation with ferric hydroxide (61). However, none of these methods
are entirely satisfactory, particularly for arsenic concentrations above
20 mg/liter.
Literature on treatment processes for removing boron from wastewaters
is not available.
The sludge resulting from the precipitation process contains the heavy
metals formerly in solution, along with the excess lime. It may also
contain various organic materials of wood origin that are flocculated
and precipitated with the lime. The sludge can be filtered to reduce
its volume and disposed of in a suitable manner. The supernatant may
be routed to a holding basin, as is currently being done by several
plants, given a secondary treatment, or released, depending upon its
oxygen demand and content of residual metals. Work is in progress to
determine if the sludge can be acidified and reused in the treating
solution (62).
Representative data on the laboratory treatment of wastewater containing
CCA-type salt preservatives and a proprietary fire-retardant formulation
composed mainly of ammonium and phosphate compounds are given in Table 54.
Data for both concentrated solutions and diluted wastewater from a hold-
ing pond are given. Average results of treatments conducted daily over
a period of a year on effluent from a plant are given in Table 55. The
latter data were obtained by analyzing effluent from equipment designed
by Russell (63) to process wastewater automatically.
Wastewaters from salt-type treatments frequently are heavily diluted
and, consequently, may contain very low metal concentrations. The im-
portance of subjecting the waste to a primary treatment to remove the
metals, even when present in only trace quantities, was alluded to
earlier. Numerous studies have shown that copper, chromium, zinc, and
arsenic have a toxic effect on biological waste treatment systems (64,
65, 66). Results of these studies were recently reviewed by Jones (46).
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DRAFT
TABLE 54 CONCENTRATIONS OF POLLUTANTS BEFORE AND AFTER LABORATORY
TREATMENT OF WASTEWATER FROM TWO SOURCES (62)
COD
As
Phenols
Cu
Cr+6
Cr+3
F
P04
NH3-N
Cone.
Influent
1700
300
Nil
170
375
0
590
640
1260
Solution
Effluent
400.
15
Nil
25
0
0
80
90
95
Dilute
Influent
112
20.8
0.03
0.35
0.52
0
19
80
80
Pond Waste
Effluent
20
1.0
Nil
0.25
0
0
9.5
25
Nil
NOTE: Values expressed as mg/1.
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DRAFT
TABLE 55 CONCENTRATION OF POLLUTANTS IN PLANT WASTEWATER CONTAINING
SALT-TYPE PRESERVATIVES AND FIRE RETARDANTS
BEFORE AND AFTER FIELD TREATMENT (62)
COD
As
Phenols
Cu
Cr+6
Cr+3
F
P04
NH3-N
Influent
10 -
13 -
0.050 -
0.05 -
0.23 -
0.0 -
4 -
15 -
80 -
Values expressed
Ranges
50
50
0.160
1.1
1.5
0.8
20
150
200
as mg/ liter
Effluent Averages
25
8.9
0.048
0.35
0.1
0.02
5.8
15
75
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DRAFT
Ion exchange resins of the sulfonated-polystyrene and quaternaryamine
types have been employed on a commercial scale for purification and re-
covery of metals used in the electroplating industry (67,68,69). The
technology involved in ion exchange has application to the wood preserv-
ing industry, but the economics of the process in the purification of
preservative wastewaters containing metal contaminants are unknown. It
has been suggested that inert sulfate and sodium ions and organic ma-
terials in these wastewaters would lower the metal-removing capacity of
the exchangers sufficiently to make the process impractical under most
circumstances (70).
Plant experience in treating wastewater from salt-type treatments is
limited. This situation arises from the fact that steam conditioning
of stock prior to preservative injection is not widely practiced among
plants that use preservative and fire-retardant salts. Consequently,
only a small volume of wastewater is generated. The better managed
plants use the wastewater that is available as make-up water in prepar-
ing fresh batches of treating solution.
Secondary Treatments
Biological treatments, chemical oxidation, activated-carbon adsorption
and various combinations of these basic methods of wastewater treatment
have been used commercially, proposed for such use, or tested in labora-
tory and pilot-plant investigations of wood preserving effluents. Each
of these methods is discussed below in terms'of: (a) characteristics
relating to sensitivity to shock loadings, availability of equipment,
and maintenance requirements; (b) efficiency with phenolic-type wastes,
as revealed by the literature; and (c) effluent characteristics of wood
preserving waste resulting from treatment. Because of the limited num-
ber of wood preserving plants that are currently providing secondary
treatment for their waste, data for item (c) is, in some instances, based
on grab samples collected in connection with this study, or on results
of pilot-plant investigations.
Biological Treatments - Where a substantial volume of waste with a high
organic load is involved, cost considerations usually dictate that bio-
logical oxidation be used as the major component in the waste treatment
program. Polishing treatments involving chlorination, and possibly
activated-carbon filtration, may or may not be required, depending upon
the design of the biological system and the waste loads involved. Each
of the several biological waste-treating systems that have present or
potential application in the wood preserving industry is covered in this
section.
Characteristics - According to Besselieure (84), trickling filters are
not unduly susceptible to disruption by shock loads and recover quickly
if disruption occurs. Their operation does not require constant atten-
tion, and, when equipped with plastic media, they are capable of handling
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DRAFT
high loading rates. The latter feature minimizes the land area required.
For package units sized for the relatively small volume of discharge at
the average wood preserving plant, an area of 186 m2 (2,000 ft2) should
be adequate for the tower (approximately 6 meters (20 feet) in diameter)
and associated equipment, including settling tank.
Processing Efficiency For Phenolic Wastes - The literature contains many
references concerning wastewater treatment using trickling filters in
the petroleum and by-product coal industries. Most of the references
report on efforts to reduce phenol concentrations to acceptable levels.
Sweets, Hamdy and Weiser (71) studied the bacteria responsible for phenol
reductions in industrial waste and reported good phenol removal from syn-
thesized waste containing concentrations of 400 mg/liter. Reductions of
23 to 28 percent were achieved in a single pass of the wastewater through
a pilot trickling filter having a filter bed only 30 centimeters (12 in.)
deep.
Waters containing phenol concentrations of up to 7500 mg/liter were suc-
cessfully treated in laboratory tests conducted by Reid and Libby (72).
Phenol removals of 80 to 90 percent were obtained for concentrations on
the order of 400 mg/liter. Their work confirmed that of Ross and Shep-
pard (73) who found that strains of bacteria isolated from a trickling
filter could survive phenol concentrations of 1600 mg/liter and were
able to oxidize phenols in concentrations of 450 mg/liter at better than
99 percent efficiency. Reid, Wortman, and Walker (74) found that many
pure cultures of bacteria were able to live in phenol concentrations of
up to 200 mg/liter, but few survived concentrations above 900 mg/liter,
although some were grown in concentrations as high as 3700 mg/liter.
Harlow, Shannon, and Sercu (75) described the operation of a commercial-
size trickling filter containing "Dowpac" filter medium that was used to
process wastewater containing 25 mg/liter phenol and 450 to 1,900 mg/liter
BOD. Reductions of 96 percent for phenols and 97 percent for BOD were ob-
tained in this unit. Their results compare favorably with those reported
by Montes, Allen, and Schowell (76), and Dickerson and Laffey (77). The
former authors obtained BOD reductions of 90 percent in a trickling fil-
ter using a 1:2 recycle ratio. Dickerson and Laffey obtained phenol and
BOD reductions of 99.9 and 96.5 percent, respectively, in a trickling
filter used to process refinery wastewater.
A combination biological waste-treatment system employing a trickling
filter and an oxidation pond was reported on by Davies, Biehl, and Smith
(78). The filter, which was packed with a plastic medium, was used for
a roughing treatment of 10.6 million liters (2.8 million gallons) of
wastewater per day, with final treatment occurring in the oxidation pond.
Removal rates of 95 percent for phenols and 60 percent for BOD were ob-
tained in the filter, notwithstanding the fact that the pH of the influ-
ent averaged 9.5.
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DRAFT
Biological treatment of refinery wastewaters was studied by Austin,
Meehan, and Stockham (79) using a series of four trickling filters.
Each filter was operated at a different recycle ratio,, The waste con-
tained 22 to 125 mg/llter of oil. BOD removal was adversely affected
by the oil, the lowest removal rates corresponding to the periods when
the oil content of the influent was highest. Phenol removal was unaf-
fected by oil concentrations within the range studied.
Prather and Gaudy (80) found that significant reductions in COD, BOD,
and phenol content of refinery wastewater were achieved by simple aera-
tion treatments„ They concluded that this phenomenon accounted for the
high allowable loading rates for biological treatments such as trickling
filtration*
Treatment of Wood Preserving Effluents - The practicality of using the
trickling filters for secondary treatment of wastewaters from the wood
preserving industry was explored by Dust and Thompson (25). A pilot
unit containing a 6,4 meter (21 feet) filter bed of plastic media was
used in their study. Creosote wastewater was applied at BOD loading
rates of from 400 to 3050 kilograms/1000 m3 per day (25 to 190 pounds/
1000 ft3 per day). The corresponding phenol loadings were 1.6 to 54.6
kilograms/1000 m3 per day (0.1 to 3.4 pounds/1000 ft3 per day). Raw
feed-to-recycle ratios varied from 1:7 to 1:28. The pilot unit was
operated and daily samples collected and analyzed over a period of seven
months that included both winter and summer operating conditions.
Because of wastewater characteristics at the particular plant coopera-
ting in the study, the following pretreatment steps were necessary:
(a) equalization of wastes; (b) primary treatment by coagulation for
partial solids removal; (c) dilution of the wastewater to obtain BOD
loading rates commensurate with the ra'.ige of raw flow levels provided
by the equipment; and (d) addition to the raw feed of supplementary
nitrogen and phosphorus. Dilution ratios of 0 to 14 were used.
The efficiency of the system was essentially stable for BOD loadings of
less than 1200 kilograms/1000 m3 per day (75 pounds/1000 ft3 per day).
The best removal rate was achieved when the hydraulic application rate
was 2.85 lpm/m2 (0.07 gpm/ft2) of raw waste and 40.7 Ipm/m2 (1.0 gpm/ft2)
of recycled waste. The COD, BOD, and phenol removals obtained under these
conditions are given in Table 56. Table 57 shows the relationship between
BOD loading rate and removal efficiency, BOD removal efficiency at load-
ing rates of 1060 kilograms/1000 m3 per day (66 pounds/1000 ft3 per day)
was on the order of 92 percent, and was not improved at reduced loadings.
Comparable values for phenols at loading rates of 19.3 kilograms/1000 m3
per day (1.2 pounds/1000 ft3 per day) were about 97 percent.
Phenol content was more readily reduced to levels compatible with exist-
ing standards than was BOD content. Consequently, the sizing of commer-
cial units from data collected from the pilot unit was based on BOD removal
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DRAFT
TABLE 56 BOD, COD, AND PHENOL LOADING AND REMOVAL RATES FOR
PILOT TRICKLING FILTER PROCESSING A CREOSOTE WASTEWATER (81)
Characteristic
Raw Flow Rate (gpm/ft2)
Recycle Flow Rate (gpm/ft2)
Influent Concentration (mg/1)
Loading Rate (Ib/M ft3/day)
Effluent Concentration (mg/1)
Removal (%)
BOD
0,07
1.0
1698
66.3
137
91.9
COD
0.07
1.0
3105
121.3
709
77.0
Phenol
0.07
1.0
31
1.2
<1.0
99+
rates. Various combinations of filter-bed depths, tower diameters, and
volumes of filter media that were calculated to provide a BOD removal
rate of 90 percent for influent having a BOD of 1500 mg/liter are shown
in Table 58 for a plant with a flow rate of 75,700 Ipd (20,000 gpd).
Activated Sludge and Aerated Lagoon - Characteristics - Activated Sludge
treatments which employ the complete-mix alternative to the conventional
process are very resistant to disruptions caused by shock loads, offer
low operation and maintenance costs, low initial cost, and have small
land requirements. Package units designed to treat the wastewater from
an average wood preserving plant could be located on an area of approxi-
mately 93 m2 (1000 ft2). Additional space would be required for a pre-
treatment equalization reservoir and, where required, flocculation tanks.
A system designed by Environmental Engineering, Inc. of Gainesville,
Florida for installation at Koppers Company's Carbondale, Illinois plant
will occupy an area of approximately 140 m* (1500 ft2), including equip-
ment for pre- and post-treatment chlorination.
An aerated lagoon is a special type of complete-mix, activated sludge
system, without sludge recycle. It normally is operated in conjunction
with a polishing pond into which waste from the lagoon is discharged.
Both the lagoon and polishing pond are usually constructed with earthen
embankments, a feature which reduced the cost of the system compared with
the activated sludge process. This method of treatment has essentially
the same advantages as the conventional complete-mix, activated sludge
system, but does require more land area.
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DRAFT
TABLE 57 RELATIONSHIP BETWEEN BOD LOADING AND TREATABILITY
FOR PILOT TRICKLING FILTER PROCESSING A CREOSOTE WASTEWATER (81)
BOD
Loading
(Ib/ft3/day)
23
26
37
53
66
76
85
115
156
Removal
(*)
91
95
92
93
92
82
80
75
62
Treatability*
Factor
0.0301
0.0383
0.0458
0.0347
0.0312
0.0339
0.0286
0.0182
0.0130
*Based on the equation:
L£= eKD/0.0-5 (Germain, 1966)
Lo
in which Le = BOD concentration of settled effluent, Lo =
BOD of feed, Q = hydraulic application rate of raw waste
in gpm/ft2, D = depth of media in feet, and K = treatability
factor (rate coefficient).
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DRAFT
TABLE 58 SIZING OF TRICKLING FILTER FOR A WOOD PRESERVING PLANT (81)
(NOTE: Data are based on a flow rate of 20,000 gallons per
day, with filter influent BOD of 1500 and effluent
BOD of 150.)
Depth of
filter
bed
(ft)
10.7
12.5
14.3
16.1
17.9
19.6
21.4
Raw flow
(gpm/ft2
filter
surface)
0.019
0.026
0.034
0.044
0.054
0.065
0.078
Recycle flow
(gpm/ft2
filter
surface)
0.73
0,72
0.71
0.70
0.69
0.68
0.67
Filter
Surface
area
(ft2)
708
520
398
315
255
210
177
Tower
dia.
(ft)
30.0
25.7
22.5
20.0
18.0
16.3
15.0
Vol ume
of
media
(ft3)
7617
6529
5724
5079
4572
4156
3810
Processing Efficiency for Phenol'c Wastes - Treatment of municipal and
mixes of municipal and industrial wastes by the activated sludge process
is common practice (82, 83, 84). In recent years the process has also
been adapted to industrial wastes similar in composition to that of ef-
fluents from wood preserving plants. Pruessner and Mancini (85) obtained
a 99 percent oxidation efficiency for BOD in petrochemical wastes. Simi-
larly, Coe (86) reported reductions of both BOD and phenols of 95 percent
from petroleum wastes in bench-scale tests of the activated sludge process.
Optimum BOD loads of 2247 kilograms/1000 m3 per day (140 pounds/1000 ft3
per day) were obtained in his work. Coke plant effluents were success-
fully treated by Ludberg and Nicks (87), although they experienced some
difficulty in start-up of the activated sludge system because of the high
phenol content of the water.
The complete mixed, activated sludge process was employed to process a
high-phenolic wastewater from a coal-tar distilling plant in Ontario.
Initial phenol and COD concentrations of 500 and 6,000 mg/liter, respec-
tively, were reduced in excess of 99 percent for phenols and 90 percent
for COD (88).
213
-------
DRAFT
Cooke and Graham (89) employed the complete-mixed, activated sludge sys-
tem to treat waste containing phenols, organic acids, thiocyanates, and
ammonia using detention times of 8 to 50 hours. At feed rates of 144 to
1605 kilograms/1000m3 per day (9 to 100 lb/1000 ft3 per day), phenol con-
tent was reduced from 281 mg/liter to 62 mg/liter, for a removal rate of
78 percent.
The employment of aerated reaction units on a continuous flow basis was
used by Badger and Jackman (90) to treat coke gasification plant waste.
They found that a two-day detention period was sufficient to remove 90
percent of the phenol from a waste stream containing up to 5,000 mg/liter
of the chemical.
Nakashio (91) successfully treated coal gas washing liquor containing
1,200 mg/liter of phenols in a study that lasted more than a year. Phenol
concentration was reduced by more than 99 percent. Similar phenol removal
rates were obtained by Reid and Janson (92) in treating wastewater con-
taining cresols by the activated sludge process.
In a report of pilot and full-scale studies performed by Bethlehem Steel
Corporation (93), phenol removal efficiencies greater than 99.8 percent
were obtained using the complete-mixed, activated sludge process. Load-
ing rates of 0.86 kilograms phenol/kilogram (0.86 Ib phenol/lb) MLSS/day
were used successfully. Phenol influent concentrations of 3,500 mg/liter
were reduced to 0.2 mg/liter in the effluent.
Treatment of Wood Preserving Effluents - Dust and Thompson (25) conducted
bench-scale tests of complete-mixed, activated sludge treatments of creo-
sote and pentachlorophenol wastewaters using 5-liter units and detention
times of 5, 10, 15, and 20 days. The operational data collected at steady-
state conditions of substrate removal for the creosote waste are shown in
Table 59. A plot of these data showed that the treatability factor, K =
0.30 days-1 (Figure 39). The resulting design equation, with t expressed
in days, is:
Lo
Le =
1 + 0.30t
A plot of percent COD removal versus detention time in the aerator, based
on the above equation, is shown in Figure 40. This figure shows that an
oxidation efficiency of about 90 percent can be expected with a detention
time of 20 days in units of this type.
Work done with pentachlorophenol waste was conducted to determine the de-
gree of biodegradability of this chemical. Cultures of bacteria prepared
from soil removed from a drainage ditch containing pentachlorophenol waste
were used to inoculate the treatment units. Feed to the units contained
10 mg/liter of pentachlorophenol and 2,400 mg/liter COD. For the two 5-
liter units (A and B) the feed was 500 and 1000 ml/day and detention times
were, in order, 10 and 5 days.
214
-------
K>
h-1
un
CO
co
Q
O
O
- 4
c
0)
uj 3
OO
O
O 2
Slope =K=0.30 day
-1
Le =
Lo
l+0.30t
5 10
Aeration Time (Days)
15
20
FIGURE 39 (25) - DETERMINATION OF REACTION RATE CONSTANT
FOR A CREOSOTE WASTEWATER
-------
N)
o
o
x 90
80
n
| 70
U
S 50
i_
o>
Q.
40
Le =
Lo
1+0.301
10
Aeration Time (Days)
15
20
FIGURE 40 (25) - COD REMOVAL FROM A CREOSOTE WASTEWATER BY
AERATED LAGOON WITHOUT SLUDGE RETURN
-------
DRAFT
TABLE 59 SUBSTRATE REMOVAL AT STEADY-STATE CONDITIONS IN ACTIVATED
SLUDGE UNITS CONTAINING CREOSOTE WASTEWATER
Aeration Time, Days 5.0 10.0 14.7 20.1
COD Raw, mg/1
COD Effluent, mg/1
% COD Removal
COD Raw/COD Effluent
447
178
60.1
2.5
447
103
76.9
4.3
442
79
82.2
5.6
444
67
84.8
6.6
Removal rates for pentachlorophenol and COD are given in Table 60. For
the first 20 days Unit A removed only 35 percent of the pentachlorophenol
added to the unit. However, removal increased dramatically after this
period and averaged 94 percent during the remaining ten days of the study.
Unit B consistently removed over 90 percent of the pentachlorophenol added.
Beginning on the 46th day and continuing through the 51st day, pentachloro-
phenol loading was increased at two-day intervals to a maximum of about
40 mg/liter. Removal rates for the three two-day periods of increased
loadings were 94, 97, and 99 percent.
COD removal for the two units averaged about 90 percent over the duration
of the study.
Also working with the activated sludge process, Kirsh and Etzel (94) ob-
tained removal rates for pentachlorophenol in excess of 97 percent using
an 8-hour detention time and a feed concentration of 150 mg/liter. The
pentachlorophenol was supplied to the system in a mixture that included
100 mg/liter phenol. Essentially complete decomposition of the phenol
was obtained, along with a 92 percent reduction in COD.
Soil Irrigation - Characteristics - The principal feature of the soil
irrigation method of wastewater treatment is its simplicity. Water that
has been freed of surface oils and, depending upon the presence of emulsi-
fied oils, treated with flocculated chemicals and filtered through a sand
bed is simply sprayed onto a prepared field. Soil microorganisms decom-
pose the organic matter in the water in much the same fashion as occurs
in more conventional waste treatment systems.
In addition to its simplicity, soil irrigation has the advantage of low
capital investment, exclusive of land costs, low operating and maintenance
costs, requires a minimum of mechanical equipment, and produces a high-
quality effluent in terms of color, as well as oxygen demand and other
217
-------
DRAFT
TABLE 60 REDUCTION IN PENTACHLOROPHENOL AND COD IN
WASTEWATER TREATED IN ACTIVATED SLUDGE UNITS
RAW EFFLUENT FROM UNIT
WASTE (% Removal)
DAYS (mg/1) "A" "B"
COD
1-5
6-10
11-15
16-20
21-25
26-30
31-35
2350
2181
2735
2361
2288
2490
2407
78
79
76
82
90
—
83
78
79
75
68
86
84
80
PENTACHLOROPHENOL
1-5 7.9 20 77
6-10 10.2 55 95
11-15 7.4 33 94
16-20 6.6 30 79
21-25 7.0 - 87
26-30 12.5 94 94
31-35 5.8 94 91
36-40 10.3 91
41-45 10.0 96
46-47 20.0 95
48-49 30.0 97
50-51 40.0 99
pertinent parameters. Its chief disadvantage is that its use requires a
minimum area of approximately one hectare per 33,000 liters/day (3500 gal/
acre/day) of discharge. This requirement makes the method impractical in
locations where space is at a premium. However, it is not a major problem
for the many plants in rural areas where land is relatively inexpensive-
Processing Efficiency For Phenolic Wastes - Effluents'from a number of
different types of industries have been successfully disposed of by soil
irrigation. Besselieure (84) listed 20 types of industrial wastes that
218
-------
DRAFT
have been treated by this method. Among these were several wastes high
in phenol content. Removal efficiencies as high as 99.5 percent for
both BOD and phenols were reported.
Fisher (95) reported on the use of soil irrigation to treat wastewaters
from a chemical plant that had the following characteristics:
pH '% to 10
Color 5,000 to 42,000 units
COD 1,600 to 5,000 mg/liter
BOD 800 to 2,000 mg/liter
Operating data from a 0.81 hectare (2 acre) field, when irrigated at a
rate of 7570 liters (2,000 gal) per acre/day for a year, showed color
removal of 88 to 99 percent and COD removal of 85 to 99 percent.
The same author reported on the use of this method to treat effluent
from two tar plants that contained 7,000 to 15,000 mg/liter phenol and
20,000 to 54,000 mg/liter COD. The waste was applied to the field at
a rate of about 9460 liters (2500 gal) per acre/day. Water leaving the
area had COD and phenol concentrations of 60 and 1 mg/liter, respective-
ly. Based on the lower influent concentration for each parameter, these
values represent oxidation efficiencies of well over 99 percent for both
phenol and COD.
Bench-scale treatment of coke plant effluent by soil irrigation was also
studied by Fisher (95). Wastes containing BOD and phenol concentrations
of 5,000 and 1,550 mg/liter, respectively, were reduced by 95+ and 99+
percent when percolated through 0.9 meters (36 inches) of soil. Fisher
pointed out that less efficient removal was achieved with coke-plant ef-
fluents using the activated sludge process, even when the waste was di-
luted with high-quality water prior to treatment. The effluent from the
units had a color rating of 1,000 to 3,000 units, compared to 150 units
for water that had been treated by soil irrigation.
Treatment of Wood Preserving Effluents - Both laboratory and pilot scale
field tests of soil-irrigation treatments of wood preserving wastewater
were conducted by Dust and Thompson (25). In the laboratory tests, 210-
liter (55 gallon) drums containing a heavy clay soil 60-centimeters (24
inches) deep were loaded at rates of 32,800, 49,260, and 82,000 liters/
hectare/day (3,500, 5,250, and 8,750 gallons/acre/day). Influent COD
and phenol concentrations were 11,500 and 150 mg/liter, respectively.
Sufficient nitrogen and phosphorus were added to the waste to provide a
COD:N:P ratio of 100:5:1. Weekly effluent samples collected at the bot-
tom of the drums were analyzed for COD and phenol,
Reductions of 99+ percent in COD content of the wastewater were attained
from the first week in the case of the two highest loadings and from the
fourth week for the lowest loading. A breakthrough occurred during the
22nd week for the lowest loading rate and during the fourth week for the
219
-------
DRAFT
highest loading rate. The COD removal steadily decreased thereafter for
the duration of the test. Phenol removal showed no such reduction, but
instead remained high throughout the test. The average test results for
the three loading rates are given in Table 61. Average phenol removal
was 99+ percent. Removal of COD exceeded 99 percent prior to breakthrough
and averaged over 85 percent during the last week of the test.
TABLE 61 RESULTS OF LABORATORY TESTS OF SOIL IRRIGATION
METHOD OF WASTEWATER TREATMENT*
Loading Rate
(Liters/ha/day)
Length Of Avg. % COD
Test Removal to
(Week) Breakthrough
COD REMOVAL Phenol
Last Week Avg. %
of Test, Removal
% (AH Weeks)
32,800
(3,500)
49,260
(5,250)
82,000
(8,750)
Loading
31 99.1 (22 wks) 85.8
13 99.6 99.2
14 99.0 (4 wks) 84.3
rates in parentheses in gallons/acre/day
98.5
99.7
99.7
*Creosote wastewater containing 11,500 mg/liter of COD and
of phenol was used.
150 mg/liter
The field portion of Dust and Thompson's (25) study was carried out on
an 0.28-hectare (0.8 acre) plot prepared by grading to an approximately
uniform slope and seeded to native grasses. Wood preserving wastewater
from an equalization pond was applied to the field at the rate of 32,800
liters/hectare/day (3,500 gallons/acre/day) for a period of nine months.
Average monthly influent COD and phenol concentrations ranged from 2,000
to 3,800 mg/liter and 235 to 900 mg/liter, respectively. Supplementary
nitrogen and phosphorus were not added. Samples for analyses were col-
lected weekly at soil depths of 0 (surface), 30, 60, and 120 centimeters
(1, 2, and 4 feet).
The major biological reduction in COD and phenol content occurred at the
surface and in the upper 30 centimeters (1 foot) of soil. A COD reduc-
tion of 55.0 percent was attributed to overland flow. The comparable
reduction for phenol content was 55.4 percent (Table 62). Average COD
reductions at the three soil depths, based on raw waste to the field,
were 94.9, 95.3, and 97.4 percent, respectively, for the 30-, 60-, and
120 centimeter (1-, 2-, and 4-foot) depths. For phenols, the reductions
were, in order, 98.9, 99.2, and 99.6 percent.
220
-------
DRAFT
TABLE 62 REDUCTION OF COD AND PHENOL CONTENT IN WASTEWATER
TREATED BY SOIL IRRIGATION (25)
Month
Raw Waste
Soil Depth (centimeters)
30
60
120
July
August
September
October
November
December
January
February
March
Apri 1
2235
2030
2355
1780
2060
3810
2230
2420
2460
2980
Average % Removal
(weighted)
COD (mg/1)
1400
1150
1410
960
1150
670
940
580
810
2410
55.0
150
170
72
121
144
101
126
94.9
170
91
127
92
102
95.3
66
64
90
61
46
58
64
64
68
76
97.4
Phenol (mg/1)
July
August
September
October
November
December
January
February
March
April
235
512
923
310
234
327
236
246
277
236
186
268
433
150
86
6
70
111
77
172
..
—
--
4.6
7,7
1.8
1.9
4.9
2.3
1.9
..
--
--
--
3.8
9.0
3.8
2.3
1.9
0.0
1.8
0.0
0.0
2.8
OoO
3.8
0.0
1.8
1.3
0.8
Average % Removal
(weighted)
55.4
98.9
99.2
99.6
221
-------
DRAFT
Color of the wastewater before and after treatment was not measured.
However, the influent to the field was dark brown and the effluent was
clear. Samples taken from the 60- and 120-centimeter (2- and 4-foot)
depths showed no discoloration.
The application of the wastewater to the study area did not interfere
with the growth of vegetation. On the contrary, the area was mowed
several times during the summer months to control the height of native
grasses that became established.
The soil percolation method for treating the creosote wastewater from
the wood preserving plant consistently showed a greater percentage re-
moval of COD and phenol than either the activated sludge or the trickling
filter methods.
Oxidation Ponds - Characteristics - Oxidation ponds are relatively simple
to operate and, because of their large volume, difficult to disrupt. Op-
eration and maintenance costs are usually lower than for other waste
treating methods. Their disadvantages are numerous. Included among these
are: (a) low permissible loading rate, which necessitates large land
areas; (b) abrupt changes in efficiency due to weather conditions; (c)
difficulty of restoring a pond to operating condition after it has .been
disrupted; (d) tendency to become anaerobic, thus creating odor problems,
and (e) effluents contain algal cells, which are themselves a pollutant.
Processing Efficiency for Phenolic Wastes - Only a few cases of the use
of oxidation ponds to treat phenolic wastes are recorded in recent lit-
erature. The American Petroleum Institute's "Manual on Disposal of Re-
finery Wastes" (96) refers to several industries that have successfully
used this method.
Montes (97) reported on results of field studies involving the treatment
of petrochemical wastes using oxidation ponds. He obtained BOD reductions
of 90 to 95 percent in ponds loaded at the rate of 84 kilograms or BOD
per hectare per day (75 pounds/acre/day).
Phenol concentrations of 990 mg/liter in coke oven effluents were reduced
to about 7 mg/liter in field studies of oxidation ponds conducted by
Biczysko and Suschka (98). Similar results have been reported by Skogen
(99) for a refinery waste.
Treatment of Wood Preserving Effluents - Oxidation ponds rank high among
the various methods that wood preserving companies plan to use to treat
their wastewater (Table 49). However, the literature contains operating
data on only one pond used for this purpose (100, 101, 102). This is
the oxidation pond used as part of a waste treatment system by Weyer-
haeuser Company at its DeQueen, Arkansas wood preserving plant.
222
-------
DRAFT
As originally designed and operated in the early 1960's, the DeQueen
waste treatment system consisted of holding tanks into which water from
the oil-recovery system flowed. From the holding tanks the water was
sprayed into a terraced hillside from which it flowed into a mixing
chamber adjacent to the pond. Here it was diluted 1:1 with creek water,
fortified with ammonia and phosphates, and discharged into the pond
proper. Retention time in the pond was 45 days. The quality of the
effluent was quite variable, with phenol content ranging up to 40 mg/
liter.
