PB81-172637
Removal of Phenolic Compounds from Wood Preserving Wastewaters
Edward C. Jordan Co., Inc.
Portland, ME
Prepared for
Industrial Environmental Research Lab.
Cincinnati, OH
Mar 81
U.S. DEPARTMENT OF COMMERCE
National Technical Information Service
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EPA 600/2-81-043
March 1981
REMOVAL OF PHENOLIC COMPOUNDS
FROM WOOD PRESERVING WASTEWATERS
by
Bruce K. Wallin
Arthur J. Condren
Roy L. Walden
Edward C. Jordan Co., Inc.
Portland, Maine 04112
Contract No. 68-03-2605
Work Directives 2(1) and 5
Project Officers
Donald L. Wilson and
Brian Westfall
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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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-6QO/2-81-043
PIENT'S ACCESSION NO.
PB81 172637
4. TITLE AND SUBTITLE
REMOVAL OF PHENOLIC COMPOUNDS
FROM WOOD PRESERVING WASTEWATERS
5. REPORT DATE
•Mi-rr.'h 1QS1
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Bruce K. Wallin,. Arthur J. Condren, Roy L. Walden
3. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO-.
Edward C. Jordan Co., Inc.
P.O. Box 7050, Downtown Station
Portland, Maine 04112
1BB610
11. CONTRACT/GRANT NO.
68-03-2605
Work Directive Nos. 21 & 5
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laborator
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
13. TYPE OF REPORT AND PERIOD COVERED
r Final: 11/20/78-5/20/80
14. SPONSORING AGENCY CODE
EPA 600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Laboratory and pilot-scale studies were undertaken to develop economically
feasible technologies for the treatment of wastewaters from wood preserving operations.
Of prime concern was the removal of phenol and its chlorinated derivatives, in particu-
lar, pentachlorophenol. Screening analysis of the wastewater indicated that penta-
chlorophenol was the only chlorinated derivative consistently present in concentrations
of approximately 100 mg/1.
Treatment technologies investigated for the treatment of these wastewaters
included: 1. adsorption; 2. biological oxidation; 3. chemical oxidation; 4. coagula-
tion; 5. extraction; and 6. pH adjustment.
Each of the above, along or in combination, was capable of yielding a measurable
reduction in the concentration of total phenols and pentachlorophenol in the untreated
wastewater.
Two technologies yielded consistently high levels of treatment:
1. pH adjustment of the wastewater, followed by adsorption with bentonite
clay and final polishing by the polymeric adsorbant, XAD-4; and
2. pH adjustment of the wastewater, followed by extraction with a mixture
of #2 fuel oil and a co-solvent such as still bottoms from aaiyl alcohol
production.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
COSATi Field/Croup
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF P£>GES
20. SECURITY CLASS (This pa^e)
Unclassified
22. PRICE
EPA Form 2220-1 (R»v. 4-77) PREVIOUS EDITION is OBSOLETE
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DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publica-
tion. 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 recom-
mendation for use.
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TORE WORD
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 improved
methodologies that will meet these needs both efficiently and economically.
Identification and evaluation of treatment techniques for removal or
reduction of pollutant discharges in an industry (in this instance the wood
preserving industry) provides.useful information relative to the treatability
of the pollutants of interest. Regulatory agencies can use such information
to assess the applicability of the technology in controlling the pollutants of
interest. The Food and Wood Products Branch, lERL-Ci, can be contacted for
further information on the subject.
David G. Stephan, Director
Industrial Environmental Research Laboratory
Cincinnati, OH
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ABSTRACT
Laboratory and pilot-scale studies were undertaken to develop economical-
ly feasible technologies for the treatment of wastewaters from wood preserving
operations. Of prime concern was the removal of phenol and its chlorinated
derivatives, in particular, pentachlorophenol. Screening analysis of the
wastewater indicated that pentachlorophenol was the only chlorinated deriva-
tive consistently present in concentrations of approximately 100 mg/1.
Treatment technologies investigated for the treatment of these waste-
waters included:
1. adsorption;
2. biological oxidation;
3. chemical oxidation;
4. coagulation;
5. extraction; and
6. pH adjustment.
Each of the above, alone or in combination, was capable of yielding a
measurable reduction in the concentration of total phenols and pentachloro-
phenol in the untreated wastewater.
Two technologies yielded consistently high levels of treatment:
•
1. pH adjustment of the wastewater, followed by adsorption with ben-
tonite clay and final polishing by the polymeric adsorbant, XAD-4;
and
2. pH adjustment of the wastewater, followed by extraction with a mix-
ture of #2 fuel oil and a co-solvent such as still bottoms from amyl
alcohol production.
Total annual operating costs for systems treating a typical 10,000 gpd of
wastewater were calculated to be $40,000 and $23,600, respectively, for the
two aforementioned technologies.
This report was submitted in fulfillment of Contract No. 68-03-2605, Work
Directives Nos. 2, Part I, and 5, by the Edward C. Jordan Co., Inc. under the
sponsorship of the U.S. Environmental Protection Agency. This report covers
the period November 20, 1978 to May 20, 1980, and work was completed as of May
20, 1980.
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CONTENTS
Foreword iii
Abstract iv
Figures vi
Tables ix
Abbreviations and Symbols xii
Acknowledgments , xiv
1. Summary 1
2. Conclusions and Recommendations 5
3. Introduction 7
4. Literature Review 8
5. Treatability Studies 11
6. Selection of Treatment Alternatives 30
References 36
Appendices
A. Review of Literature on Phenolic Treatment Technologies. . 37
1. Biological Oxidation 37
2. Foam Fractionation 57
3. Solvent Extraction 60
4. Physical/Chemical Oxidation 70
5. Carbon Adsorption 88
6. Stripping Operations 100
7. Resin Adsorption 110
8. Electrochemical Oxidation 116
9. Ionizing Radiation 118
10. Elimination of Pollutant Discharge 121
B. Analytical Methodologies 125
1. Analytical Procedures for Total Phenolics 126
2. Analytical Procedures for Pentachlorophenol - Mill A. 127
3. Analytical Procedures for Pentachlorophenol - Mill B. 129
4. Analytical Procedures for Pentachlorophenol - Gas
Chromatography/Mass Spectrometry 132
5. Quality Control/Quality Assurance Pentachlorophenol
Analysis 134
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FIGURES
Number l*£
1 Phenolic structures . 3
2 Coagulation/adsorption, process flow diagram ... 32
3 Solvent extraction with oil separation flow
diagram 35
4 Biological oxidation process schematic for coke
plant wastes 39
5 Biological oxidation process schematic for wood
preserving wastes . 40
6 Removal of 2,4-dichlorophenol and 2,4-dichlorophen-
oxyacetic acid from solution in aeration
'basin effluent by continuous aeration. ... 42
7 Removal of 2,6-dichlorophenol and 2,6-dichloro-
phenoxyacetic acid from solution in aeration
basin effluent by continuous aeration. ... 43
8 Removal of 2,4,5-trichlorophenol and 2,4,5-tri-
chlorophenoxyacetic acid from solution in
aeration basin effluent by continuous
aeration . 44
9 Removal of 2,4,6-trichlorophenol and 2,4,6-tri-
chlorophenoxyacetic acid from solution in
aeration basin effluent by continuous
aeration • . 45
10 Change in pentachlorophenol concentration in
aerated solution in aeration lagoon
effluent 46
11 Schematic of full scale biological treatment sys-
tem .... 49
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Page
Phenolic resistance to biodegradation 54
Process schematic for solvent extraction of phe-
nols from coke plant wastewaters 61
14 Dual solvent process schematic-separate cycles. . 63
15 Dual solvent process schematic-linked cycles. . . 64
16 Chem-pro solvent extraction process schematic . . 68
17 Decomposition of phenol by wet-air oxidation. . . 71
18 Percentage of phenol oxidized vs. ultrasonic in-
tensity 73
19 Ozonation of phenol 74
20 Oxidation of phenol by ozone 75
21 Oxidation of phenol by chlorine 78
22 Oxidation of phenol by chlorine dioxide 79
23 Effect of initial hydrogen peroxide/phenol ratio
on the oxidation of pure phenol 81
24 Effect of hydrogen peroxide/phenol ratio on chem-
ical oxygen demand reduction of pure phenol. 82
25 Process flow diagram-plant "A" 90
26 Process flow diagram-plant "B" 92
27 Total installed cost of two-stage adsorption con-
tacting equipment 96
a
28 Total installed cost of carbon reactivation and
handling system 97
29 Vapor pressure of various volatile organic com-
pounds 102
30 Air stripper schematic 105
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Figures (cont'd)
Number
31 Steam stripper schematic
32 Flow diagram-stripper column integral with evapor-
ator .................... 107
33 Stripping column design details ......... 108
34 Effect of pH on adsorption of p-nitrophenol . . . Ill
35 Rohm & Haas adsorption process flow diagram ... 114
36 Process flow diagram closed pulp mill ...... 122
37 Process flow diagram Rapson/Reeve salt recovery
process ................... 123
-viii-
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TABLES
Number Page
1 Phenolic Compound Identification 2
2 Individual Treatment Techniques .... 12
3 Combined Treatment Technologies 13
4 Acid Addition and Filtration 14
5 Typical Coagulation Study Results 15
6 Extraction Study Results 16
7 Combined Acid Addition Pretreatment/Chemical Oxi-
dation 17
8 Combined Acid Addition Pretreatment/Coagulation
Results 18
9 Combined Acid Addition Pretreatment/Extraction
Results 18
10 Combined Coagulation/Adsorption Results 19
11 Acid Addition Study Results 20
12 Biological Treatment Results 22
13 Solvent Extraction Results 23
14 XAD-4 Adsorption Results 24
15 Acid Addition/Extraction Results 25
16 Acid Addition/Bentonite Clay Adsorption 26
17 Acid Addition/Bentonite Adsorption/XAD-4 Adsorp-
tion 28
18 XAD-4 Resin Regeneration 29
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Tables (cont'd)
Number
19 Typical Wood Preserving Facility Wastewater
Characteristics
20 Proposed Process No. 1 Estimated Costs ..... 33
21 Proposed Process No. 2 Estimated Costs ..... 34
22 Operating Results , Biological Treatment of Wood
Preserving Wastes ............. 41
23 Biological Pilot Plant Process Parameters. ... 48
24 Full Scale (Biological) Treatment Facility Design
Parameters ................. 50
25 Comparison of the General Characteristics of Three
Bioreactors ................ 51
26 The Biochemical Oxidation of Pure Phenols by the
Activated Sludge Process .......... 55
27 Capital and Operating Costs for Various Foam
Separation Systems .......... ... 58
28 Effect of Feed Concentration on Solvent Extrac-
tion Process. . .............. 60
29 Equilibrium Distribution Coefficients for Various
Solvents .................. 62
30 Sequential Extraction of Lube-Oil Refining Waste-
water ..... . ............ . 66
31 Economic Evaluation of Phenol Removal from Process
Condensate ....... . ......... 67
32 Catalytic Oxidation of Lacquer Manufacturing
Wastewater ......... . ....... 72
33 Hydrogen Peroxide Treatment of Phenol Wastes . . 80
34 Reaction of Phenol with Fenton's Reagent .... 83
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Page
Effect of Catalysts on Phenol Oxidation 84
Phenol Adsorption Systems 89
Operating Data-Plant "A" 9.1
Operating Data-Plant "B" 93
Effects of Carbon Regeneration 94
Impurity Removal Decrease after Regeneration . . 94
41 Major Annual Cost Considerations for Adsorption
Options 98
42 Characteristics of Various Condensate Treatment
Systems at 5 Bleached Kraft Mills 103
43 Pollutant Load by Contaminated Condensates . . . 104
44 Removal of Phenol from Contaminated Condensates
by Steam Stripping 104
45 Effect of Salt Content upon Capacity of Amberlite
XAD-4 for Phenol and m-Chlorophenol Adsorp-
tion 112
46 Adsorption of Phenolic Compounds on Amberlite XAD-
4 at 25°C and Flow Rate of 0.5 gpm/cu ft. . 113
47 Effect of Gamma Irradiation and Oxygen Pres-
sure on pH, Suspended Solids and COD of
Various Pulp Mill Effluents 119
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ABBREVIATIONS
LIST OF ABBREVIATIONS AND SYMBOLS
BOD
BOD5
COD
DI
ECD
EPA
ft
ft2
ft3
FID
g
gal
GC
GC/MS
8/1
gpm
tp
in.
kg
kW
kWh
1
Ib
bl/day
min
ml
mg
mg/1
ml/1
mug/1
MLSS
MLVSS
N
nm
O&M
POTW
ppm
sec
SVI
ug/1
w
wt
—biochemical oxygen demand
—5-day biochemical oxygen demand
—chemical oxygen demand
—de-ionized
—electron capture detection
--U.S. Environmental Protection Agency
--feet (foot)
—square feet
—cubic feet
--flame ionization detection
--gram
--gallon
—gas chromatography
—gas chromatography/mass spectroscopy
—grams/liter
•-gallons per day
•-gallons per minute
•-horsepower
•-inches
•-kilogram
•-kilowatt
•-kilowatt-hour
•—liter
•-pound
•-pound/day
•-minute
•-milliliter
•-milligram
•-milligram/liter
•-milliliter/liter
•-millimicrograms/liter
•-mixed liquor suspended solids
•-mixed liquor volatile suspended solids
•-normality
•-logmeters
•-operation and maintenance
•-publicly owned treatment works
•-parts per million
•-seconds
•-sludge volume index
•-micrograms/liter
•-watt(s)
•-weight
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SYMBOLS
°C degrees Centigrade
CH2C12, dichlorome thane
°F degrees Fahrenheit
HC1 hydrochloric acid
H2S04 sulfuric acid
H20 water
NaOH sodium hydroxide
± plus or minus
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ACKNOWLEDGMENTS
This report was prepared by Dr. Bruce K. Wallin, Dr. Arthur J. Condren,
and Roy L. Walden of the Edward C. Jordan Company in Portland, Maine. Key
staff members participating in the project were Robert A. Steeves and
Frederick A. Keenan.
Laboratory analyses during the preliminary phase of the project were
conducted by EMS Laboratories, Indianapolis, IN, under the direction of Mr. C.
Stephen Gohmann. All remaining analyses were performed by the Edward C.
Jordan Company laboratory under the direction of Dr. Bruce Wallin. Throughout
the project, the Gulf South Research Institute New Orleans, LA, under the
direction of Dr. Roger Novak, provided gas chromatography/mass spectroscopy.
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SECTION 1
INTRODUCTION
The U.S. Environmental Protection Agency has been involved in extensive
investigations of toxic compounds being discharged from industrial facilities.
Primary emphasis has been on the 65 "priority" pollutants, which are contained
in the Settlement Agreement of 1976 and in the Clean Water Act of 1977
(PL 95-217). Phenolics and their chlorinated derivatives are a part of this
group and are commonly found in the wood products industry's wastewater streams.
The initial objective of this study was to evaluate the treatability of
2,4,6-trichlorophenol, parachlorometacresol, 2-chlorophenol, 2,4-dichloro-
phenol, and pentachlorophenol in. the wood products industry's wastewater. The
wood preserving industry was selected for this program because wastewater from
wood preserving facilities is usually low in volume but high in concentrations
of chlorinated phenolics. A chemical screening of the wastewater revealed
that it had a high organic content, but more significantly, it contained
pentachlorophenol in concentrations exceeding 100 mg/1. The program's focus
then shifted primarily to pentachlorophenol to the virtual exclusion of all
else, since only trace levels of other chlorinated phenolics were found.
In conjunction with the treatability aspect, the program was intended
also to explore atypical pretreatment schemes that would reduce chlorinated
phenolics, namely pentachlorophenol, in typical wood preserving wastewater to
levels at which the wastewater could be discharged to a POTW without causing
an upset. Owing to constraints imposed by time and financial resources, it
was not the objective of this program to investigate all aspects of each
treatment scheme (e.g., residual catalyst after PCP removal, toxicity of the
removal concentration, adsorptive capacity of the regenerated resin). The
objective here was also not to improve the phenol-contaminated wastewater to
drinking water quality, nor was it within the bounds of the study to make any
conclusions concerning the toxicity of the residual pentachlorophenol.concen-
tration in the wastewater that would be discharged to the POTW.
The physical/chemical properties of pentachlorophenol, as distinguished
from those of phenol, were important in considering the pretreatment systems
which would be capable of reducing concentrations to an acceptable level.
Pentachlorophenol consists of a benzene ring (C^H,) with all six hydrogen
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sites substituted by one hydroxyl group (OH) and five chlorine atoms (C15)-
The resulting compounds, C-C1 OH, is mildly acidic, boils at 309°C, and is
soluble in 50°C water at 30 mg/1. Oils or emulsions in wastewater can provide
a "carrier" effect, allowing pentachlorophenol to far exceed its normal solu-
bility in water. Table 1 summarizes the physical properties of several phe-
nolic compounds. Figure 1 presents phenolic structures for several compounds.
TABLE 1
PHYSICAL PROPERTIES OF SEVERAL PHENOLIC COMPOUNDS
Compound
Solubility in HO
mg/1 @ 25°C
Ka x 10
10
Phenol
o-Chlorophenol
m-Chlorophenol
p-Chlorophenol
2 , 4-Dichlorophenol
2 , 4 , 6-Trichlorophenol
Pentachlorophenol
o-Cresol
m-Cresol
p-Cresol
p-Chloro-m-Cresol
2,4, 6-Trichloro-m-Cresol
182
173
214
220
210
246
309
191
.201
202
196
265
93,000
28,000
26,000
27,000
4,500
900
30(50°C)
25,000
26,000
23,000
insol.
si. sol.
1.1
77
16
6.3
Large
Very Large
Very Large
0.63
0.98
0.67
Unknown
Unknown
Ka = .thermodynamic acid dissociation constant
A review of available literature assisted the investigators in identify-
ing treatment techiques for investigation. Investigations were divided into
two phases: preliminary bench-scale treatability studies and an evaluation of
batch treatment techniques.
Unlike phenol, which is quite unstable and easily oxidized either chem-
ically or biologically, pentachlorophenol is stable and resistant to oxida-
tion. In some instances, though, when wastewater containing pentachlorophenol
in concentrations which a biomass can tolerate is run through a biological
treatment system, pentachlor.opb.enol is adsorped onto the biofloc. Disposal of
the sludge, now laden with pentachlorophenol, then presents a hazardous waste
problem. Alkylinization of the sludge, a relatively common practice, would
more than likely release the pentachlorophenol into .the environment. If the
sludge were incinerated, 2,3,7,8-tetrachlorodibenzo-p-dioxin, a thermal de-
gradation product of pentachlorophenol, could be released into the atmosphere.
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PHENOLIC RESISTANCE
TO BIODEGRADATION (2)
PHENOL
0-CHLOROPHENOL
2,4 DICHLOROPHENOL
2,4,6 TRICHLOROPHENOL
PENTACHLOROPHENOL
a:
o
UJ
a
o
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ui
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a
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These rather ominous prospects make such treatment techniques as solvent
extraction and batch polymeric resin adsorption, two schemes investigated
during this study, more appealing from the standpoint of avoiding the creation
of a hazardous waste problem while improving water quality.
In the preliminary bench scale studies the investigators traveled to a
wood preserving facility on the west coast to evaluate treatment technologies,
described in the literature, designed to lower pentachlorophenol concentra-
tions. Treatment schemes tested included pH reduction, acid cracking,. chem-
ical coagulation, chemical oxidation, ultrafiltration, resin adsorption, and
solvent extraction.
After conducting the preliminary bench scale studies, the investigators
reported to representatives of the EPA. At this time, mid-course corrections
were suggested. It was suggested that the program emphasis be shifted to
focus on only those pretreatment systems that would both lower pentachloro-
phenol concentrations to levels acceptable for discharge to a- POTW and be
economically feasible for wood preservers.
To meet the revised criteria, pretreatment schemes had to be both effi-
cient and economically feasible, which essentially eliminated from consider-
ation the more elaborate treatment technologies (e.g., reductive degradation,
electrochemical oxidation, ion exchange, rotary vacuum filtration with activ-
ated carbon). The effectiveness of these cannot be denied, but the cost of
installing and operating any one of them makes it economically impractical for
wood preservers.
Batch treatment systems were set up at the southern facility to provide
some indication of which methods were cost effective. Technologies tested at
the southern facility included batch biological treatment, chemical and poly-
meric coagulation, resin adsorption, acid cracking, bentonite clay, solvent
extraction, and filtration. As at the west coast facility, a combination of
these were tested. The size of the batch treatment reactors ranged from
several liters to 50 gallons, depending on the pretreatment system being
tested.
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SECTION 2
SUMMARY AND CONCLUSIONS
Processes for the treatment of wastewaters from two wood preserving
facilities were investigated at the laboratory and pilot scale levels. In-
cluded were various chemical, physical, and biological operations selected
specifically for the removal of phenol and its chlorinated derivatives. Of
the treatment technologies investigated, two systems consistently lowered the
concentrations of pentachlorophenol in the wastewater from 100 mg/1 to less
than 1 mg/1.
