United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
January 1979
Research and Development
Post Biological
Solids
Characterization and
Removal from Pulp
Mill Effluents
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution-sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-79-037
January 1979
POST BIOLOGICAL SOLIDS
CHARACTERIZATION AND REMOVAL
FROM PULP MILL EFFLUENTS
by
R. R. Peterson
J. L. Graham
CH2M Hill, Inc.
Corvallis, Oregon 97330
Contract No. 68-03-2424
Project Officers
John S. Ruppersberger
H. Kirk Willard
Food and Wood Products Branch
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publi-
cation. Approval does not signify that the contents necessarily reflect the
views and policies of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or
recommendation for use.
ii
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FOREWORD
When energy and material resources are extracted, processed, converted,
and used, the related pollutional impacts on our environment and even on our
health often require that new and increasingly more efficient pollution con-
trol methods be used. The Industrial Environmental Research Laboratory -
Cincinnati (lERL-Ci) assists in developing and demonstrating new and im-
proved methodologies that will meet these needs both efficiently and economi-
cally.
This report summarizes the results of a study to characterize the post
biological solids of several pulp and paper mill waste treatment operations.
The nature of these solids did not suggest that these suspended solids would
adversely affect the receiving streams. Several methods for removing these
post biological solids were investigated and rated for effectiveness. If
these solids eventually show detrimental effects on aquatic life this report
will provide a useful guide for going about selecting the best technology to
reduce their concentrations. The heavy metal content for 9 mills is also
tabulated. For further information please contact Dr. H. Kirk Willard of the
Food and Wood Products Branch, IERL, Cincinnati, Ohio.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
iii
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ABSTRACT
The objective of this study was to characterize the post biological
solids in pulp and paper mill secondary effluent and to evaluate various
suspended solids removal techniques. The study was initiated as a result of
EPA guidelines development work, which might potentially require post bio-
logical solids removal to a level on the order of 10 mg/1. This bench scale
work comprised Phase I of the project. A second phase of work has been pro-
posed to extend these efforts to a pilot scale study (on site at several
mills) of the most promising of the removal techniques as determined in the
Phase I work. Phase II, however, has since been eliminated. Phase I was
formulated in three parts; solids characterization; coagulation method opti-
mization; and removal method evaluation.
Phase la, Solids Characterization, examined effluent samples from nine
representative pulp and paper mills. The post biological solids resulting
from secondary treatment of the mill wastewater were "fingerprinted" by 11
analyses for physical and chemical characteristics. An attempt was made to
correlate these findings with geographic location, pulping process, and type
of treatment process used at each mill. Results indicate that the suspended
solids are mostly biological in nature. Biochemical and chemical oxygen
demand (BOD and COD), volatile content, and nutrient content (Kjeldahl nitro-
gen and total phosphate) test results and microscopic examination tended
to support this conclusion. The predominance of negatively charged particles
indicated the potential effectiveness of trivalent aluminum and iron salts as
coagulants.
Phase Ib, Coagulation Optimization, included evaluation of three in-
organic chemicals (alum, ferric chloride, and lime) in combination with five
polymers to determine the optimum coagulant and dosage. A jar-test appara-
tus was used on effluent samples from mills number 1, 2, and 3. Alum was
selected for use with a cationic liquid polymer because this combination
provided the best floe formation and the lowest supernatant total suspended
solids (TSS) content after settling, for all samples. The cationic liquid
polymer provided the most stable floe formation, and was the easiest to mix
and feed.
Phase Ic, Solids Removal Techniques, included bench scale testing of
six tertiary treatment processes for their effectiveness in solids removal,
and response to the range of solids characteristics measured in Phase la.
The methods tested included: Coagulation/Sedimentation; Mixed Media Filtra-
tion; Sand Filtration; Microstraining; Dissolved Air Flotation; and Magnetic
Separation.
The results of the Phase Ic testing indicated that of the six methods
tested only sand filtration and mixed media filtration appeared to produce
iv
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results which would warrant further testing. Variable TSS removals, ranging
from 20 to 70 percent, were observed with the bench scale equipment used.
The purpose of this study was to identify those solids removal methods
which exhibit enough potential for significant solids removal to justify
pilot scale testing on site. However, a joint industry-regulatory task com-
mittee concluded from the Phase I data that none of the technologies investi-
gated appeared to remove suspended solids better than simple setting. Thus,
no further work on this project was merited.
This report was submitted in fulfillment of Contract No. 68-03-2424 by
CH2M Hill, Inc., under the sponsorship of the U.S. Environmental Protection
agency. This report covers the period June 1, 1976 to April 30, 1977, and
work was completed as of June 15, 1977.
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CONTENTS
Foreword
Abstract iv
Figures viii
Tables x
Abbreviations and Symbols xi
Conversion Table .xiii
Acknowledgments xiv
1. Introduction 1
General Description of Project 1
Project Conception 2
2. Conclusions; 3
3. Recommendations 8
4. Project Execution. 9
Phase la: Solids Characterization 9
Phase Ib: Coagulation Experimentation 10
Phase Ic: Solids Removal 10
Mills Selected for Use 12
5. Results and Discussion 23
Phase la: Solids Characterization 23
Phase Ib: Coagulation Experimentation ^2
Phase Ic: Solids Removal Techniques 51
References 6U
Appendices 67
Appendix A. Literature Review 67
Appendix B. Analytical Methods 73
Appendix C. Data Summaries 7^
vii
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FIGURES
Number Page
1 Mill Data Summary - Mill No. 1 13
2 Mill Data Summary - Mill No. 2 I1*
3 Mill Data Summary - Mill No. 3 15
4 Mill Data Summary - Mill No. 4 16
5 Mill Data Summary - Mill No. 5 17
6 Mill Data Summary - Mill No. 6 18
7 Mill Data Summary - Mill No. 7 19
8 Mill Data Summary - Mill No. 8 20
9 Mill Data Summary - Mill No. 9 21
10 Total Suspended Solids Concentration 2k
11 Percent Volatile Suspended Solids 26
12 BOD Content of Solids 27
13 COD Content of Solids 28
14 Nitrogen Content of Solids 29
15 Phosphorous Content of Solids 30
16 Particle Charge Characteristics 31
17 Mean Particle Size - Direct Count Method 3^
18 Effect of Sample Storage on Filtered BOD 35
19 Effect of Sample Storage on Total BOD 36
20 Effect of Sample Storage on Total and Volatile Suspended Solids 37
21 Effect of Sample Storage on Total Solids 38
22 Effect of Sample Storage on Mean Particle Size 39
23 Effect of Sample Storage on Particle Charge ^0
24 Secondary Effluent Solids - Mills 1 and 2 ^3
25 Secondary Effluent Solids - Mills 4 and 5 ^
26 Secondary Effluent Solids - Mills 6 and 7 ^5
27 Secondary Effluent Solids - Mills 8 and 9 ^6
28 Secondary Effluent Solids - Mills 4 and 9 ^7
viii
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FIGURES (Con't.)
29 Suspended Solids Removal Efficiency 52
30 Coagulation/Sedimentation Data - Mill No. 1 58
31 Coagulation/Sedimentation Data - Mill No. 2 59
32 Coagulation/Sedimentation Data - Mill No. 3 60
C-l Particle Size - Mill No. 1 82
C-2 Particle Size - Mill No. 2 83
C-3 Particle Size - Mill No. 3 8k
C-4 Particle Size - Mill No. 4 85
C-5 Particle Size - Mill No. 5 86
C-6 Particle Size - Mill No. 6 87
C-7 Particle Size - Mill No. 7 88
C-8 Particle Size - Mill No. 8 89
C-9 Particle Size - Mill No. 9 90
ix
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TABLES
Number Page
1 Summary of Post Biological Solids Characteristics 23
2 24-Hour Refrigerated Storage Effects ^1
3 Jar Test Results - Inorganic Chemicals ^9
4 Jar Test Results - Polymers 50
5 Chemical Conditioning 51
6 Suggested Media Composition 53
7 Suggested Media Filtration Results 53
8 Modified Media Composition 5^
9 Mixed Media Filtration Results 5^
10 Dissolved Air Flotation Results %
11 Microstraining Results 56
12 Sand Filtration Results 6l
13 Magnetic Separation Results 62
C-l Raw Data - 1976 75
C-2 Raw Data, Metals (Total) - 1976 77
C-3 Raw Data, Metals (Soluble) - 1976 79
C-4 Supplemental Data - 1977 8l
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ABBREVIATIONS AND SYMBOLS
AC
ADT
AL
API
A/S
BK
BLMGO
BS
C
CST
D
DAF
DIA
DMS
DT
E ,
gpin/ft^
GAL/T
H
LB/D
LB/T
MG
MGD
mg/1
ml/min
mm 2
m /s/m
N
NC
NCASI
NH
NO
NEX
NPDES
F
PS
RAS
S
SOL
SWD
T/D
TKN
TOT
TS
acre
air dryed ton
aerated lagoon treatment
American Paper Institute
activated sludge treatment
bleached kraft mill
MgO base bleached sulfite mill
ammonia base bleached sulfite mill
chlorination process
capillary suction time
chlorine dioxide process
dissolved air flotation
diameter
dimethyl sulfide
detention time
caustic extraction process
gallon per minute per square foot
gallon per ton
hypochlorite process
pound per day
pound per ton
million gallons
million gallons per day
milligrams per liter
milliliters per minute
millimeters
cubic meters per second per square meter
nitrogen
north central United States
National Council for Air and Stream Improvement
ammonia
oxides of nitrogen
northeastern United States
National Pollutant Discharge Elimination System
phosphorous
pumping system
activated sludge recovery
southern United States
soluble
side-wall depth
tons per day
total Kjeldahl nitrogen
total
total solids
XI
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ABBREVIATIONS AND SYMBOLS (Con't.)
TSS total suspended solids
TVS total volatile solids
VOL volume
UBK unbleached kraft mill
UF ultrafiltration
VSS volatile suspended solids
W western United States
xii
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To convert from
gallon (U.S. liquid)
gallon per minute
(gpm)
gallon per minute per_
square foot (gpm/ft )
pound (Ib)
pound per ton (Ib/t)
pound per day (Ib/d)
million gallons per day
(MGD)
pounds per inch
(psi)
tons per day
(t/d)
CONVERSION TABLE
to
metre3(m3)
3
metre per second
metre per second
per metre (m /s/m )
kilogram (kg)
kilogram/ kilokilogr am
(kg/kkg)
kilogram per day
(kg/d)
metre per day
(nT/d)
pascal (Pa)
kilogram/day
(kg/d)
Multiply by
3.79x10
-3
6.31x10
-5
6.79x10
-4
4.54x10
-1
5.00x10
-1
4.54x10
-1
3.79x10
6.89x10-
9.07x10
,+3
aStandard for Metric Practice. ANSI/ASTM Designation: E 380-76E, IEEE Std
268-1976, American Society for Testing and Materials, Philadelphia,
Pennsylvania, February 1976. 37pp.
xiii
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ACKNOWLEDGEMENTS
Appreciation is expressed to the environmental personnel at the parti-
cipating mills for their efforts in providing information, operating data,
and securing and shipping samples.
Valuable input was provided by the following persons who compromised
the Technical Review Committee:
Dr. T. R. Aspitarte
Mr. Curtis A. Barton
Mr. Russell 0. Blosser
Mr. Andre Caron
Mr. Bob Herrmann
Mr. Joe Kolberg
Mr. Ralph Scott
Dr. H. K. Willard
Mr. Gene Zanella
Mr, John Ruppersberger, Project Officer, provided additional valuable
assistance.
xiv
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SECTION 1
INTRODUCTION
GENERAL DESCRIPTION OF THE PROJECT
The objective of this study was to characterize the post biological
solids in secondary effluent from nine pulp and paper mills throughout the
U.S. and to identify, through bench scale tests, the tertiary solids removal
steps which produce removals great enough to justify pilot scale testing.
The study was designed to provide a better understanding of the chemical and
physical characteristics of solids in the mill effluent, and to identify
patterns of variance in these characteristics as they occur within a variety
of pulping processes, geographical locations, and types of biological secon-
dary treatment. The knowledge gained in this study should provide a basis
for designing a more detailed mill-specific pilot scale study of solids re-
moval techniques .
The project was funded by the Environmental Protection Agency (EPA). A
Technical Review Committee was formed to provide input to the project during
organization and data analysis. The committee included representatives of
the industry, EPA, Institute of Paper Chemistry and NCASI (National Council
for Air and Stream Improvement).
In developing 1983 effluent guideline limitations for the pulp and paper
industry, EPA considered several alternatives for additional end-of-pipe
treatment to remove suspended solids from biologically treated effluent. The
technology identified in the development documents was based primarily on
municipal wastewater treatment experience, since few pulp and paper mills
had applied post biological solids removal technology. As a result, the
data base from which to forecast suspended solids removals achievable on
pulp and paper effluents is severely lacking. Moreover, the liquid-phase
chemical constituents in biologically treated pulp mill effluents have dis-
persant properties which make coagulation and particle separation difficult
in comparison to municipal effluent.
These facts led EPA to undertake the characterization studies reported
herein, in an attempt to generate a more complete data base on the post bio-
logical solids characteristics and susceptibility to removal.
The results of this study, coupled with the subsequent pilot testing,
should provide a better understanding of the technology necessary to meet
future effluent suspended solids guidelines.
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PROJECT CONCEPTION
An important factor in the design of this study was the probable re-
quirement for tertiary treatment to remove post biological suspended solids,
as a result of application of effluent limitation guidelines.
This study was conducted in three steps to provide both a knowledge of
the character of post biological suspended solids, and to determine the most
promising methods for removing these solids.
The first step (Phase la) consisted of a systematic study of the
quantity and character of suspended solids in the effluents from nine mills,
to provide a current picture of the post biological solids which are present
in secondary-treated effluent. A review of related literature provided back-
ground information on the quantity and character of typical pulp and paper
mill secondary effluent, and on the most effective solids removal methods.
Mill samples were analyzed for types of suspended solids present and
physical and chemical characteristics of those solids. An attempt was made
to correlate these data with the type of pulping process as well as the
treatment process employed at each mill.
The second step (Phase Ib) consisted of an evaluation of the various
chemical coagulants and organic polymers available, to determine the most
effective chemical and the optimum dosage. The chemicals tested were chosen
on the basis of the characteristics of the solids determined in the first
step. On this basis, the number of coagulants considered was reduced to
three inorganic chemicals and five polymers.
The third step (Phase Ic) included bench scale testing of six specific
alternative processes which might be used for post biological solids removal.
The guidelines Development Document identified mixed media filtration as the
most likely process, but also suggested microstraining, coagulation/sedi-
mentation, flotation, and sand filtration. These five plus magnetic separa-
tion were tested on samples from four of the nine representative mills.
Analyses were performed in both EPA and CH2M Hill Laboratories in
Corvallis, Oregon.
Three of the test mills were located close enough to allow analyses
to be performed on "fresh" samples. However, to try to determine the
effect of time degradation on samples from more distant mills, the local
samples were split into two components. One component was immediately
analyzed and the other refrigerated for approximately 5 days (the maximum
transport and storage time from the other six mills). The same analyses
were performed at the end of the storage period to try to develop factors
related to storage effects.
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SECTION 2
CONCLUSIONS
Characterization of the suspended solids in biologically treated efflu-
ent from nine pulp and paper mills covering a range of pulping processes,
geographical locations, and biological treatment processes was completed,
along with bench scale comparative evaluation of potential treatment proces-
ses for removal of the post biological solids for four mills.
Coagulation/sedimentation, mixed media filtration, sand filtration,
microstraining, dissolved air "flotation and magnetic separation were com-
pared to determine the relative degree of suspended solids removal in each
process, and to identify the most promising process(es) for subsequent on-
site pilot testing in a later phase of the project.
Conclusions from the characterization and bench scale comparison tests
are:
Characterization
Average suspended solids (TSS) levels for the mills studied were gen-
erally between 50 and 100 mg/1.
The physical and chemical characteristics of the post biological solids
were variable, but overall averages showed 0.4 kg(lb)BOD/kg(lb)TSS, 1.8 kg
(lb)COD/kg(lb)TSS, 0.83 kg(lb)VSS/kg(lb)TSS, 0.07 kg(lb)N/kg(lb)TSS, 0.01 kg
(lb)P/kg(lb)TSS. The solids had a mean particle size by volume of 0.5 to
1.5 microns, and were negatively charged.