In 1966 the system was modified by installing a raceway containing a
surface aerator and a settling basin in a portion of the pond. The
discharge from the mixing chamber now enters a raceway where it is
treated with a flocculating agent. The floe formed collects in the
settling basin. Detention time is 48 hours in the raceway and 18 hours
in the settling basin. From the settling basin, the wastewater enters
the pond proper.
These modifications in effect changed the treating system from an oxi-
dation pond to a combination aerated lagoon and polishing pond. The
effect on the quality of the effluent was dramatic. Figure 41 shows
the phenol content at the outfall of the pond before and after instal-
lation of the aerator. As shown by these data, phenol content decreased
abruptly from an average of about 40 mg/liter to 5 mg/liter.
Even with the modifications described, the efficiency of the system re-
mains seasonally dependent. Table 63 gives phenol and BOD values for
the pond effluent by month for 1968 and 1970. The smaller fluctuations
in these parameters in 1970 as compared with 1968 indicate a gradual
improvement in the system.
Chemical Oxidation - Phenolic compounds, in addition to contributing
to the oxygen demand of wood preserving wastewaters, largely account
for the toxic properties of effluents from creosote and pentachloro-
phenol treatments. These compounds can be destroyed by chemical oxida-
tion. Oxidizing agents that have been successfully used for this pur-
pose are chlorine and ozone.
Chlorine - Many references to the chlorination of phenol-bearing waters
exist in the literature (103, 104, 105). Chlorine gas and calcium and
sodium hypochlorite have been used most extensively for this purpose.
Direct treatment with gaseous chlorine using a continuous-flow system
is simpler and less expensive than hypochlorite where large volumes of
wastewater must be treated. However, for batch-type treatments involv-
ing small wastewater volumes, hypochlorite is probably the more practical.
Chlorine dioxide may also be used to oxidize phenols. It has the advan-
tage over other sources of chlorine of short reaction time, does not re-
quire close control of pH and temperature, does not produce chlorophenols,
223
-------
45
40
35
30
-25
ho 0>
£ E
*» ••-'
*-20
O
U 15
O
c
0)
£ 10
JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV
Month
FIGURE 41 - PHENOL CONTENT IN WEYERHAEUSER1S OXIDATION POND EFFLUENT
BEFORE AND AFTER INSTALLATION IN JUNE, 1966 OF AERATOR
DEC
-------
DRAFT
TABLE 63 AVERAGE MONTHLY PHENOL AND BOD CONCENTRATIONS IN EFFLUENT
FROM OXIDATION POND AT WEYERHAEUSER1S DEQUEEN,
ARKANSAS OPERATIONS: 1968 and 1970 (100)
(mg/liter)
Month
January
February
March
April
May
June
July
August
September
October
November
December
1968
Phenol
26
27
25
11
-6
5
7
7
7
16
7
11
BOD
290
235
190'
150
100
70
90
70
no
150
155
205
1970
Phenol
7
9
6
3
1
1
1
1
1
—
--
__
BOD
95
140
155
95
80
60
35
45
25
—
—
__
225
-------
DRAFT
and is effective at ratios of chlorine to phenol of 1:1 or 2:1. Its
primary disadvantages are its lack of stability, which requires that
it be produced as used, and its relatively high cost (30).
The theoretical ratio of chlorine to phenol required for complete oxi-
dation is about 6:1. For m-cresol the ratio is 3.84:1 (106). However,
because of the presence in wastewater of other chlorine-consuming com-
pounds, much higher ratios are required. Thompson and Dust (107) found
that the minimum concentration of calcium hypochlorite needed to destroy
all phenols in creosote wastewater was equivalent to a chlorine:phenol
ratio of 14:1 to 65:1. The exact ratio varied with the pH, COD content,
and source of the wastewater. Comparable ratios for pentachlorophenol
ranged as high as 300:1 when calcium hypochlorite was used to 700:1 for
chlorine gas. Generally, approximately two times as much gaseous chlor-
ine was required to oxidize a given weight of pentachlorophenol as
chlorine from calcium hypochlorite.
In other work, Dust and Thompson analyzed wastewater samples for COD,
phenol, and pentachlorophenol content following chlorination with quanti-
ties of calcium hypochlorite equivalent to 0 to 3.0 g/liter of chlorine.
Typical results are shown in Table 64. Treatment of creosote wastewater
achieved a reduction in phenol content of 95 to 100 percent, as deter-
mined by procedures recommended by APHA (108)(NOTE: This qualification
is necessary, since the 4-amino antipyrine test for phenols does not
detect all chlorinated phenols and cresols.). However, as illustrated
in Table 64, a residual phenol content of 5 to 10 mg/liter that was re-
sistant to oxidation remained in some samples. Substantial reductions
in COD were also obtained by the treatments. However, practically all
of the reduction in COD occurred at chlorine doses of 2 g/liter or less.
TABLE 64 EFFECT OF CHLORINATION ON THE COD AND PHENOLIC CONTENT
OF PENTACHLOROPHENOL AND CREOSOTE WASTEWATERS
Ca(OCl)2 as
Chlorine
(g/liter)
0
0.5
1.0
1.5
2.0
3.0
PCP Wastewater
(mg/liter)
COD
—
8150
7970
8150
7730
7430
PCP
40.7
17.3
13.1
12.0
10.4
0
Creosote Wastewater
(mg/liter)
COD
5200
4800
4420
4380
4240
3760
Phenol
223.1
134.6
65.3
15.4
10.0
5.4
226
-------
DRAFT
In the same study, both chlorine gas and calcium hypochlorite were used
to treat pentachlorophenol wastewater adjusted to pH levels of 4.5, 7.0,
and 9.5. The results, which are summarized In Tables 65 and 66, showed
that the efficiency of the treatments, in terms of the ratio of weight
of chlorine used to weight of pentachlorophenol removed, varied with the
pH of the wastewater, the source of chlorine, and whether or not the
waste was flocculated prior to chlorination.
A large proportion of the chlorine added to the wastewater in the above
studies was consumed in oxidizing organic materials other than phenolic
compounds. This is indicated by the major reductions in COD that occurred
coincident to the chlorination treatments. For unflocculated waste, the
COD averaged 24,000 mg/liter before and 10,300 mg/liter after treatment
with calcium hypochlorite, a reduction of 58 percent (Table 67). The
comparable reduction for samples treated with chlorine gas was 55 percent.
These reductions were obtained at the maximum dose of chlorine employed;
that is, 5 g/liter for calcium hypochlorite and 10 g/liter for chlorine
gas. However, practically all of the reduction in COD occurred at chlor-
ine doses of 1 g/liter or less, in the case of samples treated with the
hypochlorite, and 2 g/liter or less for those treated with chlorine gas.
For example, a typical sample of raw waste treated with chlorine gas had
an initial COD of 20,400 mg/liter. This value was reduced to 10,250
mg/liter by a chlorine dose of 2 g/liter. The addition of 10 g/liter of
chlorine further reduced the COD only to 10,200 mg/liter. These data in-
dicate that a portion of the organic content of the wastewater was re-
sistant to chemical oxidation.
The reduction in COD caused by chlorination of raw wastewater was prac-
tically the same as that achieved by flocculation with lime and a poly-
electrolyte.
Chlorination of phenol-bearing waters has long been associated with odor
and taste problems in municipal water supplies. Phenol itself apparently
does not impart taste to water in concentrations below about 60 mg/liter.
Its significance as a taste and odor problem arises from its reaction
with chlorine to produce chlorophenols. Some of the latter group of
chemicals are reported to impart taste in concentrations as low as 0.00001
mg/liter (109).
Ingols and Ridenour (110) postulated that a quinone-like substance was
responsible for the taste and odor problem of chlorinated water, and that
this substance was an intermediate product in a succession of chlorinated
products produced by chlorine treatments of phenol. A ratio of 5 to 6
grams of chlorine per gram of phenol was found to eliminate the taste
problem. They hypothesized from this result that high levels of chlori-
nation rupture the benzene ring to form maleic acid.
227
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DRAFT
TABLE 65 EFFECT OF CHLORINATION WITH CALCIUM HYPOCHLORITE
ON THE PENTACHLOROPHENOL CONTENT OF WASTEWATER
Ca(OC1)2 as
Chlorine
(g/liter)
0
0.5
1.0
1.5
2.0
3.0
4.0
5.0
TABLE 66
THE
Unflocculated
pH
4.5 7.0 9.5
21.5 19.0 20.5
10.0 14.0 10.0
8.0 10.0 8.0
6.0 8.0 8.0
6.0 7.5 8.0
3.5 6.0 5.0
2.0 6.0 4.0
2.0 5.8 4.0
EFFECT OF CHLORINATION WITH
PENTACHLOROPHENOL CONTENT OF
4.5
12.0
6.0
4.0
2.0
0
0
0
0
Flocculated
pH
7.0
12.0
9.0
8.0
5.0
3.6
0
0
0
9.5
14.0
11.0
9.0
6.0
7.0
4.0
0
0
CHLORINE GAS ON
WASTEWATER
Pentachlorophenol (mq/liter)
Chlorine
(g/liter)
0
0.5
1.0
1.5
2.0
3.0
4.0
5.0
10.0
UnflocculatGd
pH
4.5 7.0 9.5
22.0 20.0 18.0
13.0 14.0 16.0
10.0 12.5 15.0
9.0 9.0 11.5
8.0 8.0 11.5
8.0 8.0 8.0
10.0 8.0 11.0
14.0 11.5 12.0
14.0 11.5 14.0
4.5
18.0
16.0
14.0
10.0
8.0
7.5
2.0
0
0
Flocculated
pH
7.0
17.0
14.0
13.0
14.0
10.0
8.0
6.0
2.0
2.0
9,5
19.5
16.5
11.0
11.0
8.0
8.0
6.0
4.0
2.0
228
-------
DRAFT
TABLE 67 EFFECT OF CHLORINATION OF PENTACHLOROPHENOL WASTE ON COD
Test Conditions
Calcium Hypochlorite
pH = 4.5
Calcium Hypochlorite
pH = 7.0
Chlorine Gas
pH = 4.5
Chlorine Gas
pH = 7.0
Available Chlorine
(g/liter)
0.0
Oo5
1.0
1.5
2.0
3.0
4.0
5.0
0.0
0.5
1.0
1.5
2.0
3.0
4.0
5.0
0.0
0.5
1.0
1.5
2.0
3.0
4.0
5.0
10.0
0.0
0.5
1.0
1.5
2.0
3.0
4.0
5.0
10.0
COD
(mg/ liter)
24,200
10,650
10,600
10,300
23,800
10,300
10,200
10,050
20,400
10,250
10,600
10,200
23,600
9,760
10,700
11.250
229
-------
DRAFT
Later studies by Ettinger and Ruchoft (111) largely substantiated earlier
work which showed that taste intensity increases with chlorine dosage and
then decreases with further chlorination, until no taste remains. Re-
sults of work by these authors on the chlorination of various phenolic
compounds and the quantities of chlorine required to eliminate taste are
given in Table 68. These data indicate that a chlorine-to-phenol ratio
of 5:1 would be adequate to form chlorination end products. Work re-
ported by others (106) show that for m-cresol this ratio is 3.84:1. A
ratio of 5:1 resulted in a free chlorine residual after a reaction time
of 2 hours.
More recent work by the Manufacturing Chemists Association (105) shows
that the reaction between chlorine and phenolic compounds proceeds at a
rapid rate for the first 15 minutes and is essentially complete after 2
hours contact time. For concentrations of m-cresol of 10 and 20 mg/liter,
the application of 50 and 100 mg/liter of chlorine produced a free chlo-
rine residual after 2 hours. A residual chlorine content after 2 hours
contact time was obtained for phenol only when chlorine was applied at
ten times the level of phenol. The relationship among m-cresol concen-
tration, chlorine dosage, contact time, and chlorine residual is shown
in Table 69.
In related studies, phenol in concentrations of 25 mg/liter was treated
with levels of chlorine calculated to provide an excess of phenol. Gas
chromatographic analyses of samples withdrawn after a contact time of
0.5 hour revealed the presence of 0-chlorophenol, p-chlorophenol, 2,6,
dichlorophenol, 2,4 dichlorophenol, and 2,4,6 trichlorophenol. Similar
tests with m-cresol showed the formation of a number of reaction products,
which were assumed to be a mixture of chloro-m-cresols. Positive identi-
fication was not made because chlorine-substituted cresols for use as
standards are not available commercially.
The authors proposed that the reaction proceeds in part sequentially by
the stepwise substitution of the 2,4, and 6 ring positions, and in part
simultaneously, resulting in the formation of a complex mixture of chloro-
phenols and their oxidations products. Ring oxidation was assumed to
follow the formation of 2,4,6 trichlorophenol. Other authors have postu-
lated that the reaction proceeds only by a stepwise substitution (111,
112).
Burttschell's work (112) indicated that the progression of chlorinated
products occurs as follows:
Phenol
2-Chlorophenol
4-Chlorophenol
2,4-Dichlorophenol
2,6-Oichlorophenol
2,4,6-Trichlorophenol
4,4-Dichloroquinone
Organic Acids
230
-------
DRAFT
TABLE 68 CHLORINE REQUIRED TO ELIMINATE TASTE IN AQUEOUS
SOLUTIONS OF VARIOUS PHENOLIC COMPOUNDS (111)
Phenol
0-Cresol
M-Cresol
P-Cresol
1-Napthol
2-Chlorophenol
4-Chlorophenol
2-, 4-Dichlorophenol
2-, 4-, 6-Trichloro-
Chlon'ne Required To
Eliminate Taste
(mg/1 )
4
5
5
3
4
3
3
2
Could not be tasted
Chlorine Added
To Produce Free
Residual (mg/1)
7
5
5
4
5
5
6
6
3
phenol
2-, 4-, 5-Tr1chloro-
phenol
2-, 3-, 4-, 6-Tetra-
chlorophenol
Pentachlorophenol
Could not be tasted
Could not be tasted
Could not be tasted
1.5
1.0
231
-------
DRAFT
TABLE 69 CHLORINE DEMAND OF M-CRESOL AFTER VARIOUS CONTACT TIMES (106)
Net Chlorine
m-Cresol
Concentration
(ma/1 )
10
10
10
20
20
Contact
Chlorine Time
(mg/1 ) (hr)
0.25
20 °'5
1.0
2.0
0.25
50 °°5
1.0
2.0
0.25
100 °'5
1.0
2.0
0.25
50 °°5
1.0
2.0
0.25
100 ?:§
2.0
Chlorine
Residual
(mg/1 )
3.3
1.5
0.5
0.2
30.8
30.8
28.3
17.0
81.4
77.0
61.6
61.6
16.3
11.1
8.0
8.0
61.6
58.2
56.6
46.0
mg/1
16.7
18.5
19.5
19.8
19.2
19.2
21.7
33.0
18.6
23.0
38.4
38.4
33.7
38.9
42.0
42.0
38.4
41.8
43.4
54.0
Demand
m mol cl2
m mol m-Cresol
2.5
2.8
3.0
3.0
2.9
2.9
3.3
5.0
2.8
3.5
5.9
5.9
2.6
3.0
3.2
3.2
2.9
3.2
3.3
4.1
232
-------
DRAFT
Destruction of the benzene ring was found to occur at a chlorine-to-phenol
ratio of 10:1. Burttschell attributed the taste problem associated with
chlorophenols to 2,6-dichlorophenol. The development of taste was re-
ported not to occur at pH values of less than 7.0.
Results of a study by Eisenhauer (113) supported earlier work of other
investigators that non-aromatic products are formed when phenols are
treated with high levels of chlorine.
Oxidation products resulting from the chlorination of pentachlorophenol
have not been studied intensively. However, Thompson and Dust (107) re-
ported the presence of chloranil in samples of chlorinated wastewater
analyzed using a gas chromatograph.
With the exception of the last reference cited, the studies described in
the foregoing paragraphs have dealt with phenolic compounds in solutions
not contaminated with other substances. Because of other chlorine-con-
suming materials in wood preserving wastewater, a question arises con-
cerning the levels of chlorine required to fully oxidize phenols in such
wastes. Unpublished results of a recent study (1970) at the Mississippi
Forest Products Laboratory provides a partial answer.
Creosote wastewater with phenol and COD contents of 508 and 13,500 mg/
liter, respectively, were flocculated and samples of the filtrate ad-
justed to pH values of 4.5, 7.0, and 9.5. The samples were treated with
quantities of calcium hypochlorite calculated to yield a gradient series
of chlorine concentrations. The pH readings of the samples were adjusted
to the original values after a contact period of 30 minutes. After 8
hours, the samples were filtered, analyzed for phenols by the 4-amino-
antipyrine method, and then analyzed for di- and tri-chlorophenols using
an electron capture detector. Chloro-cresols and other chlorophenols
were not included because reagent-grade materials for use as standards
could not be found. The results are given in Table 70.
Trichlorophenol was present in all samples, but the concentration de-
creased rapidly with increasing levels of chlorine. However, traces
remained in samples treated with the highest levels of chlorine. The
rate of oxidation was highest at pH 4.5 and decreased with increasing
alkalinity, although the difference between pH 7.0 and 9.5 was not great.
The relationship between results of the APHA test for phenols and levels
of chlorophenols determined using an electron capture detector was gen-
erally poor at low chlorine levels. However, low values for the APHA
test always corresponded with low concentrations of chlorophenols.
Ozone Treatments - Ozone is a powerful oxidizing agent, but its employ-
ment in waste treatment is a relatively recent development. Its princi-
pal disadvantages are its lack of stability, which requires that it be
produced as used, and its high cost both in terms of capital investment
233
-------
DRAFT
TABLE 70 CHLOROPHENOL CONCENTRATION IN CREOSOTE WASTEWATER
TREATED WITH CHLORINE
PH
4.5
7.0
9.5
Ca(OCl)2
As Chlorine
(g/1)
0
0.5
1.0
1.5
2.0
3.0
5.0
0.5
1.0
1.5
2.0
3.0
5.0
0.5
1.0
1.5
2.0
3.0
5.0
Residual
Phenols (mg/1)
by
APHA Method
438.5
256.1
30.8
0.0
0.0
0.0
0.0
300.0
101.5
7.7
0.0
0.0
0.0
315.4
101.5
11.5
0.0
0.0
0.0
ECD Analysis
2-, 4-dichloro-
phenol
—
161.0
0.0
0.0
0.0
0.0
0.0
122.0
0.0
0.0
0.0
0.0
0.0
198.0
0.0
0.0
0.0
0.0
0.0
(mg/1 )
2-, 4-, 6-tri-
chlorophenol
—
910.0
6.7
1.5
1.0
0.3
0.3
316.0
35.0
6.4
2.8
1.5
1.3
264.0
27.0
25.0
3.7
3.8
1.9
234
-------
DRAFT
in equipment and operating costs, The major cost of producing ozone is
electricity. It requires 19.8 kwh of electricity to produce one kilogram
of ozone with air feed to the generating equipment and 9.9 kwh with oxy-
gen feed (96), The high initial cost of ozonation is offset in part by
the fact that the equipment has a useful life expectancy of 25 years (114).
Treatment of wastewater with ozone may be either by batch or continuous
flow methods. Ozone reacts rapidly with phenols at all pH levels, but
the optimum pH observed by Niegowski (114, 115) was 12,0. Ozone demand
at pH 12 was less than one-half that at pH 7 in treating petroleum waste-
waters. However, the difference in demand was manifested only in oxi-
dizing the last 30 percent of the phenol in the waste. During two-thirds
of the oxidation, the reaction was so rapid that pH had very little effect.
A ratio of ozone:phenol of about 2:1 normally is required to destroy the
phenols in a solution. However, ratios as low as 1:1 and as high as 10:1
were reported by Niegowski (114) for wastewaters from different sources.
According to Gloyna and Malina (116), only about one-tenth as much ozone
is required as chlorine to oxidize the same amount of phenol.
Because of its high energy requirements and the resulting high operating
costs, ozonation does not lend itself to the treatment of wood preserving
wastewaters, and hence will not be considered further in this report.
Activated Carbon Filtration - Activated carbon is used commercially to
treat petroleum (117) and other types (118) of industrial wastewaters.
It can also be used effectively to remove phenolic compounds from wood
preserving waste streams. Although carbon has a strong affinity for non-
polar compounds such as phenols, adsorption is not limited to these ma-
terials. Other organic materials in wastewater are also adsorbed, result-
ing in a decrease in the total oxygen demand of the waste. Because the
concentration of the latter substances exceeds that of phenols in efflu-
ents from wood preserving plants, the useful life of activated carbon is
determined by the concentration of these materials and the rate at which
they are adsorbed.
Results of carbon-adsorption studies conducted by Dust and Thompson (25)
on a creosote wastewater are shown in Figure 42. Granular carbon was
used and the contact time was 24 hours. The wastewater was flocculated
with ferric chloride and its pH adjusted to 4.0 prior to exposure to the
carbon. As shown in the figure, 96 percent of the phenols and 80 percent
of the COD were removed from the wastewater at a carbon dosage of 8 g/liter.
The loading rate dropped off sharply at that point, and no further in-
creases in phenol removal and only small increases in COD removal occur-
red by increasing carbon dosage to 50 g/liter. Similar results were ob-
tained in tests using pentachlorophenol wastewater.
Results of adsorption isotherms that were run on pentachlorophenol waste-
water, and other samples of creosote wastewater followed a pattern similar
235
-------
100
80
ra
5
0)
oc
0>
.c
Q.
TJ
C
CO
Q
O
u
10 2O 30 40
Activated Carbon (gm / liter)
50
FIGURE 42 (25) -
RELATIONSHIP BETWEEN WEIGHT OF ACTIVATED
CARBON ADDED AND REMOVAL OF COD AND PHENOLS
FROM A CREOSOTE WASTEWATER ™hNOL5
236
-------
DRAFT
to that shown in Figure 42, In some instances a residual content of
phenolic compounds remained in wastewater after a contact period of
24 hours with the highest dosage of activated carbon employed, while
in other instances all of the phenols were removed. Loading rates of
0.16 kilograms of phenol and 1.2 kilograms of COD per kilogram of car-
bon were typical, but much lower rates were obtained with some waste-
waters .
Other Waste Handling Methods
Containment and Spray_Ev^apoj^ajtigji - Forty-two percent of the plants re-
sponding to the survey referrecTto in Section V indicated that they cur-
rently are storing their wastewater on company property, and therefore
have no discharge (Table 45). The popularity of this method of waste
handling undoubtedly is attributable to its low cost, in the case of
plants with ample land area, and its simplicity. The practicality of
the method is questionable in areas of high rainfall and low evapora-
tion rate, unless the rate of evaporation is increased by the applica-
tion of heat or by spraying. The latter alternative is being employed
by a number of plants in the Gulf South.
The use of spray ponds to dispose of wastewater by evaporation requires
that a diked pond of sufficient capacity to balance annual rainfall and
evaporation be constructed. The pond is normally equipped with a pump
and the number of spray nozzles necessary to deliver to the air the
volume of water calculated to provide the desired amount of evaporation,
assuming a given evaporation efficiency.
The feasibility of spray evaporation depends upon the availability of a
land area of such size that a pond large enough to permit a balance be-
tween inflow and evaporation can be constructed. Pond size and number
of spray heads are determined by waste volume and the ratio of rainfall
to surface evaporation. Where rainfall and evaporation in a region are
approximately equal, the effect of both can be neglected, if sufficient
storage capacity is provided. For areas with higher annual rainfall or
lower evaporation rate, the design of a spray evaporation system must
account for a net annual increase in water volume in the pond due to
rainfall.
Pan Evaporation^ - A few plants with small volumes of wastewater are evap-
orating it directly by application of heat. Basically, the procedure in-
volved is to channel the effluent from the oil-separation system into an
open vat equipped with steam coils. The water is then vaporized by boil-
ing, or, as in one instance, heated to approximately 71°C (160°F) and the
rate of evaporation increased by circulation of air across the surface
of the water. The method is expensive, fuel cost alone amounting to an
estimated $8 00 per 3,785 liters (1000 gallons). This estimate is based
on using natural gas as fuel and assumes an overall efficiency of 65 per-
cent for the process.
237
-------
DRAFT
Evaporation In Cooling Towers - In this process, effluent from the oil-
separation system is discharged to the basin of a cooling tower and re-
used as cooling water. Normal evaporation associated with the operation
of the tower accounts for an average loss of approximately 7,570 Ipd
(2000 gpd) for a typical tower. Evaporation of excess water is expedited
by the intermittent operation of a heat exchanger or other heating system
in conjunction with a fan. The efficiency of the condensers, both tube-
type and barometric, are reported to be unaffected by water temperatures
of up to 38°C (100°F) and by light oils that accumulate in the water.
The owner of one plant stated that oil concentrations as high as 10 per-
cent could be tolerated in the cooling water. However, problems with
condenser efficiency were reported at another plant in which the oil con-
tent of the process water used for cooling was less than 100 mg/liter.
Incineration - Two plants in the U.S. are known to operate incinerators
for wastewater disposal. The one plant for which data are available
currently operates a unit capable of "burning" 5,676 liters (1500 gal)
of wastewater per hour. Fuel cost alone for this unit, which is fired
with Bunker C oil, is $15.00 per 3,785 liters (1000 gal) of waste.
Data reported by the American Wood Preservers' Association (48) indicate
that incineration of wastewater is economical only when the oil content
of the waste is 10 percent or higher. Such high oil contents are not
common for wastewater from the wood preserving industry.
General Information
Required Implementation Time - Because of the relatively small volume of
wastewater at most wood preserving plants, "off-the-shelf" equipment
should ordinarily meet the requirements of the individual plants with re-
gard to the application of treatment technology required to be achieved
by July 1, 1977 and July 1, 1983, respectively. It is not anticipated,
therefore, that either equipment availability, or (because of the sim-
plicity of the equipment) availability of construction manpower will ser-
iously affect implementation time. For the same reason, it is not antic-
ipated that the time required to construct new treating facilities or
modify existing ones will affect implementation time for any of the treat-
ment and control technologies that are likely to be employed in the indus-
try.
Land availability will influence the choice of treatment and control tech-
nology at many wood preserving plants located in urban areas. For example,
the employment of oxidation ponds, soil irrigation, and possible aerated
lagoons will not be feasible in areas where all company land is in use
and additional acreage cannot be purchased at a reasonable price. Plants
thus located will have to select extended aeration or other treating
methods, the land requirements of which conform to the space that is
available.
238
-------
DRAFT
Effect Of Treatment Technology On Other Pollution Problems - None of the
treatment and control technologies that are currently feasible for use
in the wood preserving industry will have an effect on other pollution
problems.
i
Solid Waste - Solid wastes resulting from treatment and control tech-
nologies that have potential use in the wood preserving industry are of
two types: sludge from coagulation of wastewater and bacterial sludges
originating from biological treatments. The former material contains
oil and dissolved phenolic compounds originally in the preservative,
along with the flocculating compound used. In the case of water-soluble
preservatives, the sludge will contain traces of the metals used in the
particular preservative or fire retardant formulation involved. Bacter-
ial sludges contain the biomass from biological treatments, but are of
importance from the standpoint of disposal only in the case of treatments
that employ activated sludge and trickling filter units.
The volume of sludge involved with both types is small. Plants currently
are disposing of these materials in sanitary landfills. Incineration of
organic waste and burial of inorganic salts are possible disposal methods
that could be used.
Plant Visits
A number of wood preserving plants judged to be exemplary in terms of
their waste management programs were visited in conjunction with this
study. Selection of plants for visits was based on the type of waste-
water treating and/or disposal system employed and, insofar as possible,
geographic location. Plants that dispose of their raw waste by discharg-
ing it to a sewer, as well as those that simply store their waste on site,
were not represented among the plants visited. Exclusion of these plants
limited the number considered for a visit to the approximately 30 plants
in the U.S. that either give their waste the equivalent of a secondary
treatment before discharging it, or which have no discharge. Only four
of this number were found both to treat their waste on site and discharge
it directly to a stream. The remainder either channel their treated water
to an irrigation field or to a sewer, or have no discharge due to reuse
of wastewater, evaporation, or both.
Plant visits were used to obtain samples, the analyses of which permitted
an evaluation of the efficiency of the wastewater treating system employ-
ed. Performance data provided by the plants themselves were used in this
evaluation when available. Information was also obtained on flow rate,
annual production, and other parameters needed for the development of ef-
fluent guidelines. Cost data on wastewater treating systems were requested
of all plants and provided by some.
239
-------
DRAFT
A summary of the data obtained for each plant visited is presented in
Table 71. Flow diagrams illustrating waste treatment systems employ-
ing extended aeration, soil percolation, and combination aerated lagoon
and oxidation pond are shown in Figures 43, 44, and 45, respectively.
Detailed data on each plant are given in Supplement B.
240
-------
OR.
ro
TABLE 71 SUMMARY OF WASTEWATER CHARACTERISTICS FOR 17 EXEMPLARY WOOD PRESERVING PLANTS
Plant
No.
1
2*
3
4*
5
6
7
8
9
10
11
12
13
14
15
16
17
Average
Phenol
(mg/1)
6.00
0
0.50
35.96
—
—
3.30
0.40
—
—
—
—
--
—
—
—
2.50
2.50
COD
(mg/1)
845
10
10
1695
—
—
523
435
--
—
—
—
—
--
—
—
240
240
Oil And
Grease
(mg/1)
7
7
0
83
—
—
55
158
—
—
~
--
—
—
—
—
12
46
Suspended
Solids
(mg/1 )
100
253
60
724
—
—
103
270
—
—
--
—
--
—
—
—
82
123
Volume
of
Ef fl uent
(Ipd)
73,800
49,200
49,200
34,100
3,800
34,100
567,800
98,400
15,100
22,700
49,200
18,900
4,700
9,500
7,600
19,700
63,200
34,600
Volume
of
Discharge
(Ipd)
0
0
0
0
0
0
492,100
87,100
0
0
49,200
0
0
0
0
0
63.200
—
Daily
Produc-
tion
(m3)
283
283
266
436
210
403
708
425
178
204
93
210
62
125
34
190
223
255
Cost
($)
42,000
90,000
30,000
17,000
40,000
25,000
85,000
46,000
38,000
85,000
—
120,000
5,500
6,000
50,000
39,000
__
47,900
Fi nal
Disposition
of
Waste
Sewer
Field
Field
Field
Field
Field
Stream
Stream
Pond
Evaporated
Ditch
Evaporated
Evaporated
Evaporated
Evaporated
Sewer
Stream
*Data not included in average.
-------
Cool. Pond
Overflow
Boiler
Blow
Down
Back
Wash!