In the first system, the wastewater was first acidified to a pH of 4.0 ±
0.1, then bentonite clay was added. A polymeric adsorbant, amberlite XAD-4
was used in the final polishing process. In the second system a mixture of
No. 2 fuel oil and a cosolvent (amyl alcohol still bottoms) was used to ex-
tract pentachlorophenol from the waste stream. Reductions were consistently
in excess of 99 percent. Since No. 2 fuel oil is used often in the preserving
process, as it was at this facility, it is conceivable that a facility could
operate this extraction process without incurring any additional chemical
expense, except possibly for the cosolvent. Trials with No. 2 fuel oil alone
yielded removal efficiencies in the vicinity of 97 percent, which may be high
enough to allow the wastewater to be discharged to a POTW. For both systems
to function consistently, the wastewater first had to be subjected to free oil
separation and flow equalization. The following summarizes the findings of
other investigations, based on reductions in total phenol and/or pentachloro-
phenol concentrations.
pH Adjustment
Lowering the pH of the wastewater with sulfuric acid was found to induce
the formation of colloidal material. Subsequent removal of this colloidal
material resulted in slight reductions' in total phenol concentrations as
measured by the modified lowry procedure described in Appendix B-l. Penta-
chlorophenol concentrations, however, were consistently reduced from approx-
imately 100 mg/1 to less than 20 mg/1.
Biological Oxidation
Biological oxidation was not found to be an effective treatment technique
because bioadsorption rather than biotransformation was found to be the pri-
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mary removal mechanism. Removal rates continued to diminish as the adsorptive
capacity of the biomass was approached.
Chemical Oxidation
At high doses, chlorine yielded substantial reductions in the compounds
of concern. Hydrogen peroxide, on the other hand, had little effect. The
high chemical demand observed precludes the use of chemical oxidation as a
viable treatment alternative.
Coagulation
Coagulation with alum, ferric chloride, and/or polymers resulted in
modest pollutant reductions. These reductions were not deemed sufficient to
justify coagulation as a sole treatment technology.
Applicability of Technologies
In turning now to the applicability of the programs' findings to the wood
preserving industry as a whole, it should be understood that the utility of
any single pretreatment option is contingent upon both the volume and chemical
make-up of the waste stream. Simply put, because wood preserving processes
are so variant, each facility must be evaluated in terms of its preserving
process, its waste stream, and the capital available for investing in a pre-
treatment system. The systems devised for wood preservers in connection with
this study would probably not be transferable to the leather tanning industry
or to the paper industry, not because a No. 2 fuel oil - cosolvent mixture
would not remove pentachlorophenol from leather tanning or paper industry
effluent just as effectively as it would from wood preserving wastewater, but
because neither of these industries uses No. 2 fuel oil in its production
process (non-combustion) as do some members of the wood preserving industry.
The advantage of the fuel oil extraction process is that the pentachlorophenol
can be removed from the wastewater without creating an additional waste and
without bringing large capital and operating expense to bear on the wood
preserver.
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SECTION 3
RECOMMENDATIONS
If results obtained during these investigations are to be verified, a
continuously flowing pilot-scale system must be established. Because this
study was done on a quick response basis with limited financial resources,
researchers could not investigate all aspects of each pretreatment scheme
(e.g., residual catalyst after pentachlorophenol removal, toxicity of removal
concentrations, utility or necessity of catalysts other than amyl alcohol
still bottoms). Instead, the project provided an overview of the many eco-
nomically achievable approaches to removing pentachlorophenol from wastewater
and identified two systems especially successful in lowering pentachlorophenol
concentrations in wood preservers' wastewater to levels that would allow it to
be discharged to the POTW without causing an upset.
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SECTION 4
LITERATURE REVIEW
The treatment of toxic compounds is a new and rapidly developing field.
A detailed literature review was prepared on the removal of phenolics from
wastewaters to assess the state-of-the-art.
Applicable treatment processes identified in the literature were as
follows:
1. biological oxidation;
2. foam fractionation;
3. solvent extraction;
4. chemical oxidation;
5. Carbon adsorption;
6. gas stripping;
7. resin adsorption/ion exchange;
8. coagulation/precipitation;
9. electrochemical oxidation;
10. ionizing radiation; and
11. elimination of discharge.
None of the above exhibited universal applicability, although each was
useful in specific instances. A detailed review of each process can be found
in Appendix A, and a number of these are summarized below.
1. Biological oxidation has been shown capable of 99-percent phenol removal
under proper conditions (pH, detention time, nutrient supplements, etc.).
Although phenol bio-oxidation is a generally recognized phenomenon, the abil-
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ity of micro-organisms to chemically modify certain substituted phenols is
controversial.
2. Foam fractionation has considerable value as a pretreatment technology,
although it is not promising as an independent treatment system due to its low
efficiency for phenol removals. Its ability to limit the effects of shock
loadings and remove a portion of the wastewater's toxicity allows for more
stable, and efficient use of existing biological treatment systems.
3. Solvent extraction is extremely effective because the solvent used can be
tailored to the removal of specific compounds. Again, greater than 99 percent
phenol removal has been reported. Recovery of chemicals can offset a portion
of the operating costs. Capital costs, however, can prove excessive since
considerable equipment and instrumentation is required for efficient process
control. Additional downstream effluent polishing may be required prior to
final discharge.
A. Chemical oxidation can completely remove phenolics from wastewater.
However, the required doses of oxidizing agents are generally so high that the
processes cannot economically compete with other processes, except in special
applications. Similarly, high capital costs for the wet air oxidation process
make this process uneconomical.
5. Carbon adsorption has been demonstrated commercially to achieve greater
than 99-percent phenol removal. Reasonable service life, however, requires
some form of wastewater pretreatment. System operation is also complex. The
economical use of carbon necessitates regeneration of spent material, accom-
plished either onsite or through a contract regeneration service. A second
use of carbon is the direct addition of this material to an activated sludge
system. Removals of BOD5, COD and TOC improve, and the biological system's
ability to react to and recover from shock loadings is increased. Carbon
adsorption alone is too expensive for the treatment of pulp, paper and wood
products industry wastewaters. When combined with the proper pretreatment and
other processes, however, it can provide effective and economical treatment.
6. Gas stripping failed to remove phenolics in all studies reported in the
literature. On the other hand, steam stripping is viable. Steam stripping is
frequently used as an odor removal/chemical recovery 'system. When this is the
case, phenol removals can occur but probably not to acceptable levels since
the operating parameters would be tailored to the unit's primary function.
7. Resin adsorption can also provide greater than 99 percent phenol removal.
Under certain conditions, recovery of various marketable chemicals, such as
phenol, is also possible. Several full scale systems have been constructed
for chemical processing plants. Again, for the treatment of wood products
industry effluents, some wastewater pretreatment is necessary to protect the
resin (i.e., methanol). Operation of the system may be complex and expensive,
if conventional regenerating substances are used.
-9-
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8. Coagulation/precipitation processes for phenolic removals were reported
by the SUNY College of Environmental Science and Forestry in a report entitled
"Toxicity Reduction Through Chemical and Biological Modification of Spent Pulp
Bleaching Liquors" (EPA-600/2-80-039). It was reported that coagulation/pre-
cipitation processes remove the higher molecular weight phenolics efficiently.
The majority of toxicity, however, was attributable to the lower molecular
weight species. Appendix A contains a review of the completed phases of this
study through February 1978.
The remaining technologies investigated, electro-chemical oxidation,
ionizing radiation, and elimination of discharge, are all reported to be
highly efficient in terms of phenol removal, provided the proper operating
conditions are maintained. In most cases, however, the achievement of high
removals was economically infeasible.
•10-
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SECTION 5
TREATABILITY STUDIES
INTRODUCTION
The objective of the program was to determine the treatability of pheno-
lic compounds and its chlorinated derivatives in the wood products industry.
Of particular interest was pentachlorophenol. The wood preserving industry
was selected for this program because wastewater from wood preserving facili-
ties are typically low in volume but high in concentrations of chlorinated
phenolics, particularly pentachlorophenol.
Wastewater treatment studies were conducted at two wood preserving facil-
ities. Preliminary studies were undertaken at a west coast facility while
more in-depth efforts were completed at a facility located in the south.
Table 2 presents the individual treatment techniques investigated at each.
-11-
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TABLE 2. INDIVIDUAL TREATMENT TECHNIQUES
Facility location
Type of treatment West coast South
A. Acid addition X X
B. Biological oxidation X
C. Chemical oxidation
1 . Chlorine X
D. Coagulation
1. Alum X X
2. Ferric chloride X
3. Polymer X
E. Extraction X X
F. Resin adsorption
1. Amberlite XAD-2 X
2. Amberlite XAD-4 X
3. Bentonite clay X
Combinations of the above individual treatment techniques were also
investigated and Table 3 presents those undertaken.
-12-
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TABLE 3. COMBINED TREATMENT TECHNOLOGIES
Preliminary
Type of treatment
Intermediate
Final
Facility location
West
Coast South
Acid addition
Acid addition
Acid addition
Acid.addition
Acid addition
Acid addition
Acid addition
Acid addition
Acid addition
Alum coagulation
Alum coagulation
Ferric chloride coagulation
Alum coagulation Polymer coagulation
Acid addition Polymer coagulation
Acid addition Bentonite clay
adsorption
Chlorine oxidation X
Hydrogen peroxide
oxidation X
Alum coagulation X
Ferric chloride coagula-
tion X
Polymer coagulation X
Extraction X X
XAD-2 resin adsorption X
XAD-4 resin adsorption X
Bentonite clay adsorption X
Polymer coagulation X
XAD-2 resin adsorption X
XAD-2 resin adsorption X
XAD-4 resin adsorption X
XAD-4 resin adsorption X
XAD-4 resin adsorption X
Due to differing wood preserving processes and chemicals at these two
facilities, wastewater characteristics varied substantially. As a result,
treatment techniques applicable to the wastewaters from one facility were not
necessarily transferable to the other. Therefore,, results of the treatability
studies for each facility are presented in the order of type of treatment in-
vestigated, as in Tables 2 and 3.
The primary pollutants of concern in these studies were phenol and the
chlorinated derivatives thereof. Total phenols were measured by a modifica-
tion of the Lowry procedure, and chlorinated phenols were measured by gas
chromatography. Appendix B gives specific analytical procedures.
INVESTIGATIONS AT A WEST COAST FACILITY
The wood preserving facility located on the west coast uses the boul-
tonizing process of wood preparation and both organic and inorganic chemicals
to impart preserving and fire retardency properties to the wood products
processed. The resultant wastewater volumes approximating 10,000 gpd, are
subjected to treatment using the following processes:
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o wastewater storage/flow equalization;
o phase (free oil) separation employing a Lamella separator;
o chemical coagulation;
o filtration employing paper cartridge filters;
o ultrafiltration; and
o hyperfiltration (reverse osmosis).
The above treatment procedure was intended to remove all organic and in-
organic pollutants from the wastewater, so that the resultant water could be
used as boiler feed water. The pollutants separated from the wastewater were
to be burned in the facility's boiler, thereby recovering potential energy.
Due to problems with membrane fouling, the latter two unit operations were not
continuously operative throughout the treatability studies at this facility.
The following subsections describe the studies undertaken at this fa-
cility.
Acid Addition
Preliminary investigations indicated that alteration of the wastewater's
pH through the addition of concentrated sulfuric acid directly to the waste-
water with constant mixing resulted in the formation of particulate matter
that could be readily removed by filtration through Whatman No. 41 paper (mean
pore diameter = 0.25 microns). Table 4 presents typical results of pH ad-
justment to a value of 2 and subsequent filtration on both total phenol (as
2,4-dichlorophenol) and pentachlorophenol concentrations.
TABLE 4. ACID ADDITION AND FILTRATION
Total phenol,* mg/1 Pentachlorophenol, mg/1
Sample description Raw Treated % Removal Raw Treated % Removal
Raw waste
Lamella effluent
UF filtrate
9,800
1,300
2,500
8,400
1,300
2,300
14
0
8
14
6
40
12
4
16
14
33
60
*as 2,4-dichlorophenol
There was indication that pH adjustment to 2 may be excessive; additional
laboratory studies have shown that the solubility of pentachlorophenol at a pH
of 3.7 and at 22°C approximates 15 mg/1. With raw wastewater pentachloro-
-14-
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phenol concentrations of 80 to 100 mg/1, reductions in excess of 80 percent
were realized after mild acidification to pH 2 to 4, and filtration. This was
presumably a solubility phenomena.
Chemical Coagulation
Coagulation studies using a Phipps and Bird jar test apparatus were
conducted using a rapid mix time of one minute, a flocculation time of 10
minutes, and a settling time of one hour. The resultant supernatant samples
were then filtered through Whatman No. 41 paper prior to analysis. Optimum
conditions using alum as the coagulant were a pH of 6.0 and a concentration of
150 mg/1; the optimum conditions for ferric chloride were a pH of 8.0 and a
concentration of 300 mg/1. Typical results on the coagulation of the Lamella
separator effluent, as shown in Table 5, indicate the effectiveness of both
alum and ferric chloride for the reduction of both total phenol and penta-
chlorophenol. Based on the limited testing it was noted that as the penta-
chlorophenol concentration decreased, the removal efficiency increased.
TABLE 5. TYPICAL COAGULATION STUDY RESULTS
Coagulant
Total phenol,* mg/1 Pentachlorophenol, mg/1
Raw Treated % Removal Raw Treated % Removal
Alum
Alum
Ferric
Ferric
4,600
300
chloride 4,600
chloride 430
4
N
4
N
,200
.A.
,250
.A.
9 12
' 20
8 12
90
.5
.0
.5
.0
5
10
3
70
.0
.0
.0
.0
60
50
76
.22
*as 2,4-dichlorophenol
N.A. - not analyzed
Chemical Oxidation
Oxidation of the organics in the wastewater was investigated using sodium
hypochlorite as the oxidant. To achieve a slight chlorine residual after 30
minutes.of reaction, the applied dose, as chlorine, approximated 3,000 mg/1.
Such a dose usually reduced the total phenol concentration in Lamella separ-
ator effluent samples by approximately 70 percent (from 10,700 to 3,000 mg/1),
and the pentachlorophenol concentration by 99 percent (from 6.0 to less than
0.05 mg/1). The high oxidant demand of the wastewater was felt to be of
sufficient magnitude to terminate further chemical oxidation studies.
-15-
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Extraction
Solvent extraction experiments were undertaken using a 4:1 sample:solvent
(v/v) ratio. Lamella separator effluent samples were extracted with various
organic solvents by rapid shaking in a separatory funnel for 30 seconds,
followed by quiescent phase separation. Table 6 presents results of these
studies.
TABLE 6. EXTRACTION STUDY RESULTS
Total phenol.* mg/1 Pentachlorophenol. mg/1
Extractant Raw Treated % Removal Raw Treated % Removal
1,1,1-Trichloro-
ethane
Isobutyl alcohol
Carbon tetrachloride
Kerosene
Freon 113
Ethyl acetate
1,300
1,300
1,300
1,600
1,600
1,600
500
80
800
1,450
1,350
250
62
94
38
9
16
84
6.0
6.0
6.0
16.0
16.0
16.0
2.0
N.A.
N.A.
15.0
20.0
6.0
67
-
-
6
-
63
*as 2,4-dichlorophenol
N.A. - not analyzed
Although substantial reductions in both total phenol and pentachloro-
phenol were realized with certain extractants, additional studies were not
undertaken because of the high solubility of these solvents in water.
Resin Adsorption
Adsorption studies using Rohm and Haas Company's XAD-2 polymeric resin
were undertaken on Lamella separator effluent. Resin columns with a height to
diameter ratio of four were used in these studies and the wastewater was
passed through the columns at a rate of 0.1 bed volumes per minute. Five bed
volumes of wastewater were applied during each trial. Results were usually-a
reduction in total phenol concentration of 98 percent (from 4,600 to 100
mg/1), and a pentachlorophenol reduction in excess of. 99 percent (from 12.5 to
less than 0.05 mg/1).
-16-
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The resin was reused after regeneration with isopropyl alcohol. Regen-
eration was at a rate of 0.3 bed volumes per minute, and a total volume of
three bed volumes of isopropyl alcohol was used per regeneration.
Acid Addition/Chemical Oxidation
Chemical oxidation of the organics in Lamella separator effluent which
had been subjected to pretreatment by the acid addition process was also
investigated. Both sodium hypochlorite and hydrogen peroxide were investi-
gated as oxidizing agents. Chlorine demand of the wastewater, after 30 minutes
of reaction, approximated 3,000 mg/1, and hydrogen peroxide, 5,000 mg/1.
Table 7 presents typical results of pH adjustment to a value of 2 and subse-
quent chemical oxidation.
TABLE 7. COMBINED ACID ADDITION PRETREATMENT/CHEMICAL OXIDATION RESULTS
'Total phenol,* mg/1- Pentachlorophenol, mg/1
Chemical oxidant Raw** Treated % Removal Raw Treated % Removal
Sodium hypochlorite
Hydrogen peroxide
10
10
,700
,700
3
11
,000
,600
72
6.
6,
.0
.0
6.
4.
0
5
0
25
*as 2,4-dichlorophenol
**before pH adjustment
Comparison of the results presented in Table 7 with those presented for
individual treatment by either acid addition or chemical oxidation indicates
no benefit to combining these two methods of wastewater treatment.
Acid Addition/Coagulation
Coagulation of Lamella separator effluent that had been subjected to
pretreatment by the acid addition process previously described was also in-
vestigated. Both alum and ferric chloride were employed as coagulants.
Optimum alum dose approximated 150 mg/1 at a pH of 6.0. For ferric chloride,
the optimum dose was 300 mg/1 at a pH of 8.0. Table 8 presents results of
these studies.
-17-
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TABLE 8. COMBINED ACID ADDITION PRETEEATMENT/COAGULATION RESULTS
Total phenols,* mg/1 Pentachlorophenol, mg/1
Coagulant Untreated Treated % Removal Untreated Treated % Removal
Alum 4,700 5,400 - 12.0 3.0 75
Ferric chloride 4,700 4,300 6 12.0 5.0 58
*as 2,4-dichlorophenol
Comparison of the results presented in Table 8 with those presented in
Tables 4 and 5 indicates an increase in pentachlorophenol removal when the two
processes are combined.
Acid Addition/Extraction
Extraction of Lamella separator effluent which had been subjected to
pretreatment by the acid addition process was also investigated^ The ex-
traction technique employed was as previously described, and results' of these
studies are as follows:
TABLE 9. COMBINED ACID ADDITION PRETREATMENT/EXTRACTION RESULTS
Total
phenol,* mg/1
Extractant Untreated Treated
1,1,1-Trichloro-
e thane
'Isobutyl alcohol
Carbon tetra-
chloride
Kerosene
Freon 113
Ethyl acetate
1,300
1,300
1,300
1,600
1,600
1,600
550
100
800
1,400
1,400
N.D.
% Removal
58
92
38
13
13
>99
Pentachlorophenol ,
Untreated Treated
6.0 2.0
6.0 N.A.
6.0 N.A.
20.0 10.0
20.0 12.0
20.0 <1
mg/1
% Removal
67
-
_
50
40
• >95
*as 2,4-dichlorophenol
-18-
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Comparison of the results presented in Table 9 with those presented in
Table 6 indicates supplemental removal can be realized for certain extractants
if the wastewater is first subjected to acid addition treatment.
Acid Addition/Adsorption
Pretreatment of Lamella separator effluent with the acid addition process
followed by treatment with XAD-2 resin was also investigated. Greater than 99
percent removal of total phenols and pentachlorophenol was realized with this
combined process. Wastewater subjected to this treatment contained 4,700 mg/1
total phenols and 12.0 mg/1 pentachlorophenol.
Coagulation/Adsorption
XAD-2 adsorption of Lamella separator effluent pretreated by alum and
ferric chloride coagulation was also investigated. Coagulation conditions
were as previously reported, and Table 10 presents results of these efforts.
TABLE 10. COMBINED COAGULATION/ADSORPTION RESULTS .
Total phenol,* mg/1 Pentachlorophenol, mg/1
Coagulant Untreated Treated % Removal Untreated Treated % Removal
Alum
Alum
Ferric
4,200
5,400
chloride 4,300
N.D.
300
300
>99
94
93
5.0
3.0
3.0
N.D.
N.D.
N.D.
>99
>99
>99
*as 2,4-dichlorophenol
N.D. - none detected
Comparison of these results with those presented for adsorption alone or acid
addition/adsorption combined treatment where removals were already greater
than 99 percent indicates no supplemental removal of either total phenol or
pentachlorophenol.
INVESTIGATIONS AT A SOUTHERN FACILITY
Wood preserving at the southern facility was undertaken with organic
compounds, primarily pentachlorophenol. The wood is preconditioned using the
steaming process whereby the wood is steamed to prepare it for preservative
impregnation. Production of the preserved product results in the generation
of approximately 10,000 gpd of wastewater. The wastewater is subjected to
free oil removal before it is conveyed to a storage/evaporation pond. Some-
times discharge from this pond enters the POTW system.