The concentration of TSS, based on a mill to mill comparison, showed no
clear correlation to the type of pulping process, geographical location, or
type of treatment process (i.e., aerated lagoon versus activated sludge pro-
cess). In general, the range of TSS levels measured in three separate com-
posite samples from the same mill was comparable to the difference in TSS
levels observed from mill to mill. Examination of variations at individual
mills, from mill NPDES permit reports, indicates wide variations in TSS
levels at a given mill. At some mills, the long-term NPDES data indicates a
seasonal increase in TSS levels during cold weather months.
The BOD and COD per unit of TSS indicates a largely carbonaceous makeup
of the post biological solids. The BOD and COD per unit of TSS were gen-
erally higher for higher-rate treatment systems (i.e., short lagoon retention
time or low activated sludge age), but otherwise did not differ according to
mill pulping process or location.
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The volatile solids content (VSS/TSS) of the post biological solids
shows a possible relation to mill product in that high TSS ash content was
observed at mills using inorganic fillers and additives. A secondary effect
appears to be treatment system loading rate, with the high-rate systems
showing a higher volatile (lower ash) TSS.
The nitrogen and phosphorus content of the post biological solids sug-
gest that the solids are primarily biological in nature. Apparent solids
crude protein content (Kjeldahl N x 6.25) ranged from 25 to 75 percent by
weight, and averaged about 40 percent. Comparison of N.and P content of the
post biological solids with bacterial culture data suggests that on average,
perhaps one-fourth of the solids are of non-biological origin. Individual
mill data indicate that the non-biological fraction may range up to one-half
of the TSS.
Negative particle charges were observed in all samples. There was no
correlation between magnitude of particle charge and TSS concentration.
The mean particle size data show that a major proportion of the sus-
pended solids are less than a few microns in diameter, and will likely re-
quire coagulation to be amenable to physical removal down to low TSS levels.
Correlation between size distribution and TSS susceptibility to removal by
treatment was poor.
Refrigerated storage for a period of up to 5 days shows no conclusive
evidence of significant changes in the characteristic parameters measured in
this study when compared to fresh 24-hour composite samples.
Storage during 24-hour composite sample collection showed no signifi-
cant difference in TSS concentration as compared to fresh grab samples col-
lected during the same period. However, solids characterization studies were
performed on 24-houtx itpmpafeite samples only, so no data were obtained which
would quantify the storage effects during the 24-hour composition period.
Sample visual appearance and Imhoff cone observations suggest that some type
of natural coagulation may occur during the compositing storage period. This
emphasizes the need for pilot data intended for commercial scale-up to be
collected on fresh effluent.
Metals analysis of the effluent samples before and after filtration,
by argon plasma emission spectrometry, were not sufficiently sensitive to
allow assay of the inorganic constituents in the post biological solids by
difference. While the analytical sensitivity to determine weight-percent
metals in the solids was not achieved, there was no evidence of gross en-
richment of metals in the solids such as might occur by adsorption on floe
particles.
Microscopic observation of the samples showed the presence of bacteria
and particulate debris of unidentified origin. Fiber-type solids were found
only on occasion and represented only a minor proportion of the total parti-
cles observed.
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Coagulant Testing
Analysis of alum, ferric chloride and lime as coagulants revealed that
alum provided the most consistent flocculation at minimum dosages. Lime at
dosages short of those inducing complete precipitation (including color)
was least effective. Ferric chloride was comparable to alum in some tests,
but provided less consistent flocculation at a given dosage on samples from
the same mill.
Of the five polymers tested, none appeared significantly superior to the
others. Nalco 634 and Percol 722 produced slightly lower supernatant TSS in
jar testing. Nalco 634 liquid polymer was selected for use in the bench tests
because it was easiest to mix and meter.
Considerable variability in optimum coagulant dose was observed, both
from mill-to-mill and on different samples from the same mill. This suggests
that full-scale pulp mill effluent coagulation facilities would require fre-
quent monitoring and dosage adjustment.
Three methods of selecting optimum coagulant dosages were studied: jar
testing, Buohner funnel freeness testing, and capillary suction time (CST)
monitoring. Visual observation of jar tests was most successful in these
studies.
The Buchner funnel or CST methods might be perfected as a control techni-
que with further development. The mixed results in these studies were ob-
tained because of overall net decreases in freeness which resulted from coag-
ulant addition.
Alum dosages for optimum floe formation ranged from 40 mg/1 to 180 mg/1
(as Al- (S0,)_) for the four mills studied. A concurrent polymer addition of
2 mg/1 was judged optimum on the basis that significant further floe improve-
ment was not realized until very high (5 to 10 times greater) polymer dosages
were used.
TSS levels typically increased by up to several hundred mg/1 upon coagu-
lant addition at levels sufficient to produce floe formation. The implication
of this phenomenon on the disposal of post biological solids removed by tech-
niques requiring coagulation is significant. The amount of solids (dry weight
basis) for disposal will be much greater than the apparent (influent minus
effluent) quantity.
Mixed Media Filtration
Evaluation of five media combinations on one mill effluent indicated that
a mixture of 30 percent Ilmenite (0.2 mm grain size), 30 percent sand (0.9 mm
grain size and 40 percent anthracite (1.5 mm grain size) gave best TSS removal.
Further study would be needed to determine if the optimum media combination
is variable by mill.
TSS removal at a filtration rate of 3.4xlO"3m3/s/m2(5gpm/ft 2) ranged from
43 to 69 percent without chemical coagulation, and from zero to 85 percent
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with coagulation. The use of coagulants in an attempt to improve micron-
size particle removal was generally ineffective because of the large in-
creases in TSS level upon coagulant addition.
Consistent TSS removals to levels below 30-50 mg/1 were not achieved in
these tests; on-site pilot testing would be needed to define actual achiev-
able TSS levels.
Dissolved Air Flotation
Dissolved air flotation tests at air-solids ratios of 0.06, 0.03 and
0.01 showed poor TSS removals.
On three of the four mills tested, TSS removals were less than 10 per-
cent in every case and averaged nearly zero. On the remaining mill, re-
movals of the order of 20 percent were observed.
Microstraining
Batch microstraining tests using 1 micron to 74 micron fabric mesh
showed TSS removals in the range of zero to 37 percent without chemical
coagulant addition. More than 20 percent removal was observed at only one
of the four mills tested; two of the mills showed zero removal.
TSS increases were observed whenever coagulants were used.
The small micron mesh (less than 10 microns) blinded almost immediately,
and no data were collected for these fabrics due to the impracticality of
the short run times.
Coagulation/Sedimentation
Settling column tests conducted on three of the mill effluents with and
without chemical coagulant addition showed TSS removals of zero to 20 percent
without chemical addition, and net TSS increases with chemical addition.
For the test runs with chemical coagulation, a definite floe formation
and settling occurred. However, this appeared to result from the substantial
increase in TSS upon coagulant addition. The final supernatant TSS from the
coagulated samples never recovered to less than the starting TSS, in spite
of the formation and settling of a floe.
Massive chemical doses sufficient to precipitate color might effect net
TSS reductions by coagulation/sedimentation, but this level of coagulation
was excluded from this study.
Sand Filtration
Batch tests with a single-media 0.4 mm sand at 3.4xlO~3m3/s/m2(5gpm/ft2)
showed TSS removals between 14 and 68 percent without chemical addition and
zero to 71 percent with chemical coagulants.
The results of the sand filtration tests were generally similar to the
6
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mixed media filter tests. (See previous discussion.)
Magnetic Separation
Magnetic separation tests using a Frantz Ferrofilter with both steel
wool and steel disc media showed typical TSS removals of the order of 20
percent or less.
Sample conditioning treatments including polymer and magnetite, alone
and in combination, failed to significantly improve TSS removal.
Overview of Bench Testing Results
Of the processes tested, filtration (sand or mixed media) showed the
greatest potential for post biological solids removal.
Chemical coagulation with alum and polymer was generally ineffective in
improving TSS removal. The TSS levels consistently increased upon coagulant
addition in levels sufficient to form a visible floe, and the net effect on
TSS removal was typically deterimental rather than beneficial. (Color-pre-
cipitating chemical dosages were excluded from this study by design.)
The effluents tested showed variable TSS removals, from a standpoint of
both mill-to-mill comparisons, and repeat observations at a given mill. On-
site pilot testing is needed to adequately define consistently achievable
TSS removals.
TSS removals down to the 5-10 mg/1 levels commonly observed in municipal
wastewater treatment were not achieved (an exception is mill 2, where initial
TSS levels were of the order of 10 mg/1).
No definite correlation of TSS susceptibility to removal was observed
with respect to mill process, location, treatment process, or TSS chemical
and physical characteristics.
The availability of a reliable analytical technique to determine parti-
cle size distribution by weight (rather than number of particles) is probably
a prerequisite to establishing reasonable correlations.
Effluent monitoring data from some mills suggest that seasonal (temper-
ature-related) changes in TSS levels may be significant.
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SECTION 3
RECOMMENDATIONS
Pilot-scale studies to define performance levels for post biological sol-
ids removal should be directed toward filtration (sand or mixed media).
Pilot-scale studies should be run at individual mill sites using fresh
effluents.
A O
Pilot plants should be at least of the 10" m /s (several gpm) size to
generate sufficient backwash for backwash solids testing. Testing should in-
clude investigation of backwash disposal, fines recycle, and headless buildup
rate. The pilot plant program should also include further evaluation of sea-
sonal variations.
A good analytical technique to measure TSS size distribution by weight
should be established, to allow better evaluation of observed solids removal
performance.
Analysis of the metals content of post biological solids - particularly
calcium and magnesium - should be made to help identify the presence of non-
biological solids such as calcium-lignin precipitates.
Further research to identify coagulants which can effectively agglomer-
ate fine particles without increasing net TSS levels (short of inducing mas-
sive color precipitation) is needed.
Variation in post biological solids levels at individual mills should be
studied to fully identify the effects of such variation on achievable solids
removal efficiency. In particular, the effect of seasonal variation should
be included.
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SECTION 4
PROJECT EXECUTION
PHASE la - SOLIDS CHARACTERIZATION
An informal literature review provided the necessary technical and per-
tinent industrial data to develop this study. This information guided the
design of the study and analysis of results. The review was compiled from
sources such as EPA, NCASI (National Council for Air and Stream Improvement),
API (American Paper Institute), and other published sources, and is included
in Appendix A.
The review was separated into three sections: 1) General Studies on
Solids Characterization and Removal Processes, 2) Specific Solids Removal
Processes, and 3) Municipal Treatment Systems Solids Removal.
Industry cooperation was a key to the success of this project. Parti-
cipant mills provided data about mill processes and treatment designs, sam-
pling systems and special problems unique to each mill.
Site visits to each of these mills provided data on the mill pulping
process, bleaching sequence, treatment design and past operating experience.
At the same time, provisions were made for three samples (24-hour composite)
of mill effluent to be taken. All samples were refrigerated in transit ex-
cept the three samples from mills close to Corvallis, Oregon. These three
fresh samples, analyzed immediately, provided a baseline for time degrada-
tion factors.
To determine the full range of post biological solids present in these
samples and their physical and chemical properties, a number of tests were
run. Eight of the tests were performed by EPA's laboratory analytical
support staff. These tests were for COD (chemical oxygen demand; total and
filtered), total suspended solids, volatile suspended solids, total and
dissolved volatile solids, phosphorus (total and filtered), Kjeldahl nitro-
gen (total and filtered), ammonia, particle size (Coulter counter) and metals
(total and filtered).
The following tests were run in the CH2M Hill Laboratory:
1. Particle size, by the direct count method using a microscope
with a calibrated eyepiece.
2. Particle charge, by measuring zeta potential.
3. BOD (biochemical oxygen demand, total and filtered), by the
9
-------
standard methods procedure. For purposes of this study, the filtered
BOD was considered to be that passing the glass fiber filter used in
the TSS determination.
Results of these tests are included in Section 5, Results and Discus-
sion.
PHASE Ib - COAGULATION EXPERIMENTATION
This phase included evaluation and optimization of chemical coagulants
for use in the bench scale tests (Phase Ic).
The chemicals tested included ferric chloride, alum and lime in combi-
nation with five polymers, to evaluate their relative coagulation efficiency.
The five polymers used were: Nalco 634, Percol 722, Calgon WT-300,
Hercules 859, and Dow C31.
Four of the nine mill effluent samples were tested in Phase Ib.
The analysis at this stage included:
1. Jar testing.
2. Sludge filterability (Buchner funnel method).
3. CST (Capillary Suction Time).
PHASE Ic - SOLIDS REMOVAL TECHNIQUES
This phase covered evaluation of six potential tertiary unit processes
for solids removal. Bench scale testing was performed on effluent samples
from the same four mills tested in Phase Ib.
The purpose of this phase was to evaluate the relative efficiency of
each process for post biological solids removal. Analysis of these data
provided a reasonable basis for determining which unit processes would merit
further testing in the Phase II work.
The results were analyzed to determine: 1) a relative ranking of each
of the tertiary solids removal steps based on solids removal efficiency and
performance consistency, 2) the impact of the range of solids characteristics
measured in Phase la on the performance and relative ranking of tertiary
solids removal steps, and 3) a sound technical basis for subsequent larger
scale pilot testing of the two or three most attractive solids removal unit
processes.
The specific procedures used in the bench scale analysis of each of 6
unit processes follows:
10
-------
1. Mixed Media Filtration. Testing was conducted in 1-
inch diameter laboratory filters operated in batch
runs. The actual testing was divided into two steps.
The first step consisted of media evaluation, in which
preliminary test runs of three different media combina-
tions on one mill effluent were made. The results of
this initial testing were used to select the best media
combination.
Next, the performance tests were run using the selected
media combination on the four mill effluents. TSS
analyses were run on effluents with and without the
chemical conditioners selected in Phase Ib.
These tests provided a measure of the solids removal
performance capabilities of mixed media filtration.
One effluent sample was also shipped to a filter vendor
for independent batch tests, to capitalize on vendor
experience in this area.
2. Flotation. Dissolved air flotation tests for post-
biological solids removal were made using a 2-liter,
batch pressure chamber. Tests were conducted for three
air/solids ratios on the four effluent samples, with
and without the chemical conditioners selected in Phase
Ib.
Suspended solids removal efficiency was measured,
together with float volume and float concentration.
3. Microstraining. Batch tests were run using four sepa-
rate fabrics covering a range of micron sizes. These
tests were conducted on each of the four mill effluent
samples selected, and were run with and without chemical
conditioners.
The results of these tests gave a qualitative assessment
of the impact of fabric opening size on suspended solids
capture, the impact of chemical coagulation on relative
rates for strainer performance and a qualitative assess-
ment of probable strainer flow rates.
4. Coagulation/Sedimentation. Batch tests run in a 6-inch
diameter plexiglass settling column determined the sus-
pended solids removal achieved by chemical coagulation and
gravity clarification. The coagulant dosage was based
on the results of Phase Ib. Suspended solids removal
versus depth was measured to determine removal efficiency.
5. Sand Filtration. This test run simulated a single-
media filter. TSS removal and blinding rate were
11
-------
measured. A preliminary test run was made on a single effluent source,
using two sand grain sizes, to evaluate media effects. After a grain
size selection was made, each of the mill effluents was tested.
Three test runs were conducted to simulate mechanical cleaning of the
sand surface; two were run on a freshly drained sample, and one on a sam-
ple allowed to air dry for 24 hours prior to scraping the surface layer.
The thrust of the sand filtration experiment was to pursue a low-cost
technology which might apply where natural site conditions allow the use
of large percolation beds for solids removal.
6. Magnetic Separation. Magnetic separation is a relatively new process
which has had very little commercial application for this purpose. A
laboratory magnetic separation test unit (a Grantz Ferrofilter), loaned
by the U.S. Bureau of Mines, Albany, Oregon, was used for this testing.
The goal of the magnetic separation test was to obtain sufficient data
for a cursory evaluation of magnetic separation for suspended solids re-
moval efficiency.
MILLS SELECTED FOR USE
Nine producing pulp and paper mills participated in this study. Each
mill provided data in their operations, included herein as Mill Data Summaries
(Figures 1-9). The mills also allowed on-site visits and provided samples of
their effluent.
The mills were selected on the basis of location, pulping process type,
effluent treatment type, size and production, and willingness to participate.
The Mill Data Summaries which follow give information about the mill and gra-
phic representations of the treatment system used.