.11
Condenser
Drain
Tanks (3)
Solvent
Tank
Pit
Pumps (3)
Cylinder Pit
Treating Room
OH Drips
Cylinder Vent
And
Slowdown
To Ditch
_T
Separator ft
Decanter
IN)
L
Flow Splitter
Equalizing Tank
Chlorinator
Duplex Ext. Aer. Tank Clar.
Weir A Sludge Return
Control Valv
@10GPM
Nutrient Feed r
Irrigation
Field
1/4 Acre
1/4 Acre
Lagoon
i
I
Lagoon
1/3 Acre
Lagoon
O
FIGURE 43 -
AM FLOW DIAGRAM FOR WOOD-PRESERVING PLANT EMPLOYING
AN EXTENDED AERATION WASTE TREATMENT SYSTEM IN CONJUNCTION
WITH HOLDING LAGOONS AND SOIL IRRIGATION
-------
ro
4^
to
Penta
Storage
Tanlc
IE
-*"*•
Transfer
Pump
2,000 Gals.
5,500 Gals.
1,000 Gals.
ffl
-»—X-
Gravlmetric Penta
Separation Tank
Pit S~\
Pump v^x
-IX-
(B
i( Suet ion
(Pressure!
'
Steaming Water
Transfer Pump
n ' _ JT
n n
Barometric Float Control Valve ,-—
ftTttrcVoling &!'°pen) SP™PP©
Pond f 11 SI Skimmer
Chemical I'ciar" J ff
Mixing TankLjS^^gi -
OH ft Sludge*\^y
Separation Tank
(Normal Open)
lllfm?1 " Wormain fl
^"•"P ^blosed) II l|
.VL fine park Filter
|-f-|| ». T— — ffl»«<3« Tff
ytu n ' ' nLand"n"
j n — . — n
Sludge Oewaterlng Bed (|
I*
Holding
-n B3
Tank Transfer
Pump
(Normal ,
Closed)
Sprays
A A A A A '
Soil Percolation
Field
FIGURE 44 - WASTEWATER FLOW DIAGRAM FOR WOOD-PRESERVING PLANT EMPLOYING
CHEMICAL FLOCCULATION, SAND FILTRATION, AND SOIL IRRIGATION
To Stream
-------
To PCP
Recovery
PCP
ro
Secondary PCP
A Creo. Separation
PCP Separation
Tank
Catch Pond
Overflow and Run-olf Water
Creo./ /
Effluent
Light Oil
Recover
Creo.
Dehydration
Tank
Creo. 5eparationa
To Creo.
Recovery
To PCP
Recovery
Holding Ponds
Final Separation
Emergency Catch
Pond
D Effluent
Pump
Mixing
Chamber
Recycle fump—..yj f
Race Track -**"
FIGURE 45
WASTEWATER FLOW DIAGRAM FOR
A WOOD-PRESERVING PLANT EM-
PLOYING AN OXIDATION POND IN
CONJUNCTION WITH AN AERATED
RACEWAY
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DRAFT
SECTION VIII
COST, ENERGY, AND NON'-WATER QUALITY ASPECTS
PART A: VENEER AND PLYWOOD
Cost And Reduction Benefits of Alternative Treatment And
Control Technologies For Selected Typical Plant
A detailed analysis of the costs and pollution reduction
benefits of alternative treatment and control technologies
applicable to the veneer and plywood industry is given in
Supplement A of this document. The typical veneer and ply-
wood mill chosen as a basis for cost estimates is a mill
producing 9.3 million square meters on a 9.53 millimeter
basis (100 million square feet on a three-eighths inch
basis) per year. It is assumed to have the following:
(1) Wet decking of logs without recycle;
(2) Log conditioning by means of hot water
vats with discharge due to direct steam
impingement;
(3) No containment of dryer washwater;
(4) A phenolic glue line without recycle
or reuse of washwater.
Table 72 summarizes waste loads from each treatment and con-
trol alternative.
TABLE 72
SUMMARY OF WASTE LOADS FROM TREATMENT ALTERNATIVES
Effluent Raw
Constituent Waste
Parameters Units Loads
Resulting Effluent
Levels
BCD
BOD
COD
SS
TS
Phenols
Kjld-N
kg/day
kg/day
kg/day
kg/day
kg/day
kg/day
558
1174
363
1109
0.25
4.14
558
1174
363
1109
0.25
4.14
481
1000
378
1000
0.09
3.8
411
1000
378
1000
0.09
3.8
2.7
19
11
19
0.004
0.5
0
0
0
0
0
0
245
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Alternative A: No Waste Treatment"Or Control
Effluent waste load is estimated at 560 kilograms (1230
pounds) per day for the selected typical plant.
Costs: None
Reduction Benefits: None
Alternative B: Complete Retention of Glue Washwater
This alternative includes complete retention of glue wastes
by recycle and reuse in glue preparation. This practice has
now become standard in the industry although four years ago
only one mill practiced complete recycle. Effluent waste
load is estimated at 481 kilograms (1060 pounds) per day for
the selected typical plant at this control level. In addi-
tion, 73 percent of the phenol load is removed.
Costs: Incremental costs are approximately
$17,500 over Alternative A, thus
total costs are $17,500.
Reduction Benefits: An incremental reduction
in plant BOD is approximately 77 kilo-
grams (170 pounds) per day. Total
plant reduction in BOD would be 13.8
percent.
Alternative C: Complete Retention of Wet Decking Wastewater
This alternative includes complete retention of wet decking
wastewater by collection and recycle, but no control for
other wastes. This practice is a relatively new technology,
but it is currently used in several mills. Effluent waste
load is estimated at 409 kilograms (900 pounds) of BOD per
day for the selected typical plant at this control level.
Costs: Incremental costs are approximately
$39,000 over Alternative B, thus
total costs are $56,500.
Reduction Benefits: An incremental reduction
in plant BOD of-73 kilograms (160 pounds)
is evidenced when compared to Alter-
native B. The total plant reduction in
BOD is 26.5 percent.
Alternative D: Complete Retention'of Wastewater From Log
Conditioning
Alternative D would result in complete recycle of water from
hot water vats with containment of excess wastewaters. Modi-
fication of hot water vats to provide heat by means of coils
246
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DRAFT
rather than direct steam impingement is assumed. Effluent
waste load is estimated as three kilograms (six pounds) of
BOD per day for the selected typical plant at this control
level.
Costs: Incremental costs of approximately
$12,000 over Alternative C would be
incurred, thus producing total costs
of $68,500.
Reduction Benefits: An incremental reduction
in plant BOD of 406 kilograms (894
pounds) per day is evidenced when com-
pared to Alternative C. Total plant
reduction in BOD is 99.5 percent.
Alternative E: Complete Retention of Dryer Washwater
Alternative E would result in the complete retention of
dryer washwater. Modification of washing operations to
reduce the volume of water used is assumed. Effluent waste
load is estimated at zero kilograms (zero pounds) of BOD
per day for the selected typical plant at this control level.
Complete control of wastes without discharge to receiving
waters is effected.
Costs: Investment costs of $5,000 to $10,000
over Alternative D would be incurred,
thus producing total costs of about
$76,000 ($74,000 to $79,000).
Reduction Benefits: An incremental reduction
in plant BOD of three kilograms (six
pounds) per day is evidenced when com-
pared to Alternative D. Total plant
reduction in BOD of 100 percent.
Mills With Existing Steam Vats
In Sections I, II, and IX of this report; it is mentioned
that special consideration is recommended for mills with
existing steam vats. Since there are a number of mills with
steam vats, it is felt that these should not be treated as
rare cases to be dealt with as the occasion arises. In
Section VII, Treatment And Control Technology, it is noted
that existing technology for treatment and control of waste-
waters from steam vats consists of biological treatment
which is capable of 85 to 90 percent removal of BOD. Two
modifications of steam vats (modified steaming and hot water
sprays) which make zero discharge feasible are also discussed
in Section VII. It is evidenced, however, that these modi-
fications do not represent currently available technology
as defined by the "Act."
247
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As discussed in Section VII, Control and Treatment
Technology, biological treatment is applicable to waste-
watersFrom steam vats. A summary of costs and effluent
levels for biological treatment of wastewaters from mills
with existing steam vats is presented below.
A system consisting of a vacuum separator
followed by an aerated lagoon would cost
approximately $81,000 for the selected
typical mill utilizing a steam vat and
would reduce the load to around 41 kilo-
grams (90 pounds) of BOD per day.
An activated sludge plant may result in
slightly higher BOD removals for a cost of
about $138,000 and a resulting BOD load of
about 20 kilograms (45 pounds) of BOD per
day for the selected typical mill.
Related Energy Requirements of Alternative Treatment and
Control Technology
It is estimated that 180 kilowatt-hours of electricity are
required to produce 93 square meters (1000 square feet)
of plywood (119) . This electrical energy demand is affected
by the following factors: (1) type of wood, (2) whether or
not logs are conditioned, (3) type of dryer, (4) amount of
lighting, and (5) pollution control devices.
For a typical mill producing 9.3 million square meters (100 mil-
lion square feet) of plywood per year on a 9.53 millimeter
(three-eighths inch) basis, total energy demand is estimated at
4500 kilowatts (119) . At a cost of-one cent per kilowatt-
hour, the plant would have a yearly energy cost of $180,000.
Associated with the control alternatives are annual energy
costs. These are estimated to be:
For Alternative A: $0
For Alternative B: $800
For Alternative C: $2,100
For Alternative D: $2,200
For Alternative E: $2,300
Non-Water Quality Aspects'Of Alternative Treatment And
Control Technology
Air Pollution: While there are no appreciable air pollution
problems associated with any of the treatment and control alter-
natives, in the veneer and plywood industry there are air pol-
lution problems presently in existence that may cause water
248
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DRAFT
pollution problems. The two main sources of air pollution
are from veneer dryers and from the hog boiler (bark boiler).
Associated with each are different pollutional problems of
significance. Stack gases from the dryers contain volatile
organics and those from the boiler contain suspended particu-
late matter.
Veneer Dryers: Since there are currently no emission control
systems installed on any plywood veneer dryers, it is not pos-
sible to cite typical applications or technology. There are,
of course, method's operating on similar processes which would
be suitable and applicable for controlling emissions from
veneer dryers.
If particulate emissions were excessive, they could be ade-
quately controlled utilizing inertial collectors of the
cyclone or mechanical type. Volatile and condensable hydro-
carbon emissions could be effectively controlled by one of
the several following methods:
(1) Condensation, utilizing tube con-
densers with air or water for cooling.
(2) Absorption (scrubbing) , utilizing
water or a selective solvent.
(3) Incineration or thermal oxidation.
(4) Adsorption
(5) A combination of the above.
The water pollution potential of these-control'methods is
not great. Only condensation-and scrubbing use water. Water
used in condensation is only cooling water and is, therefore,
not contaminated, while the most efficient scrubber appears
to be that using a selective solvent rather than water for
absorption.
Boiler: The emissions from hogged fuel boilers consist of
flyash particulates. Both the sulfur oxide and nitrogen oxide
gaseous concentrations are negligible. While most hogged
fuel boilers are equipped with the multiple cyclone type of
centrifugal collectors, in most areas this solution is no
longer adequate because of increasingly stringent emissions
limitations. The solution to the flyash emission problem
appears to depend on the use of wet scrubbers.
Such a control method creates a water pollution problem. A
boiler generating 68,000 kilograms (150,000 pounds) per hour
of steam generates a flyash slurry wastewater of 190 liters
(50 gallons) per minute with a solids concentration of about
6,000 milligrams per liter (120).
249
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DRAFT
Odors: Odors presently associated with veneer'and plywood
are not considered a problem. Since'the-control and treat-
ment technology of this industry is greatly dependent on
containment ponds, there is always the danger of ponds be-
coming anaerobic. Frequently anaerobic ponds'will promote
growth of organisms which biochemically reduce compounds to
sulfur dioxide and other odor causing gases'T
Solid Waste; The bulk of the solid waste from veneer and
plywood mills is comprised of wood residues and bark. These
wastes are commonly used as fuel in the boiler.
In addition to wood wastes are the settleable solids that
accumulate in ponds and those that" are separated in screening
devices. Disposal of this material may be at the plant site
or the waste material may be collected by the local munici-
pality with disposal by landfill. While the amount of solids
generated is not expected to be great, consideration must be
given to a suitable site for landfill and, in turn, to pro-
tection of groundwater supplies from contamination by leach-
ates.
. 250
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DRAFT
SECTION VIII
PART B: HARDBOARD
COST AND REDUCTION BENEFITS OF ALTERNATIVE TREATMENT
AND CONTROL TECHNOLOGIES FOR DRY PROCESS HARDBOARD
A detailed analysis of the costs and pollution reduction
benefits of alternative treatment and control technologies
applicable to the dry process hardboard industry is given
in Supplement A of this document. The typical mill selec-
ted to represent the dry process hardboard industry has a
..production of 227 metric tons (250 tons) per day... The waste-
water discharges result only from caul washing and cooling
water. The basic results are summarized below:
Alternative A: No Waste Treatment Or Control
Effluent consists of only 950 liters (250 gallons) per day of
caul washwater and 28,500 liters (75,000 gallons) of cooling
water. There is no log or chip wash, no resin washwater,
humidifier water or housekeeping water discharges.
Costs: None
Reduction Benefits: None
Alternative B: Retention of Caul Washwater and Discharge
of Cooling Water"
This alternative includes the collecting of caul washwater in
a holding tank and trucking to land disposal after pH neutrali
zation. Cooling water would be discharged into a receiving
stream.
Costs: Incremental costs are approximately
$21,500 over Alternative A, thus total
costs are $21,500.
Reduction Benefits: Elimination of caul wash-
water as a discharge stream.
Factors Involved In The Installation Of Treatment Systems
The only treatment system involved in the representative dry
process mill is the disposal of caul washwater by hauling to
land disposal. There are no problems concerning the reli-
ability of the system as caul washwater will be put into a
storage tank, neutralized, then hauled by truck to a disposal
area. This system is not sensitive to shock loads, and start-
up and shutdown procedures do not cause a problem. This
251
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DRAFT
system can be designed and installed within one year and
requires little or no time to upgrade operational and main-
tenance practices. There are no air pollution, noise, or
radiation effects from the installation of this treatment
system. The quantities of solid waste generated from this
system are insignificant as are the additional energy re-
quirements .
COST AND REDUCTION BENEFITS OF ALTERNATIVE TREATMENT AND
OONtROL TECHNOLOGIES FOR WET PROCESS HARDbOARD
A detailed analysis of the costs and pollution reduction
benefits of alternative treatment and control technologies
applicable to the wet process hardboard industry is given
in Supplement A of this document. The typical mill selected
to represent the wet process industry has a production of
127 metric tons (140 tons) per day, a wastewater flow of
1,432 cubic meters (0.378 million gallons) per day, a BOD
of 33.75 kilograms per metric ton (67.5 pounds per ton),
and a suspended solids concentration of nine kilograms per
metric ton (18 pounds per ton). The basic results of the
cost estimates are shown below. All cost estimates are
based on August, 1971, prices.
Alternative A: Screening and"Primary Clarification
Raw wastewater characteristics for the typical mill having
a BOD of 33.75 kilograms per metric ton (67.5 pounds per
ton) represents a mill with recirculation but no inplant
treatment facilities.
Costs: $109,000
Reduction Benefits: A BOD reduction of ten
percent and a suspended solids re-
duction of 75 percent would be incurred.
Alternative B: Addition of Activated Sludge Process
This alternative includes the addition of an activated sludge
process including pH adjustment and nutrient addition to Al-
ternative A. The effluent from this system would average
3.4 kilograms per metric ton (6.8 pounds per ton) BOD and
2.25 kilograms per metric ton (4.5 pounds per ton) suspended
solids, respectively.
Costs: Incremental costs are approximately
$435,000 over Alternative A, thus the
total costs are $544,000.
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DRAFT
Reduction Benefits: An incremental reduc-
tion in BOD5 of from 2700 milligrams
per liter to 300 milligrams per
liter for a reduction of 88.9 per-
cent would be achieved. Suspended
solids would increase from 200 milli-
grams per liter to 250 milligrams per
liter for a 0.0 percent reduction.
Total plant reduction in BOD5 would
be 90 percent', and suspended solids
reduction would be 69 percent.
Alternative C: Addition of An Aerated Lagoon Treatment
System to Alternative's"
This alternative includes the addition of a five day deten-
tion time aerated lagoon to the preceding treatment system
in Alternative B. The effluent from this system would average
1.6 kilograms per metric ton (3.2 pounds per ton) BOD and
2.8 kilograms per metric ton C$.6 pounds per ton) of sus-
pended solids, respectively.
Costs: Incremental costs of $299,000 over
Alternative B would be incurred, thus
producing a total cost of $843,000.
Reduction Benefits: The BOD5 in the effluent
of this system would average 150 milli-
grams per liter for an incremental re-
duction of 50 percent and an overall
reduction of 69 percent.
Alternative D: Evaporation Of•Process Water - Activated
Sludge Treatment of Condensate
This alternative is a new process separate from those dis-
cussed previously. Alternative D consists of the" addition of
a pre-press inplant which results in wastewater discharges
totaling 442 liters per minute (117 gallons per minute) being
discharged from the pre-press and the hot press. The total
waste flow would be passed through a screen, primary clari-
fier, and evaporator. Condensate from the evaporator would
then be treated in an activated sludge system prior to dis-
charge.
Costs: Total cost of this system would
be $722,000.
Reduction Benefits: The BODc of this system
would average 0.2 kilograms per metric
ton (0.4 pounds per ton) and the sus-
pended solids 1.25 kilograms per metric
ton (2.5 pounds per ton) for an overall
reduction of 99.4 percent and 86 percent,
respectively.
253
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DRAFT
Factors Involved In The Installation of Alternative A
All existing wet process hardboard mills presently have
screening and settling or the equivalent of primary settl-
ing as part of their treatment systems. Several mills
utilize a single lagoon or pond for both settling and
sludge storage. The use of a settling and storage pond
in one unit is not desirable because of anaerobic decompo-
sition which resuspends solids and releases dissolved or-
ganics into the effluent. The primary clarifier recommended
in Alternative A consists of a mechanical clarifier with
continuous sludge wasting to a sludge lagoon.
Mechanical clarifiers are one of the simplest and most de-
pendable waste treatment systems available. They are not
sensitive to shock loads and shut-down and start-up of manu-
facturing processes have little or no effect. Primary clari-
fiers and screening devices are readily available on the
market and an estimated time of one year would be required
for the design and construction of such a facility. It is
estimated that an area less than one and one-half acres
would be required for this system. The additional energy
required to operate this system is estimated to be 22 kilo-
watt-hours .
There are no noise or radiation effects related'to this pro-
cess; however, the disposal of 285 kilograms (630 pounds) per
day of solids into a sludge lagoon may be a source of poten-
tial odor problems.
Factors Involved In the Installation" of Alternative B
Alternative B consists of an acitvated sludge system fol-
lowing the facilities previously discussed in Alternative
A. Activated sludge treatment of wet process hardboard
mill waste can be quite effective. However, the system
has all of the problems associated with activated sludge
treatment of domestic plus several more. These include
the necessity for pH- control- and nutrient addition. An-
other major problem is that the activated sludge pro-
duced does not readily settle. This can frequently cause
high suspended solids in the effluent. Temperature appar-
ently has a major effect not only by reducing the biologi-
cal reaction rates during cold weather, but also affecting
the settling rates of the mixed liquor suspended solids
(MLSS).
254
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DRAFT
Activated sludge systems require constant supervision and
maintenance. They are quite sensitive to shock loads and
to shut-down and start-up operations'of the manufacturing
process. The equipment needed for activated sludge systems
is available on the market; however, up to two years may be
required from initiation of design until beginning of plant
operation. The energy requirements as high as approximately
320 kilowatt-hours are needed to operate the process. There
is essentially no noise or radiation effects associated with
the process; however, the disposal of approximately 3.3 met-
ric tons (three tons) of waste solids each day can cause poten-
tial odor problems.
Factors Involved In The Installation Of Alternative C
Alternative C consists of an aerated lagoon following the pro-
cess described in Alternative B. Similar problems associated
with the operation of an activated sludge process hold true
with this system. Since the system will be preceded by an
activated sludge process, slug loads are not a problem. Temp-
erature does affect the system as it does'any biological
system. The only additional equipment necessary for this
system is aeration equipment of which an additional 225 kilo-
watt-hours of energy is required. The estimated time of con-
struction of this facility is one year from initiation of de-
sign. No noise or radiation problems are associated with this
process, nor are there any odor problems.
Factors Involved In The Installation Of Alternative D
Alternative D is a completely different system from those
described in Alternatives A through C. This system consists
of the installation of a pre-press inside the wet process mill
to dewater the stock between the cyclone and the stock chest.
This allows a projected decrease in wastewater flow from
1,432 cubic meters (0.378 million gallons) per day to 629 cu-
bic meters (0.166 million gallons) per day. Wastewater from
the pre-press and the wet press will first be treated through
a screening and clarification system as described in Alterna-
tive A. Next, instead of using a biological system to remove
organics, an evaporation system is used. This system produces
a saleable by-product similar to that presently being produced
by the Masonite Corporation at two mills. A portion of the
condensate is recycled back inplant and the remaining 545 cu-
bic meters (0.144 million gallons) per day is treated in an
activated sludge system similar to the system described in
Alternative B.
255
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DRAFT
Evaporation systems must be fed-at a relatively constant
rate as they are sensitive to shock loads.- Maintenance
requirements are high due to the nature of the material
being evaporated. The evaporator must be cleaned out
weekly, if not more frequently. Evaporation equipment
can be obtained on the market; however', a two year period
from initiation of design until start-up is not-unreasonable.
Noise and radiation effects are nil,but energy require-
ments for steam and electricity are significant. For
example, approximately 150 kilowatt-hours are required
to operate the system in addition to steam requirements.
Air pollution factors are related to the energy require-
ment as fuel must be burned to produce both steam and
electricity.
256
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DRAFT
PART C: WOOD PRESERVING
ALTERNATE TREATMENT AND CONTROL TECHNOLOGIES
Detailed information on the costs and benefits of various alterna-
tive treatment and control technologies applicable to the wood-
preserving industry is given in Supplement A of this hocument. As
previously indicated, Subcategory 1 and 2 plants are the only ones
for which substantial costs may be involved in achieving the re-
commended effluent limitations. Thus only these alternatives are
summarized in this section. Further data and the basis for cost
calculations are presented in Supplement A.
ENGINEERING ESTIMATES FOR A HYPOTHETICAL SUBCATEGORY 1 PLANT
Cost figures which have been obtained for wood-preserving plants
in Subcategory 1 as shown in Supplement A vary widely for a number
of reasons. In order to attempt to provide a reasonable common
basis for comparison, a hypothetical waste treatment facility was
devised to meet the suggested standards and costs estimated based
on May 1973 construction data.
The'treatments to be provided are those which already have been
recommended: A-- Oil separation; B - Coagulation and filtration;
C-| - Biological treatment in aerated lagoons; C2 - Biological
treatment by activated sludge; D - Chlorination as a polishing
treatment; and E - Effluent measurement. The two biological
treatments are alternates, either one or the other is intended to
be used. For estimating purposes, a daily wastewater flow of
53,000 liters (14,000 gallons) was used. The waste loading and
quality of effluent which is expected from each-stage of treat-
ment suggested is as follows:
mg/ liter
Parameter
COD
BOD
Phenols
Oil & Grease
Suspended Sol
Raw
Waste
40,000
20,000
190
1,500
ids 700
A
7,260
3,670
190
225
700
Treatments
B
3,630
1,865
190
80
350
C
410
260
2. "5
45
125
D
300
50
0.5
25
100
257
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DRAFT
A-Oil Separation - Standard oil separation equipment, equipped
for both surface and bottom removal, can be used for this purpose.
Capital cost estimate $ 29,760
Annualized cost including operation
and maintenance $ 0.31/ 1000 liters
B-Coagulation and Filtration - This would consist essentially of a
multi-compartmented tank equipped for rapid mix of coagulant, slow
mix, and sedimentation. Filtration would be by slow sand filters.
Capital cost estimate $ 43,320
Annualized cost including o and m $ 0.58/ 1000 liters
C1-Biological Treatment. Aerated Lagoons - A lined lagoon of about
3 meters in depth and having a surface of about 353 square meters
was selected. Two aerators of 7.5 hp each were selected to provide
the necessary aeration.
Capital cost estimate $ 21,120
Annualized cost including o and m $ 0.70/ 1000 liters
Co-Biological Treatment. Activated Sludge - An activated sludge
package plant having a capacity of 378,000 liters per day was
selected.
Capital cost estimate $120,000
Annualized cost including o and m $ 1.75/ 1000 liters
D-Polishing Treatment. Chlorination - Provision is made for dosages
of chlorine up to 500 mg/liter and a detention time of 3 to 6 hours.
Chlorine will be handled in 200-pound cylinders..
Capital cost estimate $ 8,400
Annualized cost including o and m $ 0.65/ 1000 liters
E-Effluent Measurement - A recording flow measurement device was
selected.
Capital cost estimate $ 3,600
Annualized cost including o and m $ 0.16/ 1000 liters
Total capital costs for complete treatment with lagoons $106,200
Annualized costs for same system $2.40/ 1000 liters
Total capital cost for complete treatment with activated sludge
. _. _, $205,080
Annual!zed costs for same system $3.45/ 1000 liters
ENGINEERING ESTIMATES FOR A HYPOTHETICAL SUBCATEGORY 2 PLANT
Among Subcategory 2 plants, the most common method of achieving the
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DRAFT
recommended effluent limitations is oil separation followed by
evaporation of the residual water. The cost estimate summary for
oil separation (Treatment A) has already been presented. Energy,
of course, is the most expensive item in disposing of• wastewater by
evaporation. Based on evaporation of 7,600 liters/day (2,000 GPD)
the fuel costs using natural gas are estimated at more than $4,000
per year. The total annual cost for this scheme (Treatment A plus
evaporation) would be about $ 5.98/ 1000 liters ($22.67 per 1000
gal.) of excess water evaporated.
NON-WATER QUALITY ASPECTS
None of the wastewater treatment and control technologies dis-
cussed above has a significant effect on non-water-environmental
quality. The limited volume of sludge generated by coagulation
and biological treatments of wastewater is currently being disposed
of in approved landfills by most plants. Because the organic com-
ponents of these sludges are biodegradable, this practice should
present no tfcpeat to the environment.
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DRAFT
SECTION IX
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
THE BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
EFFLUENT LIMITATIONS GUIDELINES
INTRODUCTION
The effluent limitations which must be achieved by July 1, 1977,
are to specify the degree of effluent reduction attainable
through the application of the Best Practicable Control Tech-
nology Currently Available. Best Practicable Control Technology
Currently Available is generally based upon the average of the
best existing performance by plants of various sizes, ages, and
unit processes within the industrial category and/or subcate-
gory. This average is not based upon a broad range of plants
within the timber products industry, but based upon performance
levels achieved by exemplary plants.
Consideration must also be given to:
(a) The total cost of application of tech-
nology in relation to the effluent re-
duction benefits to be achieved from
such application;
(b) The size and age of equipment and
facilities involved;
(c) The processes employed;
(d) The engineering aspects of the
application cf various types of con-
trol techniques;
(e) Process changes;
(f) Non-water quality environmental impact
(including energy requirements).
Also, Best Practicable Control Technology Currently Available
emphasizes treatment facilities at the end of a manufacturing
process but includes the control technologies within the pro-
cess itself when the latter are considered to be normal prac-
tice within an industry.
A further consideration is the degree of economic and engineering
reliability which must be established for the technology to be
"currently available." As a result of demonstration projects,
pilot plants, and general use, there must exist a high degree
of confidence in the engineering and economic practicability of
the technology at the time of commencement of construction or
installation of the control facilities.
261
NOTICE! THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUB.TECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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DRAFT
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
BEST POLLUTION CONTROL TECHNOLOGY CURRENTLY AVAILABLE~FO'R
THE VENEER AND PLYWOOD INDUSTRY
Based upon the information contained in Sections III through
VIII of this report, a determination has been made that the
degree of effluent reduction attainable through the applica-
tion of the Best Pollution Control Technology Currently Avail-
able is no discharge of wastewater (not including cooling
water) into navigable waters, with special consideration for
mills that now use steam vats and for mills that have hydrau-
lic barkers.
Identification ot best Pollution Control Technologies Cur-
rently Available"
Best Pollution Control Technology Currently Available for the
veneer and plywood industry is recycle and reuse of certain
process waters within the operation with land disposal of
excess water. To implement this requires:
(a) Recycle of sprinkling water from wet
decking. This includes screening and
suspended solids removal.
(b) Recycle of water from hot water vats.
This includes: (1) use of steam coils
rather than direct steam, (2) suspended
solids removal, and (3) pH control for
minimization of corrosive effects.
(c) Containment of dryer washwater. This
includes; (1) reduction of water
usage and (2) retention of entire flow.
(d) Recycle of glue washwater. This in-
cludes: (1) reduction in the amount
of fresh water used, (2) use of wash-
water to prepare glue, and (3) moni-
toring of glue and glue washwater to
maintain proper solids concentration.
(e) Retention of all general wastes:
e.g., floor and equipment washes.
Mills with existing steam vats are to be treated as special cases
for the following reasons: ,
(1) The development of technology for complete
retention of wastewater from steam vats is
not sufficiently advanced to be definitely
achievable by July 1, 1977.
262
NOTICE; THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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(2) Biological treatment of steam vat
wastewaters is technically feasible
and it has been reported that 85 to
90 percent removal can be obtained;
however, only one mill is known to
do this, and no verification of the
degree of treatment exists. The
cost of biological treatment is much
greater than the apparent cost to
modify steam vats to allow zero dis-
charge.
Approximate costs and effluent loads that can be achieved
with the application of biological treatment are described
in Section VIII, Cost, Energy and Non-Water Quality Aspects.
In addition to mills with steam vats, it has also been recom-
mended that mills that have hydraulic barkers also be given
special consideration concerning the July 1, 1977 deadline.
There are only a few mills with hydraulic barkers and it is
felt that by 1983, there will be none. The application of
hydraulic barkers is in the debarking of very large logs, and
the harvesting of large logs is decreasing rapidly.
Control and treatment technology for the effluent of hydraulic
barkers in non-existent. Waste characteristics are given in
Section V. From these it can be seen that suspended solids
concentrations are quite high. It is suggested that settling
be considered in dealing with effluents from hydraulic barkers.
Engineering Aspects of Control Technique Applications
The technology defined for this level is practicable since it
is practiced throughout the industry. In addition, there are
mills which are now achieving the effluent reductions set
forth herein. The concepts are proven, available for implemen-
tation, and may be readily adopted through adaptation or modi-
fication of existing production units.