-19-
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The following subsections describe the studies undertaken at this fa-
cility.
Acid Addition
Acid addition studies similar to those conducted at the west coast facil-
ity were conducted on the wastewaters from this facility. Upon decreasing the
pH of the wastewater by sulfuric acid addition, the formation of colloidal
matter was noted. Filtration through Whatman No. 41 paper would not remove
this material; however, the material could be removed by filtration of the
acidified sample through Gelman Type AE paper. The Gelman type AE paper has a
mean pore diameter of 0.45 microns, whereas the Whatman type 41 has a mean
pore diameter of 0.25 microns. Results of these acid addition/ Gelman paper
filtration studies are presented in Table 11.
TABLE 11. ACID ADDITION STUDY RESULTS
pH
Pentachlorophenol, mg/1
Trial
Initial
Final
Untreated
Treated
% Removal
1
2
3
6.0
6.0
6.0
2.0
2.0
4.0
50
128
128
4.5
10.0
7.0
91
92
95
The above data indicate a substantial reduction in pentachlorophenol
through pH adjustment.
Biological Treatment
Biological treatment (batch type) studies used three 50-gal aerobic
reactors which were operated on a 24-hr fill and draw basis. Wastewater
containing approximately 35 mg/1 pentachlorophenol was added to the bioreac-
tors according to the following schedule:
Reactor"
A
B
C
Volume added daily, gal
Wastewater
25
20
15
Tap water
0
5
10
Total
25
25
25
-20-
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Supplemental nutrients were added, as required, to insure a trace con-
centration in the supernatant withdrawn from the three bioreactors each day.
MLVSS in the bioreactors increased during the study from an average of 610 to
1,735 mg/1.
After a suitable period of bioacclimation, more in-depth sample analyses
were performed, and Table 12 presents certain results thereof.
All bioreactors were degrading certain constituents in the wastewater, as
evidenced by both COD removal and oxygen uptake rate measurements. On the
other hand, the pentachlorophenol data indicate a lesser amount of removal.
The predominant removal mechanism seems to be adsorption on the biofloc and
not biodegradation since total pentachlorophenol levels prior to settling
remained constant. This phenomenon is evidenced by the increasing effluent
concentrations with respect to time; decreasing the mass of pentachlorophenol
in the bioreactor feed tended only to postpone the time for saturation of the
biomass, and not prevention of its occurrence.
Chemical Coagulation
A number of jar tests were-undertaken using alum, ferric chloride, cati-
onic polymers, and anionic polymers. Following settling the supernatant was
filtered through Whatman No. 41 paper. These chemical coagulation studies did
not lead to any measurable reduction in the pentachlorophenol content of this
wastewater.
Extraction
At this facility, pentachlorophenol is dissolved in an 85:10 mixture of
No. 2 fuel oil and still bottoms from the production of amyl alcohol. Batch
solvent extraction studies using No. 2 fuel oil alone, and the 85:10 mixture
were undertaken. Wasterextractant volumes were constant at 4:1, and the
results for two sets of tests are presented in Table 13.
-21-
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TABLE 12. BIOLOGICAL TREATMENT RESULTS
Reactor/
date
Reactor A
5/28
5/29
5/31
6/2
6/4
6/5
Reactor B
5/28
5/29
5/31
6/2
6/4
6/5
Reactor C
5/28
5/29
5/31
6/2
6/4
6/5
0 Uptake
(mg/l/hr)
11.0
6.0
20.0
48.0
33.6
22.0
10.8
6.0
31.5
27.0
30.0
32.0
16. 0
9.6
20.0
22.0
23.0
23.0
0 (mg)
hr/gr/MLVSS
12.6
5.5
13.6
33.6
18.8
14.9
39.3
5.7
22.5
18.8
17.2
17.3
23.5
9.1
12.0
13.3
12.0
12.2
MLVSS*
(mg/1)
870
1,100
1,470
1,430
1,790
1,480
275
1,060
1,400
1,440
1,740
1,850
680
1,050
1,660
1,660
1,910
1,880
COD, (mg/1)
Raw
3,920
3,475
3,275
4,055
N.A.
3,815
1,080
2,780
2,620
3,245
N.A.
3,050
1,405
2,085
1,965
2,435
N.A.
2,290
Final
755
1,080
1,325
N.A.
1,970
N.A.
1,030
1,080
1,365
N.A.
950
N.A.
975
920
1,000
N.A.
1,075
N.A.
Pentachlorophenol
(mg/1)
Raw
37
30
N.A.
N.A.
30
35
24
24
N.A.
N.A.
24
28
35
30
N.A.
N.A.
18
21
Final
0.27
0.15
0.71
18.0
26.0
25.0
0.58
0.95
0.83
0.46
6.60
13.0
0.19
0.25
0.26
0.60
4.50
8.90
N.A. - not analyzed
*Mixed liquor volatile suspended solids.
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TABLE 13. SOLVENT EXTRACTION RESULTS
Pentachlorophenol, mg/1
Extractant Untreated Treated % Removal
No. 2 Fuel oil
85 : 10 mixture
45
45
1.2
0.3
97
99
The 85:10 mixture of No. 2 fuel oil and amyl alcohol still bottoms yielded
a higher level of treatment than No. 2 fuel oil alone.
Adsorption
Resin adsorption studies were also undertaken using Rohm and Haas Com-
pany's XAD-4 nonionic resin, using a Phipps and Bird jar test apparatus. The
XAD-4 resin was chosen for the southern facility as compared to the XAD-2 used
at the west coast facility. The XAD-4 has comparable porosity and capacity,
but the pore diameter is smaller. The investigators thought that there would
be some selectivity towards pentachlorophenol with the XAD-4 and thus increase
the capacity. Initial investigations studied the addition of the resin dir-
ectly to the wastewater. No apparent reduction in pentachlorophenol concen-
tration occurred after 1 hour of reaction time in the presence of 15 grams of
resin per liter of wastewater. Subsequent studies were conducted in which the
resin was added at 10 g/1 and the reaction time was varied. The results of
this study are presented in Table 14.
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TABLE 14. XAD-4 RESIN ADSORPTION RESULTS
Run no.
1
2
3
4
5
6
Contact time
(hrs)
24
24
23
96
20
44
Pentachlorophenol (mg/1)^
Untreated
70
35
58
58
17
17
Treated
1.4
1.9
2.0
9.0
12.0
5.2
% Removal
98
95
97
84
29
69
In all cases except Run No. 5, removal of pentachlorophenol was 69 per-
cent or greater. Regression analysis showed no significant relationship
between either contact time and percent removal or input concentration and
percent removal.
Adsorption of pentachlorophenol in the wastewater onto bentonite clay was
also investigated. Before the pH of the wastewater was adjusted, the bento-
nite stayed in suspension, and therefore this method of individual treatment
was not pursued.
Alum/Polymer Coagulation
Limited coagulation trials were conducted using combinations of alum and
polymers, followed by solids separation. These tests were conducted at the
investigators' suggestion, following discussions with chemical suppliers after
the studies at a west coast mill. This type of treatment provided less re-
moval than other techniques and, therefore subsequent investigations were
discontinued.
Acid Addition/Polymer Coagulation
As was noted, the addition of acid to the raw wastewater induced the
formation of colloidal material which had an associated pentachlorophenol
content. Attempts to coagulate this colloidal material with an anionic poly-
mer had limited success. A 46-percent pentachlorophenol reduction was real-
ized, from 70 to 38 mg/1, when 4 mg/1 of polymer was added to a wastewater
-24-
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sample at a pH of 4.0. Only a pin floe could be developed, and the floe had a
tendency to float rather than settle.
Acid Addition/Extraction
Extraction of samples subjected to acid addition pretreatment was also
investigated. The methodologies and extractant materials for these studies
were as previously described. Table 15 presents typical results of this
combined treatment technique.
TABLE 15. ACID ADDITION/EXTRACTION RESULTS
Pentachlorophenol, mg/1
Extractant pH Untreated Treated % Removal
No. 2 Fuel oil
85:10 mixture
4
4
45
45
0.5
0.2
99
>99
No. 2 fuel oil cosolvent
Comparison of these data with those presented in Table 13 indicate only a
slight increase in pentachlorophenol removal over that achieved by extraction
alone.
Acid Addition/Adsorption
A limited number of trials were conducted in which acid pretreated waste-
water was also subjected to XAD-4 adsorption. A pH of 4 in the pretreatment
step led to'a final effluent pentachlorophenol concentration ranging from 0.4
to 1.1 mg/1, independent of the concentration present in the raw wastewater.
A combination of acid pretreatment/bentonite clay adsorption also yielded
positive results since the lower pH of the waste not only allowed for adsorp-
tion of the pentachlorophenol onto the clay, but also, the subsequent gravity
phase separation of the clay from the wastewater. Results typical of this
type of treatment are presented in Table 16.
-25-
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TABLE 16. ACID ADDITION/BENTONITE CLAY ADSORPTION
Pentachlorophenol, mg/1
Trial no. Untreated Treated % Removal
1 26
2 33
3 35
4 50
5 50
6 50
7 58
2.6
4.1
3.4
7.0
5.0
6.3
5.0
90
88
90
86
90
87
91
The above results were achieved at optimum conditions of a pH of 4.0 and
a bentonite clay concentration of 2 g/1. At these conditions, rapid settling
occurred. Reductions in pentachlorophenol concentration following solids
removal averaged 85 to 90 percent in 7 trials. Acidification, bentonite clay
adsorption, solids removal and subsequent adsorption on XAD-4 resin reduced
pentachlorophenol levels to less than 1 mg/1 in.13 trials, as reported subse-
quently .
Coagulation/Adsorption
XAD-4 resin adsorption was also tried in conjunction with alum and poly-
mer coagulation, with limited success. The minimum pentachlorophenol concen-
tration obtained with this combination of treatment techniques was 1.7 mg/1.
This was deemed inadequate and further investigations in this area were dis-
continued.
Acid Addition/Coagulation/Adsorption
One study was completed which involved acid addition to a pH of 4.0,
coagulation with 4 mg/1 of an anionic polymer, and XAD-4 adsorption of the
supernatant. Raw waste pentachlorophenol concentration was 70 mg/1 and the
final treated effluent, 1.7 mg/1. Resin dose approximated 10 g/1 and reaction
time, 24 hours.
-26-
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Acid Addition/Bentonite Adsorption/XAD-4 Adsorption
To insure a high level of treatment, studies involving acid addition,
bentonite clay adsorption, and finally XAD-4 adsorption were undertaken. The
optimum conditions established were:
1. pH adjustment to 4.0 with sulfuric acid.
2. Bentonite addition at 2 g/1;
a. 30 seconds rapid mix;
b. 30 minutes flocculation;
c. 60 minutes settling; and
d. decant supernatant.
3. XAD-4 addition at 10 g/1;
a. 24 hour mixing;
b. 5 minutes settling; and
c. decant supernatant.
Table 17 gives results of this three-phased treatment approach. The
average effluent concentration from this process was 0.21 mg/1 pentachloro-
phenol.
Further work on this process indicated that the XAD-4 resin dose could be
reduced to about 3 g/1 without substantially altering the effluent quality
reported above.
XAD-4 Resin Regeneration
Spent XAD-4 resin was found to be effectively regenerated using the 85:10
mixture of No. 2 fuel oil and amyl alcohol still bottoms used at this facility
for dissolving pentachlorophenol prior to its use in the wood preserving
process. Regeneration was accomplished using a 1:4 regenerant to resin volu-
metric ratio and a reaction time of one hour. Table 18 indicates the levels
of regeneration' achieved.
-27-
-------
TABLE 17. ACID ADDITION/BENTONITE ADSORPTION/XAD-4 ADSORPTION
Pentachlorophenol, mg/1
Trial no.
1
2
3
4
5
6
7
8
9
10
11
12
13
Untreated
33
50
50
50
58
58
58
58
58
10
58
35
26
Treated
0.20
0.08
0.05
0.22
0.06
0.36
0.75
0.06
0.05
0.10
0.06
0.55
0.17
% Removal
>99.
>99.
>99.
>99.
>99.
• >99.
>98.
>99.
>99.
>99.
>99.
>98.
>99.
-28-
-------
TABLE 18. XAD-4 RESIN REGENERATION
Trial No.
1
2
3
4
5
6
Pentachlorophenol
Adsorbed, g/g Recovered, g/g
2.2
2.2
2.2
2.2
2.2
2.2
1.6
1.5
1.5
1.3
1.6
1.3
Regeneration
Efficiency (%)
73
68
68
59
73
59
Of the 2.2 grams of pentachlorophenol adsorbed per gram o.f resin, an
average of 62 percent could be recovered and reused, if desired, in the wood
preserving process.
-29-
-------
SECTION 6
SELECTION OF TREATMENT ALTERNATIVES
It must be emphasized that the characteristics of wood preserving waste-
waters are extremely variable. With such variance, it is difficult to identi-
fy one specific treatment process which can be applied uniformly across the
industry. Two batch treatment processes, however, evolved from this study
which were capable of, consistently yielding a highly treated wastewater.
To allow for optimum removal of pollutants, the wastewaters from the wood
preserving processes must first be subjected to: 1) free oil separation in a
Lamella-type separator; and 2) wastewater flow equalization. For the purposes
of estimating capital and operating costs, wastewaters from a typical wood
preserving facility were approximated and are presented in Table 19.
TABLE 19. TYPICAL WOOD PRESERVING FACILITY WASTEWATER CHARACTERISTICS
Volume 10,000 gpd
Temperature 20 to 25°C
pH 5.0 to 5.5
Penta chlo ropheno1
Average 3.6 Ib/day (43 mg/1)
Peak 10.7 Ib/day (129 mg/1)
The following subsections describe the two recommended batch treatment
processes and the associated capital and operating costs.
Proposed Process No. 1: Acid Addition/Bentonite Adsorption/XAD-4 Adsorption
Proposed batch treatment process no. 1 involves the following operations
following free oil separation and wastewater flow equalization:
1. Wastewater pH adjustment to 4.0+ using sulfuric acid. The require-
ment approximates 0.4 gal of 66° Baume sulfuric acid per 1,000 gal
of wastewater.
•30-
-------
2. The addition of 15 to 20 Ib of bentonite clay per 1,000 gal of
wastewater. Maintain suspension of the clay in the wastewater for
30 minutes with mixing; then allow gravity separation to occur for 1
hour. Remove clay sludge from bottom of reactor by pumping.
3. The addition of 25 Ib of XAD-4 resin to the acidic bentonite treated
wastewater. Maintain resin in suspension for 12 hr with mixing;
then pass wastewater-resin mixture over a sidehill screen for resin
separation.
4. Neutralize, the wastewater to a neutral pH value prior to discharge
to a POTW for further treatment.
The resin, after sidehill separation, is approximately 50-percent water
(w/w) and will require drying before regeneration. This can be accomplished
by using a vibratory fluid bed-type dryer. After drying, the resin is to be
regenerated using a 1:4 resin-to-regenerant ratio (v/v), the regenerant being
a mixture of No. 2 fuel oil and a co-solvent such as amyl alcohol still bottoms
After one hour of mixing the resin/regenerant mixture should be conveyed to
the sidehill screen for resin separation. The resin is to be stored until
required for reuse while the spent regenerant will be returned to the wood
preserving process for either reuse or disposal.. This system is graphically
depicted in Figure 2.
Table 20 presents estimated construction and operating costs (September
1979) for the 10,000 gpd treatment system utilizing acid addition, bentonite
adsorption, and XAD-4 resin adsorption processes. Based on an equipment life
of 20 years and an interest rate of 10 percent,,the equivalent uniform annual
cost was.calculated to be approximately $20,000.
Proposed Process No. 2: Acid Addition/Extraction
Proposed batch treatment process No. 2 involves the following operations
following free oil separation and wastewater flow equalization.
1. Wastewater pH adjustment to 4.0+ 0.1 with sulfuric acid, require-
ments approximating 0.4 gal of 66° Baume sulfuric acid per 1,000 gal
of wastewater.
-31-
-------
COAGULATION/ADSORPTION PROCESS FLOW DIAGRAM
LO
NJ
OIL
SEPARATION
COAGULATION
a
ADSORPTION
BENT.
HgSO,
NoOH
BENTONITE
SLUDGE
REGENERANT
SPENT
REGENEKA
HYDRO- SEIVE
RESIN
REGENERATION
FIGURE 2
-------
TABLE 20. PROPOSED PROCESS NO. 1 ESTIMATED COSTS
Construction costs
Site work $ 2,000
Mechanical 81,100
Structural 43,200
Electrical 8,100
Engineering, administration,
contingencies 33,600
Total $168,000
Annual operating expenses
Amortization $ 20,000
Labor 14,000
Power* 800
Chemicals 5,200
Total $ 40,000/yr
*Power - $0.05/kWh
2. The addition of 250 gal of extractant per 1,000 gal of.wastewater, a
typical extractant being No. 2 fuel oil and a co-solvent such as
amyl alcohol still bottoms. Mix the wastewater and the extractant
for one hour; then allow phase separation to occur for about two
hours.
3. Decant the spent extractant and return to the wood preserving pro-
cess for either reuse or disposal.
4. Neutralize the treated wastewater to a neutral pH .prior to discharge
to a POTW for further treatment.
Table 21 presents estimated construction and operating costs (September
1979) for a 10,000 gpd treatment system utilizing acid addition and extraction
processes. Based on an equipment life of 20 years and an interest rate of 10
percent, the equivalent uniform annual cost of this system was calculated to
be approximately $24,000.
-33-
-------
TABLE 21. PROPOSED PROCESS NO. 2 ESTIMATED COSTS
Construction costs
Site work $ 1,600
Mechanical 57,300
Structural 34,200
Electrical 8,500
Engineering, administration, &
contingencies 25,400
Total $127,000
Annual operating expenses
Amortization $ 15,000
Labor 5,300
Power* 300
Chemicals 3,000
Total $ 23,600
*Power - $0.05/kWh
**Chemical cost for fuel oil required above current use only.
-34-
-------
SOLVENT EXTRACTION WITH OIL SEPARATION
PROCESS FLOW DIAGRAM
OIL
SEPARATION
SOLVENT
EXTRACTION
FLOW
EQUALIZATION
-9-
SOLVENT
SOLVENT
-M-
SOLVENT HtS°4
•M-
-M-
H2S04
AUX. RECYCLE
No OH
NoOH
TREATED
EFFLUENT
FIGURE 3
-------
REFERENCES
1. National Resources Defense Council et al. versus Russell Train, United
States District Court for the District of Columbia, (8 ERC 2120), June 7,
1976.
2. Ingols, R.S., et al. "Biological activity of Halophenols." Journal of
Water Pollution Control Federation, 45(2):359-364, 1973.
3. Development Document for Effluent Limitations Guidelines and Standards
for the Timber Products Processing Point Source Category. EPA 440/1-79/
0230, U.S. Environmental Protection Agency, Washington, D.C., 1979. 427
pp.
-36-
-------
APPENDIX A
REVIEW OF LITERATURE ON PHENOLIC TREATMENT TECHNOLOGIES
1.0 BIOLOGICAL OXIDATION
Numerous investigators have demonstrated the feasibility of biologically
oxidizing phenols (1, 2, 3, 4, 5). In the laboratory, Radhakrishnan and Sinha
Ray (3) found that the bacteria B. Cereus is capable of completely metabol-
izing phenol at a calculated detention time of 26 hours. The system para-
meters developed for continuous flow cultures were:
Heterogeneous metabolism rate 0.0022 mg phenol/hr/mg bacteria
True yield coefficient
81.8%
Maximum growth rate @40°C
0.628/hr
Minimum N to phenol ratio
1:10
Kirsch and Etzel (1) had similar success when biodegrading pentachlorophenate.
They found that up to 68 percent of the radioactive pentachlorophenate added
to an acclimated culture was recovered as radioactive carbon dioxide in 24
hours.
Kostenbader and Flecksteiner (2) have reported on the Bethlehem Steel
Corporation's experience with biological oxidation of coke plant wastewaters
at their Bethlehem, Pennsylvania facility. Their treatment process is shown
schematically on Figure 4. The system was first put on line in September 1962,
and it was learned that existing aeration capabilities limited the plant's
capacity to 2,700 Ib of phenol/day. As a result, they increased the aeration
capacity in 1964, which in turn increased the plant's treatment capacity to
greater than 4,000 Ib of phenol/day. For the next 2-1/2 years, the plant
-37-
-------
processed an average daily flow of 112,000 gallons at a phenol concentration
of 1,390 mg/1 (1,300 Ib phenol/day). The system consistently removed 99.9
percent of the influent phenol which resulted in less than 0.1 mg/1 in the
effluent. It should be noted, however, that the plant was operating at ap-
proximately 35 percent of its design phenol removal capacity.
Miller (4) reported similar results when treating wastes from a cross-tie
creosoting operation. The treatment scheme for this facility, as shown on
Figure 5, consisted of nutrient addition, aeration, clarification, and land
application. Actual plant operating data are shown in Table 22. Evaluation
of this data clearly shows that 99 percent phenol reductions consistently
achieved by biological treatment.