Of the nine mills, six were located in the west (mills 1 through 6), one
in the southern region (mill 7), one in the north central region (mill 8),
and one in the northeastern region (mill 9). Three of the western mills (mill
1, 2, and 3) were within one hour's drive of the EPA and CH2M Hill laborator-
ies.
The mill processes included bleached and unbleached Kraft and bleached
sulfite with both magnesium and ammonia base. Their production ranged from
3.11 x 105 kg/d (343 tons per day (t/d)) to 1.45 x 10& kg/d (1,600 t/d) of
paper, kraft or sulfite products, or intermediary products such as bleached
or specialty pulps. All mills except 2 and 9 recovered some by-products from
their in-piant processes. All of the Kraft mills except mills 2 and 4 recov-
ered methanol and mill 8 operates a methanol stripper with off-gas combustion
in the lime kiln; mill 5 recovered crude tall oil; and mills 6, 7, and 8 re-
used condensate. \
The mills treat their effluent with either aerated stabilization or acti-
vated sludge treatment systems. Most of the treatment systems include primary
clarification and aerated ponds (mills 2, 3, 5, 7, and 8). Mill 2 also in-
12
-------
Figure 1
MILL DATA SUMMARY
MILL NO. 1 LOCATION: West
TYPE: Unbleached Kraft & NSSC
PRODUCTION: Kraft Coarse & Corrugating Paper-670T/D
NSSC Corrugating Medium - 230 T/D
PULPWOOD:
BLEACH PLANT:
PAPER MACHINES:
ADDITIVES:
86% Softwood Chips
14% Waste Paper
N/A
3 Fourdrinier(164", 169", 184")
Wet end Sizing: Alum Rosin;
Dry end Wheat or Corn Starch
no Fillers; no Defoamer
RECOVERY SYSTEM: NSSC - 3 Stage Washing
Kraft - 4 Stage Washing
600 T/D Recovery Boiler
COMMENTS:
Turpentine Recovery 1 Gal/T
30-40,000 LB/D Na2SO4 Lost to Sewer
Guargum; UF Resin
EFFLUENT TREATMENT SYSTEM
FROM
MILL
PRIMARY
SETTLING POND
VOL - 7 MG
D.T. = 3.5 HR
@ 10 MGD &
POND 80% FULL
OF SOLIDS
O O O
O O O O
O O O O
V. /
AERATED POND
VOL = 90 MG
D.T. = 9 DAYS @ 10 MGD
TOT. AERATION - 550 HP
TO
RIVER
-*
SELECTED EFFLUENT DATA
TYPICAL PRIMARY TREATED EFFLUENT:
FLOW
BOD
TSS
TYPICAL SECONDARY TREATED EFFLUENT: BOD
TSS
10.2 MGD (8.8 MGD-AVG TO
RIVER) (11,300 GAL/T)
257 MG/L (21,800 LB/D) (24 LB/T)
105 MG/L (7,732 LB/D) (9 LB/T)
31 MG/L (2,286 LB/D) (2.5 LB/T)
62 MG/L (4,556 LB/D) (5 LB/T)
-------
Figure 2
MILL DATA SUMMARY
MILL NO. 2
TYPE:
PRODUCTION:
LOCATION: West
Bleached Kraft/Tissue
Tissue - 250 T/D
Bleached Pulp - 93 T/D Air dry
PULPWOOD:
BLEACH PLANT:
PAPER MACHINES:
ADDITIVES:
65% Chips (Softwood)
35% Sawdust (Softwood)
CEHH - With Ca(OCI)2 Oxidation of E Stage Effluent for
Color Reduction or CHEH
2 - 194" Yankee Machines
Wet End - Dyes, CaCl2, Slimicide
Dry End Yankee Release Agent
RECOVERY SYSTEM: 4 Stage Washing
1 B&W 400 T/D Recovery Boiler
COMMENTS:
No By-Product Recovery
EFFLUENT TREATMENT SYSTEM
SOLIDS ACID SEWER (3.5 MGD)
PRESS LAND 1
DISPOSAL ^ 1 r
ALKALINE 1 1 I '
SEWER JL,. ± JjK O
11.5MGD^O +(\ ,8 ,<%
O
O 0 I x.
O O [ >
0 0 -^
O O ^1
V
TO
RIVER
s
PRIMARY CLARIFIER AERATED PONDS (2) SETTLING
200' DIA. TOT. VOL = 216 MG BASIN
12' SWD D.T. = 12 .DAYS
TOT. AERATION = 600 HP
SELECTED EFFLUENT DATA
TYPICAL PRIMARY TREATED EFFLUENT: FLOW = 14.9 MGD (43.000 GAL/T)
BOD = NO DATA
TSS = NO DATA
TYPICAL SECONDARY TREATED EFFLUENT: BOD = 1,550 LB/D; 12.5 MG/L (4.5 LB/T)
TSS = 2,465 LB/D; 20 MG/L (7 LB/T)
14
-------
Figure 3
MILL DATA SUMMARY
MILL NO. 3
TYPE:
PRODUCTION:
LOCATION: West
Unbleached Kraft
Kraft Paperboard - 1260 T/D
PULPWOOD:
100% Softwood Chips
BLEACH PLANT:
PAPER MACHINES:
ADDITIVES:
RECOVERY SYSTEM:
COMMENTS:
N/A
2 Fourdrinier Machines (148" & 256")
Wet End - H2S04, Alum, Cationic Starches, Polymers
Dry End Potato or Corn Starch
Fillers - 5-6 LB/T Simplot Clay, <1 LB/T Defoamer, Sizing Agent
Washing - Cont., 3 Stage; Batch - 4 Stage
2 CE 2400 T/D Recovery Boilers
Recover Turpentine & Methanol
EFFLUENT TREATMENT SYSTEM
FROM /""""X
(5.0 MGD) y / 1
CH»
FROM ^ P.S.
PAPER MILL fc, -^->. I
(4.3 MGD) IV ^r\ 1
L^ -^
PRIMARY FLOTATION
SCREEN CLAHfFIER THICKENER
130' DIA. 45' DIA.
f ^\
O O
e o
o o
© 0
0 0
^ J
AERATION POND
VOL = 69 MG
TO
RIVER
P.S.
D.T. = 5.5 DAYS @ 10 MGD
& 14 MG SLUDGE
ACCUMMULATION
TOT. AERATION = 750 HP
SELECTED EFFLUENT DATA
TYPICAL PRIMARY TREATED EFFLUENT:
FLOW
BOD
TSS
TYPICAL SECONDARY TREATED EFFLUENT: BOD
TSS
10 MGD; 8,000 GAL/T
25,000 LB/D;300 MG/L;20 LB/T
17,000 LB/D; 144 MG/L; 10 LB/T
3,200 LB/D; 38 MG/L
8,300 LB/D; 100 MG/L
15
-------
Figure 4
MILL DATA SUMMARY
MILL NO. 4
TYPE:
PRODUCTION:
LOCATION: West
MgO Base Bleached Sulfite
Dissolving Pulp - 225 T/D
Specialty Pulps - 225 T/D
PULPWOOD:
BLEACH PLANT:
PAPER MACHINES:
ADDITIVES:
75% Roundwood
25% Chips
(Mostly Softwood)
CEH
None
None
RECOVERY SYSTEM:
COMMENTS:
4 Stage Washing
3 Recovery Boilers
Treat Evaporator Condensate & Venturi Scrubber Water
EFFLUENT TREATMENT SYSTEM
(16 MGD - LOW STRENGTH) RAS
a
mr\tiH Rflii i __^_ ^* *
(4 MGD - HIGH STRENGTH)
STORAGE
POND
VOL = 12 MG
(SPILL STORAGE)
J OOOOOOO
X. ^
M ooooooo
> V f
J
M ooooooo
> <
* ooooooo
t ^
AERATION BASINS*4'
TOT. VOL = 20 MG
D.T. - 5 DAYS @ 4 MGD
TOT. AERATION = 3200 HP
|U
n
SECON
CLARI
(1) 50
(1) 60
12
^
DARY
FIERS
' DIA. TC
' DIA- D
SWD °'
t
TO
RIVER
SETTLING PONDS*4'
)T. VOL = 32 MG
T. = 1.6 DAYS <°> 20 MGD
SELECTED EFFLUENT DATA
TYPICAL PRIMARY TREATED EFFLUENT: FLOW - 4 MGD; 9,000 GAL/T
(EXCLUDING LOW STRENGTH FLOW) BOD = 110,000 LB/D; 3,300 MG/L;240 LB/T
TSS * = 5,000 LB/D; 150 MG/L;11 LB/T
TYPICAL SECONDARY TREATED EFFLUENT: BOD
(BEFORE SETTLING PONDS) Tss
6,000 LB/D;180MG/L
26,000 LB/D; 780 MG/L
16
-------
Figure 5
MILL DATA SUMMARY
MILL NO. 5
TYPE:
PRODUCTION:
PULPWOOD:
LOCATION: West
Bleached Kraft
Paperboard - 880
Tissue 50
Market Pulp- 200
100% Softwood Chips & Sawdust
BLEACH PLANT:
PAPER MACHINES:
ADDITIVES:
RECOVERY SYSTEM:
COMMENTS:
Chips - CEHHD
Sawdust - CEHD
3 Fourdrinier Machines (216", 216", 173")
1 IMPCO Wet Machine
Wet Strength Coating - Clay
Sizing Agents
Dyes
Recovery Boilers:
Recover Tupertine
& Crude Talc Oil
Soda Losses: 71 LB/T
Ti02
CE 150 T/D
CE 300 T/D
B&W 300 T/D
B&W 400 T/D
Slimicides
Corrosion Inhibitor
4 Stage Washing
EFFLUENT TREATMENT SYSTEM
FROM
BLEACH PLANT
(10 MGD)
FROM / \
(20 MGD) V J
SOLIDS -
VACUUM FILTER
^ PRESS
HOG FUEL
PRIMARY
CLARIFIER
C\
P.S.
X" ~^v
o o o N.
o o o >v
000 0\^ R?VER
V )
AERATED POND
110 AC.
VOL = 500 MG
250' DIA.
D.T. = 16.6 DAYS @ 30 MGD
TOT. AERATION = 1,950 HP
SELECTED EFFLUENT DATA
TYPICAL PRIMARY TREATED EFFLUENT:
FLOW
BOD
TSS
TYPICAL SECONDARY TREATED EFFLUENT: BOD
TSS
29.7 MGD (25,300 GAL/T)
364 MG/L (90,200 LB/D) (80 LB/T)
147 MG/L (36,400 LB/D) (32 LB/T)
33 MG/L (8,175 LB/D) (7 LB/T)
79 MG/L (19,600 LB/D) (17 LB/T)
17
-------
Figure 6
MILL DATA SUMMARY
MILL NO. 6
TYPE:
PRODUCTION:
LOCATION: West
Bleached & Unbleached Kraft; NSSC
Kraft Linerboard - 450 T/D
NSSC Corrugating Medium 250 T/D
Bleached Kraft - 200 T/D
PULPWOOD:
BLEACH PLANT:
PAPER MACHINES:
ADDITIVES:
RECOVERY SYSTEM:
70% Softwood Chips
25% Waste Wood
5% Roundwood (Eucalyptus)
CEHPH
3 Fourdrinier (144", 155", 120")
Alum Clay Coating
Rosins Biocides
Polymers Defoamer
Dyes
Onalon (Cr)
Waxes
COMMENTS:
Turpentine Recovery 30 GPD
Soap Recovered Burned
EFFLUENT TREATMENT SYSTEM
SOLIDS -
VACUUM FILTER
PRESS
RAS
BAR
SCREEN
VOL 1 75 WIG
D.T.
2.6 HR
16 MGD
AERATION BASIN
VOL = 1.8 MG
D.T. = 2.7 HR
@ 16 MGD
HP = 500
EFFLUENT
HEAD
SECONDARY CONTROL
CLARIFIERS TANK
(21 135' DIA.
13" SWD
12' DIA.
22' HIGH
SELECTED EFFLUENT DATA
TYPICAL PRIMARY TREATED EFFLUENT:
FLOW
BOD
TSS
TYPICAL SECONDARY TREATED EFFLUENT: BOD
TSS
13 MGD; 14,500 GAL/T
27,000 LB/D;250 MG/L; 30 LB/T
11,000 LB/D;101 MG/L; 12 LB/T
4,300 LB/D;40 MG/L
7,600 LB/D;70 MG/L
-------
Figure 7
MILL DATA SUMMARY
MILL NO. 7 LOCATION: South
TYPE: Unbleached Kraft
PRODUCTION: Paperboard - 1200 T/D
Kraft Wrap & Bag - 400 T/D
(150 T/D Bleached Kraft)
PULPWOOD:
40% Chips (All Softwood)
60% Roundwood
PAPER MACHINES:
ADDITIVES:
5 Fourdrinier Machines (134", 136", 167", 157", 216")
Alum Rosin Sizing Agent
Wax
Defoamer
RECOVERY SYSTEM: 2 Recovery Boilers
3 & 4 Stage Washing
COMMENTS:
Recover Turpentine, Soap, DMS
Soda Loss - 180,000 LB/D
EFFLUENT TREATMENT SYSTEM
SOLIDS -
.VACUUM FILTER
FROM
MILL
(26 MGD)
000000
o o o o o o o
o o o o
PRIMARY
CLARIFIER
300' DIA.
11.5' SWD
SELECTED EFFLUENT DATA
TYPICAL PRIMARY TREATED EFFLUENT:
AERATED POND
VOL = 247 MG
63 AC x 12' DEEP
TOT. AERATION 2025 HP
(27-75 HP UNITS)
D.T. - 9.5 DAYS @ 26 MGD
FLOW
BOD
TSS
TYPICAL SECONDARY TREATED EFFLUENT: BOD
TSS
27 MGD (16^00 GAL/T)
76,000 LB/D; 337 MG/L; 47 LB/T
NO DATA
13,000 LB/D; 58 MG/L (8 LB/T)
14,000 LB/D; 62 MG/L (9 LB/T)
19
-------
Figure 8
MILL DATA SUMMARY
MILL NO. 8
TYPE:
PRODUCTION:
LOCATION: (yjorth Central
Bleached Kraft
Coated Paper - 600 T/D
Bleached Hardwood Market Kraft - 325 T/D
83% Roundwood (~50% Hardwood)
17% Chips
Kraft - CEDED
Groundwood - Peroxide
2 Machines (300", 167")
Filler Clay Rosin Size
TiO2 Defoamer
Aluminum Hydrate
RECOVERY SYSTEM: 1 B&W Recovery Boiler - 800 T/D
PULPWOOD:
BLEACH PLANT:
PAPER MACHINES:
ADDITIVES:
COMMENTS:
3 Stage Washing
Steam Stripper
Recover Turpentine & Soap
Soda Loss -20 LB/T
EFFLUENT TREATMENT SYSTEM
S°UDS
SOLIDS
TOT. AERATION
= 570 HP
14' DEEP
D.T. = 7 DAYS
@ 30 MGD
TOT. AERATION
= 600 HP
VARIABLE DEPTH
(8-1 2 FT)
FLOCCULATOR
CLARIFIER
270' DIA.
SELECTED EFFLUENT DATA
TYPICAL PRIMARY TREATED EFFLUENT:
FLOW
BOD
TSS
TYPICAL SECONDARY TREATED EFFLUENT: BOD
TSS
30 MGD (32,400 GAL/T)
200 MG/L (50,000 LB/D) (54 LB/T)
225 MG/L (56,300 LB/D) (61 LB/T)
29 MG/L (7,260 LB/D) (8 LB/T)
57 MG/L (14,300 LB/DI (15 LB/T)
20
-------
Figure 9
MILL DATA SUMMARY
MILL NO. 9 LOCATION: Northeast
TYPE: Ammonia Base Bleached Sulfite
PRODUCTION: 300 T/D Pulp Capacity
PULPWOOD: 85% Roundwood (All Hardwood)
15% Chips
BLEACH PLANT: Single Stage Hypochlorite with Post Wash
RECOVERY SYSTEM; 2 Stage Washing
Liquor Evaporation and burn in steam boiler
COMMENTS:
Papermaking effluent treated separately by
physical-chemical treatment
FROM
PULP MILL
(2.71 MGD)
EFFLUENT TREATMENT SYSTEM
EQUALIZATION
BASIN
EFFLUENT
MONITOR
AERATION
BASINS (2)
RIVER
BASIN 1: 510 HP - 1 MG VOLUME
/ BASIN 2: 510 HP - 1 MG VOLUME
NEUTRALIZATION
SELECTED EFFLUENT DATA
TYPICAL PRIMARY TREATED EFFLUENT:
FLOW
BOD
TSS
TYPICAL SECONDARY TREATED EFFLUENT: BOD
TSS
2.71 MGD (4,500 GAL/T)
2375 MG/L (65,000 LB/D) (216 LB/T)
239 MG/L (5,400 LB/D) (18 LB/T)
90 MG/L (2,030 LB/D) (6.8 LB/T)
137 MG/L (3,100 LB/D) (10 LB/T)
21
-------
eludes a primary settling basin and mill 3 a flotation thickener for primary
treatment. Mill 1 uses a primary settling basin, rather than a clarifier.