Costs of Application
The cost of achieving zero discharge for a mill with the maxi-
mum water pollution problems is summarized in Section VIII,
Cost, Energy and Non'-Water Quality Aspects. The investment
costs associated with this level of technology represent about
one percent of the total capital investment needed to build a
veneer and plywood mill and the operating costs may be a simi-
lar contribution. It appears that the application of this level
of technology can be achieved without placing a heavy burden on
the industry.
263
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
BEST POLLUTION CONTROL TECHNOLOGY CURRENTLY AVAILABLE FOR
THE DRY PROCESS HARDBOARD INDUSTRY
Based upon the information contained in Sections III through
VIII of this report, a determination has been made that the
degree of effluent reduction attainable through the applica-
tion of the best pollution control technology currently avail-
able is no discharge of wastewater to navigable waters.
The best pollution control technology currently available for
discharge of non-contact cooling waters is described in the
Steam-electric Generation Effluent Guideline document.
Identification of Best Pollution Control
Technology Currently Available
Best pollution control technology currently available for the
dry process hardboard industry is recycle and reuse of cer-
tain process waters within the dry process hardboard mill with
land disposal of excess water. To implement this requires:
(a) The recycle of log wash or chip wash water
when used;
(b) The recycle of resin wash water;
(c) Neutralization of caul wash water followed
by land disposal;
(d) Elimination of housekeeping water by dry
cleaning;
(e) Elimination of discharge from humidifica-
tion by inplant control.
Rationale for the Selection of Best Pollution Control
Technology Currently Available
Age and Size of Equipment and Facilities. The dry process
industryTsrelatively new,therefore,the age'of the mills
is not a major factor. This coupled with the narrow size
differential between plants is insufficient to substantiate
the specifications for improvements in waste control indi-
cated.
Total Cost of Application in Relation to Effluent Reduction
Benefit's^The dry process industry as a whole is a relative-
ly minor wastewater source. The investment of a $5,000 maximum
per mill is an insignificant factor in the cost of producing
hardboard.
264
NOTICE; THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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Engineering Aspects of Control Techniques Utilized. This
level of technology is practicable because mills are pre-
sently utilizing this technology.
Process Changes. This technology requires no process
changes, rather modifications in housekeeping techniques
and existing process operation.
Non-Water Quality Environmental Impact. None.
265
NOTICE; THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE '
FOR THE WET PROCESS HARDBOARD INDUSTRY.
Based upon the information contained in Sections III
through VIII of this report, a determination has been made
that the degree of effluent reduction attainable through
the application of the best pollution control technology
currently available would allow a final BODc and suspended
solids discharge of 1.7 kilograms per ton (3.4 pounds per
ton) and 2.8 kilograms per ton (5.6 pounds per ton), res-
pectively.
Identification of Best Pollution Control Technology
Currently Available
Best pollution control technology currently available for
the wet process hardboard industry consists of the fol-
lowing recycle and reuse processes inplant, followed by
end-of-line waste treatment facilities.
(a) Recycle of process water as dilution
water utilizing temperature control
and suspended solids control to reduce
the total plant discharge to 10.2 cubic
meters per ton (2,700 gallons per ton),
the BOD to 33.8 kilograms per ton (67.5
pounds per ton) and the suspended solids
to 9 kilograms per ton (18 pounds per
ton) .
(b) The total wastewater flow to be treated
by screening, primary settling, activa-
ted sludge followed by an aerated
lagoon.
(c) Sludge to be either recycled inplant or
aerobically digested and disposed of in
sludge lagoons.
Rationale for the Selection of Best Pollution
Control Technology Currently Available
Age and Size of Equipment and Facilities. As set forth
in this report,industry competition and general improvement
in production concepts and wastewater management have led to
the modernization of plant facilities throughout the industry.
266
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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With the exception of one large mill, the size differential
between mills is insufficient to substantiate the specifica-
tions for improvements in waste control as indicated. The one
large mill should not be given special consideration.
i
Engineering Aspects of Control Technique Applications. This
level of technology is practicable because 22 percent of the
mills in the industry are presently achieving the effluent
reductions set forth herein. The concepts are proven, avail-
able for implementation, and may be readily adopted through
adaptation or modification of existing production units.
Process Changes. This technology does not require any sig-
nificant inplant modifications as the majority of mills are
presently discharging raw wastewater flows and concentrations
less than those utilized in the selection of end of pdpe
treatment systems.
Non-Water Quality Environmental Impact. There is one essen-
tial impact upon major non-water elements of the environment:
A potential effect on soil systems due to the need to utilize
land for the ultimate disposal of waste sludge. With respect
to this, it is addressed in a precautionary context only since
no evidence has been discovered which even intimates a direct
impact--all evidence points to the contrary. Technology and
knowledge are available to assure land disposal of sludge can
be done with no harmful effects to the environment.
Factors Which Might Affect Effluent Limitations
The major factor and the only factor which should be taken
into consideration is temperature. Low temperatures can have
a detrimental effect on biological systems..reducing their
treatment efficiency, causing increased concentrations of BOD
and suspended solids in the effluent. Effluent limitations
are based on an average effluent BOD and suspended solids of
150 mg/1 and 250 mg/1, respectively. It is felt that a well-
designed system as described previously can maintain this
treatment efficiency at temperatures such that the waste does
not freeze. Special considerations should be given during
periods of extreme low temperature when wastewater within the
treatment systems actually begins to freeze.
267
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
GUIDELINES AND LIMITATIONS FOR THE WOOD PRESERVING INDUSTRY
Recommendations contained in this section for the wood preserving indus-
try are based on data presented elsewhere in the report. Numerical limi-
tations on specific constituents of discharges are based on the average
of the best existing performance by plants in each subcategory. These
limitations are to be achieved by existing plants no later than July 1.
1977.
A rigid application of the effluent limitation parameters is not practi-
cal in all instances because of differences among plants in age, avail-
ability of land, production.process used, and other factors. Factors
that are pertinent in this regard are listed and described in terms of
their effect on the achievability of the recommended effluent limitations.
Consideration of these factors may require some modification of the efflu-
ent limitations in the case of particular plants.
Treatment and Control Technology Models
Treatment models representing "best practicable control technology cur-
rently available" are presented below. These models are not intended to
dictate procedures or processes, but instead are meant to illustrate the
methodology by which effluent limitation parameters can be achieved by
July 1, 1977. Alternatives to biological treatments include activated
carbon filtration and chemical oxidation. While these methods may give
the same end results, they are not judged to be economically practical at
present, except where the volume of waste is very small. Likewise, they
have never been applied on a commercial scale to wood preserving waste-
waters, and hence are not "currently available" in the sense of having a
high degree of engineering reliability.
TREATMENT MODELS; ACHIEVABLE BY JULY 1. 1977
Biological
linn
1. Oil Separation 1. Oil Separation
2. Equalization 2. Equalization
3. Chemical Coagulation 3. Chemical Coagulation
4. Sand Filtration 4. Sand Filtration
5. pH Control 5. pH Control
6. Biological Oxidation 6. Soil Irrigation
7. Secondary Clarification
Physical
"S" "T"
1. Oil Separation 1. Oil Separation
2. Coagulation 2. Coagulation
3. Sand Filtration 3. Sand Filtration
4. Evaporation 4. pH Control
5. Discharge to Sewer
268
NOTICE; THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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General
Biological oxidation is the only wastewater treating method that is both
currently available and economically feasible, by which the objectives
of the Act can be achieved by July 1, 1977. The method adopted by indi-
vidual plants will be determined in part by wastewater characteristics
and in part by such factors as volume of waste, capital investment re-
quired, land area available, and the specific stream standards that must
be met. For example, coagulation and filtration, both of which are shown
in the two models for biological treatments, will not be required for
wastewater from all plants. Secondary clarification is impractical where
treatment is by soil irrigation. The treatment methodology used, whether
extended aeration, aerated lagoon, or soil irrigation, will be determined
to a large extent by the availability of land, Finally, it is probable
that some plants will find it necessary to use a level of treatment beyond
that indicated in Models Q and R in order to meet specific stream standards.
The cost of biological treatments is generally recognized to be the lowest
among the possible methods of treatment that are compatible with current
water quality standards. A major factor that must be considered where this
method is used is cost of land. The best results achieved by exemplary
plants were obtained where there was sufficient land available to provide
lagoons with detention periods of from 120 to 180 days for the treated
wastewater. Plants with insufficient land for this purpose were unable
consistently to reduce phenol and COD content of their waste below about
2.0 and 450 mg/liter, respectively.
Models S and T, representing physical methods of waste disposal, are in-
cluded as part of the control and treatment technology achievable by Julyl,
1977 because the control methods indicated are both practical and currently
available for certain plants. With regard to Model T, approximately 15 per-
cent of the U.S. plants were discharging to publicly-owned sewers in 1972.
It is estimated that this percentage will increase to at least 25 percent
by 1977. However, the option to dispose of waste by discharging it to a
sewer is not available to all plants, depending as it does upon the prox-
imity of a plant to a sewer line and, in some instances, the treatment
charge levied by the municipality involved.
Evporation of wastewater is practical where the volume is small and, de-
pending upon the method used, the waste is of a quality that will permit
its reuse as cooling water. Two methods are currently used. In one, the
wastewater is simply boiled in an open vat equipped with steam coils until
it has all been evaporated. In the second, the process water is discharged
to a cooling tower equipped with both a fan and either steam coils or a
heat exchanger. The quantity of water in excess of that required for cool-
ing purposes is disposed of by intermittent operation of the heating sys-
tem. Costs of these methods of wastewater disposal are discussed in Sec-
tion VIII. These costs are expected to increase significantly in the fore-
seeable future because of anticipated increases in fuel cost. The economic
viability of the two methods is clearly questionable because of their high
energy requirements, except where the volume of wastewater is very small.
269
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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Because the treatment and control methods Indicated as best practicable
control technology currently available are "end-of-the-line" processes,
plant age is not considered to be a significant factor, except as indi-
cated elsewhere in this section. This is likewise true of process changes
that would need to be made to accommodate these methods. None would be
required, except as regards disposal of wastewater via a cooling tower,
as described above and indicated in Model S. This procedure is not amen-
able to plants in Subcategory 1 because of the relatively large volume
of water involved and the high energy input that would be required to
dispose of the excess water.
All of the methods proposed are standard in the sense that they are used
by a number of plants. None of them present any unique problems from
an engineering point of view.
In-Plant Control
In determining treatment and control technology achievable by July 1, 1977
the following assumptions were made:
(a) Volume of wastewater will be minimized by making the necessary in-
plant process changes to conserve water use.
(b) Oil content of influent to biological treating systems will be
limited to 100 mg/liter or less by installation of efficient oil
recovery equipment.
(c) Equipment and plumbing leaks will be eliminated and spills mini-
mized by good housekeeping practices.
(d) All discharges of contaminated water generated in processes employ-
ing salt-type preservatives and fire-retardant formulations will
be recovered and reused as make-up water in preparing fresh batches
of treating solution.
(e) Existing non-pressure processing equipment will be modified to
eliminate the introduction of water from precipitation in the
treating tank and new equipment will be designed to achieve
this result.
In-plant process changes which are currently in use in the industry, and
which will minimize the volume of wastewater that must be treated, include
the recirculation of direct-contact cooling water and segregation of con-
taminated and uncontaminated waste streams. Use of once-through, direct-
contact cooling water and mixing of contaminated and uncontaminated waste
streams are particularly incompatible with efforts to reduce wastewater
flow rate and will be reduced in order to maintain treating costs at a
reasonable level.
270
NOTICE; THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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Uncontaminated process water Includes condensate from heating coils and
heat exchangers, and non-contact cooling water. Although such water
could be discharged without treatment, its reuse is recommended. Reuse
of condensate from heating coils for boiler make-up water is economically
sound, since it is hot and essentially mineral free. The latter charac-
teristic precludes the necessity of adding scale-inhibiting chemicals
or otherwise treating it to reduce hardness.
Entrained oils are responsible for most of the pollution in the wood
preserving industry. Because of their importance, it is essential that
the efficient removal of oils be given primary consideration by plants
in the development of wastewater treating systems. The use of modified
closed steaming during conditioning and employment of low-speed, high
volume pumps in the transfer of preservatives are recommended methods
of reducing the incidence of emulsion formation. Removal of free oils
can be accomplished efficiently by well-designed, API-type separators.
Most of the residual oil in wastewater can be removed either by filtra-
tion through oil-absorbent materials or by chemical coagulation.
Control of storm water in the immediate vicinity of retorts and preserva-
tive storage tanks may be required because of the accumulation of oil
from spillage in such locations. Normally, the total area involved for
which collection of storm water is necessary should be quite small.
Collection and treatment of storm water from yards where treated products
are stored are unnecessary, based on available data, and are not econom-
ically practicable. Storage yards encompassing areas of 8 hectares (20
acres) or more are common in regions having rainfall of 100 to 150 centi-
meters (40 to 60 inches) per year. Even if the water could be channeled
into a lagoon—and this in itself would be a formidable task for plants
located on hilly terrain—the cost of treating the 95 million liters
(25 million gallons) of annual runoff from an 8-hectare (20 acre) yard,
most of which would occur during a four-month period, would far exceed
any environmental benefit that could be achieved.
Construction of a lagoon or other suitable structure at a location such
that it will intercept major spills is recommended at all plants.
Discharge Limitations
Numerical limitations on discharges for each subcategory of the wood pre-
serving industry are given in Tables 73 and 74. These values are ex-
pressed in the two tables as kilograms of pollutants per 1000 m3 of pro-
duct treated and in effluent concentration, respectively, for information
purposes only. The discharge from a plant must be limited on the basis
of total weight of pollutant per day. Total allowable discharge should
be computed from daily production data shown on the permit application.
271
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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TABLE 73 EFFLUENT LIMITATIONS BASED ON BEST PRACTICABLE CONTROL
TECHNOLOGY CURRENTLY AVAILABLE: WOOD PRESERVING INDUSTRY
(kilograms of pollutants/1000 m3 of product)*
Sub-
category
1
1
2
3
4
Wastewater
Volume
Iiters/m3
267
(2.0 gal/ft3)
—
—
—
Phenols COD
0.
(0.
No
No
No
658 109.236
041) (6.806)
discharge of
discharge of
discharge of
BOD
69.272
(4.316)
process
process
process
oil
and Suspended
Grease Solids
11.989 33.
(0.747) (2.
water permitted
water permitted
water permitted
304
075)
"Values in parentheses are discharge equivalents in pounds/1000
TABLE 74 EFFLUENT LIMITATIONS BASED ON BEST PRACTICABLE CONTROL
TECHNOLOGY CURRENTLY AVAILABLE: WOOD PRESERVING INDUSTRY
(milligrams of pollutants/liter of water)
WastewaterCRT
Sub- Volume and Suspended
category Iiters/m3 Phenols COD BOD Grease Solids
1 267 2.50 410 260 45 125
(2.0 gal/ft3)
2 — No discharge of process water permitted
3 — No discharge of process water permitted
4 -- No discharge of process water permitted
Limitations are not placed on total water usage, color, and dissolved
solids. However, when discharges containing color or dissolved solids
may cause harm to the receiving waters, or cause a violation of existing
water quality standards, limits must be established.
The pH of the final effluents from wood preserving plants should be with-
in the range of 6.0 to 8.5.
272
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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If effluent limits based on best practicable treatment currently avail-
able fail to meet existing water quality standards, such limits will be
upgraded as required.
Specific effluent parameters are given only for Subcategory 1 plants.
The effluent limitations for BOD and phenols were based on concentrations
of 2.50 mg/liter and 260 mg/liter, respectively,, For oil and grease the
value used was 45 mg/liter. The concentrations were applied to a flow
volume equivalent to 267 liters per cubic meter (2.0 gallons/ft3) of wood
treated. These flow rates were obtained from actual measurements made
over a period of 24 hours at a number of plants and from data supplied
by cooperating plants. Adjustments in measured flow were made to account
for reductions in discharge that can be achieved by procedures considered
normal for the industry and increases in discharge from storm water col-
lected around treating cylinders and preservative storage areas.
Chemical oxygen demand may be used to monitor BOD where an appropriate
correlation factor can be agreed upon. The equation, BOD = 0.497 COD + 60
expresses the relationship between the two parameters for BOD values of
150 and larger. However, the ratio of COD/BOD increases rapidly with de-
creasing BOD. For BOD values in the range of 20 to 50 mg/liter, the re-
lationship is BOD = 0.161 COD.
In general, the individual plants in the wood preserving industry do not
have the expertise required to make BOD determinations. There is, in
addition, some question regarding the reliability of BOD data from plant
to plant for this type of waste because of its characteristics. The
waste is sterile, and thus must be inoculated with bacterial cultures
previously acclimated to the waste. Differences of 200 percent in the
efficiency with which several acclimated cultures of bacteria could uti-
lize the same waste have been reported. Such differences would make
plant-to-plant comparisons of BOD values meaningless.
Factors to be Considered in Applying Effluent Limitations
The above assessment of what constitutes the best practicable control tech-
nology currently available is predicated on the assumption of a degree of
uniformity among plants within subcategories that, strictly speaking, does
not,exist. There are extenuating circumstances which make unrealistic
a rigid application of the same effluent limitations to all plants within
each subcategory. Some such factors are summarized here in the context
of their effect on the achievability of the recommended effluent limita-
tions.
Plant Age
The age of the production facilities is of primary significance in the
case of plants within subcategories for which a zero discharge restriction
is recommended. A zero discharge of pollutants from an operating wood pre-
serving plant is improbable at best, and, in the case of old plants, is
273
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INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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virtually impossible because of spills and leaks of preservatives on
plant property, adjacent roadways, and railroad right-of-way over
the years, it is inevitable that small amounts of these materials
wfll be picked up by storm water.
Recommended permissible discharge of pollutants in non-process water are
given in Table 75 for plants in Subcategories 2, 3, and 4. The discharge
is expressed in concentration only, since it is not related to quantity
of product treated. No discharge limit is given for boron because best
practical control technology currently available has not yet been deter-
mined for this element.
TABLE 75 RECOMMENDED PERMISSIBLE DISCHARGE OF SPECIFIC POLLUTANTS
IN NON-PROCESS WASTEWATER FROM WOOD PRESERVING PLANTS
IN SUBCATEGORIES 2, 3, AND 4
Plants in Plants in
Subcategory 3 Subcategories 2 and 4
Phenols
BOD
COD
Oil and Grease
Suspended Solids
Arseni c
Boron*
Chromium
Copper
Fl uori de
Zinc
0.1
25.0
155.0
5.0
15.0
.25
__
0.1
0.5
1.0
1.0
0.3
25.0
155.0
5.0
15.0
__
MM
_ _
__
__
— —
"Best control technology for boron has not been determined.
Use of Salt- and Oil-Type Preservatives in One Retort
A no discharge requirement is practical for wastewaters from salt-type
treatments (Subcategory 3) in plants where contaminated water from such
treatments can be kept segregated from other plant discharges. This is
not possible at plants where the same retort is used to treat with both
salt-type and oil-type preservatives and at those plants which apply dual
treatments. In spite of careful cleaning of all equipment preparatory to
changing from a salt-type preservative or fire-retardant to an oil-type
preservative, traces of the constituents in the former material remain in
the equipment and are picked up by and discharged with wastewater from sub-
sequent treatments using the oil-type preservative. Similarly, contamina-
tion of oily waste occurs when products treated with creosote are subse-
quently treated with salts.
274
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INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
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It Is recommended that discharges of heavy-metal Ions from plants in
Subcategory 1 thus affected be permitted in the amounts indicated in
Table 76. The proposed limitations on discharge per unit of produc-
tion are based on the concentrations shown and on a flow rate of 267
liters per cubic meter (2,0 gallons/ft3)0
The limits set for copper, chromium, fluorides, arsenic, and zinc are
based on literature reports of the maximum percent removal that can
practicably be obtained by standard chemical procedures involving re-
duction, lime flocculation, and sedimentation (122). Arsenic and
fluorides are the most difficult materials to remove from solution,
the latter because of the poor settling properties of calcium fluoride
and the solubility (8 mg/liter) of this chemical in alkaline water.
The maximum removal of arsenic by lime addition is 85 percent. Further
removals—up to a maximum of about 95 percent—have been achieved by
dual treatments involving lime addition and ferric chloride coagulant
in laboratory studies.
History of Pollution Control Effort
Some plants, prompted by state imposed deadlines, have already invested
heavily in pollution abatement and control programs (including the in-
stallation of equipment) designed to meet applicable stream standards.
In some instances, the proposed effluent limitations are more stringent
than those the plants are now required by state authorities to meet in
order to protect the receiving streams. It would impose a financial
hardship on these plants to require them to make additional outlays of
capital to meet limitations imposed by the best practicable control tech-
nology currently available while still paying off the original debt. In
addition, the plants would be placed in an unfair competitive position
with other plants, which, for one reason or another, found it unnecessary
to make the earlier investment. It is recommended, therefore, that prior
investments in pollution control programs and facilities be considered in
determining requirements for these plants, provided their effluents are
compatible with existing stream standards.
Non-Conforming Plants with High Removal Rates
Because of the particular characteristics of their wastewater, it is pos-
sible that a few plants will be unable to conform to July 1, 1977 efflu-
ent limitations even after achieving reductions of 90 percent or more in
the major pollutants identified in Section VI. It is recommended that a
variance to these limitations be allowed for plants that achieve a mini-
mum reduction of 95 percent in the major pollutants, provided that the
discharge is compatible with existing stream standards.
275
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TABLE 76
RECOMMENDED PERMISSIBLE DISCHARGES OF METALS FROM WOOD PRESERVING
PLANTS IN SUBCATEGORY 1 THAT EMPLOY THE SAME RETORT
FOR BOTH OIL-TYPE AND SALT-TYPE PRESERVATIVES
(Parenthetical values are discharge equivalents in pounds/1000 ft3)
Concentration Weight
Parameter (mg/1) (kg/1000 m3)
Arsenic
Boron*
Chromium
Copper
Fluorides
Zinc
Ammonia (as N)
Phosphorus
1.0
—
1.0
1.0
10.0
2.0
5.0
5.0
0.273
--
0.273
0.273
2.664
0.532
1.332
1.332
(0.017)
(0.017)
(0.017)
(0.166)
(0.033)
(0.083)
(0.083)
*Best practicable treatment for boron has not been determined.
276
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Avail ability of Land
As mentioned elsewhere, the best performance among plants currently oper-
ating waste treating facilities is at those with sufficient land area to
permit long-term containment of treated wastewaters. It is improbable
that a conventional biological treatment, such as trickling filtration
or extended aeration, will consistently reduce oxygen demand and phenol
content values compatible with requirements of the best practicable con-
trol technology currently available. All of the plants visited that are
applying a biological treatment to their waste prior to discharging it
to a stream have multizone lagoons that provide a total detention time
of up to 180 days after initial treatment by extended aeration or in
aerated lagoons. Plants unable to acquire the land needed for lagoon
construction should be given special consideration with regard to efflu-
ent limitation requirements.
Non-Pressure Processes
A zero discharge requirement is recommended for non-pressure plants. The
control measure necessary to attain this level of pollution abatement re-
quires only that water be kept out of the open tanks that are used in
this process. This is not feasible in the case of a few plants in cold
climates because of ice formation on stock prior to treatment. It is
recommended that these plants be permitted a discharge during winter
months equivalent to 25 percent of that allowed for plants in subcate-
gory 1.
277
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SECTION X
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
THE BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE
EFFLUENT LIMITATIONS GUIDELINES
INTRODUCTION
The effluent limitations which must be achieved by July 1,
1973, are to specify the degree of effluent reduction attain-
able through the application of the best available technology
economically achievable. The best available technology eco-
nomically achievable is not based upon an average of the best
performance within an industrial category, but is to be
determined by identifying the very best control and treatment
technology employed by a specific point source within the
industrial category or subcategory, or where it is readily
transferable from one industry process to another. A speci-
fic finding must be made as to the availability of control
measures and practices to eliminate the discharge of pollu-
tants, taking into account the cost of such elimination.
Consideration must also be given to:
(a) the age of equipment and facilities involved;
(b) the process employed;
(c) the engineering aspects of the application of
various types of control techniques;
(d) process changes
(e) cost of achieving the effluent reduction
resulting from application of the best eco-
nomically achievable technology;
(f) non-water quality environmental impact
(including energy requirements).
In contrast to the best practicable control technology cur-
rently available, the best economically achievably technology
assesses the availability in all cases of in-process controls
as well as control or additional treatment techniques employed
at the end of a production process.
Those plant processes and control technologies which at the
pilot plant, semi-works, or other level, have demonstrated
both technological performances and economic viability at a
level sufficient to reasonably justify investing in such faci-
lities may be considered in assessing the best available eco-
nomically achievable technology. The best available economically
279
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achievable technology is the highest degree of control
technology that has been achieved or has been demonstrated
to be capable of being designed for plant scale operation
up to and including "no discharge" of pollutants. Although
economic factors are considered in this development, the
costs for this level of control are intended to be the top-
of-the-line of current technology subject to limitations
imposed by economic and engineering feasibility. However,
the best available technology economically achievable may
be characterized by some technical risk with respect to
performance and with respect to certainty of costs. There-
fore, the best available technology economically achievable
-may necessitate some industrially sponsored development work
prior to its application.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
THE BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE--
EFFLUENT LIMITATIONS GUIDELINES FOR THE VENEER AND PLYWOOD
INDUSTRY
The effluent limitations reflecting this technology is no
discharge to navigable waters as developed in Section IX.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
THE BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE--
EFFLUENT LIMITATIONS GUIDELINES FOR THE DRY PROCESS HARD-
BOARD INDUSTRY
The effluent limitations reflecting this technology is no
discharge to navigable waters as developed in Section IX.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
THE BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE-- '
EFFLUENT LIMITATIONS GUIDELINES FOR THE WET PROCESS HARD-
BOARD INDUSTRY
Based upon the information contained in Sections III through
VIII of this report, a determination has been made that the
degree of effluent reduction attainable through the applica-
tion of the best available technology economically achievable
would result in the discharge of 0.2 kilograms per ton (0.4
pounds per ton) of BOD and 1.1 kilograms per ton (2.1 pounds
per ton) suspended solids.
Identification of Best Available Technology
Economically Achievable
Best available technology economically achievable for the
wet process hardboard industry is achieved by inplant
280
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modifications, recycle and reuse of certain processes within
the mill and with activated sludge treatment of the discharge
water. To implement this requires:
(a) Installation of a pre-press between the cyclone
and stock chest to reduce wastewater to 4.5
cubic meters per ton (1,186 gallons per ton),
the BOD to 33.8 kilograms per ton (67.5 pounds
per ton), and the suspended solids to 9 kilo-
grams per ton (18 pounds per ton).
(b) Recycle of process water to cyclone and stock
chest.
(c) Discharge of process water only from the pre-
press and the wet press.
(d) Treatment of the process water discharge by
screening, primary clarification and evapora-
tion.
(e) Recycle of a portion of the condensate water
back to the process.
(f) Activated sludge treatment of the excess con-
densate from the evaporator.
Rationale for the Selection of Best Pollution Control
Technology Currently Available
Age and Size of Equipment and Facilities. As set forth in
this report,industry competition and general improvement as
set in production concepts and wastewater management have led
to the modernization of plant facilities throughout the in-
dustry. With the exception of one large mill, the size dif-
ferential between mills is insufficient to substantiate the
specifications for improvements in waste control as indicated.
The one large mill should not be given special consideration.
Engineering Aspects of Control Technique Applications. The
process employed is presently being utilized by 22 percent of
the industry and,therefore, can be stated to be considered as
available technology.
Process Changes. This technology requires the installation of
a pre-press and rearrangement of process water flow. At least
one of the existing nine wet process hardboard mills is pre-
sently using the inplant process.
Non-Water Quality Environmental Impact. There is one essen-
tial impact upon major non-water elements of the environment:
A potential effect on soil systems due to the need to utilize
land as the ultimate disposition of waste sludge. With respect
281
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to this, it is addressed in a precautionary context only since
no evidence has been discovered which even intimates a direct
impact--all evidence points to the contrary. Technology and
knowledge are available to assure land disposal of sludge can
be done with no harmful effects to the environment.
Factors Which Might Affect Effluent Limitations. The major
factor and the only factor which should be taken into considera-
tion is temperature. Low temperatures can have a detrimental
effect on biological systems,reducing their treatment effi-
ciency, causing increased concentrations of BOD and suspended
solids in the effluent. Effluent limitations are based on an
average effluent BOD and suspended solids of 45 mg/1 and 250
mg/1, respectively. It is felt that a well designed system,
as described previously,can maintain this treatment efficiency
at temperatures such that the waste does not freeze. Special
considerations should be given during periods of extreme low
temperature when wastewater within the treatment systems ac-
tually begins to freeze.
BEST AVAILABLEi TECHNOLOGY'ECONOMICALLY ACHIEVABLE, GUIDELINES
AND LIMITATIONS FOR THE WOOD PRESERVING INDUSTRY
Recommendations contained in this section for the wood pre-
serving industry are based on data presented in other sections
of this report. Numerical limitations on constituents of
discharges are based in part on the existing performance of
the best control and treatment technology employed by a specific
plant within each category, and in part on the performance
achieved by control and treatment technology demonstrated in
plant studies. These limitations are to be achieved by exist-
ing plants no later than July 1, 1983.
Treatment and Control Technology Models
Treatment models representing best available technology eco-
nomically achievable are presented below. There are many
methods by which these effluent limitation requirements can be
achieved. The models shown are presented for illustrative pur-
poses only, and are not intended to limit the technology that
may be applied.
As in the case of best practical control technology currently
available, biological treatment is the primary "end-of-the-line"
method by which plants can achieve the best available technology
economically achievable requirements of best available tech-
nology economically achievable. Unlike best practical control
282
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technology currently available, best available technology
economically achievable includes additional treatment tech-
niques, the purpose of which is to achieve a reduction in
discharge beyond those capable of being achieved by July 1,
1983. These treatments include, but are not limited to,
two-stage biological treatments and polishing treatments
based on activated-carbon filtration and chlorination.
Treatment Models Achievable by July 1, 1983
Biological
U V
1. Oil Separation
2. Equalization
3. Chemical Coagulation
4. Sand Filtration
5. pH Control
6. Biological Oxidation
7. Secondary Clarification
8. Chlorination
W
1. Oil Separation
2. Equalization
3. Chemical Coagulation
4. Sand Filtration
5. pH Control
6. Biological Oxidation - 1
7. Biological Oxidation - 2
8. Secondary Clarification
1.