There was also one report of a system treating a combination of municipal
sewage and a herbicide waste high in BOD and chlorophenols.(6) This system
was unique in that a completely mixed aerated lagoon was installed between an
existing conventional activated sludge treatment facility and existing stabil-
ization ponds. The purpose of the aerated lagoon was to avoid hydraulic
overloading of the conventional plant by accepting all raw wastewaters in
excess of the conventional plant's design capacity and reduce the BOD to the
stabilization ponds. The conclusions of this study were essentially that the
organisms present in domestic sewage will remove complex phenolic compounds
when sufficient biomass and nutrients are available. The phenolic removals
actually achieved are shown graphically on Figures 6 through 10. It is inter-
esting to note that the joint treatment of chlorophenolic waste and domestic
sewage was reported to produce essentially the same biological data as a
system treating only domestic sewage.
The chemical industry has also had experience with biological oxidation
of phenols as evidenced by the work of Capestany et al(7) Wastewater from
this facility was found to contain 1,000 mg/1 of phenol. After reviewing past
work concerning phenol removal, Capestany concluded that such wastes can be
treated biologically with an acclimated, nutrient-supplemented, activated
sludge system. The same conclusion was reached by Keith, (8) based on his
work with two Georgia Kraft container board mills.
Capestany's 'initial pilot plant work found that adequate removals were
obtained only when phenol feed concentrations were less than 250 mg/1. Sub-
sequent investigations, however, revealed that sulfate deficiencies were
limiting the biological oxidation process. The pilot plant was then re-
started using the process parameters shown in Table 23. The effluent phenol
concentration immediately dropped below 1.0 mg/1 and remained there for the
duration of the pilot study. As a result of this success, the full scale
treatment facility shown on Figure 11 was constructed in 1975. The plant
design parameters are. given in Table 24. Since going on line, this facility
has had great difficulty in maintaining adequate mixing as evidenced by the
changing of aerator impellers, the installation of draft tubes, and the in-
stallation of a supplemental compressed air mixing system. Even so, the plant
-38-
-------
BIOLOGICAL OXIDATION PROCESS SCHEMATIC
FOR COKE PLANT WASTES (2)
WAL
STEAM
FRESHWAL
PHOSPHORIC
AGIO
BPW
DILUTION WATER
WASTE SLUDGE TO
SEWAGE PLANT
ACTIVATED SLUDGE
AERATION SYSTEM
260,000 go I.
35,000 cu. ft.
OXYGEN FROM SURFACE AERATORS
EFFLUENT TO STORM SEWER
FIGURE 4
-------
BIOLOGICAL OXIDATION PROCESS SCHEMATIC
FOR WOOD PRESERVING WASTES (4)
A VAPOR DRYING OUf>LEX AERATION
... ^ . EFFLUENT TANK 8 CLARIFIER
DECANTER S^A'1
"^S >»-
^s^ EQUALIZING Q
• TANK *"
^f
B CREOSOTE / B -1
*" DECANTER (4 -DAYS RETENTION) I
- -- EXCESS '
C SEPTIC C-1 CHLORINE N8P
TANK CELL SOLUTION
' A-1 B-1 C-1 D
LAGOONS
. ^ 1/4 ACRE
>. I/5AC"F ^
^^" 1/4 ACRE
SLUDGE T
IRRIGATION
8 SOAK FIELD
(NO RUNOFF)
E F
FLOW l0'000 2'000 l'000 13,000 13,000
-------
TABLE 22. OPERATING RESULTS, BIOLOGICAL TREATMENT OF WOOD
PRESERVING WASTES (4)
Influent Aeration tank Clarifiers Lagoon
Date of
startup
3/72
4/72
-5/72
6/72
8/72
; 2/73
3/73
5/73
9/73
11/73
Settleable Pro-
COD Phenol pH solids tozoa
2150 145 6.6 - 0
2900 - 7.0 - Yes
7.2
7.0
1850 140 7.3
1600 140 6.9 600 "
6.5
1100 80 . 7.0 - "
3200 300 7.2 900 "
6.1
Total
organic
carbon Phenol Phenol
80
80 0.7. 0.2
70 0.4 0.3
70 0.1 0.1
55 <0.1 <0.1
<.05 <.02
60
<0.5
<1,0
33
COD Phenol'
90
65
130
45 0.03
-
40 0.004
-
35
65
-
-------
200
150
100
REMOVAL OF 2,4-DICHLOROPHHNOL AND 2,4-DICHLORO-
PHENOXYACETIC ACID FROM SOLUTION IN AERATION
BASIN EFFLUENT BY CONTINUOUS AERATION (6 )
Initial Conditions;
64 mg/1 2,4-DCP
174 mg/1 2,4-D Acid
Aeration Lagoon Effluent
pH of acid-phenol mixture
adjusced to 7.00 just before
.with effluent
Temperature: 20-21°C.
Constant slow stream of air
bubbled through mixture.
Control samples same as above
without Aeration Lagoon
Effluent. Only distilled
water as solvent.
50
2.4-DCP Concentration
2,4-D Acid Concentration
Distilled Water Control
6 7 8 9 10
Time In Days
FIGURE 6
42
-------
i
200
REMOVAL OF 2 , 6-DICHLOROPHENOL AKD 2,6-DICHLORO-
PHENOXYACETIC ACID FROM SOLUTION IN AERATION
BASIN EFFLUENT BY CONTINUOUS AERATION (6 )
150
2,6-D Acid Concentration
100
Initial Conditions;
64 mg/1 2,6-DCP
178 mg/l 2,6-D Acid
Aeration Lagoon Effluent
pH of acid-phenol mixture
adjusted to 7.00 just before
mixing with effluent.
Temperature: 20-21°C.
Constant stream of air
bubbled through mixture.
Control samples same as above
without Aeration Lagoon
Effluent. Only distilled
water as solvent.
Distilled Water Control
50
2,6-DCP Concentration
J 1
J L
J LJ
789
Time in Days
10 11
II1
^ 13 14 15
FIGURE 7
43
-------
mg/1
60
REMOVAL OF 2,4,5-TRICHLOROPHENOL AND 2,4,5-TRI-
CHLOROPHENOXYACETIC ACID FROM SOLUTION IN
AERATION BASIN EFFLUENT BY CONTINUOUS
AERATION (s )
Initial Conditions:
50 mg/1 2,4,5-T Acid
.1.8. 8 mg/1 2,4, 5-TCP
Aeration Basin Effluent
pH of acid-phenol mixture adjusted to
7.00 just before nixing with effluent.
Temperature: 20-21CC.
Constant slow stream of air bubbled.
through mixture.
Control samples sane as above without
Aeration Basin Effluent. Only
distilled water as solvent.
50
40
30
20
10
I I I I I I V I J, I I I
Distilled Water Control
2,4,5-T Acid Concentration
Distilled Water Control
123456789 10
Time in Days
FIGURE 8
44
-------
mg/1
70
60
50
40
30
20
10
REMOVAL OF 2,4,6-TRICHLOROPHENOL AND
2,4,6-TRICHLOROPHENOXYACETIC ACID FROM SOLUTION IN
AERATION BASIN EFFLUENT BY CONTINUOUS AERATION (6)
Initial Conditions:
18.5mg/l 2,4,6-TC?
53.0mg/l 2,4,6-T Acid
Aeration Lagoon Effluent
pH of acid-phenol mixture
adjusted to 7.00 just before
mixing with effluent.
Temperature: 20-21°C.
Constant slow stream of air
bubbled through mixture.
Control samples same as above
without Aeration Lagoon
Effluent, 'only distilled
water as solvent.
2,4,6-T Acid Concentration
Distilled Water Control
V.U11U.LU-L «^
*— <*- ^
2,4,6-TCP Concentration
2 3 4 5 6 7 8 9 10 11 12 13 14 15
Time in Days
FIGURE 9
45
-------
90 H
CHANGE IN PENTACHLOROPHENOL CONCENTRATION IN'
AERATED SOLUTIONS IN AERATION LAGOON EFFLUENT ( 6 )
Experiment 2
Experiment 3
Experiment
5678
Time in Days
11 12
FIGURE 10
46
-------
consistently removed 99 percent of the influent phenol and 97 percent of the
influent BOD.
Halladay et al (9) extensively investigated the phenolic conversion
capabilities of 3 types of bioreactors:
1. continuously stirred (CSTBR);
2. packed bed (PBBR); and
3. fluidized bed (FBBR).
The results of these investigations are given in. Table 25. Evaluating these
results led to the following conclusions:
A. The CSTBR can treat the highest influent feed concentrations, is
relatively easy to operate, and the retention time may be varied.
It does, however, require the largest volume, is susceptible to
shocks and washouts, and is slow to recover from upsets.
B. The PBBR has higher degradation rates and lower retention times than
the CSTBR, and recovers quickly from shock loads. It does, however,
develop excess biomass which tends to stop flow when the biomass
sloughs.
C. The FBBR has degradation rates and retention times similar to the
PBBR and has low pressure drop characteristics. The FBBR does,
however, yield poor results with compounds requiring long retention
times. Solid-liquid disengagement is also difficult.
It should be noted that the lowest effluent phenol concentrations were ob-
tained with the FBBR type bioreactor.
Rotating biological contactors (RBC's) serve as yet another alternative
for the biological treatment of pulp and paper mill wastes. Egh and Mueller
(10) reported on a laboratory study whereby bleached kraft mill effluents were
tested at retention times varying between 2 and 16 hours. BOD_ removals in
all cases exceeded 90 percent. In addition, all acute toxicity to fish was
removed at retention times as short as two hours.
Ingols et al(ll), in their work with halaphenols, demonstrated that as
phenol becomes more substituted, there is an increased resistance to bio-
degradation. Figure 12 (7) diagrams how this resistance increases with both
the level of substitution and position of the chlorine atom. His results,
however, showed that in the absence of other organic sources low concentra-
tions of the simpler compounds can be degraded biologically in one to ten
days.
-47-
-------
TABLE 23. BIOLOGICAL PILOT PLANT PROCESS PARAMETERS (7)
Raw waste characteristics
Phenol
BOD
COD
pH
Nutrient ratios
BOD:N:S04
Process parameters
Retention time
Volumetric loading
MLSS
SVI
Sludge loading
Sludge production
1,000 mg/1
4,000 mg/1
6,000 mg/1
8.5
100:5:5
24 hr
3.92 Kg BOD/m3
6,050 mg/1
160
0.6 g BOD/day/g MLSS
0.3 g MLSS/day/g BOD removed
-48-
-------
SCHEMATIC OF FULL SCALE BIOLOGICAL
TREATMENT FACILITY OF CAPESTANY(7)
WASTE
NH
AERATOR
94,00090!.
DIGESTOR
206,000gol.
TO DRYING BEDS
FIGURE II
-------
TABLE 24. FULL SCALE (BIOLOGICAL) TREATMENT FACILITY
DESIGN PARAMETERS (7)
General
Flow
Influent BOD
Influent phenol
Aeration basin
Volume
Detention time
Oxygen requirements
(@5°C & 2 mg/1 residual)
Energy requirements
Clarifier
Overflow rate
Solids loading
Digester
Volume
Sludge age
Energy requirements
72,000 gpd
3,109 Ib/day
1,943 ib/day
93,000 gal
31 hr
136 Ib/hr
42/75 hp
360 gal/ft
16 lb/ft2
200,000 gal
20 days
15 hp
272,521 I/day
1,410 kg/day
881 kg/day
352,006 1
61.7 kg/hr
31.3/55.9 kW
14,656 1/m2
78 kg/m2
757,000 1
11.2 kW
-50-
-------
TABLE 25. COMPARISON OF THE GENERAL CHARACTERISTICS OF THREE BIOREACTORS (9)
Conditions
CSTBR
PBBR
FBBR
Maximum phenol degradation rate
for C. = 500 mg/liter, 0.99
conversion
l.Og of phenol/day/1
bioreactor
volume
4.7g of phenol/day/1
bioreactor
volume
8.5g of phenol/day/1
bioreactor
volume
Maximum phenol degradation rate
0.99 conversion of any feed
Maximum phenol degradation rate
any conversion
Normal effluent phenol cancan-
s'1 tration at maximum conversion
2.67g/l d
C. = 1,400 mg/1
Q* = 300 ml/h
J_i
2.67 g/1 d
C. = 1,400 mg/1
Q* = 300 ml/h
J_i
0.25-1.00 mg/1
4.7 g/1 d
C. = 500 mg/1
Q^ = 875 ml/h
Lt
6.0 g/1 d
C. =800 mg/1
Q* = 700 ml/h
L
0.25-1.00 mg/1
11.2 g/1 d
C. = 260 mg/1
Q^ = 18,000 ml/h
Li
21.2 g/1 d
C. = 240 mg/1
Q* = 42,000 ml/h
Li
0.01-0.50 mg/1
TOC reduction
for 0.99 conversion
0.90
0.90
0.95
Retention time necessary for
sizeable thiocyanate conversion
20 h
NDa
ND
Highest C. successfully degraded
Resistance to step hydraulic
shocks
Recovery from step hydraulic
shocks
1,400 mg/1
Poor
Slow
1-5 days
850 mg/1
Good
Fast
24 h
2200 mg/1
Fair
Fastest
24 h
Resistance to step organic
carbon shocks
Poor
Good
Good
-------
Conditions
Recovery from step carbon
shocks
Facility for aeration
Compatibility with degassing
TABLE 25 (cont'd)
CSTBR
Slow
1-5 days
Good
Good
PBBR
Fast
24-48 h
Fair
Fair
FBBR
Fastest
24 h
Good
Good
Not determined
C. = Feed concentration in mg/1
Q_ = Liquid feed rate in ml/h
-------
Preliminary investigations by Ashmore et al (12) also suggested that
certain dihydric phenols are resistant to bio-oxidation. This conclusion,
however, was based on intermittent phenol additions. When a study of continu-
ous treatment under steady state conditions was made, "none of the phenols
investigated showed undue resistance to attack." Table 26 shows the results
of this study. It will be noted that the degree of purification of both
monohydric and dihydric phenols was normally greater than 95 percent. Another
interesting finding was that high phenol concentrations cause filamentous
sludge bulking. Ammonium chloride was found to suppress the filamentous
growth.
-53-
-------
PHENOLIC RESISTANCE
TO BIODEGRADATION (II)
PHENOL
0-CHLOROPHENOL
2,4 DJ CHLORO PHENOL
2,4,6 TRICHLOROPHENOL
PENTACHLOROPHENOL
EC
O
Ul
a
Q
Ul
-------
TABLE 26. THE BIOCHEMICAL OXIDATION OF PURE PHENOLS
BY THE ACTIVATED SLUDGE PROCESS (12)
Permanganate value (mg/1)
Compounds used
Amounts in
influent(mg/1)
Influent
Effluent Percent
mean purification
Phenol
0-Cresol
m-Cresol
p-Cresol
1,680
1,120
1,120
1,120
1,340
1,625
1,580
1,535
17
10
8.4
6.9
99.4
99.4
99.5
99.5
Equal parts of
three creso'ls
Catechol
4 Me-catechol
3 Me-catechol
Resorcinol
Phenol
0-Cresol
m-Cresol
Catechol
3 Me-catchol
4 Me-catechol
Resorcinol
4 Me-resorcinol
5 Me-resorcinol
Quinol
Total
As above
1,120
1,400
1,400
840
1,400
Synthetic spent liquor
56.0
4.2
4.2
231.0
94.8
78.8
179.2
16.1
16.1
19.6
700.0
Synthetic spent liquor
700.0
1,580
1,875
1,570
950
2,325
9.5
21.7
55.4
120
18.4
99.4
98.8
96.5
87.4
99.2
kept in neutral solution
105
6.1
5.9
310
107
88.3
298
20.6
19.6
30.8
990
9.4
99.1
kept in alkaline solution
990 34.2 96.5
-55-
-------
REFERENCES
1. Kirsch, E.J. and J.E. -Etzel. "Microbial Decomposition of Pentachloro-
phenol." Journal of Water Pollution Control Federation 45(2):359-364,
1973.
2. Kostenbader, P.D. and J.W. Flecksteiner. "Biological Oxidation of Coke
Plant Weak Ammonia Liquor." Journal of Water Pollution Control Federation
41(2):199-207, 1969.
3. Radhakrishnan, I. and A.K. Sinha Ray. "Activated Sludge Studies with
Phenol Bacteria." Journal of Water Pollution Control Federation 46(10):
2393-2417, 1974.
4. Miller, M.D. "Exemplary Waste Treatment System." Presented at American
Wood Preservers Association Conference, 1974.
5. Thompson, W.S. "Wood Preservatives and the Environment." Presented at
Conference of American Wood Preservers Association, 1974.
6. EPA Project 12130 EGK 06/71.
7. Capestany, G.J. "The Influence of Sulfate on Biological Treatment of
Phenolbenzaldehyde Wastes." Journal of Water Pollution Control Federation
49 (2):256-261, 1977.
8. Keith, L.H. "Chemical Profiles of Kraft-Paper Mill Treated Wastewaters."
Abstract Bulletin of the Institute of Paper Chemistry, (45) 3, 1974.
9. Holladay, et al. "Biodegradation of Phenolic Waste Liquors in Stirred
Tank, Packed Bed, and Fluidized Bed Bioreactors." Journal of Water Pollu-
tion Control Federation 50(11):2573-2589, 1978.
10. Egh, L. and J.C. Mueller. "Rotating Biological Disc Treatment of Kraft
Mill Effluents." Journal of Water and Pollution Control, 113(5):25-29.
11. Ingols, R.S. et al. "Biological Activity of Halophenols." Journal of
Water Pollution Control Federation 38(4):629-635, 1966.
12. Ashmore, A.G. J.R. Catchpole, and R.L. Cooper. "The Biological Treatment
of Carbonization Effluents - Investigation into Treatment by The Acti-
vated Sludge Process." Water Research, Pergamon Press Vol. 1:605-624,
1967- (Printed in Great Britain.)
-56-
-------
2.0 FOAM FRACTIONATION
Foaming is generally considered a nuisance by the pulp and paper in-
dustry. There is benefit, however, in that foam formation tends to concen-
trate some of the pollutants of interest at the gas/liquid interface. Leach
et al reported that this process normally removes only one source of pollu-
tion, e.g., suspended solids, color, etc. Therefore, foam separation must be
used in conjunction with other unit processes to effect complete treatment.(1)
It has also been reported that foam separation, though readily applied to
bleached kraft whole mill effluent, is ineffective on newsprint and groundwood
mill effluents.(2)
Removal of pollutants in the foam fraction of effluents has been studied
for several years.(3, 4) The process requires a large gas-liquid interface
area (30 to 50 m /I) which may be met by conventional aeration systems such as
turbines, jet aerators, and/or porous diffusers. Foam removal also improves
the operating efficiency and stability of standard biological treatment sys-
tems by reducing toxicity and shock loadings.
Mueller et al (3) noted an increase from between 60 and 70 percent to
over 95 percent removal of toxicity on an activated sludge pilot plant with
upstream foam separation. The removed foam (generally 2 to 3 percent of the
influent volume) was subsequently treated by biological oxidation employing at
least three days aeration time. Rubin et al(5) noted 10 to 45 percent reduc-
tion (11 to 53 mg/1) in effluent COD values following foam separation, indi-
cating that organic compounds other than the ABS (alkyl benzene sulfonate)
under scrutiny were being removed with the foam. In addition, an increase in
effluent pH suggested that weakly acidic compounds (such as the phenol group)
were being removed preferentially.
More recently, Grieves et al (6) studied the removal of phenols from
aqueous solutions over the pH range 10 to 12. Synthetic phenol solutions were
used. Foam fractionation was reported to remove 40 percent of the phenol with
stoichiometric surfactant concentrations. Removal was found to be strongly
influenced by ionic strength.
Ng et al (4) stressed the pH dependency of foam fractionation. Detoxifi-
cation of whole mill effluents was found to be effective only at pH values
greater than 7. Temperature did not appear to have a great effect within the
range 25° to 40°C. Efficiency of the fractionation system was found to be
improved by using a two-stage system. Ng also reported that interfacial area
requirements and thus foam volumes, increased with the increase in toxic
compound concentration.
Operating costs for a foam separation facility were estimated at about
$1.78 to $2.71/ton at a 25 mgd effluent flow rate, including a biological
facility for treatment of the collapsed foam. Capital costs were estimated at
$1.0 to $1.7 million (1976). Ranges of costs represent differing foam gener-
-57-
-------
ation and collapse methods as shown in Table 27. Ng concluded that if sus-
pended solids removal is not required, use of a turbine system was the process
of choice. The capability to remove solids is part of dissolved air flota-
tion.