Mills 4, 6, and 9 use activated sludge treatment systems.
Flow rates range from 1.14 x 104 m3/d (3MGD) at mill 9 to 1.14 x 105
nr/d (30 MGD) at mill 5.
22
-------
SECTION 5
RESULTS AND DISCUSSION
PHASE la - SOLIDS CHARACTERIZATION
GENERAL
The analyses listed in Section 4 were run on the three samples from each
mill to determine the physical and chemical characteristics of the post bio-
logical solids. The raw data from these analyses are included in Appendix C
(Tables C-l through C-4). Average values of several parameters for each
sample have been plotted to provide a comparison of these parameters between
the various mills.
Table 1 lists the observed physical and chemical characteristics of the
post biological solids.
TABLE 1
SUMMARY OF
POST BIOLOGICAL SOLIDS CHARACTERISTICS
Average Range of Averages for
of all Mills Individual Mills
BOD per unit of TSS (mg/mg")
COD per unit of TSS (mg/mg)
Volatile Suspended Solids
(% of TSS)
Nitrogen content (% of TSS)
Phosphorus content (% of TSS)
Zeta potential of TSS
(millivolts)
Mean particle size by
volume (microns)
0.40
1.8
83
7.0
1.03
-20
-
0.16-0.60
1.2 -2.8
59 - 96
4.0 -12.4
0.46-2.35
-5 - -40
0.5 - 1.5
TOTAL SUSPENDED SOLIDS (TSS) CONCENTRATION
Figure 10 shows a comparison of TSS concentration of the samples
analyzed. The range of concentrations observed was substantial, from under
10 mg/1 to over 2500 mg/1. The greatest variation was at mill number 4,
where excess activated sludge is wasted to the secondary clarifier effluent
and is subsequently resettled in holding ponds downstream of our sample
point. The most extreme excursions observed at mill 4 occurred during
23
-------
PO
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2,500-
800 -
400 ~
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a
z
Ul
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_j 200 -
O
100 -
1
1
A-
AI
\
i
V
13
1
\Z
t
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t
i
1 3
ti
// ,
V
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! 23 456789
UBK BK UBK BLMGO BK BK UBK BK BS
AL AL AL A/S AL A/S AL AL A/S
W W W W W W S NC NE
MILL
1 , »2 - Sample No.
Figure 10
TOTAL SUSPENDED SOLIDS CONCENTRATIONS
-------
treatment process operating problems. Mill number 1 experienced a signifi-
cant increase of effluent TSS because of a seasonal change in quantity of
effluent treated. The majority of the mills, however, averaged less than
100 mg/1 TSS.
These data exhibit no significant differences attributable solely to
mill location. The widest fluctuations both occurred in samples from mills
located in the west, but otherwise the variation in TSS levels at a given
mill were typically greater than the variation from mill-to-mill.
Activated sludge treatment systems are sometimes considered to produce
better quality effluent. However, this figure shows that, in general, the
aerated lagoon systems produce equal or better effluents (in terms of TSS
concentration). This observation must be tempered by the higher feed BOD
concentrations at two of the three activated sludge plants.
The type of pulping process showed no clear correlation with the TSS
concentration, with the variations in repeat samples of the same mill being
of comparable magnitude to the mill-to-mill variations. Sulfite mill 4
showed higher concentrations, but is not directly comparable to other mills
because of high feed BOD concentrations and the previously noted sludge
wasting practices.
The lowest TSS levels were observed at mill 2, a bleached Kraft mill
with high water use per ton of production. This is also the newest of the
mills tested, and was designed with extensive flow segregation and spill
control facilities.
VOLATILE SUSPENDED SOLIDS (VSS)
The percent VSS for each mill effluent sample is shown on Figure 11.
VSS averaged 80 percent or greater for all but two of the mills tested.
VSS percent ranged from a low of 58 percent for mill number 8 to a high of
near 100 percent for mills number 7 and 9. Mill number 8 is the only one
that produces coated papers. Mill 9 operates a relatively high rate acti-
vated sludge system with very low levels of influent TSS, with the result
that effluent TSS should be nearly all biologically generated. The reason
for this high percent volatile content at mill 7 is unclear; it differs from
mills 1 and 3 primarily in its location (south) and pulpwood species.
The lower average VSS present at mill 8 may be related to the presence
of a flocculating clarifier following the two stage lagoon, which is used to
separate and recycle solids to the head end of the lagoon. Also, heavy clay
and titanium dioxide usage occurs at mill 8 due to grades manufactured. Mill
6 operates a fairly long sludge-age activated sludge process, runs some
coated grades, and also returns silt from the raw water treatment clarifiers
to the primary clarifier. These factors may explain the lower volatile con-
tent at mill 6.
BOD/TSS RELATIONSHIP
Figure 12 shows BOD per unit TSS data for each of the mill samoles.
25
-------
^SAMPLE
f NUMBER (TYP)
U
oc
ro
uu -
yu
oU
60
bu
4O
30-
20-
10-
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3
{
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k 10
UBK BK UBK BLMGO BK BK UBK BK BS
AL AL AL A/S AL A/S AL AL A/S
w w WWWW S NCNE
MILL
Figure 11
PKRCENT VOLATILE SUSPENDED SOLIDS
-------
2.5
2,0
= 1.5
OC
Q
§
1.0
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t
(
i
.3
4
f
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NUMBER (TYP
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2
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3
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2
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i
UBK BK UBK BLMGO BK BK UBK BK BS
AL AL AL A/S AL A/S AL AL A/S
WWW WWW SNCNE
MILL
Figure 12
BOD CONTENT OF SOLIDS
-------
10
oc
Ul
a.
ro
CO
a
8 4
(J
1
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'
1
2.
3
,/
'2
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1234
UBK BK UBK BLMGO B
AL AL AL A/S >
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i
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,1
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i 6 7 8 9
K BK UBK BK BS
M A/S AL AL A/S
W W S NC NE
MILL
Figure 13
COD CONTENT OF SOLIDS
-------
ro
ou
«MJ
z
z
UI on
?
OOUIIN
i-
UJ
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ui
Q.
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l
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SAMPLE -^
NUMBER (TYP)(
'1
E
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> I
^
3
7 t
S
)
UBK BK UBK BLMGO BK BK UBK BK BS
AL AL AL A/S AL A/S AL AL A/S
WWWWWWSNCNE
MILL
Figure 14
NITROGEN CONTENT OF SOLIDS
-------
CO
o
3.5)
3 0-
8
22.5-
V)
c
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E
1-
UJ 1.5-
O
E
ill
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NUMBER (TYP)
f
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AL A
W V
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,
,1
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'1
1
3456789
C UBK BLMGO BK BK UBK BK B
L AL A/S AL A/S AL AL A
V W W W W S NC t
I
NE
MILL
Figure 15
PHOSPHOROUS CONTENT OF SOLIDS
-------
<
I
2
N
ou-
-An
-30
-Zl/
-10"
<
i
3
>2
1
1
£
<
i
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*2
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1
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SAMPLE ~ -x,
NUMBER (TYP) ,
{
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2
/ 4
<
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1 2 3 4 5 6 8 <
UBK BK UBK BLMGO BK BK UBK BK BS
AL AL AL A/S AL A/S AL AL A/S
W W W W W W S NONE
MILL
Figure 16
PARTICLE CHARGE CHARACTERISTICS
-------
These data range from a low of 0.16 for mill number 4 to a maximum of 0.6
for mill number 9.
The overall average for BOD per unit TSS was 0.4. Correlation of BOD
per unit TSS with sludge age (activated sludge) and retention time (aerated
lagoons) shows a general decrease in the BOD per unit at longer sludge age/
retention times, except for mill 3 which did not follow this pattern.
COD/TSS RELATIONSHIP
The relationship between COD and TSS is shown on Figure 13 for the
mills studied. The COD per unit TSS values indicate a highly carbonaceous
material. Average COD per unit TSS varies from 1.2 for mill number 4 to 2.8
for mill number 9. Comparison of the unit BOD with unit COD indicates that a
considerable quantity of material not readily biologically oxidizable, is
present in all of the effluents tested. These data also indicate a fairly
consistent correlation between unit BOD and unit COD for the solids.
NUTRIENT CONTENT (NITROGEN AND PHOSPHOROUS)
Total Kjeldahl Nitrogen (TKN as N) and total Phosphate (as P) are plotted
as a percentage of the TSS by weight on Figures 14 and 15. Nitrogen content
ranged from about 4 percent for mill number 6 to over 12 percent for mill
number 5. Phosphorous content ranged from about 1/2 percent to over two per-
cent.
Newly-generated bacterial mass typically shows a nitrogen content of 11
to 12 percent by weight. As the bacterial mass undergoes respiration, the
average percent by weight nitrogen of the mass decreases because of the
accumulation of polysaccharide cell wall residues. Thus, the observed nitro-
gen content of a mixed bacterial culture having a mean cell age of 6 to 10
days would be of the order of 9 percent N. On this basis, the nitrogen tests
suggest that, on the average, the majority (approximately 75%) of the solids
are biological. The nonbiological fraction could be as high as 50% at some
mills, based on the individual mill test data.
The phosphorous content of biological solids averages about 1/5 the
nitrogen content, which suggests that observed phosphorous levels in the 2
weight percent range would represent whole biomass. The test results support
the view that the observed TSS are mainly biological.
PARTICLE CHARGE
Particle charge was determined by measurement of the Zeta Potential of
the samples. These data are plotted on Figure 16. Negative particle
charges were observed in every sample tested, ranging from near zero to -57
millivotls. However, the majority of the data were in the range of -5 to
-20. The negatively charged particles provide a basis for the effective use
of the trivalent aluminum and iron salts as coagulants.
There was no apparent correlation between particle charge and concen-
tration of TSS, which suggests that particle dispersion is due to causes
32
-------
other than simple charge repulsion. Limited observations of charge stabili-
zation by coagulant addition bears out the hypothesis that production of an
isoelectric charge condition will not insure effective coagulation and sepa-
ration.
It is of interest to note that the third sample collected at mill 4
showed neutral particle charge, and that this sample contained several hun-
dred mg/1 of settleable solids. As noted previously, this is representative
of an upset condition in which stable biofloc was carrying over the secondary
clarifier weirs.
PARTICLE SIZE
Figure 17 is a plot of the mean particle size data for the nine mills.
All data shown on this figure were obtained by the microspic direct count
method. The mean particle size for the majority of the samples was between
0.5 and 1.5 microns.
/
At attempt was made to refine the particle sizing by use of the Coulter
Counter. Samples from mills number 1, 2, and 3 were analyzed by this method,
using equipment made available by the EPA laboratory in Corvallis. Both
sizing methods resulted in similar mean particle size data for all three
mills. However, the Coulter Counter method was subject to significant elec-
trical interference in the size range below about 0.5 microns. Results of
analyses performed simultaneously by the EPA laboratory and Coulter Elec-
tronics, on a split sample, however, confirmed the accuracy of the data from
the EPA laboratory. Typical plots of particle size distribution by the
direct count method are included in Appendix C (Figures C-l through C-9).
Unfortunately, the analytical techniques did not allow determination of
the particle size distribution by weight, which is of more significance with
respect to tertiary solids removal. It is possible that the weight fraction
greater than, say, 5 to 10 microns would correlate with percent removal by
tertiary filtration. More research on particle size distribution by weight
is needed to explore the possibility of predicting removal efficiency, and
testing the efficiency of coagulation to create a more favorable size dis-
tribution for effective removal.
Based on the results reported here, a major quantity of the post bio-
logical solids are less than a few microns in mean diameter, and will likely
require coagulation to be removed by physical methods.
STORAGE EFFECTS
Since some of the samples analyzed in this study were kept in refriger-
ated storage for a period of up to a few days during shipment, it was of in-
terest to determine if storage significantly affected the solids' properties.
Analyses were performed on fresh samples and compared with those on samples
stored under refrigeration for a period of 5 days. Figures 18 through 23
are plots of the comparative data for mills number 1, 2, and 3. The various
fresh and stored sample data are plotted so that "no difference" is repre-
sented by the solid diagonal line on the graphs. A consistent trend of data
33
-------
2.0
v>
O
oc
O
1.5
co
OC
UJ
1.0
CO
111
,N
V)
111
cc
<
UJ
5
.5
(
2
(
.3
(
«
i
i
'3 i
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2
,1 V
3
SAMPLE --^
NUMBER (TYPJ i
i
'3
1
1 2 3 4 k
UBK BK UBK BLMGO BK B
AL AL AL A/S AL A
w w W W W I
3
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t
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3
i
i
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i
/
'3
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3789
K UBK BK BS
/S AL AL A/S
N S NC NE
MILL
MEAN PARTICLE
Figure 17
SIZE - DIRECT
COUNT METHOD
-------
CO
en
25
20
15
a.
0
UJ
cc
1
10
LEGEND
* MILL NUMBER
'"^'-SAMPLE NUMBER
2-1
,2-Z
I-/
3-3
10
15
INITIAL SAMPLE
20
25
30
Figure 18
EFFECT OF SAMPLE STORAGE ON FILTERED BOD
-------
/
INITIAL 230
STORED 192
CO
LEGEND
*» MILL NUMBER
'"'"-SAMPLE NUMBER
10
20
30 40
INITIAL SAMPLE
Figure 19
EFFECT OF SAMPLE STORAGE ON TOTAL BOD
60
70
-------
400
300
LU
_l
Q.
09
200
oc
O
CO
100
400
300-
01
1
O
UJ
K
O
200-
100-
H »3-l
Z- / vfZ-Z
^-T- ,3-E
100
200
INITIAL SAMPLE
300
400
3-3
1-3*
LEGEND
^MILL NUMBER
/'2-.-SAMPLE NUMBER
TOTAL SUSPENDED SOLIDS
Figure 20
EFFECT OF SAMPLE STORAGE ON TOTAL AND
VOLATILE SUSPENDED SOLIDS
100 200
INITIAL SAMPLE
VOLATILE SUSPENDED SOLIDS
300
-------
co
CO
/-Z.
LEGEND
MILL NUMBER
-SAMPLE NUMBER
1.600
1.400
1,200
1,000
Q.
<
V)
cc
o
tn
800
600
400
200
200 400 600
800 1000
INITIAL SAMPLE
1200 1 00 1600 1800
Figure 21
EFFECT OF SAMPLE STORAGE ON TOTAL SOLIDS
-------
oo
vo
LEGEND
* MILL NUMBER
'^-SAMPLE NUMBER
1.6
1.4"
1.2
1.0
111
o.
<
V)
cc
o
.6
.2
1-2
3-3«
.6 .8 1.0
INITIAL SAMPLE
MEAN PARTICLE SIZE
Figure 22
EFFECT OF SAMPLE STORAGE ON
MEAN PARTICLE SIZE
2-3«
1.2 1.4 1.6 1.8
-------
-pi
o
LEGEND
.-5- MILL NUMBER .
'~Z-»-SAMPLE NUMBER
-10
-30
INITIAL SAMPLE
-40
-50
-60
ZETA POTENTIAL
Figure 23
EFFECT OF SAMPLE STORAGE ON
PARTICLE CHARGE
-------
points above or below the diagonal would indicate a storage effect. These
figures show no consistent significant differences resulting from 5-day
refrigerated storage of the samples, when compared with fresh 24-hour com-
posite samples.
An additional comparison was made to determine the effect of 24-hour
refrigerated storage of a composite sample (during the sampling period) on
suspended solids concentration in comparison to grab samples collected over
the same period. Four samples of aerated lagoon effluent were taken at dif-
ferent times during a 1-day period at mill 1. Each sample was immediately
analyzed for total suspended solids (TSS), and the remaining portion stored
to make up a composite sample for the day. The composite sample was also
analyzed for TSS. Table 2 lists the average of five replicates for each
sample, with standard deviation shown in parentheses.