2.
3.
4.
5.
6.
Oil Separation
Equalization
Chemical Coagulation
Sand Filtration
pH Control
Soil Irrigation
1,
2,
3,
4,
5,
6,
7,
8,
Oil Separation
Equalization
Chemical Coagulation
Sand Filtration
pH Control
Biological Oxidation
Secondary Clarification
Carbon Filtration
1. Oil Separation
2. Equalization
3. Chemical Coagulation
4. Evaporation
Physical
1.
2.
3.
4.
Oil Separation
Equalization
Chemical Coagulation
Discharge to Sewer
It is unlikely that a conventional single-stage biological
treatment alone will consistently achieve the effluent
limitations required by July 1, 1983. Polishing treatments
employing chemical oxidation, carbon filtration, or further
biological treatment will probably be needed. The capital
283
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investments needed to install post-treatment carbon filtration
and chlorination facilities are estimated to be $8,000 and
$5,000, respectively. These costs are based on 1971 costs,
a flow rate of 19,000 liters per day (5,000 gallons per day),
and wastewater characteristics conforming with the July 1,
1977 requirements. The investment required to add a bio-
logical polishing treatment could vary widely depending upon
the type of facility added. The type chosen would be influ-
enced by theamount of land area available.
Soil irrigation is included as the best available technology
economically achievable, since it provides a means by which
zero discharge can be achieved by plants with land available
for this use. Wastewater disposal by evaporation and by dis-
charge to a sewer are included for the same reason. The extent
to which evaporation by heating will be an economically viable
method by 1983 will depend upon energy costs and volume of
wastewater involved. It is anticipated that inplant process
changes and recycling of water will reduce substantially the
total volume of water that must be disposed of. Spray evapora-
tion, if proven to be feasible at the several plants at which
the method is under test, should provide a less costly alter-
native to evaporation by other means.
Among the factors that are pertinent in determining the tech-
nology economically achievable by July 1, 1983, the process
employed in conditioning stock for treatment is of primary
importance. Because of low flow rate and favorable wastewater
characteristics, particularly the general absence of emulsions
in process water, a zero discharge is a feasible requirement
for plants that employ the Boulton process as the predominant
method of conditioning. A similar requirement is not practical
for plants using steam conditioning. Inplant process changes
and reuse of some process water will reduce the volume of dis-
charge from plants in the latter group, but to achieve zero
discharge would require the disposal of a relatively large
volume of excess water. Spray evaporation may prove to be a
feasible method of disposal, but this method will be available
only to those plants that have sufficient land area devotable
to this use.
Plant age, peculiarities of plant layout, and the process
changes needed to reduce or eliminate discharge are important
from the standpoint of their effect on cost of complying with
the 1983 requirements. However, these factors are not of
overriding importance and do not require special considerations,
except in cases mentioned elsewhere. Likewise, the engineering
aspects of the application of the control techniques needed to
284
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achieve 1983 effluent limitations are not unique and should
present little problem to plants with access to competent
engineering service.
The importance of the application of 1983 technology on non-
water quality environment will be minimal. Total energy
requirements will depend upon the exact methodology employed;
but for many plants, they will be reduced in total because of
inplant process changes that must be made to reduce total
water usage. These changes and their effect on energy require-
ments are covered elsewhere.
Inplant Control
The low wastewater flow rate and stringent limitations on
discharges that must be achieved to conform with 1983 require-
ments will necessitate a high level of water reuse, changes in
steaming technique among plants using open steaming, efficient
oil recovery systems, and the initiation of an efficient pre-
ventive maintenance and housekeeping program. The following
assumptions related to these factors were made in determining
the best available technology economically achievable.
(1) The volume of discharge will be minimized by:
(a) Recycling all direct-contact cooling water
(b) Reuse of a portion of the process water for cooling
purposes
(c) Insulation of retorts and steam pipes to reduce the
volume of cylinder condensate
(d) Use of closed steaming or modified-closed steaming
to reduce the volume of cylinder condensate and to
lessen the incidence of oil-water emulsion formation
(e) Reuse of all water contaminated with heavy metals in
preparing treating solutions of salt-type preserva-
tives and fire retardants
(f) Segregation of contaminated and uncontaminated waste
streams
(2) Oil-recovery systems will be modified or replaced, as
required, to ensure efficient removal of oils.
(3) Preventive maintenance and good housekeeping programs
will be inaugurated to reduce spills and leaks and
provide a standard procedure for cleaning up those
that do occur.
Some of the methods of reducing waste flow are standard indus-
try practice, and they would normally be adopted as early as
285
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1977. These include waste stream segregation, recycling of
contaminated cooling water, and reuse of wastewater from salt-
type treatments, Use of process water to meet cooling water
requirements is a common practice among plants in Subcategory
2. These practices are mentioned here because of their con-
tinued importance.
Closed steaming is applicable to virtually all plants using
steam conditioning. It is the single most important inplant
process change that a plant can make from the. standpoint of
both reducing the volume of wastewater that must be disposed
of and also reducing emulsion formation. Modified-closed
steaming, while reducing the volume of wastewater to a lesser
extent than closed steaming, also lessens emulsion formation.
In addition, this method substantially reduces steam require-
ments by retaining the hot steam condensate in the retort
rather than discharging it as it forms.
Like closed steaming, insulation of cylinders and pipes used
in steam transfer potentially can reduce both the volume of
condensate formed and the energy requirements for steam
generation. The heat loss from an uninsulated metal vessel
amounts to 7.3 kilogram-calories per hour per square meter
of surface area (2.7 BTU per hour per square foot) for each
degree of temperature difference between the inside and out-
side of the vessel. For an uninsulated retort 2.13 meters
(7 feet) in diameter and 36.57 meters C120 feet) long, the
daily heat loss would be 7.56 million kilogram-calories (30
million BTU's) if the inside and ambient temperatures were
121°C and 27°C (250°F and 80°F), respectively. This loss
can be cut by 70 percent by proper insulation. In addition,
the volume of condensate produced would also be reduced
significantly.
A well executed preventive maintenance and housekeeping pro-
gram is an integral part of the treatment and control tech-
nology required to achieve 1983 limitations. Spills and leaks
can largely negate the efforts directed toward other, more
obvious aspects of wastewater management if they are ignored.
The areas around and in the immediate vicinity of retorts and
storage tanks are of particular importance because of the
opportunity for storm water contamination from preservative
drips and spills associated with freshly pulled charges and
loss of preservative from plumbing and pump leaks. Considera-
tion should be given to paving the area in front of retorts
to permit channeling of drips and spills to a sump from which
the oil can be recovered.
286
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Discharge Limitations
Numerical effluent limitations to meet the best available
technology economically achievable are given in Tables 77 and
78 for each subcategory of the industry. These values are
expressed in the two tables as kilograms of pollutants per
1,000 cubic meters of product treated and in effluent concen-
trations for information purposes only. The discharge from
a plant will be limited on the basis of total weight of
pollutant per day. Total allowable discharge should be com-
puted from daily production data shown on the permit applica-
tion.
Limitations are not placed on total water usage, color, and
dissolved solids. However, when discharges containing color
and dissolved solids may cause harm to the receiving waters,
or cause a violation of existing water-quality standards,
limits will be established.
The pH of the final effluents from wood-preserving plants
shall be within the range of 6.0 to 8.5.
Effluent limitations for BOD, phenols, suspended solids, and
oil and grease are based on concentrations of 50, 0.5, 100
and 25 mg/1, respectively. A waste flow of 133 liters per
cubic meter (1.0 gallons per square feet) was assumed in
calculating permissible discharge per unit of production.
A lower ratio of discharge to volume of production is achieved
by several exemplary plants as a result of treating a much
higher proportion of dry stock than is typical for the indus-
try as a whole. A discharge of 133 liters per cubic meter (one
gallon per square foot) of product is judged to be the lowest
value that can be reasonably achieved by plants treating a
normal proportion of unseasoned stock.
Chemical oxygen demand may be used to monitor BOD where an
appropriate correlation factor can be determined. The
equation BOD = 0.497 COD + 60 expresses the relationship
between the two parameters for BOD values of 150 and larger.
However, the ratio of BOD/COD increases rapidly with decreas-
ing BOD. For BOD values of 50 and smaller, the relationship
BOD = 0.161 COD has been found to be applicable.
Factors to be Considered in Applying Effluent Limitations
The identification of treatment and control technology to
attain the best available technology economically achievable
for the various subcategories can be applied uniformly to
most plants in the industry. The exceptions are those
287
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TABLE 77 EFFLUENT LIMITATIONS BASED ON BEST AVAILABLE
TECHNOLOGY ECONOMICALLY ACHIEVABLE
(kilograms of pollutants/1000 M3 of product)3
Wastewater Oil
Sub- Volume and Suspended
Category (liters/m5) Phenols COD BOD Grease Solids
1 133 0.064 41.301 6.662 3.338 13.323
(1.0 gal/ft3) (0.004) (2.573) (0.415) (0.208) (0.830)
2 No discharge of process water permitted
3 No discharge of process water permitted
4 No discharge of process water permitted
aValues in parentheses are discharge equivalents in pounds/1000
TABLE 78 EFFLUENT LIMITATIONS BASED ON BEST AVAILABLE
TECHNOLOGY ECONOMICALLY ACHIEVABLE
(milligrams of pollutants/liter of water)
Wastewater Oil
Sub- Volume and Suspended
Category (liters/m3) Phenols COD BOD Grease Solids
1 133 0.50 310 50 25 100
(1.0 gal/ft3)
2 - No discharge of process water permitted
3 - No discharge of process water permitted
4 - No discharge of process water permitted
288
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plants which, because of age of equipment and facilities,
availability of land, or other factors, are unable to con-
form to these requirements. Some of the factors which will
have an effect on the ability of individual plants to meet
the recommended effluent limitations are summarized in this
section.
Age of Plant. The effect of plant age on the achievability
of zero discharge was previously discussed. The previous
justification for a variance of requirements to permit trace
amounts of pollutants in non-process wastewater to be dis-
charged is equally applicable in this section.
Use of Salt- and Oil-Type Preservatives in one Retort. The
inability of plants in Subcategory 1 which use a single re-
tort for both salt-type and oil-type preservatives, or which
apply dual treatments, to prevent contamination of oily
wastewater with metals from preservatives of the former type
was previously discussed. Most of the plants in this group
are small, the operation consisting of a single retort. It
is recommended that a variance to the no-discharge require-
ment for plants treating with inorganic preservatives and
fire retardants that are in this group be permitted under
1983 requirements. The proposed limitations on discharge
per unit or production given in Table 79 are based on the
concentrations shown and a flow rate of 133 liters per cubic
meter (1.0 gallon per cubic foot) of product treated.
289
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TABLE 79 RECOMMENDED PERMISSIBLE DISCHARGES OF METALS
FROM PLANTS IN SUBCATEGORY 1 THAT EMPLOY ONE
RETORT TO APPLY PRESERVATIVE TREATMENT WITH
OIL-TYPE AND SALT-TYPE PRESERVATIVES
Parameter
Boronb
Arsenic
Chromium
Copper
Fluorides
Zinc
Ammonia (as N)
Phosphorus
Concentration
(mg/1)
-
1.
1.
1.
10.
2.
5.
5.
0
0
0
0
0
0
0
Weight3
(Kg/1000
0.
0.
0.
1.
0.
0.
0.
128
128
128
330
273
666
666
(0.
(0.
(0.
(0.
(0.
(0.
(0.
m3)
008)
008)
008)
083)
017)
041)
041)
aValues in parentheses are pounds/1000 ft3.
"Best control technology for boron has not been determined.
290
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SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
INTRODUCTION
This level of technology is to be achieved by new sources. The term
"new source" is defined in the Act to mean "any source, the construc-
tion of which is commenced after the publication of proposed regula-
tions prescribing a standard of performance." New source technology
shall be evaluated by adding to the consideration underlying the ident-
ification of best available technology economically achievable a deter-
mination of what higher levels of pollution control are available through
the use of improved production processes and/or treatment techniques.
Thus, in addition to considering the best in-plant and end-of-process
control technology, identified in best available technology economically
achievable, new source technology is to be based upon an analysis of how
the level of effluent may be reduced by changing the production process
itself. Alternative processes, operating methods or other alternatives
must be considered. However, the end result of the analysis will be to
identify effluent standards which reflect levels of control achievable
through the use of improved production processes (as well as control
technology), rather than prescribing a particular type of process or
technology which must be employed. A further detennination which must
be made for new source technology is whether a standard permitting no
discharge of pollutants is practicable.
Specific Factors To Be Taken Into Consideration
At least the following factors should be considered with respect to pro-
duction processes which are to be analyzed in assessing new source tech-
nology:
a. The type of process employed and process changes;
b. Operating methods;
c. Batch as opposed to continuous operations;
d. Use of alternative raw materials and mixes of raw materials;
e. Use of dry rather than wet processes (including substitution
of recoverable solvents for water); and
f. Recovery of pollutants as by-products.
NEW SOURCE PERFORMANCE STANDARDS FOR THE VENEER AND PLYWOOD INDUSTRY
The effluent limitations for new sources is no discharge to navigable
waters as developed in Section IX.
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NEW SOURCE PERFORMANCE STANDARDS FOR THE DRY PROCESS HARDBOARD INDUSTRY
The effluent limitations for new sources is no discharge to navigable
waters as developed in Section IX.
NEW SOURCE PERFORMANCE STANDARDS FOR THE WET PROCESS HARDBOARD INDUSTRY
The effluent limitations for new sources is the same as those shown in
Section X for application of the Best Available Technology Economically
Achievable — 0.2 kilograms per metric ton (0.4 pounds per ton) BOD, and
1.0 kilograms per metric ton (2.1 pounds per ton) suspended solids.
Before discharge to a publicly-owned activated sludge or trickling fil-
ter waste water treatment plant, a wet process hardboard mill should sub-
ject its discharge to primary treatment to remove a majority of fiber
in the wastewater. In addition, the pH may have to be adjusted to 6.0
to 6.5. This would have to be decided on a plant-to-plant basis with
consideration given to the relative volume of hardboard mill discharge
compared to the domestic waste being treated.
There are no known contaminants which will pass through such a system.
NEW SOURCE PERFORMANCE STANDARDS AND PRETREATMENT STANDARDS FOR THE WOOD
PRESERVING INDUSTRY
General
The technology by which zero discharge of process water from new plants
in Subcategories 2, 3, and 4 can be achieved is both practical and cur-
rently available. Performance standards for new plants in these groups
will remain unchanged from those outlined in the two preceding sections.
The remarks which follow pertain to plants in Subcategory 1.
The process by which wood is treated by plants in Subcategory 1 is direct
and simple. Basically, it consists of placing the stock in a pressure
retort, conditioning it using steam or vapors of an organic solvent, and
impregnating it with a preservative or fire retardant. The opportunity
for change in the production process of an operation of this type is
limited. Alternative raw materials are not available. Replacement of
existing preservatives with new or different chemicals is not feasible
in the foreseeable future. Modification of preservatives to reduce pollu-
tion is practical in the case of pentachlorophenol. Two processes which
use recoverable solvents for this chemical are being used by a limited
number of plants. However, both processes are proprietary and may be used
only by licensees.
A consideration of the over-all operation reveals only two processing
steps in which the opportunity exists for changes that can lead to re-
duced discharge. Both are related to preparation of stock for preserva-
tive treatment, and both are expensive in terms of the capital investment
292
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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required. One of the methods Is to treat dry stock, and thereby abrogate
the need to steam condition It. The other method Is to steam condition
or vapor dry stock In a separate retort from the one In which the pre-
servative treatment is applied. Both methods, which are used to some ex-
tent by existing plants, serve to separate conditioning operations from
treating operations and thereby prevent contamination of water with pre-
servatives.
Approximately 30 percent of the plants in the United States currently
kiln dry a portion of their stock prior to treatment. Only about 10
percent use kiln drying for all their stock. There are two main reasons
why kilns are not used more widely than they are. First, the capital
investment is high, amounting to $60,000 per kiln. A minimum of five
kilns would be required if all the material treated by a typical three-
retort plant were dried prior to preservative treatment. Secondly, kiln
drying darkens the surface of poles so that some poles do not meet the
color standards under which an increasing percentage of the ones treated
with pentachlorophenol are sold.
The investment required to install a sufficient number of retorts so that
steam conditioning and treating are not conducted in the same vessel
would be similar to that required above. For a plant with a design capac-
ity of 850 m3 (30,000 ft3) of production per week, a minimum of three con-
ditioning cylinders 2.13 m x 36.58 m (71 x 120') would be required to sup-
ply the 15 charges of conditioned poles needed each week. The investment
required for that portion of the plant devoted to steaming, including steam
generating and vacuum equipment, would amount to an estimated $260,000.
The plant would still have wastewater to treat, albeit water that would be
much less contaminated than that from a plant steaming and treating in the
same retort.
A detailed discussion of the costs associated with kiln drying and steam-
ing is presented in Section VIII.
A reduction in the volume of discharge can also be obtained by air season-
ing stock before treating it. Some air seasoning takes place in the nor-
mal processing of material on the yard, and most plants ordinarily main-
tain an inventory of untreated stock in open stacks to expedite the fill-
ing of orders. Any seasoning that occurs here lessens the conditioning
time required when the material is treated. To air season thoroughly,
certain items, such as poles and piling, take up to six months. The
large inventory required for this imposes a financial burden on the owners
and is not practical during a prolonged period of high demand such as cur-
rently exists. Furthermore, deterioration is a problem in the South when
stock is stored for the time required for it to air season.
It is apparent from the foregoing discussion that there is no simple, eco-
nomically viable method to reduce the volume of discharge from plants in
293
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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Subcategory 1 below that based on the best available technology economi-
cally achievable. It is recommended that new sources performance stan-
dards for plants in Subcategory 1 remain the same as those developed in
Section X.
Treatment And Control Technology Models
Treatment models applicable to new source performance standards are pre-
sented below. The models are the same as those suggested in Section X,
except that polishing treatments involving chlori nation and activated
carbon filtration are not included. The use of the latter methods will
be added to the recommended methods of wastewater treatment for new sources
when additional data on their applicability to wood preserving effluents
become available.
TREATMENT MODELS; NEW SOURCE PERFORMANCE STANDARDS
Biological
1. Oil Separation 1. Oil Separation
2. Equalization 2. Equalization
3. Chemical Coagulation 3. Chemical Coagulation
4. Sand Filtration 4. Sand Filtration
5. pH Control 5. pH Control
6. Soil Irrigation 6. Biological Oxidation - 1
7. Biological Oxidation - 2
8. Secondary Clarification
Physical
1. Oil Separation 1. Oil Separation
2. Equalization 2. Equalization
3. Chemical Coagulation 3. Chemical Coagulation
4. Evaporation 4. Discharge to Sewer
Discharge Limitations
Numerical limitations for new source performance standards are given in
Tables 80 and 81 for each Subcategory of the wood preserving industry.
These values are expressed in the two tables as kilograms of pollutants
per 1000 m3 of product treated and in effluent concentrations for informa-
tion purposes only. The discharge from a plant will be limited on the
basis of total weight of pollutant per day. Total allowable discharge
should be computed from daily production data shown on the permit appli-
cation.
294
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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Limitations are not placed on total water usage, color, and dissolved
solids. However, when discharges containing color and dissolved solids
may cause harm to the receiving waters, or cause a violation of existing
water quality standards, limits will be established.
The pH of the final effluents from wood preserving plants shall be with-
in the range of 6.0 to 8.5.
TABLE 80 STANDARDS OF PERFORMANCE FOR NEW SOURCES
(kilograms of pollutants/1000 m3 of product)*
____^ Subcategory
Parameter 1 2 *
Phenols 0.064 (0.004)** No discharge of process water
COD 41.301 (2.573) permitted for plants in Sub-
BOD 6.662 (0.415) categories 2, 3, and 4.
Oil and Grease 3.338 (0.208)
Suspended Solids 13.323 (0.830)
*Based on a flow rate of 133 liters/m^ (1.0 gal/ft^).
**Parenthetical values are pounds/1000 ft3.
TABLE 81 STANDARDS OF PERFORMANCE FOR NEW SOURCES
(milligrams of pollutants/liter of water)
___^ Subcategory
Parameter 1 2 3~
Phenols 0.50 No discharge of process water
COD 310 permitted for plants in Sub-
BOD 50 categories, 2, 3, and 4
Oil and Grease 25
Suspended Solids 100
295
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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Effluent limitations for BOD, phenols, suspended solids, and oil and
grease are based on concentrations of 50, 0.5, 100, and 25 mg/liter,
respectively. A waste flow of 133 liters per cubic meter (1.0 gallons/
ft3) was assumed in calculating permissible discharge per unit of pro-
duction. A lower ratio of discharge to volume of production is achieved
by several exemplary plants as a result of treating a much high propor-
tion of dry stock than is typical for the industry as a whole. A dis-
charge of 133 liters per cubic foot (1.0 gallons/1000 ft3) of product
is judged to the lowest value than can be reasonably achieved by plants
treating a normal proportion of unseasoned stock.
Chemical oxygen demand may be used to monitor BOD where an appropriate
correlation factor can be determined. The equation BOD = 0.497 COD + 60
expresses the relationship between the two parameters for BOD values of
150 and larger. However, the ratio of BOD/COD increases rapidly with
decreasing BOD. For BOD values of 50 or smaller, the relationship BOD =
0.161 COD has been found to be applicable.
Factors To Be Considered In Applying Effluent Limitations
The identification of standards of performance for new sources for the
various subcategories can be applied uniformly to most plants in the
industry. The exceptions are those plants which, because of age of equip-
ment and facilities, availability of land, or other factors, are unable
to attain these performance levels. Some of the factors which will have
an effect on the ability of individual plants to meet the recommended
performance standards are summarized in this section.
Use of Salt- and Oil-Type Preservatives in One Retort - The inability of
plants in Subcategory 1 that use a single retort for both salt-type and
oil-type preservatives, or that apply dual treatments, to prevent con-
tamination of oily wastewaters with metals from preservatives of the
former type was discussed in Section IX. Most of the plants in this
group are small, the operation consisting of a single retort. It is
recommended that a variance to the no discharge requirement for plants
treating with inorganic preservatives and fire retardants that are in
this group be permitted under new source performance standards. The
proposed limitations on discharge per unit of production given in Table
82 are based on the concentrations shown and a flow rate of 133 liters
per cubic meter (1.0 gallons/ft3) of product treated.
P re treatment Requirements
Effluents from preservative treatments with oily preservatives contain
no constituent that is incompatible with a well designed and operated
municipal wastewater treating plant. This statement presupposes that
the concentrations of phenolic compounds and oils are within the range
296
NOTICE: THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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TABLE 82 RECOMMENDED PERMISSIBLE DISCHARGE OF METALS:
PLANTS APPLYING DUAL TREATMENTS OF SALT-TYPE AND
OIL-TYPE PRESERVATIVES, AND PLANTS USING A SINGLE
RETORT TO APPLY BOTH PRESERVATIVES
Parameter
Boron**
Arsenic
Chromium
Copper
Fluorides
Zinc
Phosphates
Nitrogen (NH3)
Concentration
Cmg/1)
-
1
1
1
10
2
5
5
.0
.0
.0
.0
.0
.0
.0
Weight*
(Kg/1000 m3)
0
0
0
1
0
0
0
.128
.128
.128
.330
.273
.666
.666
-
(0
(0
CO
(o
Co
CO
CO
.008)
.008)
.008)
.083)
.017)
.041)
.041)
*Parenthetical values in pounds/1000 ft3 of product treated
**Best control technology for boron has not been determined
297
NOTICE; THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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considered normal for such wastes. Approximately 15 percent of the plants
in the U.S. currently are disposing of their waste in this manner. The
contractor is not aware of any instance where this practice has had a
deleterious effect on the operation of a municipal sewage facility.
Disposal of raw wastewater from treatments employing inorganic salt pre-
servatives is not recommended. Copper, chromium, and arsenic are toxic
to microorganisms in.low concentrations and, based on the work of Jones
(46) are capable of disrupting a biological wastewater treating system.
Treatment of such waste to precipitate most of the heavy metals prior to
discharge to the sewer is suggested.
298
NOTICE; THESE ARE TENTATIVE RECOMMENDATIONS BASED UPON
INFORMATION IN THIS REPORT AND ARE SUBJECT TO CHANGE BASED
UPON COMMENTS RECEIVED AND FURTHER INTERNAL REVIEW BY EPA.
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SECTION XII
ACKNOWLEDGEMENTS
The preparation and writing of this document for the veneer/
plywood industry and the hardboard industry was accomplished
through the efforts of Dr. Richard H. Jones, Mr. John D. Crane,
Mr. Robert A. Morrell, and Mr. Leonard P. Levine all of Environ-
mental Science and Engineering, Inc. (ESE). Dr. John Meiler
was a consultant to ESE and provided guidance during the pre-
paration of the report. The Mississippi Forest Products Lab-
oratory was responsible for the preparation and writing of
the sections on the wood preserving industry.
Industrial Advisory Groups for both the plywood/veneer and the
hardboard industry were established and these groups assisted
this project by supplying information and making recommend-
ations. The plywood/veneer advisory group consisted of:
Mr. Bruce Greforth - National Forest Products
Association
Mr. J. Tait Hardaway - Memphis Plywood Corporation
Mr. Wallace N. Corry - Boise Cascade
Mr. W. D. Page - American Plywood Association
Mr. Carl Erb - American Plywood Association
Mr. Mac Donald - Hardwood Plywood Association
Mr. John Stover - The Mortenson Company
Mr. Matt Gould - Georgia-Pacific Corporation
Mr. Roger Sherwood - Georgia-Pacific Corporation
Mr. Don Deardorf - Agnew Plywood
Mr. Harry Bartels - Champion International
Mr. 0. B. Burns, Jr. - Westavco
Mr. Ron Presley - U. S. Plywood
The hardboard advisory group consisted of:
Mr. Ken R. Peterson - American Hardboard Association
Mr. James E. Leker - Masonite Corporation
Mr. Fred E. Blattner - Celotex Corporation
Mr. Greg M. Schaefer - Boise Cascade Institute
Mr. John M. Sims - Abitibi Corporation
Mr. Steven Myers - Abitibi Corporation
Several industrial trade associations and individual corp-
orations provided assistance and cooperation to the wood pre-
serving study. Among these were:
American Wood-Preservers' Association
American Wood-Preservers' Institute
299
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J. H. Baxter and Company
Cascade Pole Company
Fernwood Industries
Koppers Company, Inc.
L. D. McFarland Company
Moss-American, Inc.
Sheridan Pressure Treated Lumber, Inc.
W. J. Smith Wood-Preserving Company
Society of American Wood Preservers
Weyerhaeuser Company
Wyckoff Company
Akcnowledgement is also expressed for the assistance of the
Industry Coordinating Committee and the many individuals who
contributed the data for use in the study of wood preserving.
Specific appreciation is extended to:
Mr. C. W. Best - J. H. Baxter and Company
Mr. C. A. Burdell - Southern Wood Piedmont Company
Mr. L. E. Crane - Weyerhaeuser Company
Mr. P. C. Gaskin - Moss-American, Inc.
Mr. C. D. Hudson - Wyckoff Company
Mr. M. D. Miller - Koppers Company, Inc.
Dr. J. N. Roche - Koppers Company, Inc.
Mr. Richard Williams of the EPA Effluent Guidelines Division
was the Project Officer for the Timber Products Industry and
was responsible for the supervision and the preparation of
this document.
Special consideration should go to Mr. George Webster, Chief,
Technical Assistance and Information Branch, Effluent Guide-
lines Division of EPA who gave helpful advice and suggestions
throughout this project.
Acknowledgement and appreciation is given to the secretarial
staffs of Environmental Science and Engineering, Inc. and the
Mississippi Forest Products Laboratory who typed and retyped
this report numerous times.
300
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SECTION XIII
REFERENCES
1. Thompson, W. S., "Status of Pollution Control in the Wood
Preserving Industry," Proceedings, American Wood Preserver's
Association. 1973 (in press].
2. American Wood Preservers' Association, Proceedings, Vol. 68,
pg. 275, 286, 287, 1972.
3. Forest Products Industry Directory, Miller Freeman Publica-
tions, San Francisco, 1972.
4. Market Profile - Softwood and Hardwood Plywood. U.S.A. and
Canada, Forest Industries, Portland, Oregon, 1969.
5. Panshin, Alexis John et al, Forest Products: Their Sources.
Production, and Utilization, McGraw-Hill. New York, First
Edition, 1950.
6. Market Profile - Hardboard. Forest Industries, Portland,
Oregon
7. MacDonald, Ronald G., Editor, and Franklin, John N., Techni-
cal Editor, The Pulping of Wood, Second Edition, Volume I,
McGraw-Hill, New York, 1969.
8. Gehm, Harry, Industrial Waste Study of the Paper and Allied
Products Industries, Environmental Protection Agency, July,
1971.
9. "Plywood and Other Wood-Based Panels", Food and Agricultural
Organization of the United Nations, Rome, 1966.
10. Bodien, Danforth G., Plywood Plant Glue Wastes Disposal.
Federal Water Pollution Control Administration, Northwest
Region, Pacific Northwest Water Laboratory, U.S. Department
of the Interior, 1969.
11. "Fibreboard and Particle Board", Food and Agricultural Organ-
ization of the United Nations, Rome, 1958.
12. Asplund, A., The Origin and Development of the Defibrator
Process, FAO/ECE/Board Cons., Paper 5.2.
13. Watts, E. W., Industrial Experience in the Manufacture of
Smooth-2-Sides Hardboard, FAO/ECE/Board Cons.. Paper 5.11.
301
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14. Gettle, Karl, A Guide for the Study of the Manufacturing
of Hardboard, American Hardboard Association and American
Industrial Arts Association
15. Basic Hardboard - Proposed Voluntary Product Standard TS
Tl)8a, American Hardboard Association. Revision of CS Z51-
oTlTardboard, February 13, 1973.
16. Standard Industrial Classification Manual, prepared by the
Statistical Policy Division of the Office of Management
and Budget, U.S. Government Printing Office, Washington,
D.C., 1972.
17. Stephenson, J. Newell, Editor, Preparation and Treatment
of Wood Pulp. Vol. 1, McGraw-Hill, New York 1950.
18. Schaumburg, Frank D., The Influence of Log Handling on
' -¥
Environmental Protection Agency, Washington, D.C. 1973.
Water Quality, Office of Research and Monitoring
ing on
, U.S.
19. Haskell, Henry H., "Handling Phenolic Resin Adhesive Wash
Water in Southern Pine Plywood Plants," Forest Products
Journal. Vol. 21, No. 9, September 1971.