TABLE 27- CAPITAL AND OPERATING COSTS FOR VARIOUS FOAM
SEPARATION SYSTEMS (1976) (4) ^___
Foam separation
system
Capital
($)
Operating
$/1.000 gal. $/ton
Porous media
Turbine aeration
Dissolved air
flotation
1,201,346
1,012,546
1,664,646
6.29
5.34
8.13
2.10
1.78
2.71
-58-
-------
REFERENCES
1. Leach, J.M., J.C. Mueller, C.C. Walden. "Identification and Removal of
Toxic Materials from Kraft and Groundwood Pulp Mill Effluent," Process
Biochemistry. 10(1): 7-10, 1976.
2. Council of Forest Industries of British Columbia. "Pollution Control
Objectives of the Forest Products Industry:. 1976.
3. Mueller, J.C., J.M. Leach, C.C. Walden. "Detoxification of Bleached
Kraft Mill Effluents - A Manageable Problem." Tappi, 60(9): 135-137,
1977.
4. Ng, K.S., J.C. Mueller, C.C. Walden. "Foam Separation for Detoxification
of Bleached Kraft Mill Effluents." Journal Water Pollution Control Feder-
ation, 48(3): 458-472, 1976.
5. Rubin, E. , R. Everett, J.J. Weinstock, and H.M. Schoen. "Contaminant
Removal from Sewage Plant Effluents by Foaming." Report AWTR-5, U.S.
Dept. of Health, Education and Welfare, December 1963.
6. Grieves, R.B., W. Charewic, S.M. Brien. "Separation of Phenol from
Dilute Alkaline Aqueous Solution by Solvent Extraction, Solvent Sublation
and Foam Fractionation." Analytica Chimien Acta, 73(2): 293-300, 1974.
-59-
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3.0 SOLVENT EXTRACTION
Phenol removal by solvent extraction has been used extensively for the
treatment of refinery and coke by-product wastes.(1, 2, 3) Mulligan (2)
reported of an extraction process developed by the Jones and Laughlin Corpora-
tion which was capable of 99.7 to 99.9 percent phenol removal when treating
coke wastes. This process is shown schematically on Figure 13 and is reported
to produce an effluent containing 1 to 4 mg/1 phenol from an influent feed
containing 1,500 mg/1. Even though significant removals are obtained, _it was
Mulligan's opinion that some form of polishing treatment would be required
prior to direct discharge to a stream. This study also evaluated the effect
of feed concentration on- the cost of phenol recovery. For evaluation pur-
poses, it was assumed that the solvent had a high distribution coefficient
(low solvent to wastewater ratio) and that it was easy to strip from the
aqueous raffinate. Unfortunately the study did not include capital, mainte-
nance or labor expense, each of which significantly affects the cost of recov-
ery. The results of this evaluation are shown in Table 28. Mulligan con-
cluded that where solvents with a high distribution coefficient are available,
phenol recovery through extraction can be economical.
TABLE 28. EFFECT OF FEED CONCENTRATION
ON SOLVENT EXTRACTION PROCESS (2)
Energy consumption Solvent losses @0.15%
Phenol concen- Steam consumption Cost Solvent losses Cost
tration (%) Ib/lb phenol $/lb phenol Ib/lb phenol $/lb phenol
1.0
.0.1
0.01
5
50
500
$0.018
0.15
1.50
0.02
0.09
0.90
$0.004
0.018
0.18
Earhart et al (1) have done extensive work with the recovery of various
organic pollutants through solvent extraction. Important process parameters
are summarized below:
1. Solvent solubility should be minimal;
2. The solvent's equilibrium distribution coefficient DO should be
high (Table 29 contains experimental values for K.^ for various
solvents and solutes); „
-60-
-------
PROCESS SCHEMATIC FOR SOLVENT EXTRACTION
OF PHENOLS FROM COKE PLANT WASTEWATERS (2)
EXTRACTION
COLUMN
FEED-
SURGE TANK
1
— v
-€?
CONDENSER
3-
CONDENSE
•
PHENOL
SOLVENT
RECOVERY
COLUMN
STILL
RECYCLE SOLVENT
RAFFINATE
FIGURE 13
-------
3. The ratio KS/W should be between 1.5 and 3.0, where
K= wt fraction of solute in solvent
wt fraction of solute in water
S = mass flow rate of solvent
W = mass flow rate of water; and
4. The solvent circulation rate should be minimized.
TABLE 29. EQUILIBRIUM DISTRIBUTION COEFFICIENTS
_ FOR VARIOUS SOLVENTS (20 to 25°C) (1) _
n-Butyl Methyl Isobutyl
Solute Isobutane Isobutylene Benzene Acetate _ Ketone
Phenol
o-Cresol
M Cresol
o-Ethylphenol
0.2 0.7
4.8
2.7
__ __
2.9
16
10
63
65
—
150
__
110
--
260
__
o-Chlorophenol — — -- 290 490
When removing phenols, it has been determined that lower values of S/W
can be used with polar solvents than with volatile hydrocarbons. Unfortu-
nately, with polar solvents, there is considerable carryover in the effluent.
These solvents do, however, have a high distribution coefficient for extrac-
tion into volatile hydrocarbon solvents. As a result, Earhart et al proposed
the processes shown on Figures 14 and 15 for phenol removal. In each case, a
polar solvent such as butyl acetate is used for phenol extraction and a vola-
tile hydrocarbon suc'h as isobutane is used to remove residual butyl acetate
from the aqueous fraction. The solvents are then regenerated in- two distilla-
tion columns to isolate the recovered pollutants and recycle the solvents. A
mini-pilot plant was used to test this process for 'treating wastewater from a
lube oil refining operation. Two sets of sequential extractions with n-butyl
acetate and isobutylene were carried out at a water flow rate of 3.21 gal/hr.
Solvent flowrates for each pair of runs were:
Run No. n-butyl acetate Iso-butylene
I 0.37 gal/hr 0.55 gal/hr
H 1.11 gal/hr -0.55 gal/hr
-62-
-------
DUAL SOLVENT PROCESS SCHEMATIC
SEPARATE CYCLES (I)
LOADED P.S
PURIFIED WATER
FIGURE 14
63
-------
DUAL SOLVENT PROCESS SCHEMATIC
LINKED CYCLES (I)
WASTE
WATER
LOADED MIXED SOLVENT ^
MIXED
SOLVENT
EXTRACTOR
VOLATILE
SOLVENT
EXTRACTOR
V.S. - P.S.
SPLITTER
RECYCLE P.SS.
P.S.-POLLUTANTS
SPLITTER
POLLUTANTS
J»EC_YCL_E_ Yi£- I
^- V.S. VAPOR
HOLDING
TANK
PURIFIED WATER
FIGURE 15
64
-------
Table 30 summarizes the results of the above pilot plant studies.
Grieves et al (4) compared the relative efficiencies of solvent extrac-
tion, solvent sublation, and foam fractionation for phenol removal. Extrac-
tions with amyl acetate were found to provide 80 to 95 percent phenol removal
over a pH range of 7.0 to 10.7. Removals sharply declined when the pH was
above 11.0. Solvent sublation with amyl acetate over the aqueous phase in a
cylindrical foam separation column was found to provide removals similar to
solvent extraction. However, sublation had two distinct advantages over
solvent extraction
•1. There is no equilibrium dissolution of the solvent in the aqueous
phase.
2. It permits the use of a lower phase/volume ratio.
Lorton (3) evaluated the economics of three alternative methods of re-
moving phenols from coal gasification process condensate - biological oxida-
tion, solvent extraction, and adsorption. Of the three alternatives, solvent
extraction appeared to be the most economical. The evaluation was made using
a hypothetical flow rate and phenol concentration typical for gasification
processes producing phenols. Manufacturers of commercial processes then
developed process designs and cost estimates for use in the evaluation. The
results are given in Table 31. The recommended process, as shown on Figure
16, was a product of the Chem-Pro Equipment Corporation. This system has been
proven commercially at the Jones and Laughlin Steel Mill in Pittsburgh, Penn-
sylvania. (1, 2) Though liquid extraction was the recommended process, actual
pilot plant data should be obtained for each of the above alternatives before
making a firm selection.
-65-
-------
TABLE 30. SEQUENTIAL EXTRACTION OF LUBE-OIL REFINING WASTEWATER (1)
o>
Butyl-acetate Extraction
Concentration, ppm
Component KD
Feed Prod. ^Removal
Isobutylene Extraction
Concentration, ppm
KD Feed Prod. %Removal
Overall
% Removal
S/W for Butyl Acetate Extraction = 0.100:
Methyl Ethyl Ketone 4.6
Phenol 65
o-Cresol
ri-Butyl Acetate
TOD
COD
12
8
52
54
,200 5,900 52
,800 104 98.8
890 6.5 99.3
0 7,100
,900
,500
2.5 5,600 3,600 36
0.7 310 230 26
4.8 24 2.3 91
168 7,100 11.0 99.8
9,350
8,570
69
99.1
99.9
82
84
a
S/W for Butyl Acetate Extraction = 0.30:
Methyl Ethyl Ketone 4.6
Phenol 65
o-Cresol
n-Butyl Acetate
TOD
COD
12
8
' 52
54
,200 2,500 82
,800 77 99.1
890 4.3 99.5
0 6,800
,900
,500
2.5 2,800 1,890 33
0.7 230 190 17
4.8 18.0 2.8 84
168 6,800 15.2 99.8
5,110
4,690
88
99.3
99.9
90
91
-------
TABLE 31. ECONOMIC EVALUATION OF PHENOL REMOVAL
FROM PROCESS COMPENSATE (3)
•v
Incremental capital requirements
Extraction
1.
2.
3.
4.
5.
Initial plant investment
Chemicals & catalysts
Royalties
Startup costs
Working capital
Subtotal
base
base
base
base
base
base
Adsorption
$9,100,000
1,700,000
200,000
200,000
100,000
$11,300,000
Bio-oxidation
$22,500,000
0
0
600,000
200,000
$23,300,000
Incremental operating costs
6. Utilities base $ 500,000 $ 900,000
7. Chemicals & catalysts base 300,000 600,000
8. Labor base 100,000 400,000
9. Administration & overhead base 100,000 200,000
10. Supplies base 100,000 200,000
11. Taxes & insurance base 100.000 . 500,000
Subtotal base $1,200,000 $ 2,800,000
12. Credit for sale of base 0 (-1,100,000)
phenol byproduct
Total base $12,500,000 $27,200,000
9
**NOTE: Plant capacity is 250 x 10 Btu/day of pipeline quality gas
from western coal at a 90% stream factor
-67-
-------
CTJO
a m
"i
0 =
CHEM-PRO SOLVENT EXTRACTION PROCESS SCHEMATIC (3)
PMCI91 COMANUTI
1
r~D
ntmtr «^i
IMIMU
TOF-llll-
TO t MMMII MCV1HT W«N 0»« WILL M MriMII
itrouLiHt IN TM tot.HINT MMiifa is KMMMJ PILOT *IMI
•ILL MM we i mi LIICUHOOO or rouiiMi, MI CMH-MO H
PRELIMINARY
rxNa aiwMft
r= „ filMM MM
awm ' - .
tM/M
11* TM
MLVMT
OTU IM/HB
_- •*«* -
~Moan
tMHHUTI
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MB
'•!.«•*
\»»
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t,OIO
•oo
• 0
— " "
H*.IU
1,0(0
pwa*
CMWsrMJl
IM.OOO
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IM
»*.<••
l»
MML
MOOUCI
«.oo«
_ 100
. .._>»
*.
-------
REFERENCES
1. Earhart et al. "Recovery of Organic Pollutants via Solvent Extraction."
Chemical Engineering Progress, 73(5): 67-73, 1977.
2. Mulligan, T.J. and R.D. Fox "Treatment of Industrial Wastewaters."
Chemical Engineering, 83(22): 49-65, 1976.
3. Lorton, G..A- "Removal of Phenols from Process Condensate." U.S.
Department of Energy Contract No. EX-76-C-01-224Q October 1977, 24 pp.
4. Grieves, R.B. et al. "Separation of Phenol from Dilute Alkaline
Aqueous Solutions by Solvent Extraction, Solvent Sublation and Foam
Fractionation." Analytical Chemica Acta 73(2): 293-300, 1974.
-69-
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4.0 PHYSICAL/CHEMICAL OXIDATION
Numerous researchers have demonstrated the technical feasibility of
physical/chemical oxidation of phenols. Their work has been centered prima-
rily around use of the following oxidants:
o oxygen
o ozone
o chlorine
o chlorine dioxide
o hydrogen peroxide
Additionally, oxidation by ultrasonic, ultraviolet radiation, and cata-
lytic contact treatments has been demonstrated.
Oxygen - Oxygen has been used with and without catalysts as well as in
combination with ultraviolet radiation or ultrasound.(1) One such use is the
wet air oxidation process in which the waste temperature is increased to the
point where air (oxygen) reacts with oxidizable material autogenously. Wil-
helm and Ely (2) reported a 99.99+ percent COD removal (Figure 17) when using
this process. The Pulp and Paper Institute of Canada reported several addi-
tional methods of oxidizing phenols with oxygen.(1) Waste from a lacquer and
varnish manufacturer was oxidized using oxygen (in air) and acid treated
pyrolusite (MnO.) as a catalyst. The results are listed in Table 32. Suc-
cessive uses of the catalyst resulted in a decrease in its activity. It was,
however, possible to regenerate the catalyst with a 1.5 to 2.0 percent sul-
furic acid solution.
Examples of the photo-oxidation of dilute phenol solutions were also
included in the Canadian report.(1) A waste containing 200 mg/1 phenol was
irradiated with ultraviolet light (300 to 400 nm) using 5,000 mg/1 of ZnO as a
catalyst. Ninety percent of the phenol was oxidized to CO within 44 to 68
hours, depending on the depth of the waste stream. Even though dissolved
oxygen was found to be necessary for oxidation, aeration did not significantly
affect the phenol oxidation rate. When TiO^ was substituted as the catalyst
under the same conditions, a maximum 80 percent phenol reduction occurred
after 72 hours irradiation. Similar results were also obtained when 300 g/1
of beach sand was used as the catalyst.
Ultrasonic irradiation (ultra high frequency sound) was also found to
produce significant phenol reductions.(1, 3) Wastes containing 100 mg/1
phenol were reported to be completely oxidized in four hours when subjected to
a field of 800 KHz at 33 watts/cm . When the waste concentration was in-
creased to 500 mg/1, a 70-percent reduction was achieved in 6 hours. As
-70-
-------
DECOMPOSITION OF PHENOL
BY WET-AIR OXIDATION (?)
100
10
o
111
(T
O
Z
III
1.0
O.I
0-01
20 40 €0 80
COD REDUCTION, %
100
FIGURE 17
71
-------
shown on Figure 18, phenol reduction was found to be proportional to irradi-
ation intensity. Even though significant phenol reductions were obtained, it
was pointed out that this process appears to oxidize phenols to products with
a higher oxygen content and not to carbon dioxide. Consequently, this treat-
ment may not necessarily reduce toxicity.
Ultrasonic irradiation in the presence of various catalysts was also
investigated by Chen.(4) In experiments with metal oxides, platinum, rhubi-
dium and Raney-nickel, an inhibition of sono-oxidation was noted. Howevsr, as
indicated by TOG analysis, more complete oxidation occurs since approximately
eight percent of the products of oxidation was carbon dioxide (CO ).
TABLE 32. CATALYTIC OXIDATION OF LACQUER MANUFACTURING WASTEWATER (1)
Phenol concentration (raw waste) 8,000 mg/1
Formaldehyde concentration (raw waste) 1,400 mg/1
pH (raw waste) 7.0
Aeration period 2 hr
Percent removals
Phenol 99%
Formaldehyde 87 to 95%
Ozone - Ozone has been shown to be extremely effective in the oxidation
of many complex organics including phenols. Eisenhauer reported that when
ozone initially reacts with phenol, catechol is formed. This compound, in
turn, degrades to carboxylic acids and carbon dioxide, as shown on Figure
19.(1, 5)
However, Dence,(6) reporting on the ozonation of spent chlorination and
caustic extraction liquors, stated that "in no instance does ozonation cause a
substantial reduction in the toxicity . . . and under alkaline conditions, a
decided increase is produced." He goes on to state that "it seems safe to
assume that the phenolic components of the liquors are not responsible."
Apparently, under alkaline conditions, ozone partially decomposes to hydroxyl
groups and could form more toxic products.
The phenol content of coke plant effluent has been reduced from 2,000
mg/1 to less than 1 mg/1 with an average ozone dose of 1.7 g/g of phenol. (5)
Cleary and Kinney (7) also worked with coke wastes. Their results, as shown
on Figure 20, led to the following conclusions:
-72-
-------
PERCENTAGE OF PHENOL OXIDIZED
VS
ULTRASONIC INTENSITY (I)
Q
UJ
X
o
o
z
Ul
a.
ui
60-
50-
40-
30
Ul
o
£ 20
10 20 30
ULTRASONIC INTENSITY, wafts/cm2
40
FIGURE 18
73
-------
OZONATION OF PHENOL ( 1,5)
OH
-f- COOH HOOC
COOH
FIGURE 19
-------
OXIDATION OF PHENOL BY OZONE (7)
200
400 600 800
OZONE DOSAGE, PPM
1000
1200
FIGURE 20
75
-------
1. Ozone oxidation of phenol is maximized at pH 11.8.
2. The required ozone dose is independent of temperature.
3. Undertreatment with ozone does not form additional toxic compounds.
4. No pretreatment of the waste is required.
Similarly, phenols in refinery wastes have been reduced from 11,600 to
2.5 mg/1 with an applied ozone dose of 2.0 g/g of phenol.(5) Gould and Weber
(8) evaluated phenol oxidation with ozone and found that near-complete removal
was achieved when four to six moles of ozone were consumed per mole of phenol
initially present. They also determined that when a plot of COD reduction vs.
ozone dosage is made, there is a sharp transition from one linear relationship
to another at a much lower rate. The break point between the two functions
was found to correspond to the point of near-complete phenol removal.
Little work has been done on the influence of catalysts on phenol removal
with ozone. The Pulp and Paper Research Institute of Canada (1) reported that
the oxidation rate is increased twofold when Raney-nickel is used as a cata-
lyst.
Many researchers reported that the cost of ozonation is excessive. Dence
(9) states that in the case of spent liquors, "other components compete . . .
successfully with phenols for the ozone, requiring excessive amounts of ozone
for phenol reduction." Eisenhauer(S), in reporting on the work of Peppier and
Fern, stated that the cost of ozonation is four to seven times that of biolog-
ical oxidation. Thompson (10) similarly disregarded ozonation as a viable
treatment alternative due to high capital and operating costs. Gould and
Weber (8) stated that ozonation for complete removal would be exceedingly
costly and time consuming. In general, most researchers said that ozonation
would only be economically feasible as a polishing step after some other
treatment process.
Chlorine - Chlorine is a powerful oxidant and as such will readily oxi-
dize phenol. Thompson (10) reported that chlorination of phenolic wastes to
an excess actually breaks the benzene ring to form organic acids. There is
similar evidence to show that chlorine oxidizes pentachlorophenol to chlor-
anil. Thompson did not feel, however, that chlorination alone will adequately
treat wood preserving wastes. Too many oxygen demanding substances, including
residual phenolic fractions, sometimes remain in the effluent, even after
massive chlorine dosages. Frequently a ratio of chlorine to pentachlorophenol
of 700:1 is required for near-complete oxidation. This reduces the economic
feasibility of such a treatment alternative. Thompson did feel, however, that
chlorination could be used as a polishing step for biological treatment plant
effluents.
-76-
-------
Cleary and Kinney (7) investigated chlorine oxidation of coke wastes at
both the laboratory and pilot plant levels.
They found that once the waste's ammonia demand is satisfied, substantial
phenol reductions can be obtained with small increases in the chlorine dose.
The reaction reaches a point, however, where increasingly larger doses are
required for small increases in phenol destruction. The relationship between
chlorine dose and phenol remaining is shown on Figure 21.
They also found that phenols can be destroyed at pH values between 1.8
and 11.0. To prevent the formation of chlorophenols and nitrogen trichloride
the pH should be between 7.0 and 10.0. Temperature should also be reduced to
45°C to prevent chlorate formation. There is some indication that pH affects
the amount of chlorine demand which is satisfied prior to beginning phenol
destruction. It seems to be easier to oxidize phenols at a high pH when other
chlorine consuming compounds are present.
Based on the > above, complete destruction of phenol with chlorine is
technically feasible. It does, however, require an excess of several hundred
mg/1 of chlorine, to accomplish complete destruction.
Oxidation by chlorination, however, may produce harmful side effects.
Dence et al, (6) in current research at SUMY-Syracuse, have reported distinct
increases in the toxicity of spent chlorination liquors following chlorine
treatments, even though up to 70 percent phenol reduction was noted at dosages
of 0.8 mgCl/ml spent liquor. Similar results occurred when hypochlorous acid
was used as treatment. Phenol reduction of 82 percent was experienced at a
dosage of 0.37 mg HOCl/ml spent liquor. Similarly, a sodium hypochlorite
treatment at 2 mg/ml of liquor produced at 95 percent reduction in phenol
concentration in nine hours at 60°C. A decided increase in toxicity was again.
noted in the 'treated samples.