TABLE 2
24-HOUR REFRIGERATED STORAGE EFFECTS
Sample No. TSS (mg/1)
averaqe std. deviation
1 (8:00 a.m.)
2 (12:30 p.m.)
3 (4:30 p.m.)
4 (8:00 p.m.)
composite
111
104
119
108 1
101 1
10.11)
8.94)
9.89)
[ 7.30)
' 8.69)
T-hese data provide no conclusive evidence of changes in suspended solids
concentration due to natural coagulation during 24-hour composite sampling
storage. The.general tendency of the solids to blind the filter media before
accumulating sufficient TSS for accurate weighing contributes to the fairly
high standard deviation on replicate samples. As a result, the variation in
individual TSS determinations overshadows any differences between the grab
and composite results.
Although no significant increase in TSS due to natural coagulation was
observed during this test, subsequent observations of settleable solids at
the same mill suggest that some changes in solids characteristics may in fact
occur during compositing. Grab samples placed in an Imhoff cone for 30 min-
utes showed zero to trace settleable solids, whereas the composite sample
typically contains a noticeable amount of particulate deposit in the bottom
of the container. This amplifies the need to base final conclusions regard-
ing achievable TSS removals on pilot data collected on fresh rather than
stored effluent.
METALS
Metal scans were performed on total and filtered samples using argon
plasma emission spectrometry. This analytical technique was not sufficiently
sensitive to allow determination of metals content of the post biological
solids by difference (i.e., total sample minus filtered sample). As a result
41
-------
no meaningful data are available on the metal content of the TSS.
Although the necessary sensitivity for determining weight-percent metals
in the TSS was not achieved, there was no evidence of gross enrichment of
metals on the TSS, such as might occur by adsorption on floe particles.
Metals content is an area which requires further research, since some
researchers* have found evidence that a significant part of bleached kraft
mill post biological TSS is a calcium-lignin precipitate. Further investi-
gation of this hypothesis is needed. Particularly on the post biological
TSS samples having low volatiles (high ash) content, further research on the
makeup of the ash fraction is also needed.
MICROSCOPIC PHOTOGRAPHS
Several methods were investigated for preparation of samples to photo-
graph. These included: light microscopy - wet mount; light microscopy -
dry mount (with and without staining), phase contrast microscopy; and electron
microscopy.
The wet mount method with the light microscope was not satisfactory be-
cause of the following limitations: A high magnification was required to
make the small particles clearly visible, thus making it very difficult to
focus on a sufficient number of particles at one time.
Electron microscopy was rejected due to problems resulting from prepara-
tion of samples with significant salt concentration. The salts crystalize
during preparation, obscuring the solids particles.
Phase contrast microscopy was attempted, as well as dry mount without
staining. However, dry mount with methylene blue staining appeared to pro-
vide the best material for photography. Photographs taken using this pre-
paration method are shown on Figures 24 through 28.
The photos show bacteria and some clumps of debris, but in general, do
not indicate the presence of fiber type solids.
PHASE Ib - COAGULATION EXPERIMENTATION
GENERAL
The purpose of this testing phase was to evaluate the effect of various
conditioning chemicals on the effluent samples, and to select chemicals for
use in the Phase Ic bench scale testing. The following chemicals were in-
cluded in this evaluation:
* See British Columbia Forest Products, Ltd., CPAR Project Report 371-2;
Origin and Removal of Precipitated Suspended Solids in Bleached Kraft Pump
Mill Effluents, Sept. 30, 1976.
42
-------
50 MICRONS
MILL NO. 1 - 450x
UBK-AL-W
MILL NO. 2 - 450x
BK-AL-W
Figure 24 Secondary Effluent Solids
SAMPLE NO. 3
43
-------
50 MICRONS
MILL NO. 4 - 450x
BMGO-ASW
50 MICRONS
MILL NO. 5 - 450x
BK-AL-W
Figure 25 Secondary Effluent Solids
SAMPLE NO. 3
-------
50 MICRONS
MILL NO. 6 - 450x
BK-AS-W
50 MICRONS
MILL NO. 7 - 450x
UBK AL-S
Figure 26 Secondary Effluent Solids
SAMPLE NO. 3
45
-------
50 MICRONS
MILL NO. 8 - 450x
BK-AL-NC
fl t'.
50 MICRONS
MILL NO. 9- 450x
BNHa-AS-NE
Figure 27 Secondary Effluent Solids
SAMPLE NO. 3
4!
-------
MILL NO. 4 - 1000x
BMGO-AS-W
50 MICRONS
MILL NO. 9 - lOOOx
BNH3 AS-NE
50 MICRONS
Figure 28 Secondary Effluent Solids
SAMPLE NO. 3
-
-------
Inorganic Chemicals
Alum
Ferric Chloride
Lime
Polymers
Allied Colloids Percol 722
Calgon WT-3000
DOW Purifloc C-31
Hercules Hereofloc 859
Nalco 634
The comparisons were made with a jar-test apparatus, using samples from
mills 1, 2, and 3. The general procedure for each sample was as follows:
;
o Each inorganic chemical was tested over a range of concen-
trations to determine the quantity required to produce
adequate coagulation of the sample.
o A coagulant concentration was selected and used in con-
junction with several different concentrations of the
polymers listed.
o The best polymer and concentration for Phase Ic testing
was selected from these tests, based on visual observation
of floe formation and supernatant Total Suspended Solids
CTSS) after settling.
RESULTS
Inorganic Chemicals
Table 3 lists the results of jar tests using alum, ferric chloride and
lime. Six different concentrations of each chemical were used, but TSS data
were obtained only for those concentrations which exhibited reasonable visual
flocculation characteristics (i.e.: flocculation occured within 5 minutes
with floe particles which separated rapidly).
48
-------
TABLE 3
JAR TEST RESULTS
INORGANIC CHEMICALS
Supernatant TSS (mg/1)
Chemical
Alum (as Al? (SOJ.J
C* " O
Ferric chloride
Lime
Chemical Dose mq/1
0
40
80
120
160
200
240
40
120
160
200
240
120
160
200
Mill
1
87
-
_
77
98
56
28
«
80
53
47
-
175
_
-
Mill
2
4
_
_
61
7
5
-
_
-
4
0
2
_
11
-
Mil]
3
76
62
45
_
20
_
-
48
40
56
38
-
_
_
100
Concentrations of lime ranging from 40 mg/1 to 240 mg/1 resulted in very
poor floe formation to no floe formation, and those concentrations tested
showed an increase in supernatant TSS.
Ferric chloride additions in the range of 40 mg/1 to 240 mg/1 showed
variable results. Mill 1 and 2 samples required about 200 mg/1 of FeClq to
achieve a reasonable supernatant TSS level. The mill 3 sample produced good
flocculation, but the floe tended to float to the surface.
Alum appeared to provide the most consistent flocculation and settling
for all samples, and was selected for use with polymers. Alum also appeared
to remove some color, basically in proportion to alum dosage.
Test runs involving varying pH during alum and ferric chloride coagu-
lation showed no dramatic effect of pH in the range of pH 5-7. Terminal pH
for the alum coagulation was in the range of 6 to 6.5 for all samples.
For the lime dosages tested, the terminal pH was 9.8 to 10.6 for those
49
-------
samples with noticeable floe development. Higher lime dosages could have
been used to induce massive precipitation (including color removal) but this
approach was incompatible with the goals of this project.
Polymers
Selected polymers, at various concentrations were added, in conjunction
with alum at a concentration slightly less than the minimum required to
achieve maximum flocculation. Polymer concentrations of 1/2 mg/1 through
8 mg/1 were used in the jar test apparatus. The results of this testing are
shown in Table 4.
TABLE 4
JAR TEST RESULTS - POLYMERS
Polymer
Concentration
Supernatant TSS (mg/1)
Mill Mill Mill
1 2 3
(120 mg/1) (160 mg/1) (40 mg/1)
Polymer
Initial TSS
Calgon WT-3000
Hereof loc 859
Percol 722
Nalco 634
DOW C-31
(mg/1)
-
2
3
2
3
2
3
2
3
Alum
87
64
100
64
-
-
Alum
4
9
11
13
1
13
Alum
76
44
64
56
48
64
The data indicate that most of the polymers tested showed some improve-
ment in the character of the floe, but none really stood out from the rest
in terms of TSS removal.
Nalco 634 liquid polymer was selected for use in Phase Ic. Percol 722
powder showed comparable TSS removals, but 634 was chosen because the liquid
was easier to work with and provided a more consistent stock solution for
polymer addition.
APPLICATION
Jar tests were run on the samples obtained for Phase Ic testing to con-
firm the chemical concentration requirements. The results for mill T and 2
samples showed an optimum alum concentration of 100 mq/1 (as A12 (SQ.)3). The
50
-------
previous testing required 120 mg/1 for the mill 1 sample and 160 mg/1 for the
mill 2 sample. Cursory testing indicated that this change could be due to a
greater pH shift which is presumably the result of change in alkalinity of
the samples, ..This .also.indicates..a substantial variability in chemical addi-
tion requirements for these wastewaters.
Polymer concentration requirements appeared to be about the same as that
used previously. Therefore, the concentrations were: 100 mg/1 alum; and
2 mg/1 Nalco 634 polymer for mills 1 and 2; 40 mg/1 alum and 2 mg/1 Nalco 634
for mill 3; and 180 mg/1 alum and 2 mg/1 Nalco 634 for mill 5.
Terminal pH for the samples tested in this study was in the range of 6
to 6.5 for all four mill samples. Evidence from the jar testing work suggests
that chemical dosages and terminal pH will be variable at a given mill, and
it is probable that a pH control system will be needed to maintain proper pH
conditions in a commercial scale plant.
Testing of coagulation effectiveness by "freeness" measurements using
the Buchner funnel and capillary suction time (CST) devices yielded mixed
results for two reasons. First, the chemical conditioning produced increased
TSS levels to the uncoagulated samples. Second, the wastewaters were suffi-
ciently variable that repeat testing on the limited number of samples used in
this study did not produce a reliable basis for comparison. For the extent
of data available, the freeness tests showed no advantage over jar tests for
coagulant optimization. It is possible that extensive testing at a specific
mill site would yield a useful technique that is easier and faster than jar
testing, but a larger data base is needed to refine these techniques.
PHASE Ic - SOLIDS REMOVAL TECHNIQUES
GENERAL
Bench scale tests were run on four samples using the following six solids
removal techniques: Mixed media filtration; air flotation; microstraining;
coagulation/sedimentation; sand filtration; and magnetic separation. Tests
were run with and without chemical conditioning. Table 5 lists chemical con-
ditioning used in these studies.
TABLE 5
CHEMICAL CONDITIONING
Alum Dose Polymer Dose
Mill mg/1 as Al?(S04h mg/1 Nalco 634
1 100 2
2 100 2
3 40 2
_5 180 2
Figure 29 is a bar diagram showing the relative solids removal efficiency
of each method, for each of the four mills. This figure shows that mjxetfy
51
-------
cn
1 UU
10 .
SS
0
IJJ
O 60
3
ff
9
8
o
Ul
Z «0
D
in
20-
1"
2
3
5
1
2
3
5
SAND FILTRATION
NO CHEM
W/CHEM
I I
1
2
3
i |
5
1
2
3
5
MIXED MEDIA
FILTRATION
NO CHEM [ W/CHEM
1 2
3
5
1235
MICRO STRAINING
NO CHEM
W/CHEM
1
2
3
5
1235
DISSOLVED AIR
FLOTATION
NO CHEM
W/CHEM '
1
2
.
3
5
I
1
2
35 12351 235
MAGNETIC SEPARATION
NO CHEM
w/ ] w/ w/
POLYMER MAGNITITE POLYMER
AND
MAGNITE
Mill No.
Figure 29
SUSPENDED SOLIDS REMOVAL EFFICIENCY
-------
media filtration and sand filtration appear to be the most promising, removal
methods.
The results of these bench scale tests are discussed in the remainder of
this chapter.
MIXED MEDIA FILTRATION
Media Evaluation
The initial tests relative to mixed media filtration consisted of eval-
uation of the various media to determine the optimum grain sizes and quanti-
ties to use for the actual testing. Table 6 lists suggested media combina-
tions obtained from a manufacturer of mixed media filtration systems.
TABLE 6
SUGGESTED MEDIA COMPOSTTION
Material
Standard
Ilmenite
Sand
Coal
Fine
Ilmenite
Sand
Coal
Coarse
Garnet
Sand
Coal
Grain Size
0.2 mm
0.4 mm
1.1 mm
0.2 mm
0.4 mm
1 .1 mm
0.5 mm
0.9 mm
1.5 mm
Depth*
1 in.
3 in.
6 in.
3 in.
3 in.
4 in.
1 in.
3 in.
6 in.
* Fine media at top of column and coarse material at bottom.
Two runs were made (mill 1 effluent, without chemical addition) using
each of the media combinations listed in Table 6. The resultant total sus-
pended solids (TSS) removals are listed in Table 7.
TABLE 7
SUGGESTED MEDIA FILTRATION RESULTS
Media TSS Removal
Standard 14
Fine 11
Coarse 14
53
-------
Two runs were then made using modifications of the standard and fine
media to try to improve TSS removal. Table 8 lists the composition of these
modified media.
TABLE 8
MODIFIED MEDIA COMPOSITION
Media
Grain Size
Depth
TSS Removal (%)
Standard
Ilmenite
Sand
Coal
Fine
Ilmenite
Sand
Coal
0.2 mm
0.9 mm
1.5 mm
0.2 mm
0.9 mm
1 .5 mm
1 in.
3 in.
6 in.
3 in.
3 in.
4 in.
40
52
On the basis of this testing, the modified fine media combination was
selected for use in all subsequent testing.
Filtration Tests
All tests were run at a flow rate of approximately 1QO ml/min.2 This
resulted in a filter loading rate of about 3.4x10" m /s/m (5 gpm/ft ), based
on the size of the filter column used. Changes in flow rate occurred on
some runs as a result of the variation in solids content of the samples. The
flow rate was measured periodically during each run.
Table 9 lists average results of mixed media filtration tests, with and
without chemical addition, for effluent samples from the four mills.
TABLE 9
MIXED MEDIA FILTRATION RESULTS
Mill No.
1
2
3
5
Initial TSS
(mq/1)
160
6
70
60
TSS
W/Chemical
69
0
85
0
Removal (%}
s W/0 Chemicals
69
58
67
43
The poor TSS removal for mills number 2 and 5 resulted from a signifi-
cant increase in TSS concentration with chemical addition, and failure of
the filter to remove a quantity of solids as large as that added. Therefore,
a net increase in solids was measured, based on the original TSS concentra-
tion in the sample.
54
-------
The removal efficiency reported for mill number 2 is somewhat suspect
because of the very low initial TSS concentration. A small change in TSS
concentration would result in a major difference in removal efficiency.
Chemical addition increased the TSS from the initial value of 6 mg/1 to 200
mg/1. The filtrate TSS concentration with chemical addition was 16 mg/1
showing a net increase.
A similar phenomenon occurred with the other samples. Mill number 1
TSS increased from 160 mg/1 to 300 mg/1 and for mill number 3 the increase
was from 70 mg/1 to 120 mg/1, with the addition of chemicals.
Additional samples from mills number 1 and 3 were secured and sent to
a mixed media filter manufacturer for independent TSS removal evaluation.
The tests were conducted using a continuous filtration apparatus with a sam-
ple volume of about 1.9x10" m^S gall. Both samples were run with a filter
loading rate of about 3.4x10" mVs/m (5 gpm/ft2) without chemical addition.
TSS removal recorded by the manufacturer for mill number 1 averaged 30
percent and for mill number 3, 41 percent. The headless increased at a rate
of about 1.3 to 1.6 feet per hour. The manufacturer concluded that adding
chemicals directly to the filter did not appear to be feasible because of
the high solids loading. They also concluded that chemical treatment with
settling prior to filtration might be required to improve filter efficiency.
DISSOLVED AIR FLOTATION (DAF)
Two runs were made on each sample at air/solids ratios of 0.06, 0.03 and
0.01, with extremely poor results. Most of the samples tested showed no re-
moval at all. The only significant removals observed were on samples from
mill number 3. Table 10 lists the DAF data (average of two runs).