20. Mortenson, A. W. , Private Communications (Inferno Steam
Systems, Portland, Oregon) April - June, 1973.
21. Gran, Gunnar, Waste Water From Fiberboard Mills. Stockholm,
Sweden
22. Leker, James E., Masonite Corporation, Private Communica-
tions, January - June, 1973.
23. Thompson, W.S. and Dust, J.V.,"Pollution Control in the Wood
Preserving Industry. Part 1. Nature and Scope of the Prob-
lem," Forest Products Journal. 21(9), pp 70-75, 1971.
24. Mississippi Forest Products Laboratory, Unpublished Data,
Mississippi State University, State College, Mississippi,
1970.
25. Dust, J. V., and Thompson, W. S., "Pollution Control in the
Wood Preserving Industry, Part 4. Biological Methods of
Treating Wastewater." Forest Products Journal, in press, 1973.
26. Sohlman, L., "Measures Taken by the Wallboard Mill of Skinn-
skatteberg to Control Water Pollution," International Congress
on Industrial Wastewater, Stockholm,Sweden.
302
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27. Nepper, M., "Biological Treatment of Strong Industrial Waste
from a Fiberboard Factory," Purdue Waste Water Conference,
1967.
28. Buckley, D. B. and McKeown, J. J., An Analysis of the Per-
formance of Activated Sludge and Aerated Stabilization
BTsin Systems in Controlling the Release of Suspended~Solids
in Treated Mill Effluents to Receiving Waters, National
Council of the Paper Industry for Air and Stream Improve-
ment, Inc., 1973.
29. Thompson, W. S., "Contribution of the Wood Preserving Indus-
try to Water Pollution," Proceedings, Conference on Pollution
Abatement and Control in the Wood Preserving Industry, Missis-
sippi Forest Products Laboratory, Mississippi State University
State College, Mississippi 1971, pp 50-75.
30. American Petroleum Institute, Manual on Disposal of Refinery
Wastes. Vol. I. Waste Water Containing Oil [6th Edition! .
92 pp, 1959"; ~~~~^
31. Thompson, W. S., Pollution Control, Chapter 11, D.D. Nicholas
and W. E. Loos, Editors, Syracuse University Press, In Press,
1973.
32. Anonymous, The Cost of Clean Waste; Vol. Ill, Industrial
Waste Profiles, NO. 5 - Petroleum Refining, U.S. Department
of the Interior, Washington, D.C. 1967.
33. Wallace, A. T., Rohlich, G. A., and Villemonte, J. R., "The
Effect of Inlet Conditions on Oil-Water Separators at SOHIO's
Toledo Refinery," Proceedings. 20th Purdue Industrial Waste
Conference, pp. 618-6Z5, 1965. "~~~~
34. Thompson, W. S., "Pollution Abatement by In-Plant Process
Changes and Sanitation," Proceedings. Conference on Pollution
Abatement and Control in the Wood Preserving Industry, MissTs"-
sippi Forest Products Laboratory, Mississippi State University,
State College, Mississippi, pp. 116-129, 1971.
35. Jones, R. H., and Frank, W. R., "Wastewater Treatment Methods
in the^Wood Preserving Industry," Proceedings. Conference on
n0lj:ut^?n Abatement and Control in the Wood Preserving Industry,
w. s. Thompson, Editor, Mississippi Forest Products Laboratory,
Mississippi State University, State College, Mississippi, 1971,
pp. 206-216.
36. Simonsen, R. N.,"0il Removal by Air Flotation at SOHIO Refin-
eries»" Proceedings. American Petroleum Institute, 42CIII).
pp. 399-4U6, 1962. ~~~~
303
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37. Western, R. F. and Merman, R. G., "The Chemical Flocculation
of a Refinery Waste," Proceedings, American Petroleum Insti-
tute, 34(111), pp 207-224, 1954?
38. Middlebrook, E. J., "Wastes From The Preservation of Wood,"
Journal, Sanitary Engineering Division, ASCE, 94, pp 41-56,
1968.
39. Gaskin, P. C., "A Wastewater Treating Plant for the Wood
Preserving Industry," Proceedings, Conference on Pollution
Abatement and Control in the Wood Preserving Industry,
(W.S.Thompson, Editor) Mississippi Forest Products Labora-
tory, Mississippi State University, State College, Mississippi,
pp 271-281, 1971.
40. van Frank, A. J. and Eck, J. C., "Water Pollution Control in
the Wood Preservation Industry," Proceedings, American Wood
Preservers* Association, 65, pp 157-161, 1969.
41. American Wood Preservers' Association, Report on Information
and Technical Development Committees, Proceedings, American
Wood Preservers' Association, Washington, D.C., 52, pp 187-194,
1956.
42. Halff, A. H., "Slow Sand Filtration of Wood Treating Plant
Waste," Proceedings, American Wood Preservers' Association,
55, pp 184-188, 1959.
43. Halladay, W. B. and Crosby, R.H., "Current Techniques Of Treat-
ing Recovered Oils and Emulsions," Proceedings, American Petro-
leum Institute, 44(111), pp 68-73, 1964.
44. Dust, J. V., "Sludge Production and Dewatering," Proceedings
Conference on Pollution Abatement and Control in the Wood Pre-
gerving Industry [W. S. Thompson. Editor)t Mississippi Forest
Products Laboratory, Mississippi State University, State College,
Mississippi, pp 85-95, 1971.
45. Schwoyer, W., "The Permutit DCG Unit," Proceedings, Conference
on Pollution Abatement and Control in the Wood Preserving In-
dustry,(W.S. Thompson, Editor), Mississippi Forest Products
Laboratory, Mississippi State University, State College,
Mississippi, pp 96-115, 1971.
46. Jones, R. H., "Toxicity in Biological Waste Treatment Proces-
ses," Proceedings. Conference on Pollution Abatement and Con-
trol in the Wood^PrFseVving Industry,(W.S. Thompson, Editor)
Mississippi Forest Products Laboratory, Mississippi State
University, State College, Mississippi, pp 217-231, 1971.
304
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47. Dodge, B. F., and Reams, D. C., Jr., "Disposing of Plating
Room Waste," Research Report No. 9, American Electroplaters
Society, New York, New York 1949.
48. American Wood Preservers' Association, Report on Informa-
tion and Technical Development Committees, Proceedings,
Washington, D.C., 54, pp 188-190, 1958.
49. Bliss, H., "Developing a Waste Disposal Process," Chem.
Eng. Progr.. 44, pp 887-894, 1948.
50. Chamberlin, N.S., and Day, R.V., "Technology of Chrome Re-
duction with Sulfur Dioxide," Proceedings, llth Industrial
Waste Conference. Purdue University, pp 129-156, 1956.
51. Nyquist, O.W. and Carroll, H.R., "Design and Treatment of
Metal Processing Wastewaters," Sew. Indus. Wastes, 31,
pp 941-948, 1959.
52. Stone, E.H.F., "Treatment of Non-Ferrous Metal Process
Waste of Kynoch Works, Birmingham, England," Proceedings,
25th Industrial Waste Conference, Purdue University, pp 848-
855, 1967.
53. Hansen, N.H., and Zabban, W., "Design and Operation Problems
of a Continuous Automatic Plating Waste Treatment Plant at
the Data Processing Division, IBM, Rochester, Minnesota,"
Proceedings. 14th Purdue Industrial Waste Conference, pp 227-
249, 19597
54. Anderson, J.S. and lobst, E.H., Jr., "Case History of Waste-
water Treatment at a General Electric Appliance Plant," Jour.
Water Pollution Control Federation, 10, pp 1786-1795, 19~oTT
55. Zabban, W. and Jewett, H.W., "The Treatment of Fluoride Waste"
Proceedings, 22nd Purdue Industrial Waste Conference, pp 706-
716, 19677 ~'
56. Gulp, R.L. and Stoltenburg, H.A., "Fluoride Reduction at La
Crosse, Kansas," Jour. AWWA, 50, pp 423-437, 1958.
57. Wamsley, R. and Jones, W.F., "Fluoride Removal," Water and
Sewage Works. 94, pp 372-376, 1947.
58. Magnusen, L.M., Waugh, T.C., Galle, O.K., and Bredfeldt, J.,
"Arsenic in Detergents, Possible Danger and Pollution Hazard"
Science, 168, pp 389-390, 1970.
305
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59. Shen, Y.S. and Chen, C.S., "Relation Between Black-Foot
Disease and the Pollution of Drinking Water by Arsenic in
Taiwan," Proceedings. 2nd International Conference Water
Pollution Research! Tokoyo. Pergamon Press. New York.
pp 173-190, 1964.
60. Irukayama, K., Discussion of Paper "Relation Between Black-
Foot Disease and the Pollution of Drinking Water by Arsenic
in Taiwan," 1964. (See Shen and Chen, Reference 59)
61. Cherkinski, S.N. and Genzburg, F.I., "Purification of Arsen-
ious Waste Waters," Water Pollution Abstracts. 14, pp 315-
316, 1941.
62. Russell, L.V., "Heavy Metals Removal From Wood Preserving
Wastewater," Proceedings. 27th Purdue Industrial Waste Con-
ference, 1972, in press.
63. Russell, L.V., "Treatment of CCA-, FCAP-, and FR-type Waste-
waters," Proceedings. Conference on Pollution Abatement and
Control in the Wood Preserving Industry, [W.S. Thompson. Ed.)
Mississippi Forest Products Laboratory, Mississippi State
University, State College, Mississippi, pp 249-260, 1971.
64. Barth, E.F., Salotto, B.V., English, J.N., and Ettinger, M.B.,
"Effects of a Mixture of Heavy Metals on Sewage Treatment
Processes," Proceedings. 18th Industrial Waste Conference.
Purdue University, Lafayette, pp 616-635, 1964.
65. Kugelman, I.J., and McCarty, P.L., "Cation Toxicity and
Stimulation in Anaerobic Waste Treatment," Journal, WPCF,
37(1):97-116, 1965.
66. McDermott, G.N., Barth, E.F., Salotto, B.V., and Ettinger,
M.B., "Zinc in Relation to Activated Sludge and Anaerobic
Digestion Process," Proceedings. 17th Industrial Waste Con-
ference, Purdue University, pp 461-475, 1964.
67. Young, "Anionic and Cationic Exchange for Recovery and Puri-
fication of Chrome from Plating Process Wastewaters," Pro-
ceedings. 18th Industrial Waste Conference, Purdue University,
pp 454-464, 1964.
68. Gilbert, L., Morrison, W.S., and Kahler, F.H., "Use of Ion
Exchange Resins in Purification of Chromic Acid Solutions,"
Proceedings. Amer. Electroplating Soc., 39, pp 31-54, 1952.
69. Costa, R.L., "Regeneration of Chromic Acid Solutions by Ion
Exchange," Ind. Eng. Chem.. 42, pp 308-311, 1950.
306
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70. American Wood Preservers' Association, Report on Informa-
tion and Technical Development Committees, Proceedings,
American Wood Preservers' Association, Washington, D7c.,
53, pp 215-220, 1957.
71. Sweets, W.H., Hamdy, M.K., and Weiser, H.H., "Microbiolog-
ical Studies on the Treatment of Petroleum Refinery Phenolic
Wastes," Sewage Ind. Wastes, 26, pp 862-868, 1954.
72. Reid, G.W. and Libby, R.W., "Phenolic Waste Treatment Studies,"
Proceedings. 12th Industrial Waste Conference. Purdue Uni-
versity, pp 250-258, 1957.~~
73. Ross, W.K., and Sheppard, A.A., "Biological Oxidation of
Petroleum Phenolic Wastewater," Proceedings. 10th Industrial
Waste Conference. Purdue University, pp 106-119, 1955.
74. Reid, G.W., Wortman, R. and Walker, R., "Removal of Phenol
with Biological Slimes," Proceedings, llth Industrial Waste
Conference. Purdue University, pp 354-357, 1956.
75. Harlow, H.W., Shannon, E.S., and Sercu, C.L., "A Petro-
chemical Waste Treatment System," Proceedings. 16th Indus-
trial Waste Conference, Purdue University, pp 156-166, 1961.
76. Montes, G.E., Allen, D.L., and Showell, E.B., "Petrochemical
Waste Treatment Problems," Sewage Ind. Wastes, 28, pp 507-
512, 1956. *
77. Dickerson, B.W. and Laffey, W.T., "Pilot Plant Studies of
Phenolic Wastes from Petrochemical Operations," Proceedings,
13th Industrial Waste Conference, Purdue University, pp 780-
799, 1958."
78. Davies, R.W., Biehl, J.A., and Smith, R.M., "Pollution Con-
trol and Waste Treatment at an Inland Refinery," Proceedings,
21st Industrial Waste Conference, Purdue University, pp 126-
138,1967.
79. Austin, R.H., Meehan, W.F., and Stockham, J.D., "Biological
Oxidation of Oil-Containing Wastewaters," Ind. Eng. Chem.,
46, pp 316-318, 1954. fi
80. Prather, B.V., and Gaudy, A.F., Jr., "Combined Chemical,
Physical, and Biological Processes in Refinery Wastewater
Purification," Proceedings. American Petroleum Institute,
44(111), pp 105-112, 1964.
307
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81o Davies, J.J. , "Economic Considerations of Oxidation Towers','
Proceedings, Conference on Pollution Abatement and Control
in the Wood Preserving Industry,(W.S. Thompson, Editor}
Mississippi Forest Products Laboratory, Mississippi State
University, State College, Mississippi, pp 195-205, 1971.
82. Ullrich, A.H., and Smith, M.W., "The Biosorption Process
of Sewage and Waste Treatment," Sewage and Ind. Wastes,
23, pp 1248-1253, 1951.
83. Ullrich, A,Ho, and Smith, M.W. , "Operation Experience With
Activated Sludge Biosorption at Austin, Texas," Sewage and
Industrial Wastes, 29 pp 400-413, 1957.
84. Besselieure, E.Be, The Treatment of Industrial Wastes,
McGraw-Hill, New York, 1969.
85. Preussner, R.D., and Mancini, J., "Extended Aeration Acti-
vated Sludge Treatment of Petrochemical Waste at the Houston
Plant of Petro-Tex Chemical Corporation," Proceedings, 21st
Industrial Waste Conference, Purdue University, pp, 591-599,
1967.
86. Coe, R.H., "Bench-Scale Method for Treating Waste by Acti-
vated Sludge," Petroleum Processing, 7, pp 1128-1132, 1952.
87. Ludberg, J0E0, and Nicks, G.D., "Phenols and Thiocyanate
Removed From Coke Plant Effluent," Ind. Wastes (November)
pp 10-13, 1969.
88. American Wood Preservers' Association, Report of Wastewater
Disposal Committee, Proceedings, American Wood Preservers'
Association, Washington, D.C.7 56, pp 201-204, 1960.
89. Cooke, R., and Graham, P.W., "The Biological Purification
of the Effluent from a Lurgi Plant Gasifying Bituminous
Coal," Int. Jour. Air Water Pollution. 9(3), pg. 97, 1965.
90. Badger, E.H.M. and Jackman, M.I., "Loading Efficiencies in
the Biological Oxidation of Spent Gas Liquor," Journal and
Proceedings, Inst. Sewage Purification, 2:159, 1961.
91. Nakashio, M. , "Phenolic Waste Treatment by an Activated-
Sludge Process," Hakko Kogaku Zasshi 47:389, Chem. Abs.
71(8):236, 1969.
92. Reid, G.W., and Janson, R.J., "Pilot Plant Studies on Phenolic
Wastes at Tinker Air Force Base," Proceedings. 10th Purdue
Industrial Waste Conference, p 28, 1955.
308
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93. Kostenbader, P.O. and Flacksteiner, J.W. (Bethlehem Steel
Corporation), "Biological Oxidation of Coke Plant Weak
Ammonia Liquor," J.WPCF, 41(2) :199, 1969.
94. Kirsh, E.J. and Etzel, J.E., "Microbial Decomposition of
Pentachlorophenol," (Submitted for Publication, J.WPCF)
Personal Correspondence from E.J. Kirsh to Warren S. Thomp-
son, 1972.
95. Fisher, C.W., "Koppers ' Experience Regarding Irrigation of
Industrial Effluent Waters and Especially Wood Treating
Plant Effluents," Proceedings, Conference on Pollution Abate
ment and Control in the Wood Preserving Industry (W.S. Thomp
son, Editor), Mississippi Forest Products Laboratory, Missis
sippi State University, State College, Mississippi, pp 232-
248, 1971.
96. American Petroleum Institute, Manual on Disposal of Refinery
Wastes. Vol. I. Waste Water Containing Oil (6th Edition),
92 pp,
97. Montes, G.E., Allen, D.L., and Showell, E .B. /'Petrochemical
Waste Treatment Problems," Sewage Ind. Wastes. 28:507-512,
1956. - -
98. Biczysko, J. and Suschka, J., "Investigations on Phenolic
Wastes Treatment in an Oxidation Ditch," in Advances in
Water Pollution Research, Munich Conference, Vol. z, pp 285-
289, Pergamon Press, New York, 1967.
99. Skogen, D.B., "Treat HPT Wastes With Bugs," Hydrocarbon Pro-
cessing. 46(7):105, 1967. -
100. Crane, L.E., "An Operational Pollution Control System for
Pressure Treating Plant Waste," Proceedings. Conference on
Pollution Abatement and Control in the Wood Preserving In-
dustry. (W.S. Thompson, Editor) Mississippi Forest Products
Laboratory, Mississippi State University, State College,
Mississippi, pp 261-270, 1971.
101. Gaudy, A.F., Jr., Scudder, R. , Neeley, M.M., and Perot, J.J.,
"Studies on the Treatment of Wood Preserving Wastes," Paper
presented at 55th National Meeting, Amer. Inst. Chem. Eng. ,
Houston, Texas, 1965.
102. Gaudy, A.F., Jr., "The Role of Oxidation Ponds in A Wood
Treating Plant Waste Abatement Program," Proceedings, Con-
ference on Pollution Abatement and Control in the WoodnP7e-
serving Industry. [W.S. Thompson. Editor] Mississippi Forest
Products Laboratory, Mississippi State Univ., State College,
Mississippi, pp 150-164, 1971.
309
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103. Vaughan, J.C., "Problems in Water Treatment," Jour.,
American Water Works Association, 56(5):521, 19"oT7
104. Woodward, E.R., "Chlorine Dioxide for Water Purification,"
Jour. Pennsylvania Water Works Operators' Assoc., 28:33,
1956, ~~"
105. Glabisz, 0., "Chlorine Dioxide Action on Phenol Wastes,"
Chem. Abs.. 65:10310, 1966.
106. Manufacturing Chemists Association, "The Effect of Chlori-
nation on Selected Organic Chemicals," Environmental Pro-
tection Agency, Water Pollution Control Research Series,
Project 12020 EXE, 104 pages, 1972.
107. Thompson, W.S. and Dust, J.V., "Pollution Control in the
Wood Preserving Industry. Part 2. In-Plant Process Changes
and Sanitation," Forest Prod. J.. 22(7):42-47, 1972.
108o American Public Health Association, Standard Methods for
the Examination of Water and Wastewater, New York. 1965.
109. Corbitt, R.A., "The Wood Preserving Industry's Water Pol-
lution Control Responsibility in Georgia and Neighboring
States," Proceedings. Conference on Pollution Abatement
and Control in the Wood Preserving Industry,[W.S. Thomp-
son, Editor) Mississippi Forest Products Laboratory,
Mississippi State University, State College, Mississippi,
pp 19-35, 1971.
110. Ingols, R.S. and Ridenour, G.M., "The Elimination of
Phenolic Tastes by Chloro-Oxidation," Water and Sewage
Works, 95:187, 1949.
111. Ettinger, M.B., and Ruchoft, C.C., "Effect of Stepwise
Chlorination on Taste-and-Color-Producing Intensity of
Some Phenolic Compounds," Jour. American Water Works As-
sociation. 43:651, 1951.
112. Burttschell, R.H., "Chlorine Derivatives of Phenol Caus-
ing Taste and Odor," Jour. American Water Works Assoc.,
51:205-214, 1959.
113. Eisenhaeur, H.R., "Oxidation of Phenolic Wastes," Jour.
Water Pollution Control Federation. 36(9):1116-112TTrT964.
114. Niegowski, S.J., "Destruction of Phenols by Oxidation with
Ozone," Ind. Eng. Chem.. 45(3):632-634, 1953.
310
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115. Niegowski, S.J., "Ozone Method for Destruction of Phenols
in Petroleum Wastewater," Sewage and Ind. Wastes, 28(10):
1266-1272, 1956.
116. Gloyna, E.F. and Malina, J8F., Jr.,"Petrochemical Wastes
Effects on Water, Part 3. Pollution Control," Ind. Water
and Wastes (January - February, pp 29-35, 1962.
117. Gloyna, E.F., and Malina, J.F., Jr., "Petrochemical Waste
Effects on Water, Part 2. Physiological Characteristics,"
Ind. Water and Wastes, (November-December) pp 157-161, 1962.
118. Gould, M. and Taylor, J., "Temporary Water Clarification
System," Chem. Eng. Progress. 65 (12):47-49, 1969.
119. Thomas E. Gates § Sons, Inc., Personal Correspondence to
Environmental Engineering, Inc., Gainesville, Florida,
June 1973.
120. Effenberger, Herman K., Cradle, Don D. and Tomany, James
P., Hogged Fuel Boiler Emissions Control, A Case History,
Environmental Division Conference of TAPPI, Houston, Texas
May 1972.
121. Powell, S.T., Water Conditioning For Industry, McGraw-Hill,
New York, New York 1954.
122. Patterson, J.W., and Minear, R.A., "Wastewater Treatment
Technology," Illinois Institute for Environmental Quality,
Report No. PB-204521, 280 pages, 1971.
ADDITIONAL REFERENCES
Back, Ernst,L. and Larsson, Stig A., "Increased Pulp Yield as
Means of Reducing the BOD of Hardboard Mill Effluent,"
Swedish Paper Journal, October 15, 1972.
Boydston, James R., "Plywood and Sawmill Liquid Waste Disposal,"
Forest Products Journal. Vol. 21, No. 9, September 1971.
Fisher, C. W., "Soil Percolation and/or Irrigation of Industrial
Effluent Waters—Especially Wood Treating Plant Effluents,"
Forest Products Journal, Vol. 21, No. 9, September 1971.
Freeman, H.G. and Grendon, W.C., "Formaldehyde Detection and Con-
trol in the Wood Industry," Forest Products Journal. Vol. 21,
No. 9, September 1971.
311
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Gehm, Harry, State-of-the-Art Review of Pulp and Paper Waste
Treatment, Office of Research and Monitoring, U.S. Environ-
mental Protection Agency, Washington, D.C., April 1973.
Gehm, Harry W. and Lardieri, Nicholas J., "Waste Treatment in
the Pulp, Paper, and Paperboard Industries," Sewage and
Industrial Wastes. Vol. 28, No. 3, March 1956.
GLOSSARY - Water and Wastewater Control Engineering, Prepared
by Editorial Board representing American Public Health
Association, American Society of Civil Engineers, American
Water Works Association, Water Pollution Control Federation,
1969.
Gould, M. and Taylor, J., "Temporary Water Clarification System,"
Chemical Engineering Progress, Vol. 65, No. 12, December 1969.
Groth, Bertil, Waste Water From Fiberboard Mills, Annual Finnish
Paper Engineers' Association Meeting, Helsinki, April 12, 1962.
Hansen, George, (Task Force Chairman) Log Storage and Rafting in
Public Waters, Pacific Northwest Pollution Control Council,
August 1971.
Hoffbuhr, Jack, Blanton, Guy, and Schaumburg, Frank, "The Charac-
ter and Treatability of Log Pond Waters," Industrial Waste,
July/August 1971.
Kleppe, Peder J., and Rogers, Charles N., Survey of Water Utili-
zation and Waste Control Practices in the Southern Pulp and
Paper Industry, Water Resources Research Institute, Univer-
sity of North Carolina, June 1970.
Leker, James E., and Parsons, Ward C., "Recycling Water - A Simple
Solution?,11 Southern Pulp and Paper Manufacturer, January 1973.
Luxford, R.F., and Trayer, George W., (Forest Products Laboratory,
University of Wisconsin) Wood Handbook, U.S. Department of
Agriculture, Washington, B.C.1935.
Malo, Bernard A., "Semichemical Hardwood Pulping and Effluent
Treatment," Journal Water Pollution Control Federation,
Vol. 39, No. 11, November 1967.
McHugh, Robert A., Miller, LaVerne S., and Olsen, Thomas E., The
Ecology and Naturalistic Control of Log Pond Mosouitos in
the Pacific Northwest, Division of Sanitation and Engineering,
Oregon State Board of Health, Portland, 1964.
312
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Parsons, Ward C., "Spray Irrigation of Wastes from the Manufac-
ture of Hardboard," Purdue Waste Water Conference. 1967.
Parsons, Ward C., and Woodruff, Paul H., "Pollution Control:
Water Conservation, Recovery, and Treatment," TAPPI, 53:3,
March 1970.
Quirk, T.P., Olson, R.C. and Richardson, G., "Bio-Oxidation of
Concentrated Board Machine Effluents," Journal. Water Pollu-
tion Control Federation. Vol. 38, No. 1, January 1966.
Reinhall, Rolf, and Vardheim, Steinar, Experience With the DKP
Press. Appita Conference, Australia, March 1965.
Robinson, J.G., "Dry Process Hardboard," Forest Products Jour-
nal, July 1959.
Sawyer, Clair N., Chemistry For Sanitary Engineers. Second Edi-
tion, McGraw-Hill, New York, 1967.
Shreve, Norris, Chemical Process Industries. McGraw-Hill, New
York, 1967. ~~~~
Timpe, W.G., Lang, E., and Miller, R.L., Kraft Pulping Effluent
Treatment and Refuse - State of the Art." Office of Research
and Monitoring, U.S. Environmental Protection Agency, Wash-
ington, D.C., 1973.
Tretter, Vincent J., Jr., "Pollution Control Activities at
Georgia-Pacific," Forest Products Journal. Vol. 21, No. 9,
September 1971.
Wood Products Sub-Council, "Principal Pollution Problems Facing
the Solid Wood Products Industry," Forest Products Journal.
Vol. 21, No. 9, September 1971.
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SECTION XIV
GLOSSARY
"Act" - The Federal Water Pollution Control Act Amendments
oFT972.
Activated Sludge - Sludge floe produced in raw or settled
wastewater by the growth of zoogleal bacteria and other
organisms in the presence of dissolved oxygen and accumula-
ted in sufficient concentration by returning floe previously
formed.
Activated Sludge Process - A biological wastewater treatment
process in which a mixture of wastewater and activated
sludge is agitated and aerated. The activated sludge is
subsequently separated from the treated wastewater (mixed
liquor) by sedimentation and wasted or returned to the pro-
cess as needed.
Aerated Lagoon - A natural or artificial wastewater treat-
ment pond in which mechanical or diffused-air aeration is
used to supplement the oxygen supply.
Aerobic - Condition in which free, elemental, oxygen is pre-
sent .
Additive - Any material introduced prior to the final con-
solidation of a board to improve some property of the final
board or to achieve a desired effect in combination with
another additive. Additives include binders and other
materials. Sometimes a specific additive may perform more
than one function. Fillers and preservatives are included
under this term.
Air Drying - Drying veneer by placing the veneer in stacks
open to the atmosphere, in such a way as to allow good
circulation of air. It is used only in the production of
low quality veneer.
Air-felting - Term applied to the forming of a fiberboard
from an air suspension of wood or other cellulose fiber and
to the arrangement of such fibers into a mat for board.
Anaerobic - Condition in which free elemental oxygen is
absent.
Asplund Method - An attrition mill which combines the steam-
ing and defibering in one unit in a continuous operation.
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Attrition Mill - Machine which produces particles by forcing
coarse material, shavings, or pieces of wood between a sta-
tionary and a rotating disk, fitted with slotted or grooved
segments.
Back - The side reverse to the face of a panel, or the poorer
side of a panel in any grade of plywood that has a face and
back.
Bag Barker - See debarker
Blue Stain - A biological reaction caused by a stain pro-
ducing fungi which causes a blue discoloration of sapwood,
if not dried within a short time after cutting.
Biological Wastewater Treatment - Forms of wastewater treat-
ment in which bacterial or biochemical action is intensified
to stabilize, oxidize, and nitrify the unstable organic mat-
ter present. Intermittent sand filters, contact beds,
trickling filters, and activated sludge processes are examples
Slowdown - The removal of a portion of any process flow to
maintain the constituents of the flow at desired levels.
BOD - Biochemical Oxygen Demand is a measure of biological
decomposition of organic matter in a water sample. It is
determined by measuring the oxygen required by micro-
organisms to oxidize the organic contaminants of a water
sample under standard laboratory conditions. The standard
conditions include incubation for five days at 20°C.
Bolt - A short log cut to length suitable for peeling in a
lathe.
Boultonizing
A conditioning process in which unseasoned wood is heated
in an oily preservative under a partial vacuum to reduce its
moisture content prior to injection of the preservative.
Casein - A derivative of skimmed milk used in making glue.
Caul - A steel plate or screen on which the formed mat is
placed for transfer to the press, and on which the mat
rests during the pressing process.
CCA-Type Preservative - Any one of several inorganic salt
formulations based on salts of copper, chromium, and arsenic.
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Chipper - A machine which reduces logs or wood scraps to
chips.
Clarifier - A unit of which the primary purpose is to reduce
the amount of suspended matter in a liquid.
Clipper - A machine which cuts veneers to various widths and
also may remove defects.
Closed Steaming - A method of steaming in which the steam
required is generated in the retort by passing boiler steam
through heating coils that are covered with water. The
water used for this purpose is recycled.
COD - Chemical Oxygen Demand. Its determination provides a
measure of the oxygen demand equivalent to that portion of
matter in a sample which is susceptible to oxidation by a
strong chemical oxidant.
Coil Condensate - The condensate formed in steam lines and
heating coils.
Cold Pressing - See pressing
Commercial Veneer - See veneer; hardwood
Composite Board - Any combination of different types of
board,either with another type board or with another sheet
material. The composite board may be laminated in a sepa-
rate operation or at the same time as the board is pressed.
Examples of composite boards include veneer-faced particle
board, hardboard-faced insulation board and particle board,
and metal-faced hardboard.
Conditioning - The practice of heating logs prior to cutting
in order to improve the cutting properties of the wood and
in some cases to facilitate debarking.
Construction - Arrangement of veneers, lumber or wood
composition board in plywood.
Container Veneer - See veneer; hardwood
Cooling Pond - A water reservoir equipped with spray aera-
tion equipment from which cooling water is drawn and to
which it is returned.