Chlorine Dioxide - Chlorine dioxide is another strong oxidant which can
be used for treating industrial wastewater. Unlike chlorine, however, this
chemical has been reported to be selective for cyanide, phenol, sulfides, and
mercaptans. It does not react with many other organics such as alcohols and
organic acids.(11) Cleary and Kinney (7) have found in their work with coke
plant wastewaters that pretreatment was not required. They found that the
best results were obtained when a 2 to 1 mixture of chlorine to chlorine
dioxide was applied together. When chlorine dioxide was used alone, a small
chemical dosage was found to produce a large phenol reduction. As shown on
Figure 22, additional phenol removal required increasingly higher chemical
doses. Mulligan and Fox (11) reported that approximately 1.5 Ib chlorine
dioxide was required to convert one" pound of phenol to quinone. They also
reported that "because of its cost, approximately $4/lb, its use will be as a
selective polishing treatment for destruction of trace amounts of specific
compounds in industrial effluents."
-77-
-------
OXIDATION OF PHENOL BY CHLORINE (7)
100
S
Q.
0.
z
z
bJ
CC
V)
o
z
UJ
X
0.
1000
2000 3000 4000
CHLORINE DOSAGE , PPM
500O
6000
FIGURE 21
78
-------
OXIDATION OF PHENOL BY CHLORINE DIOXIDE (7)
100
80
2
a.
Q.
o"
Z 60
2
Ixl
(T
UJ
I
a.
40
20
\
148 PPM
1000 2000
CHLORINE DIOXIDE DOSAGE, PPM
3OOO
FIGURE 22
79
-------
Chlorine dioxide, though expensive, has two major advantages over chlor-
ine. (7) First, the ammonia content of the waste does not affect the chemical
dose required for phenol destruction. This is significant because approxi-
mately 10 mg/1 of chlorine is required to oxidize 1 mg/1 of ammonia and that
all ammonia must be oxidized prior to phenol removal with chlorine. Also, a
chlorine dioxide residual is not required. Underdosing reduces phenol concen-
trations, but according to the colorimetric tests used by Cleary,(7) does not
form chlorophenols.
Hydrogen Peroxide - The FMC Corporation, a manufacturer of hydrogen
peroxide, has done extensive work with phenol oxidation.(12, 13) They have
reported that in the presence of trace amounts of iron salts, hydrogen per-
oxide will rapidly oxidize phenol first to catechol and hydroquinone, then to
dibasic acids, and ultimately to carbon dioxide and water. Eisenhauer, how-
ever, has disagreed and stated that the reaction stops with the formation of
muconic acid.(14)
As part of their work with phenols, FMC has studied the effect of the
H?0 /phenol ratio on the extent of phenol oxidation. The results of this work
are shown on Figure 23. (12) Similar work also led to the development of a
relationship between H 0?/COD and phenol reduction as is shown on Table 33 and
Figure 24.(12)
TABLE 33. HYDROGEN PEROXIDE TREATMENT OF PHENOL WASTES* (12)
H 02/COD
wt ratio
0.3
0.4
0.6
0.7
0.8
1.0
Reduction in phenol
(%)
86
94
99
99.8
99.9
100
Reduction in COD
(%)
28
32
40
44
52
69
*Initial phenol concentration 2,000 mg/1
Eisenhauer (14) developed a similar relationship using Fenton's reagent;
or in other words a combination of hydrogen peroxide and a ferrous salt.
Table 34 shows the results of this work.
-80-
-------
EFFECT OF INITIAL HYDROGEN PEROXIDE/
PHENOL RATIO ON THE
OXIDATION OF PURE PHENOL (12)
00
5
_i
O
I
Q.
in
LU
OL
\50-t
125 -
100-
75-
50-
25-
INITIAL PHENOL CONC =
500 Mg/Lifer
70° F 5 Minutes
0.1% ,Fe Calolyst
Initial pH = 5.5
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
HYDROGEN PEROXIDE/ PHENOL WEIGHT RATIO
4.5
FIGURE 23
-------
EFFECT OF HYDROGEN PEROXIDE / PHENOL RATIO
ON CHEMICAL OXYGEN DEMAND REDUCTION OF
.PURE PHENOL (12)
CO
N3
Q
Z
<
5
ui
Q
X
o
o
2
1200
1000-1
'800-
60O-
400-
200-
INITIAL PHENOL CONC :
500 Mg /Liter
70'F 5 Minutes
. 01% Fe Catalyst
Initial pH =5.5
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.O
- HYDROGEN PEROXIDE/PHENOL WEIGHT RATIO
FIGURE 24
-------
TABLE 34. REACTION OF PHENOL WITH FENTON'S REAGENT* (14)
Phenol concentration
a.- c v,rc.n , ) 2 *-OUA J 2
(moles/mole
of phenol)
0.1
0.25
0.5
1
1
1
1
1
O f
(moles/mole
of phenol)
9
9
9
9
3
2
1
0.5
2
min
33.6
21.2
3.0
0
2.0
13.2
16.0
22.4
5
min
27.8
11.6
0
0
0
8.8
14.2
19.0
15
min
8.5
0
0
0
0
8.0
13.6
16.0
*Solutions containing 50 mg/1 of phenol were reacted at pH 3 and 10°C
with air agitation.
Eisenhauer concluded that optimum phenol oxidation takes place when the reac-
tion is carried out at a 3:1 mole ratio of peroxide to phenol. Unfortunately,
when this reagent was applied to phenolic industrial wastes, the peroxide
requirement increased three to six times. This increase was believed to be a
result of other organics in the waste. Eisenhauer also reported that cost of
phenol removal to be $2.40/lb of phenol (1964 prices), which was too expensive
to compete with other removal processes-
In addition to the work described above, the FMC Corporation has also
investigated the effect of temperature and various catalysts on phenol oxida-
tion. (13) Temperatures between 70° and 120°F were found to have no practical
effect on the reaction. Catalysts such as ferrous sulfate, iron wool, nickel
salts and aluminum salts were also evaluated. As shown in Table 35, ferrous
sulfate appeared to be the most practical of all the catalysts studied. This
finding was also supported by Ross (15) and Keating et al.(l6) Keating also
compared the effectiveness of ferrous and ferric iron and found no differences
with the testing conditions used. He did note, however, that the reaction
seemed to begin sooner when ferrous iron was used as evidenced by an earlier
color change. FMC similarly tested potassium persulfate both with hydrogen
peroxide and alone with an iron catalyst. Even though good oxidaton was
obtained, the results were the same as if hydrogen peroxide alone had been
used.(13)
A 1961 Russian article, as reported by- the FMC Corporation, "gave the
following order of catalytic activity for the peroxide oxidation of phenol;
-83-
-------
Al' ' , Cr'''. The catalytic Fe' and Cu'' activity was also said to be
enhanced by the presence of Al ." (13) The previously described work of FMC
does not verify this conclusion. FMC has pointed out, however, that the
Russian work was performed on a much more dilute solution.
Merour (17) took another approach to the problem and found that oxidiz-
able material may be removed from wastes as follows:
1. saturate the waste streams with oxygen then add hydrogen per.oxide;
TABLE 35. EFFECT OF CATALYSTS ON PHENOL OXIDATION (13)
H2°2/
phenol
ratio
Catalyst
Phenol
0*8/1)
TOC
(mg/1)
COD
none none 500.0 383
0.5 none 499.0 365
1.0 none - 493.0 375
0.5 0.01% Fe 88.0 380
1.0 0.01% Fe 7.0 360
2.0 0.01% Fe 0.3 310
3.0 0.01% Fe 0.2 150
4.0 0.01% Fe 3ppb 138
0.5 0.03% Fe 118.0 365
1.0 0.03% Fe 22.0 345
2.0 0.03% Fe 0.2 315
3.0 0.03% Fe 4.04 210
0.5 0.01% Fe, 0.01% Al 79.0 380
1.0 0.01% Fe, 0.01% Al 4.0 310
2.0 0.01% Fe, 0.01% Al 0.1 300
3.0 0.01% Fe, 0.01% Al 0.05 200
4.0 0.01% Fe, 0.01% Al 6ppb 196
1.0 0.03% Fe, 0.03% Al 5.7 310
2.0 0.03% Fe, 0.03% Al 0.3 320
3.0 0.03% Fe, 0.03% Al 0.2 225
1.0 Steel wool (room 16.0
temp., 10-min.
retention)
0.5 0.01% Ni (as NiCl2 • 496.0 370
6H..O) (room temp.
test)
Initial phenol concentration - 500 mg/1. 120°F, 30-min. retention
time; initial pH = 5.5. Fe added as ferrous sulfate; Al added as
aluminum sulfate.
1,105
(theory 1,19-0)
974
679
392
106
66
1,020
620
418
150
971
625
495
172
105
510
405
210
-84-
-------
2. adjust the pH to 6-7; and
3. activate the mixture with light having a wavelength of 200 to 500 nm
and an energy of 0.5 w/atom of carbon eliminated.
This process was found to require 0.1 to 1.5 atoms of active oxygen per
atom of carbon removed.
Keating et al, (16) reported on three commercial installations where
phenolic wastes are being successfully treated with hydrogen peroxide. One
installation used a batch treatment system. During a typical treatment opera-
tion, approximately 10,000 gallons of wastewater were received and tested to
determine the phenolic concentration, the HO /phenol rates, and the required
treatment time. The waste was then adjusted to pH 5-6, iron added to equal 15
|Jg/g Fe, and the required amount of peroxide is added. After the necessary
treatment time, the waste was retested for phenol; and if found satisfactory,
discharged to the receiving stream.
Hydrogen peroxide has also been used as a standby system for biological
treatment. At one of the facilities studied, inadequately treated wastewater
was diverted to a holding pond where it was stabilized with hydrogen peroxide.
It is interesting to note that the amount of hydrogen peroxide required for
treatment was well in excess of that required for phenolics (H^O^/phenol ratio
of 8:1). This was primarily attributed to the presence of otner oxidizable
compounds. This same treatment system also used hydrogen peroxide to counter-
act the effects of biological shock loadings. If upstream testing detected a
heavy load of phenols, hydrogen peroxide would be added to an equalization
basin until phenols were reduced to a level tolerable to the bio-system.
The final commercial application reported by Keating (16) was effluent
polishing to remove the last traces by phenol after.biological treatment.
This type application, however, is necessary only when there are stringent
effluent limitations.
Reductive Degradation - Sweeny (9) reported catalyzed iron to be a low
cost, effective treatment, replacing substituted chlorine atoms with hydrogen.
This removal of chlorine is stated to generally lead to products of greatly
reduced toxicity, for example, the degradation of chlorobenzene to cyclo-
hexanol. Use of a column to provide the required contact was investigated in
two variations - diluted and fluidized beds. The fluidized bed was found to
be most efficient, allowing flow rates as high as 23 gpm/ft . A degradation
trial with an influent concentration of 2,000 mug/1 p-nitrophenol at a flow
rate of 22.8 gpm/ft produced an effluent containing only 1.5 mug/1, a 99.8
percent reduction.
An operating pH range of 5.5 to 8.0 was reported to avoid excessive
reluctant usage or precipitation in the bed.
-85-
-------
REFERENCES
1. Pulp and Paper Research Institute of Canada "Review of Catalytic Oxida-
tion of Pulp and Paper Mill Effluents", CPAR Project Report 147-1, March
1973. 48 pp.
2. Wilhelmi, A.R. and R.B. Ely. "A Two-Step Process for Toxic. Wastewaters."
Chemical Engineering, 83(4): 105-109, 1976.
3. Chen, J.W., J.A. Chang, and G.V. Smith, Sonocatalytic Oxidation in Aqueous
Solutions." Vol. 67 (item 109): 18-26, 1971.
4. Chen, J.W. & G.V. Smith. "Feasibility Studies of Applications of Cata-
lytic Oxidation in Wastewater." EPA Water Pollution Control Research
Series 7020-ECI-11/71.
5. Eisenhauer, H.R. "The Ozonization of Phenolic Wastes." Journal Water
Pollution Control Federation 40(11): 1887-1899, 1968.
6. Dence, C.W., R. Hartenstein, C.J.K. Wang. "The Elimination of Phenolic
and Chlorophenolic Materials in Spent Chlorination and Caustic Extraction
Bleaching Liquors using Chemical and Biological Approaches." Progress
Report to February 1978, SUNY Syracuse, New York.
7- Cleary, E.J. and J.E. Kinney. "Findings from a Cooperative Study of
Phenol Waste Treatment." In: Proceedings of the Sixth Industrial Waste
Conference Purdue University, 1951.
8. Gould, J.P. and W.J. Weber Jr. "Oxidation of Phenols by Ozone." Journal
Water Pollution Control Federation, 49(1): 47-60, 1976.
9. Sweeny, K.H. "Reductive Degradation: Versatile, Low Cost." Water and
Sewage Works. 126(1): 40-42, 1979.
10. Thompson, W.S. "Wood Preservatives and the Environment: The Treating
Plant." Presented at Conference of American Wood Preservers Association,
1974.
11. Mulligan, T.J. and R.D. Fox. "Treatment of Industrial Wastewaters."
Chemical Engineering. 83(22): 49-65, 1976.
12. FMC Corporation bulletin entitled "Industrial Waste Treatment."
13. FMC Pollution Control Release No. 84. "Phenols in Refinery Waste Water
Can Be Oxidized with Hydrogen Peroxide."
-86-
-------
14. Eisenhauer, H.R. "Oxidization of Phenolic Wastes." Journal Water Pollu-
tion Control Federation 36(9): 1116-1128, 1964.
15. Ross, L.W., A.K. Chowdhury. "Catalytic Oxidation of Strong Waste Waters."
Presented at Conference of American Society of Mechanical Engineers, July
1977.
16. Keating, E.J., R.A. Brown E.S. Greenberg E.S. "Phenolic Problems Solved
with Hydrogen Peroxide Oxidation." Industrial Water Engineering, 15(7):
22-27, 1978.
17. Merour, Yves. "Elimination of Oxidizable Materials from Polluted Waters."
Chemical Abstracts, Vol. 87 (28610), 1977.
-87-
-------
5.0 CARBON ADSORPTION
Carbon adsorption is basically a surface phenomenon (1) and is influenced
by such factors as the hydrophobic nature of dissolved organics in the waste
stream, and the affinity of the organic for the sorbent.
Adsorption is related directly to a compound's hydrophobic behavior in
that organics of low solubility are more readily adsorbed.(1) With respect to
phenols, Strier (2) described the order of increasing adsorptivity on acti-
vated carbon as:
Solubility in water
Compound Molecular weight mg/1 at 25°C
Phenol
2,4,6 Trichlorophenol
Penta chlo ropheno 1
94.1
197.5
266.3
8.2 x 104
9.0 x 102
3.0 at 50°C
This is also the order of increasing molecular weight and decreasing
solubility, which supports the above statement concerning solubility and
adsorptivity. The solubilities reported above by Strier, however, do not
agree with other published data. The affinity of the organic for the sorbent
is due to a combination of electrostatic attraction, physical adsorption, and
chemical adsorption.(1) Since activated carbon is negatively charged, it is
"more amenable to complexing with increasingly more positively charged aro-
matic (benzene) compounds such as the more highly chlorinated phenol ico,
thereby facilitating adsorption".(2) Strier concluded that:
"...pentachlorophenol could best be removed from industrial waste ef-
fluents by oil-water separation and/or by precipitation and filtration at
low pH, as pretreatment, followed as necessary by carbon adsorption
and/or biological oxidation, to remove other phenolics and organics."
There are basically two techniques for using activated carbon in waste
treatment:
1. The waste stream can contact granular carbon in a treatment column;
or
2. Powdered carbon can be added directly to the wastewater.
Numerous researchers have reported on the effectiveness of contacting
type carbon columns for phenol removal. Zogorski and Faust (3) conducted 25
experiments using laboratory prepared phenol solutions and fixed beds of
-88-
-------
granular activated carbon. From their work, they concluded that between 20
seconds and two minutes of contact time is required to reduce phenols below
analytical sensitivity. They also found that granular activated carbon rapid-
ly removes phenols, therefore filters with a bed depth of 3-to-5 ft can be as
efficient as the much larger units currently being designed. Hager (4) con-
ducted similar laboratory adsorption studies using actual industrial waste-
waters and found a 99 percent phenol reduction in all five samples analyzed.
He also reported on five full scale adsorption systems installed between March
1973 and March 1975. A brief description of these systems is included in
Table 36. Bernardin (5) also reported on two full scale adsorption systems.
Plant "A" was a chemical plant manufacturing, among other compounds, phenol.
A basic process flow diagram is shown on Figure 25. The carbon adsorption
system consisted of two moving bed steel adsorbers, each of which was 12 ft
diameter by 36 ft sidewall height. Each contained approximately 124,000 Ib of
Calgon Filtrasorb granular activated carbon and was designed for a flow rate
of 175 gpm. A summary of typical plant operation data is shown on Table 37.
Plant "B" manufactured phenolic resins and produced a waste containing float-
ing oils, suspended solids, phenolics, and other organics. A basic process
flow diagram is shown on Figure 26. The carbon adsorption system consisted of
two fixed bed adsorbers operated in series. Each column was 10 ft diameter by
11 ft sidewall height and contained approximately 20,000 Ib of granular acti-
vated carbon. A summary of typical plant operating data is shown on Table 38.
TABLE 36. PHENOL ADSORPTION SYSTEMS (4)
Phenol concentration
Plant Flow Contact time (mg/1)
No. (1,000 gpd) Pretreatment (min) Influent Effluent
1 50 Settling, equalization, 165 200 0.1
mixed media filtration
2 200 Equalization 41 600 100
3 350 Biological, mixed 24 800 0.05
media filtration
4 150 Sand filtration, settling 55 1,200 1.0
5 500 Biological, settling, 33 80 1.0
multi-media filtration
-89-
-------
PROCESS FLOW DIAGRAM (5)
PLANT "A"
TO STREAM
VO
o
pH ADJUSTMENT
NON IONIC
POLYMER
f '
EQUALIZATION
t
FLOCCULATION
WASTE -*•
FIGURE 25
-------
TABLE 37. OPERATING DATA - PLANT "A" (5)
Raw waste characteristics
Flow
BOD
COD
Phenol
Effluent characteristics
BOD
COD
Suspended solids
Phenol
400,000 gpd
16,000 Ib/day
27,000 Ib/day
1,500 Ib/day
1,450 Ib/day
2,675 Ib/day
22 Ib/day
0.5 Ib/day
-91-
-------
PROCESS FLOW DIAGRAM (5)
PLANT "B"
vo
NJ
OIL
SEPARATOR
FLOCCULATION
DLYMER
•H SEDIMENTATION
WASTE
CARBON
ADSORPTION
*•
MIXED MEDIA
FILTRATION
TO STREAM
FIGURE 26
-------
TABLE 38. OPERATING DATA - PLANT "B" (5)
Raw waste Clarifier effluent Carbon effluent
Suspended solids
Oil/grease
TOC
Phenol
220 mg/1
50 mg/1
1,200 mg/1
160 mg/1
45 mg/1
25 mg/1
650 mg/1
130 mg/1
10.0 mg/1
5.0 mg/1
25 mg/1
0.1 mg/1
*Plant flow is approximately 100,000 gpd
It is interesting to note that when the raw wastewater toxicity was eval-
uated using bluegill sunfish, all specimens died within the first 15 minutes
of exposure. In a similar test with the final effluent, however, there were
no adverse reactions even after a 10-day exposure test period.
Thompson (6) pointed out that even though activated carbon has been used
to treat various types of industrial wastewaters, it has not been commercially
applied to wood preserving effluents. Laboratory tests have, however, shown
that activated carbon provides good phenolic removals from raw creosote waste-
water. Unfortunately, other organics are also adsorbed and these reduce the
useful life of the carbon to the point where regeneration is essential.
Carbon regeneration equipment is generally too expensive for individual plants
to install.
Carbon regeneration has been shown to significantly affect the adsorption
process. DeJohn and Adams (7) found that the phenol and COD adsorption per-
formance of bituminous coal activated carbon was sharply reduced after regen-
eration. Data supporting this finding are shown in Tables 39 and 40.
-93-
-------
TABLE 39. EFFECTS OF CARBON REGENERATION (7)
Iodine number
Molasses number
Phenol, % removal
COD % removal
Virgin
carbon
950-1,000
230
99.9
71
Regenerated
carbon
560-680
280
63
13
Percent
change
-27 to -44
+22
-37
-82
TABLE 40. IMPURITY REMOVAL DECREASE AFTER REGENERATION (7)
Impurity removal
(Ib/lb carbon applied)
TOC
COD
Phenol
Virgin
carbon
0.17
0.73
0.01
Regenerated
carbon
0.096
0.35
0.03
Percent
change
-44
-52
-25
As stated, .powdered activated carbon added directly to the wastewater
serves as a viable carbon adsorption treatment technique. This technique,
however, is normally used in conjunction with an activated sludge system.