MICROSTRAINING
Results of microstraining tests using a batch laboratory unit are pre-
sented in Table 11. Several different fabric mesh sizes were tested, ranging
from 1 micron openings to 74 micron opening, both with and without chemical
conditioning. In general, poor results were obtained. The fabrics tended
to blind very rapidly, resulting in short filter runs. Only samples from
mill number 3, without chemical addition, produced any significant TSS re-
movals. The best removals were observed with the 74 micron openings, the
largest tested. This was an unexpected phenomenon because particle size
measurements showed that most of the solids were less than 2 microns in
size. This condition may be the result of stapling and bridging effects of
the solids on the strainer media.
55
-------
TABLE 10
DISSOLVED AIR FLOTATION RESULTS
Mill
1
(110)*
2
(5.5)
3
(70)
5
A/S Ratio
0.06
0.03
0.01
0.06
0.06
0.03
0.01
0.06
Final TSS TSS Removal
w/chem w/o chem w/chem
145
160
170
100
40
66
113
152
100
125
110
7.5
60 43
53 6
53
60
(«)
w/o chem
9
0
14
25
25
0
* Initial
TSS concentration.
TABLE 11
MICROSTRAINING RESULTS
Will
1 (110)*
2 (5.5)
3 (70)
5 (60)
Fabric
35 micron
35 micron
17 micron
21 micron
74 micron
35 micron
21 micron
35 micron
21 micron
10 micron
Final TSS TSS Removal
w/chem w/o chem w/chem
290
190
220
100
135
120
330
no
12
8
45
50
50
64
60
48
w/o chem
0
37
29
29
0
20
* Initial TSS Concentration
56
-------
COAGULATION/SEDIMENTATION
Settling column tests were run on samples from mills number 1, 2 and 3.
Two columns were used and tests were run simultaneously, with and without
chemical addition. No settling column tests were run on mill number 5 efflu-
ent because the volume required and the distance involved made shipping such
a large sample under refrigerated conditions impractical.
Figure 30 is a plot of the settling data for the mill number 1 sample.
This figure shows the relationship between TSS concentration at each column
port and settling time, both with and without chemical addition. The settl-
ing was monitored by periodic sampling at each port over a 6-hour period.
These results illustrate the characteristic increase in TSS with chemi-
cal addition. They also show that, while settling was rapid during the first
hour, the overall settling after six hours did not reach a TSS level as low
as the concentration in the untreated sample. Therefore, it appears that
chemical addition, at least the concentration used in this test run, was not
beneficial in reducing the effluent TSS concentration.
With no chemical addition, the TSS concentration at all ports, after
six hours settling, was essentially the same as the initial concentration.
Figures 31 and 32 are similar plots for mills number 2 and 3 respective-
ly. These samples exhibited settling characteristics similar to those of
mill number 1.
An attempt was made to develop a settling rate correlation between the
three samples tested and the sample from mill number 5 because an inadequate
quantity of sample for a settling column test was available for mill number
5. Jar tests were run simultaneously with the settling column test on sam-
ples from mills number 1 and 3. Similar jar tests were run on the sample
from mill number 5. However, due to the poor settling characteristics of
the solids, no trends were observed and no significant comparisons could be
made.
SAND FILTRATION
Media Evaluation
Two runs each were made using fine sand (0.4 mm) and coarse sand
(0.9 mm), and TSS removals were measured as a basis to select a media for use
in the actual testing. No significant difference in TSS removal was observed
between the two media grain sizes. The fine sand was selected for testing.
Filtration Tests
The sand filtration tests were run using the same filter columns as for
the mixed media tests. The filter loading rate was approximately 3.4x10
m /s/m (5 gpm/ft ), which required a flow rate of about .100 ml/minute.
Table 12 lists average TSS removals for test runs on each sample, with
57
-------
3OO
ZOO
100
o
*~ 5OO
J
Z 4OO
Of 30O
i
2 200
'00
2 soo
Q
01
400
300
2OO
100
I 1
PORT NO. 7
PORT NO, 8
2345
TIME hrs.
LEGEND
- With Chemical Treatment
o-o No Chemical Treatment
figure 30
COAGULATION/SEDIMENTATION DATA MILL NO. 1
58
-------
200
1OO
\
V
p<
>RT N
J. 2
O zuu
4
P- too
UI
o
2 A
0 °
1
8
a
UJ o
Q
29ftn
UI
t/> f OO
o
\
N
\
\
*\
N
0~»^<
>«»<
^^.
> t
P(
PC
p<
)RT N
>RT N
to
>RT N
1. 4
1. 6
j
3. 8
3
1234
TIME, hrs.
5 6
LEGEND
- With Chemical Treatment
oo No Chemical Treatment
Figure 31
COAGULATION/SEDIMENTATION DATA MILL NO. 2
59
-------
zoo
too
2OO
too
= 200
J
o
E
h-
jl
V,
r"«L
""--<
>---.__
PO
RT NC
L~f~..
t
1. 2
\
<**. 3
*
too
200
§
O
8
o
-------
and without chemical addition.
TABLE 12
SAND FILTRATION RESULTS
TSS Removal (35)
Mill Initial TSS (mg/1) w/chem w/o chem
1
2
3
5
no
5.5
70
60
64
71
14
36
68
23
Mills number 2 and 5 showed no TSS removal with chemical addition,
again, as with the mixed media filtration tests, due to the significant in-
crease in TSS with chemical addition. These data indicate that, with the
exception of mill number 1, there was no significant advantage to chemical
addition.
MAGNETIC SEPARATION
Magnetic separation tests were run using a device called a Frantz Ferro-
filter. This device operates on the basis that by placing the proper type
of steel media into the magnetic field generated, concentrated magnetic force
sites will be produced, which will tend to attract particles with a net
charge. The flow rate through the filter was maintained at approximately
750 ml/minute for each run. Two different media were testedpacked steel
wool and steel discs.
Several runs using steel wool media were made. The use of steel wool
was discontinued after these runs for the following reasons: a review of
the literature on magnetic separation revealed that steel wool is very diffi-
cult to magnetize because of its high void content, and the Ferrofilter does
not have the capacity to generate the magnetic intensities needed to ade-
quately magnetize steel wool; and the steel wool tended to act as a filter,
thus, removing solids from the flow by physical rather than magnetic means.
Test runs included untreated samples, and those treated with polymer.
alone, magnetite alone, and a combination of polymer and magnetite. The con-
centration of magnetite added was varied for each sample to try to improve
its function. The concentration added for mill Number 1 was 3 times the TSS
concentration; for mill number 2 was 2.5 times TSS; and for mill number 3
was 1 times the TSS concentration.
Table 13 lists the TSS removal data for mills number 1, 2, and 3. The
data for mill number 1 includes both steel wool media and disc media tests.
Steel wool media removal was greater than that of the discs because of the
physical solids removal as discussed previously.
TSS removals for mill number 2 appeared to be reasonably good. However,
these data may be misleading because of the very low TSS concentration in the
61
-------
sample. As the table shows, a very small difference in TSS concentration
results in a large change in percent removal.
In each case, TSS removal appeared to be better for runs with untreated
samples or with only polymer addition. This is an indication that the addi-
tion of magnetite to the samples not only failed to improve TSS removal, but
was detrimental to removal.
This condition was likely due to the failure of the suspended solids to
strongly adhere to the magnetite. The magnetite being strongly magnetic in
character, would be attracted to the media much more rapidly than the
weakly-magnetic or non-magnetic suspended solids particles. This would likely
have the effect of reducing the magnetic attraction for the suspended solids.
Thus, even though the magnetite may have been completely removed from the
liquid, fewer of the suspended solids would have been removed.
TABLE 13
MAGNETIC SEPARATION RESULTS
Mill
No.
Run
No.
Magnetite
Effluent
Polymer TSS (mg/1)
TSS
Removal %
(HO)'
(5)
1
2
3
4
No
No
Yes
Yes
Yes
No
No
Yes
Yes
No
Yes
No
Yes
Yes
No
Yes
Yes
Yes
90
90
100
110
100
3
3
4
4
18
18
9
0
9
40
40
20
20
3 ,
(65)'
1
2
3
4
No
No
Yes
Yes
No
Yes
No
Yes
50
50
70
60
23
23
8
Initial TSS Concentration
2 Steel Wool Media
OVERVIEW OF BENCH SCALE TEST RESULTS
In general, the bench scale testing showed several common elements.
Attempts to chemically coagulate the TSS to facilitate removal were variable
and - short of a massive chemical dose to induce full precipitation of both
TSS and color - frequently resulted in net increases in effluent TSS. The
fact that coagulants invariably increased the TSS levels before subsequent
removal (e.g., filtration) is an important factor in determing the quantity
of sludge for disposal. Sludge disposal quantities for the coagulated efflu-
62
-------
ent may be several times the value calculated from the net change in efflu-
ent TSS. The generation of increased TSS through coagulation will also
affect the commercial plant operating condition, for example, filter run
times and backwash fines recycle.
The effluents were highly variable, from a standpoint of both mill-to-
mill comparisons, as well as repeat observations at a given mill. To ade-
quately define effluent TSS variability factors for a tertiary removal pro-
cess will require on-site pilot testing over a period of at least several
weeks. Furthermore, review of effluent monitoring data from some mills
suggests that seasonal (temperature-related) changes in TSS levels may be
significant, which indicates the need for "summer" and "winter" pilot data.
The low effluent TSS levels (10 mg/1 TSS or less) commonly achieved in
municipal secondary effluents were not achieved by even the best of the post
biological solids removal process tested. (An exception is mill 2, where
initial TSS levels before testing were normally 10-20 mg/1.) Because of the
variability, it is impossible to state a generalized "achievable TSS level."
The performance of the TSS removal processes tested did not correlate
with a single identifiable attribute of the mill production process or treat-
ment system. A comparison of mills 3 and 5, both west coast kraft mills with
aerated lagoons, shows that mill 3 effluent TSS was consistently more sus-
ceptible to removal than mill 5. Mill 5 is bleached, whereas mill 3 is un-
bleached. The aerated lagoon at mill 5 has a much longer retention time than
the one at mill 3, and operates at slightly lower average effluent TSS levels,
Mills 1 and 3 are both unbleached kraft with aerated lagoon treatment.
In spite of higher initial TSS levels at mill 1 during these tests, the TSS
from mill 1 were less susceptible to removal than mill 3. Mill 1 has a
slightly longer lagoon retention time (9 days, versus 5.5 days at mill 3) and
mill 1 also has an NSSC plant coupled-with the kraft process.
No definitive correlations between TSS susceptibility to removal and
TSS physical and chemical characteristics were observed. As noted earlier,
availability of size distribution by weight rather than volume might yield
a meaningful correlation.
Finally, it appears that filtration processes - either sand or mixed
media - offer the greatest degree of TSS removal of the processes tested.
63
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REFERENCES
1. "Preliminary Report: Fate and Effects of Suspended Solids from Secon-
dary Biological Treatment of Wastewater." Report published by the Acad-
emy of Natural Sciences of Philadelphia, Division of Limnology and Ecol-
ogy, Philadelphia, Pennsylvania, (June 1976).
2. Smith, O.D., Stein, R.M. and Adams, C.E., Jr., "Analysis j)f Alternatives
for Removal of Suspended Solids in Pulp and Paper Mill Effluents." Tap-
_, 58, 10, 73 (1975).
3. Beak Consultants Limited. "The Nature, Fate and Impact of Primary Non-
Settleable-Solids." CPAR Project Report 241-1, Canadian Forestry Ser-
vice, Ottawa, Ontario, Canada, (1974).
4. Stein, R.M. and Adams, C.E., "Analysis of Alternatives for Reduction of
Effluent Suspended Solids." AWARE, Inc., Nashville, Tennessee, (1974).
5. Berov, M.B., Shapchenko, V.M., and Lobko, V.V., "Optimum Conditions for
Chemical Purification of Effluents." Bumazh. Prom. No. 2: 17-19 (Feb-
ruary 1975). (Russ.) A.B.I.P.C., 46., 2 (1975).
6. Gove, G.W. and Gellman, I., "Paper and Allied Products." Annual Litera-
ture Review, Journal Water Pollution Control Federation. 47, 6 (1974).
7. Gove, G.W. and Gellman, I., "Paper and Allied Products." Annual Litera-
ture Review, Journal Water Pollution Control Federation, 47, 6 (1975).
8. Gove, G.W. and Gellman, I., "Paper and Allied Products." Annual Litera-
ture Review, Journal Water Pollution Control Federation. 46_, 6 (1974).
9. Gove, G.W. and Gellman, I., "Paper and Allied Products." Annual Litera-
ture Review, Journal Water Pollution Control Federation, 45, 6 (1973).
10. Kendall, D.R., "Investigation of the Problem of Determining Total Sus-
pended Solids in Pulp and Paper Effluents." Tappi . 59, 9 (1976).
11. Baskerville, R.C., and Gale, R.S., "A Simple Automatic Instrument for
Determining the Filterability of Sewage Sludges." Journal of the Insti-
tute of Water Pollution Control, 67., 2, (1968).
12. Lee, E. G-H. , Mueller, J.C., and Walden, C.C., "Analysis and Characteri-
zation of Suspended Solids in Pulp and Paper Mill Effluent." B.C. Re-
search, Vancouver, British Columbia, Canada, (No Date).
64
-------
13. Surcheck, J.G. and Tutein, T.R., "Simplified Method Determines Cost Per-
formance of.Polymeric Flocculants." Water and Sewage Works. January
I j IO
14. Sakuma, M., Kimura, M., and Takahashi, 0., "Application of Polyacryla-
mide to Pulp Mill Effluents." Japan Tappi. 27, 6, (1973), A.B.I.P.C.,
45, 11 (1975).
15. Neptune Microfloc, Inc., "A Report on an Effluent Treatment Pilot Study,
for Georgia Pacific Corporation, Toledo, Oregon, and Cornell, Howland,
Hayes and Merryfield, Engineers and Planners, Corvallis, Oregon." Un-
published report (1968).
16. Das, B.S. and Lomas, H., "Flocculation of Paper Fines. I* Adsorption
of and Flocculation by Polyelectrolytes. II. Study of the Nature of
the Solid Surface and Soluble Impurities." Pulp and Paper Magazine of
Canada. 74, 8 (1973).
17. New Brunswick Research and Productivity Council, "Removal of Post Bio-
logical Solids by High Rate Granular Media Depth Filtration." Project
Report 80-1, Canadian Forestry Service, Ottawa, Ontario, Canada, (1972).
18. "Pilot Plant Studies of Turbidity and Residual Cell Material Removal
from Mill Effluent by Granular Media Filtration." NCASI Stream Improve-
ment Technical Bulletin No. 266 (1973).
19. Nachbar, R.H., "Pilot Plant Evaluation of Multi-Media Filters for Terti-
ary Treatment." Preliminary Report (unpublished) (1968).
20. Envirocon Limited, "Assessment of Filtration and Straining for the Re-
duction of Effluent Suspended Solids." CPAR Project Report No. 236-1,
Canadian Forestry Service, Ottawa, Ontario, Canada (1973).
21. Kolm, H., Oberteuffer, J. and Kelland, D., "High Gradient Magnetic Sep-
aration." Copy of paper - Source unknown.
22. Mitchell, R., Bitton, G., and Oberteuffer, J.A., "High Gradient Magnetic
Filtration of Magnetic and Non-Magnetic Contaminants from Water." Sep-
aration and Purification Methods. £, (2), (1975).
23. Helfgott, T., Hunter, J.V., and Rickert, D., Analytic and Process Class-
ification of Effluents." Journal of the Sanitary Engineering Division.
ASCE Proc., 96, SA3 779 (ISTOT
24. Rickert, D.A., and Hunter, J.V., "Collodial Matter in Wastewaters and
Secondary Effluents." Journal Water Pollution Control Federation. 44_,
1 (1972).
25. Tchobanoglous, G. and Eliassen, R., "The Filtration of Treated Sewage
Effluent." Proc. 24th Industrial Waste Conference, Purdue University
(1969).
65
-------
26. Faust, S.D. and Manger, M.C., "Distribution of Electromobility Values of
Particulate Matter in Domestic Wastewater." Presented at the 37th Ann-
ual Conference, WPCF, Bal Harbour, Florida, (1964).
27. Sundaram, T.R. and Santo, J.E., "Microfiltration of Military Waste Ef-
fluents." Paper presented at the Seventh Annual Symposium of Environ-
mental Research: "Environmental Technology - Military Waste Effluents
and Installation Restoration," Edgewood Arsenal, Maryland, (1976).
28. Barton, C.A., Byrd, J.F., Peterson, R.C., Walter, J.H., and Woodruff, P.
H., "A Total Systems Approach to Pollution Control at a Pulp and Paper
Mill." Journal Water Pollution Control Federation. 40_, 8 (1968).