Core - Also referred to as the center. The innermost por-
tion of plywood. It may be of sawn lumber joined and
glued, or it may be of veneer, or of wood composition board.
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Creosote - A complex mixture of organic materials obtained
as a by-product from coking and petroleum refining opera-
tions that is used as a wood preservative.
Crossband, v. - To place the grain of the layers of veneer
at right angles in order to minimize swelling and shrinking.
Crossband. n. - The layers of veneer whose grain direction
is at right angles to that of the face piles, applied par-
ticularly to five-ply plywood and lumber core panels, and
more generally to all layers between the core and the faces.
Curing - The physical-chemical change that takes place
either to thermosetting synthetic resins (polymerization)
in the hot presses or to drying oils (oxidation) used for
oil-treating board. The treatment to produce that change.
Cutterhead Barker - See debarker.
Cylinder Condensate - Steam condensate that forms on the
walls of the retort during steaming operations.
Debarker - Machines which remove bark from logs. Debarkers
may be wet or dry, depending on whether or not water is
used in the operation. There are several types of de-
barkers including drum barkers, ring barkers, bag barkers,
hydraulic barkers, and cutterhead barkers. With the excep-
tion of the hydraulic barker, all use abrasion or scraping
actions to remove bark. Hydraulic barkers utilize high
pressure streams of water.
All types may utilize water, and all wet debarking opera-
tions may use large amounts of water and produce effluents
with high solids concentrations.
Decay - The decomposition of wood caused by fungi.
Defiberization - The reduction of wood materials to fibers.
Delamination - Separation of the plies through failure of
the adhesive.
Digester - 1) Device for conditioning chips using high
pressure steam, 2) A tank in which biological decomposi-
tion (digestion) of the organic matter in sludge takes
place.
Disc Pulpers - Machines which produce pulp or fiber through
the shredding action of rotating and stationary discs.
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DO - Dissolved Oxygen is a measure of the amount of free
oxygen in a water sample. It is dependent on the physical,
chemical, and biochemical activities of the water sample.
Drum Barker - See debarker.
Dry-clipping - Clipping of veneer which takes place after
drying.
Dry Decking - See log storing.
Dryers - Most commonly long chambers equipped with rollers
on belts which advance the veneer longitudinally through
the chamber. Fans and heating coils are located on the
sides to control temperature and humidity. Lumber kilns
are also sometimes used. See also veneer drying.
Dry-felting - See air-felting.
Dry Process - See air-felting.
Durability - As applied to wood, its lasting qualities or
permanence in service with particular reference to decay.
May be related directly to an exposure condition.
End-checking - Cracks which form in logs due to rapid
drying out of the ends when stacked on land for storage.
Exterior - A term frequently applied to plywood, bonded
with highly resistant glues, that is capable of with-
standing prolonged exposure to severe service conditions
without failure in the glue bonds.
Face - The better side of a panel in any grade of plywood
calling for a face and back; also either side of a panel
where the grading rules draw no distinction between faces.
Face Veneer - See veneer; hardwood.
Fiber (Fibre) - The slender thread-like elements of wood or
similar cellulosic material, which, when separated by chemi
cal and/or mechanical means, as in pulping, can be formed
into fiberboard.
Fiberboard - A sheet material manufactured from fibers of
wood or other ligno-cellulosic materials with the primary
bond deriving from the arrangement of the fibers and their
inherent adhesive properties. Bonding agents or other
materials may be added during manufacture to increase
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strength, resistance to moisture, fire, insects or decay,
or to improve some other property of the product. Alter-
native spelling: fibreboard, Synonym: fibre building board.
Fiber Preparation - The reduction of wood to fiber or pulp,
utilizing mechanical, thermal, or explosive methods.
Figure - Decorative natural designs in wood which are prized
in the furniture and cabinet making industries.
Finishing - The final preparation of the product. Finishing
may include redrying, trimming, sanding, sorting, molding,
and storing, depending on the operation and product desired.
Fire Retardant - A formulation of inorganic salts that im-
parts fire resistance when injected into wood in high concen-
trations.
Flitch - A part of a log which has been so sectioned as to
best display a particular grain configuration or figure in
the resulting veneer.
Flotation - The raising of suspended matter to the surface
of the liquid in a tank as scum--by aeration, the evolution
of gas, chemicals, electrolysis, heat, or bacterial decom-
position- -and the subsequent removal of the scum by skimming.
Formation (Forming) - The felting of wood or other cellulose
fibers into a mat for fiberboard. Methods employed: air-
felting and wet-felting.
Glue - Adhesive which is used to join alternate ply veneers
together in plywood. There are three types most often used
in the manufacture of plywood, depending on raw material
and intended product usage. They are 1) protein, 2) phenol
formaldehyde, and 3) urea formaldehyde. The first is ex-
tracted from plants and animals while the other two are
synthetic and thermosetting.
Glue Spreaders - Means of applying glue to veneer, either
by the use of power driven rollers or spray curtain-coater
applicators.
Glue Line - The part of the plywood production process
where the glue is applied to the veneer and the plywood
layers assembled.
GPP - Gallons per day.
GPM - Gallons per minute.
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Grading - The selection and categorization of different
woods as to its suitability for various uses. Criteria
for selection include such features of the wood as color,
defects, and grain direction.
Grain - The direction, size, arrangement, and appearance
of the fibers in wood or veneer.
Green Clipper - A clipper which clips veneer prior to being
dried.
Green Stock - Unseasoned wood.
Hardboard - A compressed fiberboard of 0.80 to 1.20 g/cm3
C50 to 75 pounds per cubic foot) density. Alternative
term: fibrous-felted hardboard.
Hardboard Press - Machine which completes the reassembly
of wood particles and welds them into a tough, durable,
grainless board.
Hardwood - Wood from deciduous or broad-leaf trees. Hard-
woods include oak, walnut, lavan, elm, cherry, hickory, pecan,
maple, birch, gum, cativo, teak, rosewood, and mahogany.
Heartwood - The inner core of a woody stem composed of
non-living cells and usually differentia ed from the outer
enveloping layer (sapwood).
Heat-treated Hardboard - Hardboard that has been subjected
to special heat treatment after hot-pressing to increase
strength and water resistance.
Holding Ponds - See impoundment.
Hot Pressing - See pressing.
Humidification - The seasoning operation to which newly
pressed hardboard are subjected to prevent warpage due to
excessive dryness.
Hydraulic Barker - See debarker.
Impoundment - A pond, lake, tank, basin, or other space,
either natural or created in whole or in part by the build-
ing of engineering structures, which is used for storage,
regulation, and control of water, including wastewater.
Industry Categorization - Subdivision of the industry into
categories in order that separate effluent limitations and
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standards may be developed for each category, if it is
determined that separate regulation is necessary.
Kiln Drying - A method of preparing wood for treatment in
which the green stock is dried in a kiln under controlled
conditions of temperature and humidity.
Kjld"N - Kjeldahl Nitrogen - Total organic nitrogen plus
ammonia of a sample.
Lagoon - A pond containing raw or partially treated waste-
water in which aerobic or anaerobic stabilization occurs.
Land Decking - Another term for dry-decking. See log
storing.
Leaching - Mass transfer of chemicals to water from wood
which is in contact with it.
Log Bed - Device which holds a log and moves it up and
down past a stationary blade which slices sheets of veneer.
Log Ponding - See log storing.
Log Storing - Retaining large inventories of logs to main-
tain a continuous supply throughout the year. The three
common methods are:
1) Dry-decking - stacking logs on land
2) Wet-decking - sprinkling land-decked logs
with water to minimize end-checking.
3) Log Ponding - storing logs by floating
them in a body of water. This method
is used for long term storage.
MGD - Million gallons per day.
mg/1 - Milligrams per liter (equals parts per million, ppm,
when the specific gravity is one).
ml/1 - Milliters per liter.
Modified Steaming - A technique for conditioning logs which
is a variety of the steam vat process in that steam is pro-
duced by heating water with coils set in the bottom of the
vat.
Moisture - Water content of wood or a timber product ex-
pressed as a percentage of total weight or as percentage of
the weight of dry wood.
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Non-Pressure Process - A method of treating wood at
atmospheric pressure in which the wood is simply soaked
in hot or cold preservative.
Nutrients - The nutrients in contaminated water are
routinely analyzed to characterize the food available
for micro-organisms to promote organic decomposition.
They are:
Ammonia Nitrogen (NH-Q , mg/1 as N
Kjeldahl Nitrogen CON), mg/1 as N
Nitrate Nitrogen (N03), mg/1 as N
Total Phosphate (TP), mg/1 as P
Ortho Phosphate (OP), mg/1 as P
Oil-Recovery System - Equipment used to reclaim oil from
wastewater.
Oily Preservative - Pentachlorophenol-petroleum solutions
and creosote in the various forms in which it is used.
Open Steaming - A method of steam conditioning in which
the steam required is generated in a boiler.
Particle - Distinct fraction of wood or other lignocellulo-
sic material produced mechanically for use as the aggregate
for a particle board. Types of particles include:
Flake - Specially generated thin flat particles,
with the grain of the wood essentially parallel
to the surface of the flake, prepared with the
cutting action of the knife in a plane parallel
to the grain but at an angle to the axis of the
fiber.
Flax Shives - Fine rectangular-shaped particles
of lignocellulosic material obtained by longi-
tudinal division of the stalk of the flax plant
during scutching of the retted flax.
Granule - A particle in which length, width and
thickness are approximately equal, such as a
sawdust particle.
Shaving - A thin slice or strip of wood pared
off with a knife, plane or other cutting
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DRAFT
instrument, with the knife action approximately
along the axis of the fiber, such as the shav-
ings produced in planing the surface of wood.
Sliver - Particle of nearly square or rectangular
cross-section with a length parallel to the grain
of the wood of at least four times the thickness.
Splinter - An alternate term for sliver.
Strand - A relatively long (with respect to
thickness and width) shaving.
Wood-wood (Excelsior) - Curly slender strands
of wood used as an aggregate component for
particle board, also used in mineral-bonded
boards and as packing for fragile articles.
Particle Board - A sheet material manufactured from small
pieces of wood or other ligno-cellulosic materials (e.g.
chips, flakes, splinters, strands, shives, etc.) agglomera-
ted by use of an organic binder together with one or more
of the following agents: heat, pressure, moisture, a catalyst,
etc. (Wood-wool and other particle boards with inorganic
binders are excluded.)
Pearl Benson Index - A measure of color producing substances.
Pentachlorophenol - A chlorinated phenol with the formula
C15C6OH and formula weight of 266.35 that is used as a wood
preservative. Commercial grades of this chemical are usually
adulterated with tetrachlorophenol to improve its solubility.
p_H - pH is a measure of the acidity or alkalinity of a
water sample. It is equal to the negative log of the hydro-
gen ion concentration.
Phenol - The simplest aromatic alcohol.
Pitch - An organic deposit composed of condensed hydrocar-
bons which forms on the surface of dryers.
Plant Sanitation - Those aspects of plant housekeeping which
reduce the incidence of water contamination resulting from
equipment leaks, spillage of preservative, etc.
Plywood - An assembly of an odd number of layers of wood,
or veneers, joined together by means of an adhesive. Ply-
wood consists of two main types:
324
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DRAFT
1) hardwood plywood - has a face ply of
hardwood and is generally used for
decorative purposes.
2) softwood plywood - the veneers typically
are of softwood and the usage is gene-
rally for construction and structural
purposes.
Plywood Pressing Time - The amount of time that plywood
is in a press. The time ranges from two minutes to 24
hours, depending on the temperature of the press and the
type of glue used.
Point Source - A discrete source of pollution.
Pressing - The step in the production operation in which
sheets are subjected to pressure for the purpose of consoli
dation. Pressing may be accomplished at room temperature
(cold pressing) or at high temperature (hot pressing).
Press Pit - A sump under the press.
Pressure Process - A process in which wood preservatives
and fire retardants are forced into wood using air or
hydrostatic pressure.
Radio Frequency Heat - Heat generated by the application
of an alternating electric current, oscillating in the
radio frequency range, to a dielectirc material. In re-
cent years this method has been used to cure synthetic
resin glues.
Resin - Secretions of saps of certain plants or trees.
It is an oxidation or polymerization product of the
terpenes, and generally contains "resin" acids and
ethers.
Retort - A steel vessel in which wood products are pres-
sure impregnated with chemicals that protect the wood from
biological deterioration or that impart fire resistance.
Also called treating cylinder.
Ring barker - See debarker.
Rotary lathing - See veneer cutting.
Roundwood - Wood that is still in the form of a log, i.e.
round.
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DRAFT
Saw Kerf - Wastage of wood immediately adjacent to a saw
blade due to the cut-cleaning design of the blade, which
enlarges the cut slightly on either side.
Sawn Veneer - See veneer cutting.
Sedimentation Tank - A basin or tank in which water or
wastewater containing settleable solids is retained to
remove by gravity a part of the suspended matter.
Segment Saw - A modern veneer saw which consists of a heavy
metal tapering flange to which are bolted several thin,
steel saw segments along its periphery. The segment saw
produces considerably less kerf than conventional circular
saws.
Semi-Closed Steaming - A method of steam conditioning in
which the condensate formed during open steaming is re-
tained in the retort until sufficient condensate accumula-
tes to cover the coils. The remaining steam required is
generated as in closed steaming.
Settling Ponds - An impoundment for the settling out of
settleable solids.
Slicing - See veneer cutting.
Sludge - The accumulated solids separated from liquids,
such as water or wastewater, during processing.
Smooth-two-sides (S-2-S) - Hardboard, or other fiberboard
or particle board produced when a board is pressed from a
dry mat to give a smooth surface on both sides.
Softwood - Wood from evergreen or needle bearing trees.
Soil Irrigation - A method of land disposal in which
wastewater is sprayed on a prepared field. Also referred
to as soil percolation.
Solids - Various types of solids are commonly determined
on water samples. These types of solids are:
Total Solids (TS) - The material left after eva-
poration and drying a sample at 103-105°C.
Suspended Solids (SS) - The material removed from
a sample filtered through a standard glass fiber
filter. Then it is dried at 103-105°C.
326
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DRAFT
Dissolved Solids (PS) - The difference between
the total and suspended solids.
Volatile Solids (VS) - The material which is lost
when the sample is heated to 550°C.
Settleable Solids (STS) - The material which set-
tles in an ImmhoFf cone in one hour.
Spray Evaporation - A method of wastewater disposal in which
the water in a holding lagoon equipped with spray nozzles
is sprayed into the air to expedite evaporation.
Spray Irrigation - A method of disposing of some organic
wastewaters by spraying them on land, usually from pipes
equipped with spray nozzles.
Steam Conditioning - A conditioning method in which un-
seasoned wood is subjected to an atmosphere of steam at
120°C (249°F) to reduce its moisture content and improve
its permeability preparatory to preservative treatment.
Steaming - Treating wood material with steam to soften
it.
Sump - (1) A tank or pit that receives drainage and stores
it temporarily, and from which the drainage is pumped or
ejected, (2) A tank or pit that receives liquids.
Synthetic Resin (Thermosetting) - Artificial resin (as op-
posed to natural) used in board manufacture as a binder.
A combination of chemicals which can be polymerized, e.g.
by the application of heat, into a compound which is used
to produce the bond or improve the bond in a fiberboard or
particle board. Types usually used in board manufacture
are phenol formaldehyde, urea formaldehyde, or melamine
formaldehyde.
Tapeless Splicer - A machine which permits the joining
of individual sheets of veneer without the use of tape.
Individual sheets are glued edge to edge, and cured, thus
saving on tape costs and sanding time during finishing.
Taping Machine - A machine which joins individual sheets
of veneer by taping them together. The tape is later
sanded off during the finishing operations.
Tempered Hardboard - Hardboard that has been specially
treated in manufacture to improve its physical properties
327
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DRAFT
considerably. Includes, for example, oil-tempered
hardboard. Synonymous: superhardboard.
Thermal Conductivity- The quantity of heat which flows
per unit time across unit area of the subsurface of unit
thickness when the temperature of the faces differs by
one degree.
Thermosetting - Adhesives which, when cured under heat
or pressure, "set" or harden to form films of great
tenacity and strength. Subsequent heating in no way
softens the bending matrix.
TOC - Total Organic Carbon is a measure of the organic
contamination of a water sample. It has an empirical
relationship with the biochemical and chemical oxygen
demands.
T-POy|-P - Total phosphate as phosphorus.
Turbidity - (1) A condition in water or wastewater caused
by the presence of suspended matter, resulting in the
scattering and absorption of light rays. (2) A measure
of the fine suspended matter in liquids. (3) An analytical
quantity usually reported in arbitrary turbidity units
determined by measurements of light diffraction.
Underflow - (wet decking) - water which runs off the logs.
Vacuum Water - Water extracted from wood during the vacuum
period following steam conditioning.
Vapor Drying - A process in which unseasoned wood is heated
in the hot vapors of an organic solvent, usually xylene, to
season it prior to preservative treatment.
Vat - Large metal containers in which logs are "conditioned,"
or heated prior to cutting. The two basic methods for heat-
ing are by direct steam contact in "steam vats," or by
steam heated water in "hot water vats."
Veneer - A thin sheet of wood of uniform thickness produced
by peeling, slicing, or sawing logs, bolts, or flitches.
Veneers may be categorized as either hardwood or softwood,
depending on the type of woods used and the intended purpose.
Softwood Veneer is used in the manufacture of
softwood plywood and in some cases the inner
plies of hardwood faced plywood.
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DRAFT
Hardwood Veneer can be categorized according
to use, the three most important being:
(1) face veneer - the highest quality used to
make panels employed in furniture and
interior decoration.
(2) commercial veneer - used for crossbands,
cores, backs of plywood panels and con-
cealed parts of furniture.
(3) container veneer - inexpensive veneers used
in the making of crates, hampers, baskets,
kits, etc.
Veneer Cutting - There are four basic methods:
(1) rotary lathing - cutting continuous strips
by the use of a stationary knife and a lathe.
(2) slicing - consists of a stationary knife and
an upward and downward moving log bed. On
each down stroke a slice of veneer is cut.
(3) stay log - a flitch is attached to a "stay
log," or a long, flanged, steel casting
mounted in eccentric chucks on a conventional
lathe.
(4) sawn veneer - veneer cut by a circular type
saw called a segment saw. This method
produces only a very small quantity of veneer.
(see also "segment saw.")
Veneer Drying - Freshly cut veneers are ordinarily unsuited
for gluing because of their wetness and are also susceptible
to molds, fungi, and blue stain. Veneer is usually dried,
therefore, as soon as possible, to a moisture content of
about 10 percent.
Veneer Preparation - A series of minor operations including
grading and matching, redrying, dry-slipping, joining, tap-
ing and splicing, inspecting! and repairing. These opera-
tions take place between drying and gluing.
Water-Borne Preservative - Any one of several formulations
of inorganic salts, the most common which are based on cop-
per, chromium, and arsenic.
Water Balance - The water gain (incoming water) of a mill
versus water loss (water discharged or lost).
Wet Barkers - See debarker.
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DRAFT
Wet-Felting - Term applied to the forming of a fiberboard
from a suspension of pulp in water usually on a cylinder,
deckle box or Fourdrinier machine; the interfelting of
wood fibers from a water suspension into a irat for board.
Wet Process - See Wet-Felting.
Wet Scrubber- An air pollution control device which involves
the wetting of particles in an air stream and the impinge-
ment of wet or dry particles on collecting surfaces, fol-
lowed by flushing.
Wood Extractives - A mixture of chemical compounds, pri-
marily carbohydrates, removed from wood during steam con-
ditioning.
Wood Preservatives - A chemical or mixture of chemicals with
funsistatic and insecticidal properties that is injected
into wood to protect it from biological deterioration.
330
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APPENDIX A
INVENTORY OF VENEER AND PLYWOOD MILLS IN THE UNITED STATES
331
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DRAFT
APPENDIX A
LIST OF VENEER AND PLYWOOD MILLS "IN THE UNITED STATES
SOFTWOOD PLYWOOD PLANTS
ALABAMA
Birmingham Forest Products, Inc.
Div. of U. S. Steel $
Champion International
Dixon Plywood
Div. of Dixon Lumber Company
Andalusia, Alabama
MacMillan Bloedel Inc.
Div. of MacMillan Bloedel Ltd.
Pine Hill, Alabama
Scotch Plywood Company
Fulton, Alabama
Sumter Veneer Works
Eutaw, Alabama
Union Camp Corporation
Building Products Division
Chapman, Alabama
ARIZONA
Arizona Building Components
Prescott, Arizona
ARKANSAS
Arkla Chamical Corporation
Div. of Arkansas Louisiana"Gas Co,
Gurdon, Arkansas
Georgia-Pacific Corporation
Crossett Division, Plant #1
Crossett, Arkansas
Georgia-Pacific Corporation
Crossett Division, Plant #2
Crossett, Arkansas
Georgia-Pacific Corporation
Crossett Division, Fordyce Plant
Fordyce, Arkansas
Olinkraft, Inc.
Sub. of Olin Corporation
Huttig, Arkansas
The Singer Company-
Wood Products Division
Trumann, Arkansas
Weyerhaeuser Company
Dierks, Arkansas
Weyerheauser Company
Mt. Pine, Arkansas
CALIFORNIA
American Forest Products Corp.
Sub. of The Bendix Corp.
Amador-Calaceras Division
Martell, California
Arcata Plywood Corporation
Arcata, California
Boise Cascade Corporation
Union' Lumber Company Div.
Fort1 Bragg, California
Cloverdale Plywood Company
Div. of Fibreboard Corporation
Cloverdale, California
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DRAFT
Diamond International Corporation
California Lumber Division
Red Bluff, California
Fortuna Veneer Company
Div. of Arcata Plywood Corp.
Fortuna, California
Georgia-Pacific Corporation
Samoa, California
International Paper Company
Long-Bell Division
Weed Operations
Weed, California
The Pacific Lumber Company
Scotia, California
Pickering Lumber Company
Div. of Fibreboard Corporation
Standard, California
Plywood Fabricators, Inc.
Redwood Valley, California
Simpson Timber Company
Mad River Plywood Plant Div.
Arcata, California
Simpson Timber Company
Fairhaven Plywood Plant Div.
Eureka, California
Standard Veneer § Timber Company
Crescent City, California
COLORADO
Montezuma Plywood Company
Sub. of Southwest Forest Ind., Inc.
Cortex, Colorado
FLORIDA
Boise Cascade Corporation
Pensacola Plywood
Cantonment, Florida
Georgia-Pacific Corporation
Chiefland, Florida
GEORGIA
Georgia-Pacific Corporation
Monticello, Georgia
Georgia-Pacific Corporation
Savannah, Georgia
Great Northern Plywood Co.
Sub. of Great Northern
Nekoosa Corporation
Cedar Springs, Georgia
Tolleson Lumber Company
Perry, Georgia
U. S. Plywood
Div. of Champion International
Waycross, Georgia
IDAHO
Idaho Veneer Company
Post Falls, Idaho
Potlatch Forests, Inc.
Clearwater Plywood
Lewiston, Idaho
Potlatch Forests, Inc.
Jaype Plywood Plant
Pierce, Idaho
Potlatch Forests, Inc.
St. Maries Plywood Co. Sub,
St. Maries, Idaho
333
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DRAFT
LOUISIANA
Anthony Forest Products Company
Plywood Division
Plain Dealing, Louisiana
Georgia-Pacific Corporation
Crossett Division
Urania, Louisiana
Louisiana Plywood Corporation
Aff. of Willamette Industries, Inc.
Dodson, Louisiana
Olinkraft, Inc.
Plywood Operation
Sub. of Olin Corp.
Winnfield, Louisiana
Santiam Southern Company
Aff. of Willamette Industries, Inc.
Ruston, Louisiana
Tremont Lumber Company
Joyce, Louisiana
U. S. Plywood
Div. of Champion International
Holden, Louisiana
Vanply Incorporated
Florien, Louisiana
Vanply Incorporated
Oakdale, Louisiana
Wilmar Plywood, Inc.
Aff. of Willamette Ind., Inc.
Natchitoches, Louisiana
Woodard-Walker-Willamette, Inc.
Aff. of Willamette Ind., Inc.
Minden, Lousisiana
MARYLAND
Chesapeake Bay Plywood Corp,
Div. Champion International
Pocomoke City, Maryland
MICHIGAN
Iron Wood Products Corp.
Bessemer, Michigan
MISSISSIPPI
Delta Pine Plywood Company
Beaumont, Mississippi
Georgia-Pacific Corporation
Crossett Division
Gloster, Mississippi
Georgia-Pacific Corporation
Crossett Division
Louisville, Mississippi
Georgia-Pacific Corporation
Crossett Division
Taylorsville, Mississippi
International Paper Company
Long-Bell Division
Wiggins Operations
Wiggins, Mississippi
Weyerhaeuser Company
Philadelphia Operations
Philadelphia, Mississippi
MONTANA
C § C Plywood Corporation
Kalispell, Montana
334
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DRAFT
Evans Products Company
Van-Evans Operations
Missoula, Montana
Pack River PLywood Company
Poison, Montana
Plum Creek Lumber Company
Columbia Falls, Montana
St. Regis Paper Company
Forest Products Division
Libby, Montana
NEW HAMPSHIRE
Frye $ Son, Inc.
Wilton, New Hampshire
NORTH CAROLINA
Evans Products Company
Building Materials Group
Kings Mountain, North Carolina
Prescott Products Corporation
Elizabeth City, North Carolina
Thomason Plywood Corporation
Fayetteville, North Carolina
Triangle Plywood Corporation
Sub. of Boise Cascade Corp.
Moncure, North Carolina
Weyerhaeuser Company
Jacksonville, North Carolina
Weyerhaeuser Company
Plymouth, North Carolina
OKLAHOMA
Weyerhaeuser Company
Wright City, Oklahoma
OREGON
Agnew Plywood
Div. of Fourply, Inc.
Grants Pass, Oregon
Alpine Veneers, Inc.
Portland, Oregon
Astoria Plywood Corporation
Astoria, Oregon
Bate Plywood Company, Inc.
Div. of Fibreboard Corp.
Merlin, Oregon
Bohemia Lumber Company, Inc
Gulp Creek, Oregon
Boise Cascade Corporation
N. W. Oregon Region
Albany Division
Albany, Oregon
Boise Cascade Corporation
Mt. Emily Division
Elgin, Oregon
Boise Cascade Corporation
N. W. Oregon Region
Independence Division
Independence, Oregon
Boise Cascade Corporation
Southern Oregon Region
Medford, Oregon
Boise Cascade Corporation
N. W. Oregon Region
Sweet Home Division
Sweet Home, Oregon
Boise Cascade Corporation
N. W. Oregon Region
Valsetz Division
Valsetz, Oregon
335
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DRAFT
Brand S Corporation
Alsea, Oregon
Brand S Corporation
Corvallis, Oregon
Brookings Plywood Corporation
Brookings, Oregon
Brooks-Willamette Corporation
Aff. of Willamette Industries, Inc.
Redmond, Oregon
Cabax Mills
Plywood Division
Eugene, Oregon
Carolina Pacific Plywood, Inc.
Sub. of Southwest Forest Industries
Grants Pass, Oregon
Carolina Pacific Plywood Inc.
Sub. of Southwest Forest Industries
White City, Oregon
Coos Head Timber Company
Coos Bay, Oregon
Drain Plywood Company
Drain, Oregon
Ellingson Timber Company
Plywood Division
Baker, Oregon
Eugene Stud $ Veneer Inc.
Eugene, Oregon
Fir Ply Incorporated
White City, Oregon
Georgia-Pacific Corporation
Coos Bay, Oregon
Georgia-Pacific Corporation
Coquille, Oregon
Georgia-Pacific Corporation
Springfield Division
Camp Adair Plant
Corvallis, Oregon
Georgia-Pacific Corporation
Eugene Division
Eugene, Oregon
Georgia-Pacific Corporation
Springfield Division
Springfield, Oregon
Georgia-Pacific Corporation
Toledo, Oregon
Georgia-Pacific Corporation
Yarnell Plywood Division
Yarnell, Oregon
Giustina Bros. Lumber §
Plywood Company
Eugene, Oregon
Glendale Plywood Company
Sub. of The Robert Dollar Co.
Glendale, Oregon
Mines Lumber Company
Mines, Oregon
Mines Lumber Company
Westfir, Oregon
International Paper Company
Long-Bell Division
Gardiner Operations
Gardiner, Oregon
336
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DRAFT
International Paper Company
Long Bell Division
Vaughn Operations
Veneta, Oregon
Lane Plywood Incorporated
Eugene, Oregon
Leadings Plywood Corporation
Eugene, Oregon
Linnton Plywood Association
Portland, Oregon
Medford Corporation
Medford, Oregon
Medford Veneer § Plywood Corp.
White City, Oregon
Mid Plywood Incorporated
Sweet Home, Oregon
Millwaukie Plywood Corporation
Millwaukie, Oregon
Multnomah Plywood Corporation
St. Helens, Oregon
Nordic Plywood, Inc.
Aff. with Nordic Veneers, Inc.
Sutherlin, Oregon
North Santiam Plywood Co.
Mill City, Oregon
Oregon-Washington Plywood Co.
Garibaldi, Oregon
Publishers Paper Company
Dwyer Division
Portland, Oregon
Rogue Valley Plywood, Inc.
White City, Oregon
Rosboro Lumber Company
Springfield, Oregon
Roseburg Lumber Company
Dillard, Oregon
Roseburg Lumber Company
Roseburg, Oregon
Roseburg Lumber Company
Riddle, Oregon
Roseburg Lumber Company
Coquille, Oregon
SWF Plywood Company
Div. of Southwest Forest Industries
Grants Pass, Oregon
SWF Plywood Company
Div. of Southwest Forest Industries
Springfield, Oregon
Simpson Timber Company
Albany Plywood Plant
Albany, Oregon
Southern Oregon Plywood Inc.
Grants Pass, Oregon
Structural Laminates, Inc.
Beaverton, Oregon
Tillamook Veneer Company
Tillamook, Oregon
Tim-Ply Company
Division of Timber Products Co.
Grants Pass, Oregon
U. S. Plywood
Div. of Champion International
Gold Beach, Oregon
U. S. Plywood
Div. of Champion International
Mapleton, Oregon
337
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DRAFT
U. S. Plywood
Div. of Champion International
Roseburg, Oregon
U. S. Plywood
Div. of Champion International
Willamina, Oregon
Warm Springs Forest Products
Mardas, Oregon
Western States Plywood Cooperative
Port Orford, Oregon
Weyerhaeuser Company
Cottage Grove, Oregon
Weyerhaeuser Company
Klamath Falls, Oregon
Weyerhaeuser Company
Coos Bay Branch
North Bend, Oregon
Weyerhaeuser Company
Springfield, Oregon
White City Plywood Company
McMinnville, Oregon
White City Plywood Company
White City, Oregon
Willamette Industries, Inc.