DeJohn and Adams (7) have reported on four full scale activated sludge systems
which have tried this treatment alternative. At plant No. 1, a maximum BOD
removal of 90-95 percent was achieved with carbon addition vs. 23 percent for
the post test control. Similarly, the effluent COD was reduced from an aver-
age of 1,800 mg/1 without activated carbon to 350 mg/1 with addition. At
plant No. 2, the raw waste TOC varied between 100 and 1,000 mg/1. After
activated carbon addition, however, the effluent TOC was maintained below 20
mg/1, even during shock load periods. Plant No. 3 involved a refinery waste
in which effluent TSS and COD removals improved 40 percent when activated
carbon was added to the second stage of a two stage conventional activated
sludge system. Similar improvements were also noted at plant No. 4. It
should be noted that even though the above results are expressed in terms of
TOC and COD removals, there was a correlation between such removals and phenol
reduction.(8)
-94-
-------
Rizzo and Shepherd (9) have outlined the various factors which should be
considered in an economic evaluation of a contacting type adsorption system.
These factors have been broken down into three general categories:
1. capital cost of the contacting system;
2. capital cost of the reactivation system; and
3. operation and maintenance expenses.
Figure 27 presents estimated equipment costs (installed) for two stage,
fixed bed, downflow contacting systems of various capacities. Figure 28
presents the equivalent costs for onsite regeneration facilities. Typical
examples of operation and maintenance expenses are presented in Table 41.
Since these items are extremely variable and difficult to estimate, no attempt
was made to develop typical costs. Instead the report itemized the major
components of each cost and provided guidelines to assist in estimating them.
-95-
-------
TOTAL INSTALLED COST OF TWO STAGE
ADSORPTION CONTACTING EQUIPMENT (9)
6 -i
— 5 -
to
K
o
~ 4 -
o
o
in
O
OT
O
O
3 -
2 -
TOTAL INSTALLED COST
WITH ONSITE STORAGE
TOTAL INSTALLED COST WITHOUT
ONSITE STORAGE
23456
FLOWRATE , I05gal/d
10
FIGURE 27
-------
TOTAL INSTALLED COST OF CARBON REACTIVATION
AND HANDLING SYSTEM (9)
o
•o
O
O
16
14 -
12
10
8-
6
4
2
0
•TOTAL INSTALLED COST
2000 6000 10,000 14,000
CARBON USAGE, Ib/d
18,000
FIGURE 28
-------
TABLE 41. MAJOR ANNUAL COST CONSIDERATIONS
FOR ADSORPTION OPTIONS (9)
Ons ite
reactivation
Carbon makeup
Depreciation
Electricity
Fuel
Interest
Labor
Maintenance
Monitoring
Steam
Offsite
reactivation
Carbon makeup
Depreciation
Electricity
Interest
Labor
Maintenance
Monitoring
Reactivation cost
Transportation
Throwaway
carbon
Carbon disposal
Carbon makeup
Depreciation
Electricity
Interest
Labor
Maintenance
Monitoring
'
Service
Electricity
Labor
Service fee
-98-
-------
REFERENCES
1. Mulligan, T.J. and R.D. Fox. "Treatment of Industrial Wastewaters"
Chemical Engineering, 83(22): 49-65, 1976.
2. Memorandum, M.P. Strier to R.B. Schaffer. "Treatability of Pentachloro-
phenol." April 24, 1978.
3. Zogorski, J.S. and Faust, S.D. "Waste Recovery: Removing Phenols via
Activated Carbon." Chemical Engineering Progress, 73(5): 65-66, 1977.
4. Hager, D.G. "Wastewater Treatment via Activated Carbon." Chemical Engi-
neering Progress, 72(10): 57-60, 1976.
5. Bernardin, F.E. "Selecting and Specifying Activated-Carbon-Adsorption
Systems." Chemical Engineering, 83(22): 77-82, 1976.
6. Thompson, W.S. "Wood Preservatives and the Environment: The Treating
Plant." Presented at Conference of American Wood Preservers Association,
1974.
7. DeJohn, P.B. and Adams, A.D. "Activated Carbon Improves Wastewater
Treatment." Hydrocarbon Processing, 54(10): 104-111, 1975.
8. FMC Corporation Bulletin. "Industrial Waste Treatment."
9. Rizzo, J.L. and A.R. Shepherd. "Treating Industrial Waste with Activated
Carbon." Chemical Engineering. 84(1): 95-100, 1977.
-99-
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6.0 STRIPPING OPERATIONS
Stripping operations involve passing a gas or vapor through a liquid with
sufficient contact that volatile components are transferred from the liquid to
the gas phase. The driving force for such an operation is the concentration
differential between the liquid and concentrated equilibrium point of the gas.
The transferred compound may then be recovered by condensing the stripping
vapor.
It may be noted that stripping is essentially the reverse of adsorption.
The equipment utilized for stripping operations generally consists of a tower
or mliimn containing multiple bubble-cap or perforated plates. Packing of the
tower, with a high surface area medium, is also a reported practice. (1) An
external condenser cools the gas.
As in many other cases of mass transfer, a more complete separation of
components may be obtained through refluxing of one or both of the process
streams. In this case, reflux of stripped condensates is a common practice.
The principal processes investigated dealing with wastewater treatment
have been air and steam stripping. A single reference was noted (2) reporting
favorable phenol removal with carbon dioxide stripping at elevated tempera-
tures (65 to 90°C).
As evidenced by the lack of published data, air stripping has failed to
exhibit the capability to remove phenolic compounds from' wastewater within
reasonable contact times. Air stripping was, however, capable of removing 90
percent of total reduced sulphur compounds and 10 to 20 percent of BOD from
contaminated condensate streams.(3) Effective odor removal has also been
noted.(1)
Steam stripping is currently practiced at a number of pulp and paper
mills, but mainly as an odor control, water reuse, or chemical recovery mea-
sure. These mills include Great Northern (Port Edwards, Wisconsin), Mead
(Escanaba, Michigan), Weyerhaeuser (Springfield, Oregon), Scott (Somerset,
Maine), St. Regis (Rhinelander, Wisconsin), Georgia Pacific (Bellingham,
Washington), Flambeau (Park Falls, Wisconsin), and Simpson Lee (Anderson,
California). Very little data, however, were found in the search relating to
phenol stripping. Work is currently underway in this area.(4)
The relative steam volatility of organic compounds is a complex property
involving water solubility, boiling point, vapor pressure and tendency to form
hydrogen bonding. Organic compounds that have undergone ionization are not
volatile to steam. For example, at alkaline pH, the hydroxyl (OH) groups of
phenolic compounds would tend to ionize to the negatively charged phenolate
ion and would not be removed by steam stripping. Thus the relative acidities
and process pH should be major considerations .in attempts to apply steam
stripping for phenol removal.
•100--
-------
A plot of relative .vapor pressures is included as Figure 29 illustrating
one aspect of the sequential susceptability to steam stripping of organic
compounds. In general, steam volatility increases as boiling point, water
solubility and hydrogen bonding decrease.
Steam stripping of pulp and paper mill wastewaters is capable of removing
60 to 85% of the influent BOD while reducing TRS (total reduced sulpher com-
pounds), and toxicity by 95 percent.(3) Recovery of the column streams may
also result in salable products such as methanol, ethyl acetate, and fur-
fural.(l)
Operations utilizing steam stripping were reported (3) to maintain a
steam usage of about 15 to 18 percent (by weight) of contaminated condensate
flow. Rates as low as 6 percent have also been reported. (5) A two percent
rate was calculated as the optimal economic rate by Maahs et al. A 1967 cost
estimate for a 130,000 Ib/hr stripping system was $84,000 with annual oper-
ating costs amounting to about $0.32/ADT.
A more recent study (1977) by Guttierrez et al (6) quantified steam
stripping efficiency for phenol. Stripper steam/condensate ratios varying
from 5.6 to 14.4 percent were noted in a survey of five installations, as
shown in Table 42. Table 43 indicates the variability in phenol content of
the mills' condensate streams. It was reported that the lower steam/con-
densate ratios greatly affected BOD5_ removal which decreased from the pre-
viously noted 60 to 85 percent to less than 5 percent. Phenol removal ranged
from 0.4 to 61 percent, but this variability was attributed to the rectifi-
cation section rather than the steam ratio. Table 43 presents the removal
data. The best phenol removal, 61 percent, still was not considered high
enough to qualify steam stripping as an effective removal technology. Con-
tinuing work in this area may refute this conclusion.
-101-
-------
VAPOR PRESSURES OF VARIOUS
VOLATILE ORGANIC COMPOUNDS
o
NJ
CO
LJ
OL
UJ
co
o
100
50
10
1.0
0.5
0.05
0.01
-50
x^X
/w*
kHV
X*
50 100
TEMPERATURE °C
150
200
250
FIGURE 29
-------
TABLE 42.
CHARACTERISTICS OF VARIOUS CONDENSATE TREATMENT SYSTEMS AT
FIVE BLEACHED KRAFT HIU.S (6)
Mill
code
Production
(ADT/day)
Wood furnish
Type of
digesters
Contaminated condensates being treated
Stripping system
Flow
Origin
% of total
condensate
General characteristics
Steam
Ratio %
OJ
970 Mixed fir, Kamyr Digester area: Steam vessels 547 64
balsam, and #2 flash tank; turpentine
hemlock, decanter underflow; digester
spruce area vents.
Evaporators area: Evaporator
effect #5; evaporator surface
condensor & vacuum system'.
450 Mixed Batch Digester area: Digesters' blow 100 31
hardwood condensate.
Evaporators area: Evaporators'
surface condensor and vacuum
system.
510 45% spruce Kamyr Digester area: Steam vessels 103 12
45% pine and flash tank #2.
10% balsam Evaporators area: Secondary
fir surface condensors and vacuum
system.
1100 86-80% 7-Batch Digesters area: Digesters' 493 24
Douglas fir blow condensate.
14-20% pine 1-Kamyr Evaporators area: Surface
condensor and vacuum system.
280 69-70% pine Batch Digesters area: Digester's 235 46
40-30% blow condensate and turpen-
hardwood tine decanter underflow.
Evaporators area: Evaporators'
effect #5; surface condensors
and vacuum system.
Free standing stripper using 5.6
live steam, no condensor,
reflux or decanter.
Free standing stripper using 6.4
live steam. Has rectifying
section.
Free standing stripper using 11.3
live steam and some digester
relief steam, with condensor
decanter and reflux.
Free standing stripper using J3.3
live and relief steam. Column
has rectifying section.
Stripper built into the 14.4
evaporator train between 1
and 2 effect. Uses steam
from 1st effect and some
live steam.
-------
TABLE 43. POLLUTANT LOAD BY CONTAMINATED COMPENSATES * (6)
Source
Literature
Mill A
Mill B
Mill C
Mill D
Mill E
PH
range 7.5 to 10.5
8.3
10.0
9.6
8.3
9.9
Phenol
fag/1)
4 to 40(6>13)
5.8
33.2
17.6
26.6
29.1
(Ib/ADT)
0.03 to 0.3**
0.04
0.09
0.04
0.14
0.29
*Contaminated condensates analyzed are those segregated by the mills
for steam stripping.
**Calculated on the basis of foul condensates flow of 1,000 gal/ADT.
TABLE 44. REMOVAL OF PHENOL FROM CONTAMINATED
CONDENSATES BY STEAM STRIPPING (6)
Phenol
Mill
source
A
B**
C
0**
E
Steam ratio
(%)
5.6
6.4
11.3
13.3
14.4
Feed
(mg/1)
5.8
33.2
17.6
26.6
29.1
Treated
(mg/1)
5.0
15.8
13.1
10.0
26.2
Removed
(%)*
9.0
49.0
17.0
61.0
0.4
Removed
(Ib/ADT)
0.0036
0.0441
0.0068
0.0854
0.0012
*Corrections have been made for the dilution effects by
condensed steam.
**Column equipped with rectifier.
-104-
-------
AIR STRIPPER SCHEMATIC (3)
CONT. COND.
FEED TANK
SEPARATOR
TO INCINERATOR
FAN
COLUMN
t AIR SUPPLY
STRIPPED
CONDENSATE
FIGURE 30
105
-------
STEAM STRIPPER SCHEMATIC (3)
STEAM
;LEAN
CONDENSATE
CONDENSATE
PRE-HEATER
CONDENSERS
COLD WATER
HOT >•
GAS
WATER
FEED TANK
REFLUX TANK PRODUCT TANK
FIGURE 31
106
-------
.FLOW DIAGRAM
STRIPPER COLUMN INTEGRAL W/ EVAPORATOR (3 )
TO LIME KILN CONDENSER
___
4T--TT -*] * ~+\ r~*\ { 1 CONDENSER
| j * -*Q [_.
1 J 1 1 1 1
STRONG B.L.
STEAM
COND.
i ,
_f-p
DIG. CONDENSATE METH
V
t i LJ-
i
*) 1 *I '
t> 2 L 3 t_ 4 ^5
t r ...^ . i
-r r-r- -r- r-7- -^ '
STRIplpER 1 ' ' " ''
!
• i . , . (
ii i *
r-n 1 'I
_Tl-J T
r'T-r' L
i I ' l — »
»L
r I 1
U-| I 1 f1 1 FOUL CONDENSATE
— 1 j 1 — 1 I
ANOL REFLUX WEAK B.U
FIGURE 32
J
-------
STRIPPING COLUMN DESIGN DETAILS (7)
VAPOR
FEED
NOZZLES
/ N
I )
REFLUX
•MANWAYS
ALTERNATE
PLATES
STEAM
s \
"STEEL
SHELL-
BOTTOMS
.DOWNCOMER
FIGURE 33
LIQUID
FLOW
108
-------
REFERENCES
1. Rowbottom, R.S. and J.G. Wheeler. "Condensate Stripping and Waste Gas
Incineration as an Odor Control Measure at Domtar's Cornwall Kraft Mill."
2. Schutt, H. "Device for Purification of Wastewater from an Organic Chemi-
cal Preparation Process." Chemical Abstracts, Vol. 80 (112285), 1974.
3. Hough, G.W. and R.W. Sallee. "Treatment of Contaminated Condensates."
Tappi 60(21): 83-86, 1977.
4. E.G. Jordan Co., Inc. (Contractor), Portland, Maine. EPA Project No.
68-03-2605.
5. Willard, H.K. "Pulp Mill Wastewater Stripping by Air & Steam." Paper and
Forest Industries Research, National Environmental Research Center, EPA,
Corvallis, Oregon.
6. Gutierrez, L.A., J.C. Mueller, and C.C. Walden. "Steam Stripping of Con-
densates for Removal of Odor, BOD 5 Toxicity & Fish Tainting Propensi-
ties." Paper presented at CPPA Environment Improvement Conference, Monc-
ton, NB, November 1977.
7. Foust, A.S. L.A. Wenzel C.W. Slump, L. Mails, and L.B. Anderson, Prin-
ciples of Unit Operations Wiley & Sons, Inc., New York, 1960. 578 pp.
-109-
-------
7.0 RESIN ADSORPTION
Synthetic polymeric resins are known to not only effectively remove
phenol but also to permit recovery of this valuable chemical. Crook et al,
(1) did extensive work with industrial wastewater effluents containing phenol,
bisphenol A and p-nitrophenol. One of their studies found that Amberlite
XAD-4 reduced the wastewater phenol concentration from 6,700 to less than 1
mg/1. Acetone or methanol was used for regeneration. Both acetone and phenol
(99 percent purity) were recovered by subsequent distillation. It was' also
noted that bisphenol A could be removed by adsorption onto a combination of
XAD-4 and XAD-7. Adsorption capacities of each resin for bisphenol A were
found to be 34 and 16 g/1, respectively. In this case, resins were regen-
erated with ethanol. Both Herve (2) and Chamberlain (3) had similar success
using resin adsorption for phenol removal.
Rohm and Haas (4) has stated that the phenol adsorption capacity of
polymeric resins depends on the type and concentration of phenolics in the
wastewater, as well as the pH, temperature, viscosity, polarity, surface
tension and background concentrations of other organics and salts. Resin
adsorptive capacity changes dramatically with increasing pH. One explanation
for this is that the phenolic molecule changes from a neutral, poorly dis-
sociated form at low pH to an anionic, charged form at high pH. Kim et al.
(5), based on their work with p-nitrophenol (PNP), support this statement.
They also found, with weak acids, however, that as pH decreased below a cer-
tain value, the adsorptive capacity was a "maximum in the pH region in which
the resin was predominantly in the free base form and the PNP was present as a
neutral species." The effect of pH on the adsorption of PNP to a weakly basic
resin is shown on Figure 34.
A high salt background has been noted to enhance phenol adsorption. Rohm
and Haas conducted experiments in which aqueous solutions of phenol and
m-chlorophenol, both with and without salt addition, were passed through
columns of XAD-4. The results, as shown in Table 45, clearly indicate that
the adsorptive capacity for both solutes was greatly increased by the presence
of salt.
-110-
-------
EFFECT OF pH ON ADSORPTION OF P-NITROPHENOI_(4)
"0 P
i .0-
X
I
I .0
10
Pr*> On AclivoKd
Carbon (Rtfi Z9, 30)
7 9
pM
PTunol On
Activottd Carbon
(R«t. XI)
Phtnol On ES-J3
I I I I
13 19
FIGURE 34
111
-------
TABLE 45. EFFECT OF SALT CONTENT UPON CAPACITY
OF AMBERLITE XAD-4 FOR PHENOL & m-CHLOROPHENOL ADSORPTION (4)
Solute in influent
solute adsorbed, Ib/ft
Solute
Phenol
Phenol with 13% NaCl
m- chl o r opheno 1
m-chlorophenol with 13% NaCl
ppm
250
250
350
350
milli-
mol/1
2.7
2.7
2.7
2.7
Zero
leakage
0.78
0.98
2.40
3.10
10 ppm
leakage
0.83
1.09
2.53
3.43
As with carbon adsorption, solute solubility is reported to serve as a
guide to the adsorptive capabilities of XAD-4. "This is illustrated by the
adsorption of phenol, monochlorophenol; 2,4 dichlorophenol and 2,4,6 tri-
chlorophenol. The solubility of these compounds in water decreases with the
level of chlorine substitution, but the adsorptive capacity exhibited by
Amberlite XAD-4 for them increases with the level of chlorine substitu-
tion. "(4)
As shown in Table 46, the specific adsorption of phenols and chlorinated
phenolics on Amberlite XAD-4 resin has been researched. Even with this data,
however, column studies should be performed to select the best resin and
establish operating parameters for specific industrial wastewaters.
Kim et al, (5) in addition to their work with specific resins, summarized
various feasibility studies for using resins for phenol adsorption. One
summary reported the work of Anderson and Hansen in which the hydroxide form
of strong base resins were found to have much greater adsorption capacity than
the chloride form of the same resin, or of a weak base resin. They also found
that the strong base resin could-not be regenerated as efficiently using an
alkaline solution or polar solvent as a weak base resin. The work of Pollis
and Kunin was also included in the summary. These researchers found that the
free base form of weak base resins had an appreciable phenol adsorption ca-
pacity and it could be regenerated with either polar solvents or caustic.
Adsorption was also found to be independent of the organic salt concentration.
•
To regenerate a resin adsorbent, the attractive forces between the phenol
molecules and the resin must first be overcome. Numerous researchers have
stated that this is normally accomplished with either a caustic solution or a
polar solvent for non-ionic adsorbents. (1, 2, 4, 5) Kim et al stated that
acidic or salt solutions may also be used to regenerate ion exchange resin
systems following treatment of phenolic bearing wastewaters.
-112-
-------
TABLE 46. ADSORPTION OF PHENOLIC COMPOUNDS ON AMBERLITE XAD-4
AT 25°C AND FLOW RATE 0.5 gpm/ft
Compound Influent concentration _ Resin capacity
(ppm) (Ib/ft at 0.1 ppm leakage)
Phenol 6,700 5.4
Phenol 3,000 4.5
Phenol (in 13% sodium 250 1.0
chloride)
Phenol
m-Chlorophenol
2 , 4-Dichlorophenol
2,4, 6-Trichlorophenol
250
350
430
510
0.8
2.4
5.1
12.0
As previously described in the Solvent Extraction section, Lorton (6)
evaluated the economics of removing phenols from coke plant process condensate
using biological oxidation, solvent extraction and adsorption. Of these three
alternatives, solvent extraction was the most economical followed by adsorp-
tion and finally, biological oxidation. The results of this evaluation are
shown in Table 31. The adsorption system used in the analysis was developed
by the Rohm and Haas Company and is shown on Figure 35. This process, with
the exception of the superloading step, has been proven at two chemical pro-
cessing plants. One such plant has been in operation since August 1975 and is
reducing wastewater phenolic concentrations from 6,000 to 20,000 mg/1 to less
than 3 mg/1.
-113-
-------
ROHM a HAAS ADSORPTION PROCESS FLOW DIAGRAM (6)
o o
. o
m —
o
MOCCU COMMUTE KIIN ADIOWTKM ««fMiuiiaifnui nuciKMTMHfO »lucTkHUTmmw nucticttMai MUH-mfML FHACIIOMAIM 'MCIICH.TM macnauTM MfiOM
«IHU>a(ll MUM CONMNSm DNUH K1IIM9I11IIUUH BOTTM! CWA1H
Nail. *ut* vai.ri. rTh«a MIMDEW.H.