29. British Columbia Forest Products, Ltd, "Origin and Removal of Precipated
Suspended Solids in Bleached Kraft Pulp Mill Effluent," CPAR Project Re-
port 371-2, 30 September 1978.
30. "Characterization of Dispersed Residual Solids in Biologically Treated
Pulp Mill Effluents," NCASI Stream Improvements Technical Bulletin 303,
February 1978.
31. Bewers, J.M. and Pearson, "The Behavior of Particulate Material in the
Treatment Lagoons of a Bleached Kraft Mill." Water, Air, and Soil Pol-
lution, 1 (1972) 347-358 (Reidel Publishing Company, Dordrecht, Holland).
32. "Pulp and Paper Mill Effluent Nitrogen and Phosphorus Requirements for
Biological Treatment and Residuals after Treatment," NCASI Stream Im-
provement Technical Bulletin No. 296, August 1977.
33. Herrman, R.B., "Character and Environmental Impact of Pulp Mill Treat-
ment System Particulates," Environmental Technology Department Report,
Weyerhaeuser Company, (1977).
66
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APPENDIX A
LITERATURE REVIEW
This informal technical review provided both theoretical scientific and
practical industrial background for this study. Three areas of study were
examined. General Studies on Solids Characterization and Removal Processes
summarizes broad-spectrum solids characterization studies, and multimedia
removal processes. Specific Solids Removal Techniques examines studies of
individual types of solids removal techniques: coagulation/sedimentation,
filtration, microstraining, and magnetic separation. These studies cover
both jar testing and paper mill applications. Finally, the Municipal Treat-
ment Systems examines secondary treatment systems for their potential capa-
bility in solids removal. This section includes studies of solids character-
ization and removal techniques which have been tested in secondary treatment
systems in both domestic and military wastewater.
GENERAL STUDIES ON SOLIDS CHARACTERIZATION AND REMOVAL PROCESSES
Solids characterization studies were performed on nine samples of efflu-
ent from an activated sludge system at an ammonia-base, bleached sulfite
mill. The major conclusions were:
o The effluent suspended solids were almost exclusively biological
in nature.
o The particles ranged in size from 1 to 6 microns.
o The majority of the particles observed were dispersed cells
(1 to 6 microns), with the next most common being floe
particles (5 to 15 microns).
o The samples contained suspended solids concentrations of 90
to 379 mg/1 (milligrams per liter), with no significant
settleable material.
o <4 to 90 percent of the suspended solids were volatile.
o A preliminary bio-assay test indicated no toxicity to
test organisms.
Effluent suspended solids removal studies were conducted at an un-
bleached Kraft-NSSC (neutral sulfite semi-chemical) cross recovery pulp and
paper mill in the southern U.S. The studies included analyses of: coagu-
lation; clarification; and multi-media filtration. Coagulation studies pro-
67
-------
vided the following conclusions:
o Suspended solids levels increased with the addition of polymer.
o Alum was determined to be the best coagulant.
o Optimum coagulation occurred with 70 to 100 mg/1 of alum at
pH 4.5.
Sedimentation studies showed that, for a 24 hour settling time, pH
adjustment and approximately 70 mg/1 alum were required to achieve signi-
ficant suspended solids removals. Multi-media filtration tests showed sus- «
pended solids removals of about 50 percent at a flow rate of 1.35x10" m /s/ra
(2 gpm/ft ), without chemical addition. The effective media sizes were:
coal - 0.95 mm (millimeters); sand - 0142 mm; and garnet - 0.3 mm.
A Canadian report3 lists the physical and chemical characteristics of
both settleable and non-setteable primary clarifier effluent solids from a
Kraft pulp mill. They reported a solids size range of 6 to 80 microns. The
authors concluded that Kraft mill effluents may be expected to contain non-
proteinous organic nitrogen, making Kjeldahl nitrogen values suspect in terms
of the actual food potential of the solids.
Particle size analyses were performed using a Coulter Counter industrial
model B, with a 200 micron aperture. The samples were pre-filtered through
a 100 micron mesh filter.
A
Stein and Adams studied the feasibility of suspended-solids removal
from an integrated unbleached Kraft-NSSC pulp and paper mill. They concluded
that optimum sedimentation of the solids occurred with the addition of 70 to
100 mg/1 alum at pH 4.5. They also reported suspended solids?removals of
about 50 percent at a flow rate of 1.35x10 m/s/m (2 gpm/ft ) without chem-
ical addition.
5
A Russian paper discussed treatment of biologically purified Kraft
mill effluents with aluminum sulfate (alum). The conclusions were that the
pH after alum treatment steadily increased to acceptable levels through re-
action of hydrogen ions with dissociated hydroxyl groups of ligm'n.
Gove and Gellman ' * ' presented a review of the literature pertaining
to pulp and paper wastes. Their review included many papers related to
solids removal and advanced treatment of pulp mill wastewater.
Five techniques for determining total suspended solids in pulp and paper
effluents were investigated by Kendal. The most promising method appeared
to be centrifugation, followed by filtration through a 2.4 cm (centimeter)
fiberglass filter in a porous-bottomed crucible.
Baskerville and Gale described the use of an instrument for determin-
ing the filterability of sludge easily and rapidly. The instrument, called
a capillary suction time (CST) meter, measures the specific resistance to
filtration of the sample, using the principle of capillary suction of a
68
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filter paper such as chromotography paper. Good, reproducible results were
reported.
12
Lee, et al. reported on the nature of suspended solids in the efflu-
ent from bleached and unbleached Kraft and groundwood pulp mills and a fine
paper mill. The analyses performed included: total suspended solids (using
three different filter types); non-setteable solids; BOD-n; total Kjedahl
nitrogen; total phosphates; color; and bio-assays. They concluded that non-
settleable solids settle and degrade very slowly in receiving waters, and
that BOD30 and nutrient loading was very low. They also found that the
solids were not toxic to fish.
29
British Columbia Forest Products identified calcium-lignin precipi-
tates as a significant source of non-setteable suspended solids in bleached
Kraft mill aerated lagoon effluent. Addition of a brownstock washer at a
mill, to reduce soda losses from 2.4x10 kg(55'lb)/ADT down to 5.6 kg(12.4 lb)/
ADT (as saltcake), resulted in improved effluent TSS levels.
NCASI , in studies conducted at 3 mills and a pilot plant, found that
the suspended solids in biologically-treated effluent were biological in
nature, and consisted of particles from 1 to several, but generally less than
eight microns in diameter. On the order of 25% of the solids were said to
be viable biomass. Resistance to coagulation was attributed to adsorption of
hydrophilic colloids, rather than charge repulsion.
31
Bewers and Pearson used serial filtration on Millipore and Whatman
filters to determine the size distribution by weight at a modified natural
lagoon system serving a bleached Kraft mill in Nova Scotia. They found that
about 2/3 of the suspended solids were 0.5-1.0 micron or smaller, and that
only 13% of the suspended solids were 5 microns or larger.
op
NCASI reviewed the nitrogen and phosphorus of biological solids, and
reported typical values of 9-10 percent nitrogen and 2-3 percent phosphorus.
Herrmann3 studied the characteristics of pulp mill treatment system
particulates from 3 mills, and found that the solids were nonfibrous material
of high carbon and protein content. The particulates were small (<30 micron),
and were said to contain appreciable concentrations of calcium and magnesium.
Metal-lignin precipitates were postulated to represent a portion of the
particulates.
SPECIFIC SOLIDS REMOVAL PROCESSES
COAGULATION/SEDIMENTATION
13
A method was presented by Surcheck and Tutein for developing a cost-
performance factor to determine the best polymer for a given wastewater. The
method consists of jar testing using different polymers at different concen-
trations and then relating optimum dosage to polymer cost.
Sakuma, et a!.14 discussed the clarification of bleached Kraft mill ef-
fluents by addition of polyacrylamide (PAA). The variables considered were:
69
-------
alum dosage; PAA molecular weight and dose rate; and the effect of pH on
coagulant efficiency. They concluded that the PAA molecular weight must be
greater than 5 x 10 for satisfactory results.
A pilot study to evaluate sedimentation equipment developed by Neptune
Microfloc, Inc., and evaluate treatment processes capable of producing re-
usable water was conducted.
Das and Comas reviewed theoretical adsorption of water-soluble macro-
molecules onto suspended solids to give either stable dispersions or sensi-
tized flocculation. They also developed a new procedure for use of cationic
polyelectrolytes as flocculants for paper fines.
FILTRATION
Canadian researchers studied filtration of a bleached Kraft mill sec-
onday effluent. Secondary treatment consisted of an aerated lagoon system
producing an effluent suspended solids (SS) concentration of 50 to 60 ppm
(parts per million). The study concluded that SS removals by filtration were
in the range of 40 to 50 percent, mainly due to the fine particle size (one
micron range) of the dispersed bio-mass solids. The best performance was
achieved using a medium grade sand (effective size, 0.56 mm). Granular
media filtration by itself was not recommended for solids removal because
of the voluminous floe formed after chemical treatment. They also found the
optimum alum dosage (at pH 5) to be about 90 ppm, and that 260 ppm alum was
required at pH 7.3.
They concluded that lime addition was not an economical coagulation
method because of the large quantity required (1,000 ppm).
I Q
The NCASI studied the applicability of granular media filtration
for removing suspended solids from secondary effluents, from boxboard,
bleached Kraft, filled and coated fine paper mills. The study demonstrated
on a pilot scale that application of a variety of granular media filtration
systems to such diversified effluents could remove only 25 to 50 percent of
the residual suspended solids. Backwash materials could not be readily de-
watered alone.
19
Nachbar conducted a pilot plant study of multi-media filtration of
activated sludge secondary effluent from a Virginia pulp mill. He concluded
that multi-media filtration can remove about 50 percent of the^suspended
solids and about 30 percent of the BOD at a loading of 3.4x10 m/s/m
(5 gpm/ft ). Backwash was reported to be a continual problem.
MICROSTRAINING
20
A report by a Canadian firm reviewed current filtration and straining
methods and research. One of the methods reviewed was microstraining. One
installation claimed to obtain 97 percent removal of suspended solids with,
coagulation, using 35 micron mesh openings, a hydraulic loading of 3.1x10
m/s/m (4.6 gpm/ft ) and a feed concentration {of suspended solids) of about
130 mg/1. Problems tended to occur with adhesive solids blinding the fabric
70
-------
media and requiring large quantities of backwash water.
MAGNETIC SEPARATION
The concept of high gradient magnetic separation is described by Kolm,
et al. They also discussed the work of Samual Frantz, who developed a
lab scale separator called the Frantz Ferrofilter. They found that this
unit could not economically achieve the magnetic field intensities required
to magnetically saturate steel wool or to magnetize weakly magnetic materials,
and, thus, has limited application.
22
Mitchell, et a!. described the use of a magnetic device designed to
remove weakly magnetic particles from solution. They reported greater than
90 percent removal of coliform bacteria using a device called a high-gradient
magnetic separator, with the addition of magnetite to the sample. They also
claim 69 percent BODg removal from pulp mill effluent, using the same tech-
niques in their laboratory.
MUNICIPAL TREATMENT SYSTEMS SOLIDS REMOVAL
Identification of the components found in secondary effluents (domestic)
was presented by Helfgott, et al. Both chemical analyses (organic) and
physical properties were discussed.
24
Rickert and Hunter, working with municipal wastewater, studied the
nature and origin of colloidal meterials present in secondary effluents.
They concluded that most of the colloidal particles were formed during secon-
dary treatment rather than being present in the raw wastewater, and were,
therefore, biological in nature.
25
Tchobanogious and Eliassen reported on a studies of filtration of
treated domestic wastewater, including information on effluent characteris-
tics. They found the particle size distribution to be bimodal in nature,
with the mean size of the smaller particles ranging from 3 to 5 microns and
the larger particles ranging from 80 to 90 microns. The weight fraction of
the smaller particles was estimated to be 40 to 60 percent of the total. The
method used was dark field observation with a stereoscope.
The mean charge on the particles in terms of zeta potential, was about
-20 millivolts.
Effluent suspended solids varied between 7 and 14 mg/1. Removal effi-
ciency varied from 15 percent with a 1.0 mm sand size to240 percent with a
0.5 mm sand size, at a filtration rate of 3.4x10" m /s/m (5 gpm/ft ).
yc
Faust and Manger studied the electromobility of colloidal and supra-
colloidal particles (less than 100 microns) in domestic wastewater. They
concluded that the particles were predominantly negatively charged, and that
the chemical composition of membrane-filtered particles may be homogeneous.
Sundaram and Santo27 described the results of laboratory tests on micro-
filtration using microporous tubes. They reported almost total removal of
71
-------
suspended solids from military wastes (including laundry, sewage, oil-water
emulsions, and turbid water) at filtration pressures of about 3.4x10 pascals
(5psi).
72
-------
APPENDIX B
ANALYTICAL METHODS
The methods used for analyses of samples in the work covered by this
report and performed by CH2M Hill are listed below. The standard method
number given refers to the method in the 14th edition of Standard Methods
for the Examination of Water and Wastewater, APHA (1975). Methods modified
by CH2M Hill are available on request.
TSS and VSS - Standard Methods 208D and 208E, respectively, modified by
CH2M Hill; samples filtered through Reeve Angel 934AH, 4.25 cm
filter.
Zeta Potential - Procedure as specified in the Zeta-meter Manual 2nd
Edition, as established by Zeta-meter, Inc., New York, N.Y.
(1968).
BOD - Standard Method 507.
Particle Size Distribution - Direct count method by visual measurement
using a calibrated eyepiece.
73
-------
APPENDIX C
DATA SUMMARIES
TABLE C-l
RAW DATA 1976
SAMPLE
NO.
1
2
3
1
2
3
1
2
3
1
2
3
PARAMETER
BOD (TOT)
BOD (SOL)
BOD (TOT)
BOD (SOL)
BOD (TOT)
BOD (SOL)
COD (TOT)
COD (SOL)
COD (TOT)
COD (SOL)
COD (TOT)
COD (SOL)
TSS
VSS
TSS
VSS
TSS
VSS
TS
TVS
TS
TVS
TS
TVS
MILL NO.
1
29
11
22
8
230
30
288
188
290
231
824
236
48
42
37
34
354
287
777
210
920
260
960
430
2
22
4
11
5
20
' 12
249
192
310
292
237
222
8
7
13
11
12
8
1,330
410
1,600
380
1,310
304
3
11
3
24
4
50
10
214
39
224
46
304
70
70
63
77
61
124
108
1,090
200
880
112
1,030
222
4
114
18
124
84
413
103
3,175
1,940
800
630
5,665
2,630
928
850
151
145
2,510
2,310
6,000
3,030
1,360
7,885
4,020
5
38
12
35
9
78
23
660
528
665
520
694
545
81
71
79
61
90
74
2,100
544
2,100
1,370
2,205
480
6
27
6
31
10
36
10
670
519
425
346
593
478
120
91
72
50
78
55
1,840
326
1,970
336
1,960
390
7
32
8
118
36
41
20
615
476
805
584
945
739
52
50
76
76
91
85
1,200
432
1,240
478
1,370
540
8
10
3
16
4
27
12
230
208
285
240
405
306
19
11
30
18
62
36
1,090
230
1,220
1,240
300
9
90
40
87
56
89
42
3,050
2,700
3,035
2,975
3,325
3,070
92
92
50
42
74
67
5,900
4,750
6,300
1,730
6,340
2,430
NOTE: All units in mg/l
74
-------
TABLE C-l (continued)
RAW DATA 1976
SAMPLE
NO.
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
PARAMETER
P (TOT)
P (SOL)
P (TOT)
P (SOL)
P (TOT)
P (SOL)
TKN
NO. /NO,
NH3
TKN
NO2/N03
NH,
J
TKN
NO2/NO3
NH3
PARTICLE SIZE
PARTICLE SIZE
PARTICLE SIZE
ZETA POT.
ZETA POT.
ZETA POT.
MERCURY
MERCURY
MERCURY
MILL NO.