Dallas Division
Dallas, Oregon
Willamette Industries, Inc.
Foster Division
Sweet Home, Oregon
Willamette Industries, Inc.
Griggs Division
Lebanon, Oregon
Willamette Industries, Inc.
Lebanon Division
Lebanon, Oregon
Willamette Industries, Inc,
Springfield Division
Springfield, Oregon
Willamette Industries, Inc
Sweet Home Division
Sweet Home, Oregon
SOUTH CAROLINA
Cheraw Plywood Company, Inc.
Cheraw, South Carolina
Georgia-Pacific Corporation
Russellville, South Carolina
Holly Hill Lumber Co., Inc.
Holly Hill, South Carolina
TEXAS
Blodkstein Company
Houston, Texas
Georgia-Pacific Corporation
Corrigan, Texas
Georgia-Pacific Corporation
Crossett Division
New Waverly, Texas
International Paper Company
Long-Bell Division
Nacogdoches Operations
Nacogdoches, Texas
Kirby Lumber Corporation
Silsbee, Texas
Owens-Illinois, Inc.
Jasper, Texas
Owens-Illinois, Inc.
Lufkin, Texas
338
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DRAFT
Temple Industries, Inc.
Plywood Division
Diboll, Texas
Walker Plywood
Kirby Lumber Corporation
Cleveland, Texas
VIRGINIA
Georgia-Pacific Corporation
Emporia, Virginia
WASHINGTON
Biles-Coleman Lumber Company
Omak, Washington
Bingen Plywood Company
Bingen, Washington
Boise Cascade Corporation
Kettle Falls, Washington
Boise Cascade Corporation
Yakima, Washington
Centralia Plywood Inc.
Centralia, Washington
Elma Plywood Corporation
Elma, Washington
Evans Products Company
Building Materials Group
Softwood Lumber § Plywood Div.
Harbor Mill
Aberdeen, Washington
Everett Plywood Corporation
Everett, Washington
Farwest Plywood Company
Tacoma, Washington
Fort Vancouver Plywood Company
Vancouver, Washington
Hardel Mutual Plywood Corp.
Olympia, Washington
Hoquaim Plywood Company, Inc.
Hoquaim, Washington
International Paper Company
Long-Bell Division
Chelatchie Operations
Amboy, Washington
Lacey Plywood Company, Inc.
Lacey, Washington
Lyle Wood Products Inc.
Tacoma, Washington
Mt. Baker Plywood Inc.
Bellingham, Washington
North Pacific Plywood, Inc.
Tacoma, Washington
Peninsula Plywood Corporation
Sub. of ITT
Port Angeles, Washington
Pope § Talbot, Inc.
Kalama, Washington
Publishers Forest Products Co.
Div. of Publishers Paper Co.
Anacortes, Washington
Puget Sound Plywood, Inc.
Tacoma, Washington
339
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DRAFT
Simpson Timber Company
McCleary, Washington
Simpson Timber Company
Olympic Plant
Shelton, Washington
Stevenson Co-Ply, Inc.
Stevenson, Washington
U. S. Plywood
Div. of Champion International
Grays Harbor Division
Hoquaim, Washington
Weyerhaeuser Company
Longview, Washington
Weyerhaeuser Company
Snoqualmine Falls, Washington
SOFTWOOD VENEER PLANTS
ARKANSAS
Beisel Veneer Hoop Company
West Helena, Arkansas
FLORIDA
Franklin Crates, Inc.
Micanopy, Florida
CALIFORNIA
Carolina Pacific Plywood, Inc.
Sub. of Southwest Forest Ind.
Slayer, California
Carolina Pacific Plywood, Inc.
Sub. of Southwest Forest Ind.
Happy Camp, California
Hoopa Veneer Company
Hoopa, California
Medford Veneer § Plywood Corp.
Crescent City, California
Miller Redwood Company
Sub. of Stimson Lumber Company
Crescent City, California
Orleans Veneer § Lumber Company
Div. of Arcata Plywood Corp.
Orleans, California
Rochlin Veneer § Plywood Co.
Willow Creek, California
West Coast Veneer Company
Crescent City, California
GEORGIA
Pearson Basket Mills
Fort Valley, Georgia
MARYLAND
Stenersen Mahogany Corp.
Cockeysville, Maryland
MINNESTOA
Wahkon Veneer Mill
Wahkon, Minnesota
NEW JERSEY
Rapp Package Company
Carpentersville, New Jersey
NORTH CAROLINA
Armentrout Veneer Company
High Point, North Carolina
340
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DRAFT
Collins-Davis Chair Company
Hudson, North Carolina
Lenderink Incorporated
Wilson, North Carolina
Mayo Veneers, Inc.
Whitakers, North Carolina
Thomasville Veneer Company
Thomasville, North Carolina
Weyerheauser Company
Jacksonville, North Carolina
OREGON
Baflam Veneer Corporation
Corvallis, Oregon
Boise Cascade Corporation
Chemult, Oregon
Coburg Veneer Corporation
Coburg, Oregon
Conrad Veneers, Inc.
Tualatin, Oregon
Dillard Veneer Company
Riddle, Oregon
The Robert Dollar Company
Glendale, Oregon
Douglas Lumber Company
Roseburg, Oregon
Firwood Lumber Company, Inc.
Sandy, Oregon
Freres Lumber Company, Inc.
Lyons, Oregon
G L Pine Incorporated
John Day, Oregon
Georgia-Pacific Corporation
Norply Veneer Division
Norway, Oregon
Georgia-Pacific Corporation
Powers Veneer Division
Powers, Oregon
Georgia-Pacific Corporation
Rogue River Veneer Division
Rogue River, Oregon
Georgia=Pacific Corporation
Sutherlin Division
Sutherlin, Oregon
Goshen Veneer Inc.
Goshen, Oregon
Edward Hines Lumber Company
Mount Vernon, Oregon
Kogap Manufacturing Company
Medford, Oregon
Lawyer Veneer Company
White City, Oregon
Menasha Corporaiton
Doyle Veneer Division
Myrtle Point, Oregon
The Murphy Company
Florence, Oregon
Nordic Veneers, Inc.
Roseburg, Oregon
Olympic Manufacturing Co.
Gresham, Oregon
Pope § Talbot, Inc.
Oakridge, Oregon
341
-------
DRAFT
Rex Veneer Company
Philomath, Oregon
Roseburg Lumber Company
Dixonville, Oregon
Stimson Lumber Company
Forest Grove, Oregon
Sun Studs, Inc.
Sun Veneer Division
Roseburg, Oregon
Sweet Home Veneer, Inc.
Sweet Home, Oregon
Timber Products Company
Medford, Oregon
Triangle Veneer Inc.
Eugene, Oregon
Zip-0-Log Veneer, Inc.
Eugene, Oregon
SOUTH CAROLINA
Highland Crate Co-op.
St. Stephen, South Carolina
TEXAS
Solver Crate
Rusk, Texas
Lumber Mill Co.
WASHINGTON
Allen Logging § Veneer Co.
Forks, Washington
Bay Veneer Incorporated
Townsend, Washington
Cowlitz Stud Company
Randle, Washington
Hegewald Timber, Inc.
Stevenson, Washington
Ly-Col Veneer, Inc.
Roslyn, Washington
Mt. Adams Veneer Company
Randle, Washington
Oregon Washington Plywood Co,
Tandle, Washington
Solid Wood, Inc.
Olympia, Washington
Winlock Veneer
Winlock, Washington
WISCONSIN
Dufeck Manufacturing Co.
Denmark, Wisconsin
Menasha Corporation
Neenah, Wisconsin
VIRGINIA
Ferrum Veneer Corporation
Ferrum, Virginia
342
-------
DRAFT
HARDWOOD PLYWOOD
ALABAMA
Alabama Veneer § Panel Company
Mexia, Alabama
Belcher Lumber Company, Inc.
Centerville, Alabama
Decatur Box § Basket Company, Inc
Decatur, Alabama
Dixie Veneer Company
Abbeville, Alabama
Fox Lumber Company
Centerville, Alabama
Howell Plywood Corporation
Dothan, Alabama
Taylor Veneer Company, Inc.
Demopolis, Alabama
Thompson $ Swaim Plywood, Inc.
Tuscaloosa, Alabama
Union Camp Corporation
Building Products Division
Chapman, Alabama
ARKANSAS
Chicago Mill § Lumber Company
West Helena, Arkansas
Delta Plywood Corporation
Cotton Plant, Arkansas
Evans Products Company
West Memphis, Arkansas
McKnight Veneer § Plywoods, Inc,
West Helena, Arkansas
CALIFORNIA
Birchwood of Los Angeles, Inc.
Los Angeles, California
General Veneer Manufacturing Co
South Gate, California
Karpen Plywood Company
Div. of U. S. Plywood-
Champion Papers, Inc.
Compton, California
Lorenz Lumber Company
Div. of Fibreboard Corp.
Burney, California
Plywood Manufacturing of Calif.
Torrance, California
Sunset Plywood, Inc.
Los Angeles, California
FLORIDA
Boise Cascade Corporation
Pensacola Division
Cantonment, Florida
Costal Variety Works, Inc,
Blountstown, Florida
Florida Plywoods, Inc.
Greenville, Florida
343
-------
DRAFT
GEORGIA
Bradley Plywood Corporation
Savannah, Georgia
The Day Company
Cuthbert, Georgia
Georgia-Pacific Corporation
Savannah, Georgia
Georgia Plywood Corporation
Dublin, Georgia
Patat Plywood Corporation
Rockmart, Georgia
Pearson Basket Mills
Fort Valley, Georgia
ILLINOIS
Jasper Wood Products Co., Inc.
Newton, Illinois
INDIANA
General Plywood Corp., Inc.
Indiana Division
New Albany, Indiana
Hoosier Panel Company, Inc.
New Albany, Indiana
Jasper Stylemasters, Inc.
Div. of Jasper Corporation
Jasper, Indiana
Jasper Veneer Mills, Inc.
Jasper, Indiana
Jasper Wood Products Co., Inc.
Jasper, Indiana
Paramount Plywood Products, Inc,
New Albany, Indiana
KENTUCKY
Gamble Brothers, Inc.
Louisville, Kentucky
LOUISIANA
Chicago Mill $ Lumber Co.
Tullulah, Louisiana
U. S. Plywood
Div. of Champion International
Hammond, Louisiana
MAINE
J. M. Huber Corporation
Patten, Maine
Kennebec, Inc.
Bingham, Maine
Allen Quimby Veneer Company
Div. of Scoville Mfg. Co.
Bingham, Maine
MICHIGAN
Contour Products, Inc.
Bay City, Michigan
Ironwood Products Corp.
Bessemer, Michigan
344
-------
DRAFT
Ply Curves Incorporated
Grand Rapids, Michigan
Plycoma Veneer Corporation
Nashville, Michigan
MINNESOTA
Buffalo Veneer § Plywood Co,
Buffalo, Minnesota
Mill City Plywood Company
Minneapolis, Minnesota
MISSISSIPPI
Chicago Mill § Lumber Co.
Greenville, Mississippi
The Day Company
Waynesboro, Mississippi
Iron Wood Products
Bessemer, Mississippi
Pavco Industries, Inc.
Pascagoula, Mississippi
Perry County Plywood Corp.
Beaumont, Missippi
Tuscaloosa Veneer Company
Meridian, Mississippi
NEW HAMPSHIRE
Frye § Son Incorporated
Wilton, New Hampshire
Keller Products, Inc.
Manchester, New Hampshire
NEW YORK
Jamestown Plywood Division
AVM Corporation
Jamestown, New York
U. S. Veneer Company, Inc.
Div. of John Lagenbacher
Bronx, New York
NORTH CAROLINA
Beck Brothers Veneer Co., Inc.
Zubulon, North Carolina
Benson Veneer Company, Inc.
Benson, North Carolina
Boise Cascade Corporation
Face Veneers Division
Pelham, North Carolina
Boliva Lumber Company
Wilmington, North Carolina
Calypso Plywood Company, Inc.
Calypso, North Carolina
Carolina Panel Company, Inc.
Lexington, North Carolina
Carolina Plywood Company, Inc.
Apex, North Carolina
Columbia Panel Manufacturing Co
Thomasville, North Carolina
Davis Wood Products, Inc.
Lexington, North Carolina
Denny Plywood Company, Inc.
Roseboro, North Carolina
345
-------
DRAFT
Doxey Plywood Corporation
Fayetteville, North Carolina
Hasty Plywood Company
Maxton, North Carolina
Hayworth Roll § Panel Co.
High Point, North Carolina
Horner Veneer Company
New Bern, North Carolina
Ingram Plywoods, Inc.
Thomasville, North Carolina
Lea Lumber § Plywood Co.
Div. of Lea Industries, Inc.
Windsor, North Carolina
Lenoir Veneer Company
Lenoir, North Carolina
McLeod Plywood Box Co., Inc.
Wadesboro, North Carolina
Rankin Brothers Company
Fayetteville, North Carolina
Rowland Wood Products Co., Inc.
Rowland, North Carolina
Rural Hall Veneer Company
Rural Hall, North Carolina
Southern Box § Plywood, Inc.
Wilmington, North Carolina
Statesville Plywood § Veneer Co,
Statesville, North Carolina
Thomason Industries, Inc.
Fayetteville, North Carolina
Weldon Veneer Company, Inc.
Weldon, North Carolina
Whiteville Plywood Company
Whiteville, North Carolina
OREGON
Columbia Plywood Corporation
Klamath Plywood Division
Klamath Falls, Oregon
Dougals Fir Plywood Company
Coquille, Oregon
Georgia-Pacific Corporation
Eugene/Springfield Division
Junction City, Oregon
Publishers Paper Company
Dwyer Division
Portland, Oregon
Roseburg Lumber Company
Dillard, Oregon
Southern Oregon Plywood, Inc.
Grants Pass, Oregon
States Veneer, Inc.
Div. of Wood Slicing Corp.
Eugene, Oregon
Timber Products Company
Medford, Oregon
PENNSYLVANIA
Jasper Wood Products Co., Inc.
Watsontown, Pennsylvania
Thompson Mahogany Company
Philadelphia, Pennsylvania
346
-------
DRAFT
Timber Products Company
Medford, Pennsylvania
Westavco Corporation
Tyrone, Pennsylvania
SOUTH CAROLINA
Carolina Veneer § Plywood Co.
Florence, South Carolina
Cheraw Plywood Company, Inc.
Cheraw, South Carolina
Darlington Veneer Company
Darlington, South Carolina
Davis Wood Products, Inc.
S. C. Division
Blenheim, South Carolina
Dillon Veneer § Plywood Company
Dillon, South Carolina
Furniture Veneers, Inc.
Conway, South Carolina
Georgia-Pacific Corporation
Williams Furniture Division
Sumpter, South Carolina
King Veneer Company, Inc.
Florence, South Carolina
Marsh Plywood Corporation
Paplico, South Carolina
The Plywood Company
Sumpter, South Carolina
Powe Veneer Company
Camden, South Carolina
Standard Plywoods, Inc.
Clinton, South Carolina
Stilley Plywood Company, Inc.
Conway, South Carolina
Tinsley Plywood Corporation
Florence, South Carolina
U. S. Plywood
Div. of Champion International
Orangeburg, South Carolina
Winnsboro Plywood Company
Winnsboro, South Carolina
TENNESSEE
Panoply Corporation
Lexington, Tennessee
Southern Laminating Company
Memphis, Tennessee
Tennessee Veneer Company
Memphis, Tennessee
Tri-State Veneer § Plywood Co
Memphis, Tennessee
TEXAS
Bruce Company of Texas
Div. of Cook Industries, Inc.
Center, Texas
Center Plywood Company, Inc.
Center, Texas
Liberty Veneer § Panel Co.
Liberty, Texas
VERMONT
Bradford Veneer § Panel Co.
Bradford, Vermont
347
-------
DRAFT
Consolidated Electronics Ind-
ustries Corporation
Atlas Plywood Division
Morrisville, Vermont
Rutland Plywood Corporation
Rutland, Vermont
Vermont-Pacific Corporation
Bethel, Vermont
Weyerhaeuser Company
Wood Products Division
Hancock, Vermont
VIRGINIA
Atkins Plywood Company, Inc.
Atkins, Virginia
Boise Cascade Corporation
Decorative Paneling Division
Danville, Virginia
Burkeville Veneer Company
Burkeville, Virginia
Day Companies, Inc.
Suffolk, Virginia
Eastern Door § Panel Corp.
Danville, Virginia
Henry County Plywood Corp.
Ridgeway, Virginia
Multi-Ply Corporation
Danville, Virginia
Old Dominion Plywood Corp.
Bristol, Virginia
Virginia-Carolina Veneer Corp,
Danville, Virginia
Virginia Plywood Corporation
Danville, Virginia
Whittle Plywood Corporation
Chatham, Virginia
WASHINGTON
Buffelen Woodworking Company
Tacoma, Washington
Everett Plywood Corporation
Everett, Washington
Mt. Baker Plywood, Inc.
Bellingham, Washington
North Pacific Plywood, Inc.
Tacoma, Washington
Pasquier Panel Products, Inc,
Sumner, Washington
WEST VIRGINIA
Allegheny Lumber Company
Elkins, West Virginia
WISCONSIN
All-Wood Incorporated
Bayfield, Wisconsin
Birchwood Manufacturing Co.
Rice Lake, Wisconsin
Blum Brothers
Marshfield, Wisconsin
Eggers Plywood Company
Two Rivers, Wisconsin
Gillett Veneer § Plywood Co.
Gillett, Wisconsin
Larson Plywood Company, Inc.
Sheboygan, Wisconsin
Linwood Incorporated
Gillett, Wisconsin
348
-------
DRAFT
Lullabye Furniture Company
Div. of Questor Corporation
Stevens Point, Wisconsin
Marion Plywood Corporation
Marion, Wisconsin
Nelson Plywood Corporation
Gillett, Wisconsin
Pluswood Industries
Oshkosh, Wisconsin
U. S. Plywood
Div. of Champion International
Algoma Operations
Algoma, Wisconsin
Warvel Products, Inc.
Gillett, Wisconsin
Weber Veneer § Plywood Co.
Shawano, Wisconsin
Weyerhaeuser Company
Marshfield, Wisconsin
Wisconsin Laminates, Inc.
Pewaukee, Wisconsin
349
-------
DRAFT
HARDWOOD VENEER
ALABAMA
Bacon-McMillan Veneer
Manufacturing Co., Inc.
Stockton, Alabama
Browder Veneer Works
Montgomery, Alabama
Sumpter Veneer Works
Eutaw, Alabama
Winborn Veneer Company
Allen, Alabama
FLORIDA
Franklin Crates, Inc.
Micanopy, Florida
Grower's Container Co-op., Inc.
Leesburg, Florida
Highland Crate Co-op.
Jacksonville, Florida
Telley's Box Company, Inc.
Palatka, Florida
GEORGIA
Alexander Wood Products, Inc.
Athens, Georgia
C § H Veneer Company
Hawkinsville, Georgia
Cornelia Veneer Company
Cornelia, Georgia
Perry Veneer Company
Perry, Georgia
Truax Veneer Company, Inc.
Sub. of Lenderink, Inc.
Lyons, Georgia
ILLINOIS
Swords Veneer § Lumber Co,
Sub. of General Woods and
Veneers, Ltd.
Rock Island, Illinois
INDIANA
Amos-Thompson Corporation
Sub. of National Lead Company
Edinburg, Indiana
Central Veneer Incorporated
Indianapolis, Indiana
Cummings Veneers, Inc.
New Albany, Indiana
Curry § Sons, Inc.
New Albany, Indiana
Farrell Box Company, Inc.
Decker, Indiana
Hill Brothers Veneer Co.
Div. of Hammerhill Paper Co.
Edinburg, Indiana
Hoosier Veneer Company, Inc.
New Albany, Indiana
Indiana Veneers, Inc.
Indianapolis, Indiana
National Veneer $ Lumber Co.
Seymour, Indiana
Pierson-Hollowell Co., Inc.
Lawrenceburg, Indiana
350
-------
DRAFT
Roberts § Strack Veneer Co., Inc.
Clarksville, Indiana
Chester B. Stem, Inc.
New Albany, Indiana
David R. Webb Company
Div. of The Walter Reade Org., Inc
Edinburg, Indiana
IOWA
Bacon Veneer Company
Hubbard Walnut Division
Dubuque, Iowa
Spencer Veneers, Inc.
Spencer, Iowa
KENTUCKY
The Freeman Corporation
Winchester, Kentucky
Laminating Services
Sub. of American Standard Corp.
Louisville, Kentucky
Robins Veneer Company
Louisville, Kentucky
Wood Mosaic Corporation
Sub. of Olin Mathierson Chemical Co,
Louisville, Kentucky
LOUISIANA
Louisiana Veneer Co., Inc.
Chathan, Louisiana
Winnfield Veneer Company
Winnfield, Louisiana
Wood Mosaic Corporation
New Orleans, Louisiana
MAINE
Indian Head Plywood Corp.
Presque Isle, Maine
MARYLAND
Stenersen Mahogany Corporation
Div. of Universal Oil Prod. Co.
Escanaba, Michigan
Manthei Incorporated
Petoskey, Michigan
Soo Veneer Mill
Sault Ste. Marie, Michigan
MINNESOTA
Elk River Box Factory
Elk River, Minnesota
Wahkon Veneer Mill
Wahkon, Minnesota
MISSISSIPPI
Central Box Company
Crystal Springs, Mississippi
Natchez Veneer § Lumber Co., Inc,
Natchez, Mississippi
Rhymes Veneer Incorporated
Collins, Mississippi
MISSOURI
Enterprise Veneer Corporation
Pleasant Hill, Missouri
351
-------
DRAFT
Missouri Valley Veneers
Div. of C § D Sales, Inc.
St. Joseph, Missouri
NEW JERSEY
Ichabod T. Williams § Sons, Inc.
Carteret, New Jersey
NEW YORK
Gross Veneer Company
Potsdam, New York
Knight Veneer § Panel Corp.
Sub. of Maddox Table Co.
Falconer, New York
Riverside Veneer Company, Inc.
Heuvelton, New York
Robbins Veneer, Inc.
Falconer, New York
Webster Basket Company
Webster, New York
NORTH CAROLINA
Armentrout Veneer Co., Inc.
High Point, North Carolina
Atlantic Veneer Corporation
Beaufort, North Carolina
Beaufort Face Veneer Co., Inc.
Beaufort, North Carolina
Carolina Veneer Company
Thomasville, North Carolina
Chadbourn Veneer Company
Chadbourn, North Carolina
Chowan Veneer Company, Inc.
Edenton, North Carolina
Coastal Veneer Company, Inc.
Wilhan, North Carolina
Davidson Veneer Company, Inc.
Lexington, North Carolina
Duplin Face Veneer Co., Inc.
Mount Olive, North Carolina
Lenderink Incorporated
Wilson, North Carolina
Linwood Manufacturing Co.
Linwood, North Carolina
Quality Veneer Company, Inc.
Liberty, North Carolina
Southern" Veneer Company, Inc.
Thomasville, North Carolina
Stubbs Veneer Company
Windsor, North Carolina
Thomasville Veneer Company
Thomasville, North Carolina
Timber Products Company
Div. of Fitco, Inc.
Murphy, North Carolina
U. S. Plywood
Div. of Champion International
Guilford Veneer Operations
High Point, North Carolina
Wilson Veneer Company, Inc.
Wilson, North Carolina
Womble Veneer Company
Southern Pines, North Carolina
352
-------
DRAFT
OHIO
Edon Manufacturing Company
Edon, Ohio
Hartzell Hardwoods, Inc.
Piqua, Ohio
OREGON
Conrad Veneers, Inc.
Tulatin, Oregon
The Dean Company
Olympic Manufacturing Co. Div,
Gresham, Oregon
Northwest Veneer, Inc.
Grande Ronde, Oregon
Olympic Manufacturing Co.
Sub. of the Dean Company
Gresham, Oregon
PENNSYLVANIA
Cornelia Veneer Company
Philadelphia, Pennsylvania
J. A. Habig Veneer Company
Montgomery, Pennsylvania
Weyerhaeuser Company
Ridgeway, Pennsylvania
Williamson Veneer Company
Sub. of Evans Products Co.
New Freedom, Pennsylvania
Woody Veneer § Lumber Co., Inc,
Glen Rock, Pennsylvania
SOUTH CAROLINA
BeauforfWood'Products Co., Inc
Yemassee, South Carolina
Bennettsville Veneer Company
Bennettsville, South Carolina
Carolina Wirebounds, Inc.
Springfield, South Carolina
Denmark-Veneer Company
Denmark, South Carolina
Elloree Veneer Company
Elloree, South Carolina
Kearse Manufacturing Co., Inc.
Olar, South Carolina
TENNESSEE
Ashby Veneer § Lumber Company
Jackson, Tennessee
Dyer Fruit Box Company
Dyer, Tennessee
VERMONT
Indian Head Plywood Corp.
Div. of Columbia Plywood Corp,
Newport, Vermont
VIRGINIA
Blue Ridge Veneer $ Plywood Corp,
Waynesboro, Virginia
Perrum Company
Sub. of Mead Corporation
Ferrum, Virginia
353
-------
DRAFT
Helms Veneer Corporation
Rocky Mount, Virginia
Penrod, Jurden § Clark Co.
Norfolk, Virginia
Stubbs Veneer Company, Inc.
Div. of Henry County Plywood Corp,
Ridgeway, Virginia
U. S. Plywood
Div. of Champion International
Champion Veneer Works
Pulaski, Virginia
Virginia Log Company, Inc.
West Point, Virginia
WEST VIRGINIA
Breece Veneer Company
Kenova, West Virginia
Martinsburg Veneer Corp.
Martinsburg, West Virginia
WISCONSIN
Bennett-Box § Veneer Company
Rice Lake, Wisconsin
Ebner Box Incorporated
Cameron, Wisconsin
Hatley Veneer Company, Inc.
Hatley, Wisconsin
Houghton Wood Products, Inc.
Wausau, Wisconsin
354
-------
DRAFT
SOFTWOOD AND HARDWOOD PLYWOOD
ALABAMA
Sumpter Veneer Works
Eutaw, Alabama
Union Camp Corporation
Building Products Div.
Chapman, Alabama
FLORIDA
Boise Cascade Corporation
Pensacola Plywood
Cantonment, Florida
GEORGIA
Georgia-Pacific Corporation
Savannah, Georgia
MICHIGAN
Iron Wood Products Corp.
Bessemer, Michigan
NEW HAMPSHIRE
Frey § Son, Inc.
Wilton, New Hampshire
NORTH CAROLINA
Thomason Plywood Corporation
Fayetteville, North Carolina-
OREGON
Georgia-Pacific' Corporation
Eugene Division
Eugene, Oregon
Publishers Paper Company
Dwyer Division
Portland, Oregon
Southern Oregon Plywood Inc.
Grants Pass, Oregon
SOUTH CAROLINA
Cheraw Plywood Company, Inc.
Cheraw, South Carolina
TEXAS
Walker Plywood
Kirby Lumber Corporation
Cleveland, Texas
WASHINGTON
Everett Plywood Corporation
Everett, Washington
Mf. Baker Plywood, Inc.
Bellingham, Washington
North Pacific Plywood, Inc.
Tacoma, Washington
Pugef Sound-Plywood, Inc.
Tacoma', 'Washington
355
-------
DRAFT
SOFTWOOD AND HARDWOOD VENEER
FLORIDA
Franklin Crates Incorporated
Micanopy, Florida
GEORGIA
Pearson Basket Mills
Fort Valley, Georgia
OREGON
Conrad Veneers, Inc.
Tualatin, Oregon
Olympic Manufacturing Co,
Gresham, Oregon
Timber Products Company
Medford, Oregon
MARYLAND
Stenersen Mahogany Corp.
Cockeysville, Maryland
VIRGINIA
Ferrum Veneer Corporation
Ferrum, Virginia
MINNESOTA
Wahkon Veneer Mill
Wahkon, Minnesota
NORTH CAROLINA
Armentrout Veneer Co., Inc.
High Point, North Carolina
Lenderink Incorporated
Wilson, North Carolina
Thomasville Veneer Company
Thomasville, North Carolina
356
-------
APPENDIX B
ENGLISH-METRIC CONVERSION TABLE
357
-------
l/l
OO
CONVERSION TABLE
Multiply (English Units) by To Obtain (Metric Units)
English Unit Abbreviation Conversion Abbreviation Metric Unit
acre
acre-feet
British Thermal
Unit
British Thermal
Unit/pound
cubic feet
per minute
cubic feet
per second
cubic feet
cubic feet
cubic inches
degree Fahrenheit
feet
gallon
ac
ac ft
BTU
BTU/lb
cfm
cfs
cu ft
cu ft
cu in
oF
ft
gal
0.405
1233.5
0.252
0.555
0.028
1.7
0.028
28.32
16.39
0.555(°F-32)1
0.3048
3.785
ha
cu m
kg cal
kg cal/kg
cu m/min
cu m/min
cu m
1
cu cm
°C
m
1
hectares
cubic meters
kilogram- calories
kilogram calories
per kilogram
cubic meters
per minute
cubic meters
per minute
cubic meters
liters
cubic centimeters
degree Centigrade
meters
liters
Actual conversion, not a multiplier
-------
CONVERSION TABLE (CONTINUED)
Multiply (English Units) by To Obtain (Metric Units)
English Unit Abbreviation Conversion Abbreviation Metric Unit
gallon per
minute
gallon per
ton
horsepower
inches
inches of
Mercury
pounds
pound per ton
million gallons
per day
mile
pounds per square
gpm
gal/ton
hp
in
in Hg
Ib
Ib/ton
mgd
mi
psig
.0.0631
4.173
0.7457
2.54
0.03342
0.454
0.5005
3,785
1.609
(0.06805 psig+1)1
I/sec
1/kkg
kw
cm
atm
kg
kg/kkg
cu m/day
km
atm
liters per
second
liters per
metric ton
kilowatts
centimeters
atmospheres
(absolute)
kilograms
kilograms per
metric ton
cubic meters
per day
kilometer
atmospheres
inch (gauge)
Actual conversion, not a multiplier
(absolute)
-------
CONVERSION TABLE (CONTINUED)
Multiply (English Units) by To Obtain (Metric Units)
English Unit Abbreviation Conversion Abbreviation Metric Unit
square feet
square inches
tons (short)
yard
sq ft
sq in
t
y
0.0929
6.452
0.907
0.9144
sq m
sq cm
kkg
m
square meters
square centimeters
metric tons
(1000 kilograms)
meters
OJ
o
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