".^t-^
MCNOL ITOfUM
:p~i
t 1.«>_^ »«••_ J j-o
I !• 00*1 •< MCTCHM TNI Ifluioul *-*
rtl fltlfCn. UMNIIM TO TM M1IMM3CM
'*IM TO M«»IMMO« fHI Mllh LMV1H
I tHl tMIDDII) llllHilf MUfiM
HimiM JCITDC PUMP
HkllMUM no*
«ATI
MO
IIO
4M
4M
• M
CMMIWTI
I,OM
DOO
KM.I10
•04^1M
I.MO
«MH.Mri
IOO
I,*...
IliJH
•in
«KU
"»
NkMO
• M«0 .
iro
jL
•\000
«../.
»M»i
ita
1MW4JW
I
1 !•,«!•
;»,4tl
< Mtiaa
IliO
at
1 1.010
11.1 u
w
1LITUM
,,,.™
IW44O
rM.40U
'M
^
•l.ooa
«4,«40
IUO,I»
'•°
IV\ "
.*?'
nuinc
4O
>i«,i4r
11*400
*••
MOMbf
:
•.1*0
1,110
10
PRELIMINARY
FIGURE 35
-------
REFERENCES
1. Crook, E.H. et al. "Removal and Recovery of Phenols from Industrial
Waste Effluents with Amberlite XAD Polymeric Adsorbents." Industrial &
Engineering Chemistry Product Research and Development, 14(2): 113, 1975.
2. Herve, D. "New Procedure for Treating Wastewaters Containing Phenol."
Chemical Abstracts, Vol. 77, (143609), 1972.
3. Chamberlin, T.A. "Oxazoline and/or Oxazine - Modified Polymers." Chem-
ical Abstracts, Vol. 86, (141260), 1977-
4. Correspondence with the Rohm and Haas Company, Philadelphia, Pennsyl-
vania .
5. Kim, B.R. et al. "Adsorption of Organic Compounds by Synthetic Resins."
Journal Water Pollution Control Federation, 48(1): 120-133, 1976.
6. Lorton, G.A. "Removal of Phenols from Process Condensate." U.S. Depart-
ment of Energy Contract No. EX-76-C-01-2240, October 1977- 24 pp.
-115-
-------
8.0 ELECTROCHEMICAL OXIDATION
Electrochemical oxidation, sometimes referred to as electrolysis, in-
volves the generation of an electrical potential across a cell through which
wastewater is flowing. As a wastewater treatment method, this technology
dates back at least as far as 1900. (1) Available data indicate that no or-
ganic decomposition occurred in these early installations, but it was noted
that significant amounts of sodium hypochlorite were generated from lead
dioxide, graphite and platinum electrodes. The sodium hypochlorite may have
caused interferences with the analytical techniques employed. It was further
noted that low conductivity of wastewaters led to uneconomical power consump-
tion.
More recently, Westinghouse Electric Corporation (2) reported 100 percent
removal of phenols by electrolysis in the presence of an oxidative catalyst
(MnO or CrO») suspended as agglomerated particles in the reaction cell.
Graphite electrodes were used with a 0.5 to 800 Hz current being passed through
the cell. The wastewater, a coking effluent containing 200 mg/1 phenol, was
treated in this manner for one hour and resulted in the complete elimination
of detectable phenols.
A Russian effort (3) investigated electrochemical oxidation on biological
treatment plant effluents, black liquor, first stage alkali extraction efflu-
ents and evaporator condensates. Additionally, a variety of electrode ma-
terials and electroconductive additives were studied. Phenolic removals
ranged from 78 to 100 percent. Current densities and pH were noted as major
operating parameters; 2 to 4 amp/dm showed marked improvement in COD reduc-
tion while a slightly alkaline pH, 7 to 9, was reported as suitable with lead
electrodes. Sacrificial aluminum anodes were reported to be useful for a
greater range of both current densities and pH. Less power was required with
this arrangement also. A major drawback of the process still appears to be
excessive power consumption.
-116-
-------
REFERENCES
1. Miller, H.C. and W. Knipe "Electrochemical Treatment of Municipal Waste-
water." U.S. Department of Health, Education and Welfare, Public Health
Service, Report AWTR-13, March 1965.
2. Westinghouse Electric Corp. "Apparatus and Method for Removing Oxi-
dizable Contaminants from an Aqueous Medium." Chemical Abstracts Vol. 87
(188952), 1977.
3. Serbodol Skii, E.N., M.I. Anisimova, V.A. Babkin, and G.N. Permyakova.
"Purification of Kraft Pulping Effluents by Electrochemical Oxidation."
Abstract Bulletin of the Institute of Paper Chemistry, 49(5): entry No.
4099, 1978.
-117-
-------
9.0 IONIZING RADIATION
Sufficient excitation of organic compounds in wastewater through exposure
to ionizing radiation can lead to their oxidation. Lenz et al (1) studied the
effect of gamma irradiation on pulp mill effluent constituents while varying
aeration parameters. The studies indicated (via COD reduction data) that
oxidation of organic compounds is accelerated by gamma irradiation. It was
noted that oxygen transfer rates were the limiting reaction rate factor since
turbulent air flow produced better results than static high pressure oxygen.
The authors expressed doubts about the economic feasibility of the process due
to the high cost of radioactive source materials. Table 47 contains the
results of their investigations.
Sunada (2) also reported favorably on the phenol reductions experienced
when a chemical plant effluent was exposed to 0.01 Mrad.
Touhill et al, (3) studied the effect of a 175,000 rad/hr dosage of gamma
radiation from a cobalt-60 source on oxygenated phenol solutions. The solu-
tions varied in phenol concentration from 10 to 1,000 mg/1. This-study also
indicated that oxidation was limited by oxygen transfer rates since the rate
of phenol removal was relatively independent of initial concentration. Solu-
tions containing 1,000 mg/1 phenol required 20 hr for 99 percent phenol des-
truction. When oxygen was added to the solution 75 percent phenol destruction
of a 100 mg/1 solution occurred in 60 minutes. At a lower initial concen-
tration of 10 mg/1, an oxygenated solution experienced 95 percent phenol
destruction within 30 minutes. No significant difference between the use of
air or oxygen was noted, although the rate of degradation was greatly ac-
celerated by the addition of either gas at the lower initial concentrations.
Higher dosages of radiation resulted in higher rates of degradation.
•
Nenodovic (4) prepared an article setting forth the principles and prac-
tical applications of ionizing radiation for wastewater treatment. Reduction
of phenols is referred to as a viable application.
Most researchers concluded that the treatment was effective, but too
costly. An apparent reason for this was that the chain reactions expected in
pulp and paper effluents failed to occur.
-118-
-------
TABLE 47. EFFECT OF GAMMA IRRADIATION AND OXYGEN PRESSURE ON pH,
SUSPENDED SOLIDS AND COD OF VARIOUS PULP MILL EFFLUENTS (1)
Irradiation
Sample intensity
no. (million rad/hr)
Pressure Time
Gas (p.s.i.) (hr:min) pH
Suspended
solids
(mg/1)
COD
(mg/1)
COD
removal
A. Kraft strong effluent
1-1
1-2
1-3
1-4
1-5
1-6
Control
8
8
8
8
8
1,900
2,100
2,100
2,000
500
2,100
4:00
0:30
1:00
1:40
2:00
2:00
9.08
8.19
7.52
7.30
7.33
7.05
7.30
48
264
34
60
74
104
59
3,218
2,846
2,461
1,920
1,379
1,092
1,152
11.6
23.
40
57.
66
64.2
B. Kraft strong effluent
II-l
II-2
II-3
II-4
II-5
II-6
Control
6
8
4
8
8
—
-
-
air
bubbled
air
C12
Cl
bubbled
-
-
2,100
-
2,100
2,100
_
1:30
0:30
00
00
30
9.08
8.40
7.58
8.64
6.06
2.98
3.73
48
44
140
152
78
642
680
3,218
2,759
2,410
1,260
1,841
2,442
2,875
14.5
25.1
60.8
42.8
24.1
10.6
C. Kraft weak effluent
III-l
III-2
III-3
III-4
III-5
Control
6
4
bubbled
1
1,900
2,000
2,000
1:30
0:20
4:00
0:20
2:00
6.84
6.61
7.28
02
25
6.82
166
128
152
160
120
174
500
387
260
421
348
245
22.6
48.0
15.8
30.4
51.0
D. NSSC main mill effluent
IV-1
IV-2
IV-3
Control
1,500
1,500
2:00
2:00
6.02
6.18
6.78
112
148
104
862
715
130
17.1
84.9
E. NSSC Woodroom Effluent
V-l
V-2
V-3
Control
1,500
1,500
2:00
1:00
5.31
7.12
6.51
680
236
116
2,911
1,075
482
63.1
83.4
-119-
-------
REFERENCES
1. Lenz, B.L. et al. "The Effect of Gamma Irradiation on Kraft and Neutral
Sulfite Pulp and Paper Mill Aqueous Effluents." Pulp and Paper Canada,
72(2): 75-80, 1971.
2. Sunada, T. "Wastewater Treatment by Radiation." Chemical Abstracts Vol.
80 (112211), 1974.
3. Touhill et al. "The Effects of Radiation on Chicago Metropolitan Sanitary
District Municipal and Industrial Wastewaters." Journal Water Pollution
Control Federation. 41(2), Part 2): R44-R60, 1969.
4. Nenadovic, M.O. Micic, 0. Gal. "Wastewater Treatment by Use of Ionizing
Radiation." Hem. Ind. 28 (5): 217-220, 1974 (Russian).
-120-
-------
10.0 ELIMINATION OF POLLUTANT DISCHARGE
To date, the only published technology for the total elimination of
phenolic discharges is effective indirectly in that it involves the elimina-
tion of any wastewater effluent. A demonstrated technology to accomplish this
feat involves the Rapson-Reeve salt recovery process, substitution of chlorine
dioxide for a majority of the chlorine used in the bleach plant and major
reductions in water usage by complete counter-current bleach plant washing
followed by brown stock washing with the same water. This process is cur-
rently being pioneered at Great Lakes Paper Company's Thunder Bay installa-
tion - an 800 ton/day kraft pulp mill.
In the D/CEDED bleach plant, 70 percent of the chlorine demand is sup-
plied by chlorine dioxide rather than chlorine. This results not only in a
reduction in chloride ion within the system (an approximate 80-percent reduc-
tion) but also maintains pulp quality at the higher temperatures counter
current washing imposes. Water use in the bleach plant is anticipated to drop
to 4,000 gal/ton of pulp. This 4,000 gal/ton will be recycled as brown stock
wash water.
The major innovation is the Rapson-Reeve salt recovery process. Complete
reuse of the bleach plant white liquor would induce the recycle of large
quantities of salt. Recycling of the salt would result in a build-up of the
salt to saturation levels within the system, ultimately causing problems. The
recovery process begins by concentrating the bleach plant white liquor to
26-30 percent NaOH + Na2S. This allows for precipitation of Na2CO., and Na SO,,
but not NaCl. Following removal of these crystals, the liquor is further con-
centrated to 36 to 42 percent NaOH + Na S which causes the NaCl to precipi-
tate. The supernatant liquor is then returned to the digesters while the
precipitate is purified and stocked for production of NaOH and chlorine/-
chlorine dioxide.
Although this method is not specific for the subject pollutants, its use
would eliminate their discharge to the environment.
-121-
-------
PROCESS FLOW DIAGRAM
CLOSED PULP MILL( 1,2,3)
UNBLEACHED
BLEACHED PULP
--fc — ^-~
•—-^ PULPING •
1
^EVAPORATORS) ^
A
H20,C02 0
/^L~ "NTO ATMOS. g
/FURNACEV5^" ^ 1
^\ s H f
> — ^ i f
If * I
• f PULPING CHEM ^
1 L_ .,. REfiFNERATION
1 SMELT AND NoCI
| RECOVERY
1
WATER
WOOD
CHIPS
BLEACHING ~~
Na2S04
TO FURNACE
\
H2S04 \
\ )
Cl BLEACHING
^ CHEMICAL
i
o
o
°
u
i-
<
%
0 1
o m
REGENER.
FIGURE 36
122
-------
PROCESS FLOW DIAGRAM
RAPSON/REEVE SALT RECOVERY PROCESS ( 1,2,3)
STAGE I
STEAM
LIQUOR FROM
STAGE
^.LIQUOR TO
STAGE 2
WATER
CONCENTRATED
WHITE LIQUOR
TO DIGESTERS
PC PROCESS CONDENSATE
SC STEAM CONDENSATE
H E HEAT EXCHANGE
LEACH LIQUOR
TO STAGE I
FIGURE 37
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REFERENCES
1. Stevens, F. "First Pollution-Free Bleached Kraft Mill Gets Green Light."
Pulp and Paper Canada, 76(10): 27-28, 1975.
2. Stevens, F. "The No. 2 Kraft Mill, and What's New About It." Pulp and
Paper Canada 77(11): 28-32, 1976.
3. Stevens F. "Effluent-Free Bleached Kraft Mill is Pioneered at Great Lakes
Paper." Pulp and Paper Canada,. 78(3): 94-98, 1977.
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APPENDIX B
ANALYTICAL PROCEDURES
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B-l
ANALYTICAL PROCEDURES FOR TOTAL PHENOLICS
1.0 TOTAL PHENOLICS
Modified Lowry procedure (Folin-Ciocalteau) of Markwell, Mass, Bieber and
Tolbert, Anal. Biochem. 87, 206-210, (1978). Details:
Reagent A:
2.0 percent sodium carbonate
0.4 percent sodium hydroxide
0.16 percent sodium tartrate
1 percent sodium dodecylsulfate
Reagent B:
4 percent copper sulfate pentahydrate
IN Folin phenol reagent:
2N Folin-Ciocalteau reagent (Fisher Scientific) 1:1 with
deionized water
In the procedure 100 parts of reagent A are mixed with 1 part reagent B
to form reagent C. Standard curve prepared by incubating a sample volume o'f
1.0 ml containing 10 to 50 micrograms of 2,4-dichlorophenol (a surrogate
standard) with 3.0 ml reagent C for 10 to 60 minutes at room temperature. 0.3
ml of IN Folin reagent is then added, mixed, and incubated 45 minutes at room
temperature. Absorbancy is read at 660 nm. Samples are diluted in deionized
water to provide readings within the standard range. Note: pentachlorophenol
does not react in this analysis.
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B-2
ANALYTICAL PROCEDURES FOR PENTACHLOROPpNOL - MILL A
The phenol extraction procedure for FID/ECD analysis is as follows:
1. Place a 25 ml to 100 ml aliquot of each sample in a 125 ml or 250 ml
separatory funnel and adjust to pH 12 with ION NaOH.
2. Extract once with 50 ml hexane, drain the water layer into a 250 ml
beaker and cover with a watch glass.
3. Back extract the hexane once with 25 ml of IN NaOH, combine the
aqueous layers and discard the hexane.
4. Bring the solution to pH <3 with concentrated HC1 (use a hood) and
transfer to a 125 ml or 250 ml separatory funnel.
5. Rinse a beaker with 50 ml of nanograde dichloromethane* then add to
the separatory funnel. Extract the aqueous layer and dry the chlor-
omethane* layer through anhydrous sodium sulfate washed with chloro-
methane*. Drain the aqueous portion into a 500 ml flask equipped
with an ampule.
6. Perform three extractions with 50 ml of dichloromethane* as des-
cribed in step 5.
7. Concentrate the organic portion on a steam bath.
8. Adjust the volume to 6 ml and store in a 2 dram vial with Teflon
seal cap.
9. Analyze via G.C. using the analytical conditions shown below:
1% SP1240DA
on 100/120 Supelcoport, 3 ft x 2mm I.D. glass
Helium carrier gas @ 30 ml/min (FID), Argon/methane
95:5 @ 30 ml/min (ECD)
Column temperature 80°C 2 min to 180°C/@ 8°/min.,
Det @ 250°C, injector 250°C
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All glassware acid washed, rinsed with distilled deionized water,
acetone, and CH^Cl^.
*Petroleum ether is used instead of CH^Cl^ for ECD analyses. Standard
curves prepared using authentic PCP.
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B-3
ANALYTICAL PROCEDURES FOR PENTACHLOROPHENOL - MILL B
1. Place 50 ml sample in 250 ml separately funnel. Adjust to pH <2 with
concentrated HC1.
2. Extract with 50 ml nanograde petroleum ether. Collect organic layer.
3. Repeat step 2 twice with 25 ml nanograde petroleum ether. Combine or-
ganic extracts and dry over anhydrous sodium sulfate.
4. Concentrate on a steam bath using a Kuduna-Danish concentrator composed
of a 500 ml flask, a 3-state Snyder Column and a graduated 10 ml ampule
when necessary for FID analysis.
5. ECD analysis performed on extracts directly or diluted with petroleum
ether as necessary.
6. Analyze via GC using the conditions shown below:
1 percent SP-1240 DA on 100/120 Supelcoport, 3 ft. x 2 mm ID glass.
A. ECD:
Argon/methane carrier gas (95/5) at 30 ml/min.
Injector temperature - 250°C.
Detector temperature - 350°C.
Temperature program - Isothermal @170°C.
Volumes injected - 2-10 microliters.
B. FID:
Helium carrier gas at 30 ml/min.
Injector temperature - 250°C.
Detector temperature - 350°C.
Temperature program - 85°C for 2 minutes to 190°C
at 10°C/minute increments.
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7. Chromatographic performance of underivatized pentachlorophenol was accom-
plished by the following passification procedure.
A. Glass Column and Injector Sleeve Cleanup
Aspirate 20 to 25 ml of the following slowly through in order given:
1. Chloroform or dichloromethane
2. Acetone
3. Water
4. 50 percent KOH in water
5. Water
6. Concentrated nitric acid
7. Water
8. Concentrated hydrochloric acid
9. Water
10. 85 percent phosphoric acid
11. 200 to 250 ml water
12. Acetone
13. Chloroform .
14. Dichloromethane
15. Dry at 100°C in oven
B. Treatment of Glass Wool with Phosphoric Acid
Place. quantity of silanized glass wool in 85 percent phosphoric acid.
Let stand 10 or 15 minutes. Rinse well with water. Soak in acetone, chloro-
form, and finally dichloromethane. Dry in 100° C oven.
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REFERENCES
1. Unpublished information, I.E. Acree and B. K. Wallin,
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B-4
ANALYTICAL PROCEDURES FOR PENTACHLOROPHENOL,
GAS CHROMATOGRAPHY/MASS SPECTROMETRY (GC/MS)
EXTRACTION CONDITIONS
1. Adjust pH of 1 liter sample to <2 with concentrated HC1.
2. Spike with deuterated internal standards* (200 to 400 ppb).
3. Serial extraction with nanograde dichloromethane (125x50x50 ml).
4. Break emulsions by glass wool filtration or solvent addition.
5. Dry combined dichloromethane extracts with anhydrous sodium sulfate
6. Concentrate sample by Kuduna-Danish evaporation to 1.0 ml.
7. Add 100 micrograms d.. anthracene.
MASS SPECTROMETER - HP 5985
amu range: 35450
Scan speed: 300 amu/sec
A/D per 0.1 amu: 3
GAS CHROMATOGRAPH - HP 5840
Column: SE-30 SCOT, (SGE D grade 40,000 Ngff)
Flow rate: 22 on/sec at 200°C
Injection volume: 1 microliter, splitless injection
*phenol - d,, octadecanoic acid - d3_, naphthalene -
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Temperature program: 30 to 260 at 6°C/min.
DERIVATIZATION CONDITIONS
Place 100 microliters sample plus 50 microliters N-methyl N-trimethyl-
silyl trifluoroacetamide in conical vial, heat for 15 min. at 70°C, cool
to room temperature prior to injection.
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B-5
QUALITY CONTROL/QUALITY ASSURANCE -
PENTACHLOROPHENOL ANALYSIS
A. Recovery pentachlorophenol, Gas Chromatography Extraction Procedures:
Trial No.
1
2
3
4
mg/1 mg/1 Percent
pentachlorophenol pentachlorophenol pentachlorophenol
added extracted recovery
1.0
1.0
1.0
1.0
1.07
0.89
0.99
1.00
107
89
99
100
B. GC/FID, GC/ECD, GC /MS comparison:
mg/1
pentachlorophenol
Sample No. GC/FID GC/ECD
5/21/1
5/22/4
5/22/2
5/22/15
5/23/1
5/23/6
5/23/7
5/23/15
5/23/23B
6/1/15
5/31/19
6/6/13
6/7/4
4/26/79
5/23/24A
5/23/27A
5/24/6
74
85
26
71
164
259
35
31
187
1.35
0.18
48
61
45
36
76
98
26
82
128
293
40
37
140
.1.55
0.42
0.112
2.88
50
57
59
31
GC2/MS*
0.170
2.60
36.5
*Corrected for phenol - d_ recovery;
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