1
.35
.05
.24
.05
__
5.9
.26
.16
4.2
.03
.14
_
.54
.68
1.1
-11.4
-21.5
-44.3
<.025
0.5
<.025
2
.95
.59
.93
.62
__
5.8
.16
3.3
8.1
.04
4.7
_
.60
.68
1.4
-6.8
-28.2
-12.0
<.025
<013
<.025
3
.78
.06
1.1
.04
1.1
.05
5.4
.16
.12
8.0
.04
.23
_
.06
.02
*
.57
.60
.95
-5.4
-15.6
-21.2
<.025
<.003
<.025
4
7.8
3.5
_
31
.02
.08
_
.04
.05
.92
1.0
.68
-12.0
-32.7
0
<.025
<.025
5
.84
.18
.84
.15
5.2
.12
.15
_
.04
.30
_
_
1.0
.95
.95
-10.8
-8.5
-15.3
<.025
<.025
<.025
6
2.4
1.4
4.9
3.5
3.5
8.6
.12
1.2
_
.28
1.8
4.5
.50
.28
.62
1.1
1.3
-10.0
-15.7
-20.5
<.025
<.01
<.025
7
.54
.08
.06
5.0
.18
.28
_
0
.13
.78
.74
.97
-19.9
-27.2
-37.0
<.025
<.01
<.025
8
.82
.61
4.7
.10
.83
__
.58
.70
1.3
-12.5
-17.4
-20.3
<013
<025
9
8.3
6.2
4.3
4.0
5.2
4.7
6.7
.05
9.74
9.0-1
.03
44
9.0-f
.25
52
.96
.65
.80
-4.0
-5.3
-5.3
2.0
<.002
<.025
NOTE: All units in mg/l
75
-------
TABLE C-2
RAW DATA METALS (Total) 1976
SAMPLE
NO.
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
PARAMETER
CALCIUM
CALCIUM
CALCIUM
MAGNESIUM
MAGNESIUM
MAGNESIUM
IRON
IRON
IRON
MANGANESE
MANGANESE
MANGANESE
ALUMINUM
ALUMINUM
ALUMINUM
ANTIMONY
ANTIMONY
ANTIMONY
ARSENIC
ARSENIC
ARSENIC
BORON
BORON
BORON
MILL NO.
1
>100
17.1
25.8
3.1
1.6
2.1
.84
.43
1.2
.40
.19
.40
.65
1.4
>2.0
<.04
<.04
<.04
<.04
<.04
<04
<-005
.25
.30
2
>100
199
152
3.1
3.3
3.3
.84
.90
1.3
.40
.51
.48
.65
.66
.51
<.04
<.04
<.04
<.04
<.04
<.04
<.005
.03
.03
3
7.8
32.0
41.0
2.7
3.2
3.7
1.2
1.2
.94
.20
.43
.53
1.4
1.8
1.8
<.04
<04
<.04
<.04
<.04
<.04
<.005
.07
.14
4
29.6
14.2
30.0
230
63.9
286
1.2
1.1
2.0
<1.0
.71
4.0
.75
.31
.85
<.04
<.04
<.04
<.04
<04
<.04
.04
.13
.74
5
131
113
151
5.3
5.2
5.8
1.3
1.5
1.5
.57
.68
71
1.8
1.9
1.8
<.04
<04
<.04
<.04
<.04
<.04
<.005
.06
.05
6
49.0
14.6
32.0
29.8
1.3
30.5
.99
.77
.70
.33
.57
.30
>2.0
2.0
2.0
<.04
<.04
<.04
<.04
<.04
<.04
.29
.14
.35
7
22.1
>100
11.4
1.7
33.8
1.5
.83
.92
.98
.48
.26
.59
>2.0
>2.0
>2.0
<.04
<.04
<.04
<.04
<.04
<.04
<.005
.29
.11
8
76.0
85.0
72.0
15.3
15.8
15.6
.62
.72
.71
.63
.67
.76
.94
.99
1.3
<.04
<.04
<.04
<.04
<.04
<.04
.09
.10
.08
9
328
314
305
10.3
6.3
7.2
1.1
1.0
1.2
.81
.76
>1.0
1.6
1.4
1.6
<.04
<.04
<.04
<.04
<.04
<.04
.07
.06
.07
NOTE: All units in mg/l
76
-------
TABLE C-2 (continued)
RAW DATA METALS (Total) 1976
SAMPLE
NO.
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
PARAMETER
COLUMBIUM
COLUMBIUM
COLUMBIUM
CHROMIUM
CHROMIUM
CHROMIUM
COBALT
COBALT
COBALT
COPPER
COPPER
COPPER
LEAD
LEAD
LEAD
MOLYBDENUM
MOLYBDENUM
MOLYBDENUM
NICKEL
NICKEL
NICKEL
VANADIUM
VANADIUM
VANADIUM
ZINC
ZINC
ZINC
SELENIUM
SELENIUM
SELENIUM
STRONTIUM
STRONTIUM
STRONTIUM
ZIRCONIUM
ZIRCONIUM
ZIRCONIUM
1
.01
<-005
.01
.05
.02
.04
<.04
<.04
<04
<.20
.01
.03
<.04
<.04
.08
.04
<.02
<.04
<1.0
<.04
<.04
.07
.03
.04
<.20
.04
.08
<.04
<.04
.05
.22
.07
.10
<.01
.01
.01
MILL NO.
2
<.02
0
<.005
.07
.02
.02
<.08
<.04
<.04
<.14
.01
.02
.20
<.04
<04
.31
.09
.10
<1.0
.01
<.04
.03
.01
.01
.30
.05
.09
.06
.01
<.04
1.1
.39
.35
.01
<-005
.01
3
<.005
<.005
.01
.11
.03
.03
<.04
<.04
<.04
<.11
.03
.09
<.14
<.04
.07
.12
<.02
.11
.07
<.04
<.04
.10
.02
.02
<.40
.07
.10
.08
<.04
.05
.36
.17
.20
.01
<.005
.01
4
.01
.02
.05
.02
<.04
<.04
.02
.03
_
<.04
<.04
<.04
.14
<.04
<.04
0
.03
.06
.36
<.04
.10
_
<.04
.22
<.005
.01
5
<.01
.01
.05
.04
<.04
<.04
<.05
.01
<.08
<.04
.08
.11
<.04
<.04
.01
.01
<22
.05
.08
<.04
.27
.28
.01
.01
6
.01
<.005
.04
.07
<.04
<.04
.03
.35
_
.08
<.04
<.04
<.04
<.04
<.04
.01
<.005
.06
2.1
.05
<.04
.09
.31
<-005
<.005
7
<.01
<.005
<.13
.04
<.04
.10
<.19
<.04
<.02
<.04
<.05
<.04
.01
<.005
<.25
3.6
.09
<.04
.27
.33
.20
<.005
8
<.005
.01
.01
.01
.02
.02
<.04
<.04
<.04
.01
.01
.03
<.04
<.04
<.04
<.02
.09
.09
<.04
<.04
<.04
.01
.01
.03
.07
.08
.13
<.04
.05
.05
.18
.20
.18
<.005
.01
.01
9
.01
.01
.01
.03
.03
.08
<.04
<.04
<.04
.04
.03
.09
.07
<07
<.04
.18
.16
<.04
<.04
<.04
<.04
.01
.01
<.005
.07
.05
.14
.06
<-04
<04
.29
.18
.38
.01
.01
.02
NOTE: All units in mg/l.
77
-------
TABLE C-3
RAW DATA METALS (Soluble) 1976
SAMPLE
NO.
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
PARAMETER
CALCIUM
CALCIUM
CACLIUM
MAGNESIUM
MAGNESIUM
MAGNESIUM
IRON
IRON
IRON
MANGANESE
MANGANESE
MANGANESE
ALUMINUM
ALUMINUM
ALUMINUM
ANTIMONY
ANTIMONY
ANTIMONY
ARSENIC
ARSENIC
ARSENIC
BORON
BORON
BORON
MILL NO.
1
>100
13.4
16.9
5.3
1.4
2.4
<1.0
.55
1.6
.55
.17
.36
5.3
1.6
5.3
<.04
<.04
<.04
<.04
<.04
<.04
.14
.23
.20
2
<100
117
11.6
2.8
2.9
<1.3
.84
1.3
1.6
.35
.20
2.3
.73
.65
<.04
<.04
<.04
<.04
<.04
<.04
<.005
.03
.19
3
100
112
7.3
5.1
<2.2
1.6
.81
.67
3.5
2.8
<.04
<.04
<.04
<.04
<.005
.15
6
10.8
27.0
_
1.1
26.0
_
.81
1.1
.51
.27
_
2.7
4.5
_
.05
<.04
<.04
<.04
_
.10
.20
7
>20.0
27.2
5.7
25.7
<3.0
1.4
1.6
.15
8.5
4.5
<.08
<.04
<-05
<.04
.09
.15
8
54.6
72.7
57.0
13.2
14.2
13.0
.62
.74
.76
.58
.35
.66
1.8
2.5
4.8
<.04
<.04
.05
<.04
<.04
<.04
.04
.10
.08
9
133
111
234
8.4
5.8
5.8
.94
.84
1.3
.70
.75
.91
1.4
1.0
2.0
.06
.05
<.04
<.04
<.04
<.04
.07
.12
.18
NOTE: All units in mg/l.
78
-------
TABLE C-3 (continued)
RAW DATA METALS (Soluble) 1976
SAMPLE
NO.
1
2
3
1
2
3
1,2,3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
PARAMETER
COLUMBIUM
COLUMBIUM
COLUMBIUM
CHROMIUM
CHROMIUM
CHROMIUM
COBALT
COPPER
COPPER
COPPER
LEAD
LEAD
LEAD
MOLYBDENUM
MOLYBDENUM
MOLYBDENUM
NICKEL
NICKEL
NICKEL
VANADIUM
VANADIUM
VANADIUM
ZINC
ZINC
ZINC
SELENIUM
SELENIUM
SELENIUM
STRONTIUM
STRONTIUM
STRONTIUM
ZIRCONIUM
ZIRCONIUM
ZIRCONIUM
M
1
<.005
<.005
<.005
.02
.02
.05
<.04
.01
.01
.04
<.04
<.04
.06
.06
<.02
.12
<.04
<.04
.04
.01
.04
.05
.06
.04
.08
^^^^^^^^^^
<.04
<.04
<.04
.28
.08
.12
.01
<.005
.01
2
<.005
.02
<.005
.02
.02
.03
<.04
.01
.02
.02
<-04
<-04
<.04
.07
.10
.12
<.04
.08
.06
.01
.02
.02
.06
.13
.11
^IHBHIBWBIH^l^H
<.04
<.04
<.04
.28
.40
.38
.01
.01
.01
3
<.005
<.005
.01
.02
.03
.02
<.04
.02
.02
.11
<04
<.04
<.04
.06
<.02
.07
<.04
.05
<.04
-.03
.02
.02
.06
.11
.09
^WHIBH
<.04
<.04
<.04
.10
.19
.22
.01
<.005
<.005
4
.01
.02
.03
.06
.06
.08
<.04
.02
.02
.11
<.04
<.04
.09
<.02
.03
.10
<04
<.04
.11
.02
.01
.04
.26
.09
.46
^^IWHW^MIIM
<.04.
<.04
.05
.27
.09
.28
<.005
.01
;01
LL NO.
5
<.005
.01
.02
.02
.03
.03
<.04
.01
.02
.02
<.04
<.04
<.04
<.02
.40
.12
<.04
.04
.06
<.005
.01
.01
.05
.14
.07
^«^_^^^^_
<.04
<.04
<.04
.20
.30
.35
<.005
.0!
.01
6
.01
.01
.02
.01
.05
.03
<.04
.02
.03
.07
<.04
<.04
<04
<.02
.10
.10
<.04
<.04
<.04
.01
.01
.02
1.2
.12
1.9
^AAO^^^^^BH
<.04
<.04
<.04
.40
.10
.38
<.005
.01
.01
7
<.005
.02
.02
.03
.03
.02
<.04
.03
.06
.03
.06
<.04
<.04
.02
.03
.10
<.04
.04
.06
<.005
.02
.01
.05
>2.0
.09
^^^i
<.04
<.04
<.04
.09
.39
.11
<.005
.01
.01
8
.01
.01
.01
.02
.02
.03
<.04
.02
.02
.03
<.04
<.04
<.04
.03
.03
.12
<.04
<.04
<.04
.01
.01
.02
.08
.08
.15
WMIIIIIII
<.04
<.04
<.04
.20
.22
.21
<.005
<.005
.01
9
.02
.02
.02
.03
.03
.03
<.04
.04
.03
.04
<.04
<.04
<.04
.17
.14
.17
.06
.06
.06
.01
.02
.02
.08
.06
.12
(^Ml
.04
.04
<.04
.40
.33
.50
.01
.01
.01.
NOTE: All units in mg/l.
79
-------
TABLE C-4
SUPPLEMENTAL DATA 1977
PARAMETER
TSS
VSS
TS
TVS
TKN (TOT)
TKN (SOL)
ORGANIC N (TOT)
ORGANIC N (SOL)
NH -N
MILL NO.
1
67
58
1,090
430
4.9
2.4
4.7
2.2
0.23
2
8
8
1,600
710
5.0
4.1
3.1
2.2
1.9
3
89
65
820
280
9.6
2.0
8.6
1.0
1.0
4
843
792
5,490
2,750
3.4
3.2
0.20
5
45
37
2,260
710
6.1
1.7
5.8
1.4
0.31
6
60
40
3,180
740
4.7
1.9
4.5
1.7
0.21
NOTE: All units in mg/l.
80
-------
100 1
80
60 -
oo
u
K
1.0
2.0 3.0 4.0
SIZE - MICRONS
Figure C-l
MILL NUMBER 1
PARTICLE SIZE (DIRECT COUNT METHOD)
-------
40
oo
ro
30 -
u.
O 20
u>
U
oc
111
a.
10 -
3 4
SIZE - MICRONS
Figure C-2
MILL NUMBER 2
PARTICLE SIZE
-------
40-1
00
CO
30 J
o
,K
111
Q.
10 4
3 4
SIZE-MICRONS
Figure C-3
MILL NUMBER 3
PARTICLE SIZE
-------
40 -
30 -
20 -
UJ
U
cc
00
-ps.
10 -
/
/v
\
3 4
SIZE-MICRONS
Figure C-4
MILL NUMBER 4
PARTICLE SIZE
-------
40 -
00
cn
30 -
o
u.
O
E
ui
20 -
10 -
SIZE - MICRONS
Figure C-5
MILL NUMBER 5
PARTICLE SIZE
-------
40 -J
00
30 -I
20 -I
ut
O
K
ui
0.
10 A
3 4
SIZE - MICRONS
Figure C-6
MILL NUMBER 6
PARTICLE SIZE
-------
40 -
30 -
oo
o
u.
O
ui
U
K
LU
20 -
10 -
T
T
3 4
SIZE - MICRONS
Figure C-7
MILL NUMBER 7
PARTICLE SIZE
-------
oe
OS
o
o
a
UJ
\- or
3MOHOIM - 3SI8
8-0
8 flaaMUM JJIM
3SI8 3JOITflA9
-------
40 -
30 -
00
lO
e
O 20
ui
U
c
IU
a.
10 -
3 4
SIZE - MICRONS
Figure C-9
MILL NUMBER 9
PARTICLE SIZE
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-79-037
3, RECIPIENT'S ACCESSION-NO.
4. TITLE ANDSUBTITLE
5. REPORT DATE
Post Biological Solids Characterization
and Removal from Pulp Mill Effluents
January 1979 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
R. R. Peterson
J. L. Graham
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
CH2M HILL, INC.
P. 0. Box 428
Corvallis, OR 97330
10. PROGRAM ELEMENT NO.
1BB610
11. CONTRACT/GRANT NO.
68-03-2424
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Lab - Cinn,
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING
7/76-1/77
3 AGENCY CODE
EPA/6.0 0/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The study characterized the post biological solids in pulp and
paper mill secondary effluent and evaluated various suspended solids
removal techniques. Characterization was performed on samples from 9
mills, representing various locations, pulping processes and treatment
system types. Results indicate the solids are mostly biological in
nature. Coagulation by alum in conjunction with a cationic polymer
appeared to provide the best results. Six solids removal techniques
were tested but only mixed media filtration and sand filtration
appeared effective enough to warrant further investigation.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS
COSATI Field/Group
Paper mills,Pulp Mills,
Filtration, Sand Filtration*,
Coagulants*, Coagulation, Flotation,
Flocculants, Effluents, Solids*,
Sedimentation, Waste Treatment
Mixed Media Filtra-
tion*, Dissolved Air
Flotation*, Micro^
straining*, Solids
Removal, Magnetic
Separation, Secondar
Effluents
13B
8. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
104
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
» U.S. GOVERNMEin PRINTING OFFICE; 1979-657-060/1585
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