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- EPA 560/6-77-005
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PCBs INVOLVEMENT IN THE
PULP AND PAPER INDUSTRY
Task 4
Roderick A. Carr, Robert L. Durfee, and Edward G. McKay
EPA Contract No. 68-01-3259
EPA Project Officer: Thomas Kbpp
Environmental Protection Agency
Office of Toxic Substances
4th and M Streets, S.W.
Washington, D. C. 20460
February 25, 1977
U.S. Environmental Protection
Region b, Library (PL-12J)
77 West Jackson Boufevard, 12th Fl«r
IL 60604-3590
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REVIEW NOTICE
This report has been reviewed by the Office of Toxic Substances, EPA
and approved for publication. Approval does not signify that the contents
necessarily reflect the views and policies of the Environmental Protection
Agency, nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
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ABSTRACT
The sources, distribution, and losses of PCBs in the U.S. pulp and paper
industry are discussed in detail. The major source of PCBs to the industry is
recycled carbonless copy paper manufactured from 1957 to 1971, but the amounts
of PCBs from this source diminished rapidly after 1971. A model showing past
and projected PCBs content in product and wastewaters from the industry is pre-
sented and discussed. Estimated costs (worst-case basis) for wastewater treat-
ment to achieve one ppb PCBs in effluents from the industry are developed;
results indicate a 3 to 5 percent product cost increase will result from such
treatment.
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ACKNOWLEDGEMENTS
The authors wish to express their appreciation to .the many industry
representatives who provided extensive information and guidance, to Mr. Tom
Kopp, the Project Officer for EPA OTS for overall guidance, to Mr. Fred Smith
of EPA OSWMP for assistance in the recycling field, and to Mrs. Nancy Downie
and Mrs. Lillette Steeves for their preparation of the report.
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TABIE OF CONTENTS
Page
1.0 EXECUTIVE SUMMARY 1
1.1 Historical Background 1
1.2 Carbonless Copy Paper 2
1.3 PCBs in Paper Mill Effluents 3
1.4 Purpose and Objective of the Reported Work 4
1.5 Major Results of the Study 4
2.0 PROCESS TECHNOLOGY OF THE PULP AND PAPER INDUSTRY 7
2.1 Background 7
2.2 General Pulping Techniques 7
2.2.1 Mechanical Pulping 8
2.2.2 Chemical Pulping 9
2.2.3 Semichemical Pulping 12
2.2.4 Secondary Fiber Pulping 13
2.2.5 Dissolving and Special Pulps 13
2.3 EPA Classification of Mills by Pulping Method 14
2.4 Papermaking Processes 17
2.4.1 Background 17
2.4.2 Fourdrinier Paper Machine Process 18
2.4.3 Cylinder Paper Machine Process . 19
2.5 Paper Industry: Size and Distribution 21
2.5.1 Water Usage 21
2.5.2 Production History 22
3.0 TRANSPORT OF PCBs IN THE PAPER INDUSTRY 24
3.1 PCB Sources to the Industry 24
3.1.1 Influent Waters 24
3.1.2 Process Chemicals 25
3.1.3 Inks 25
3.1.4 Recycled Waste Paper 27
3.1.5 Other Potential Uses or Sources of PCBs in Paper Mills . 27
3.2 PCB Content of In-Plant Streams and Reservoirs 27
3.2.1 PCBs in Deinking and Pulping Process Water 29
3.2.2 Distribution of PCBs in the Papermaking Process 29
3.2.3 Fate of PCB-Containing Microspheres 31
3.3 PCB Losses from the Pulp and Paper Industry 32
3.3.1 Wastewater 32
3.3.2 Vaporization Losses 34
ill.
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TABLE OF CONTENTS (con't)
Page
3.3.2.1 losses During Papermaking ............ 34
3.3.2.2 losses from Effluent Treatment Ponds ...... 34
3.3.3 Incineration losses ................... 35
3.3.3.1 Bark Burning .................. 35
3.3.3.2 Sludge, Spent Liquor and Carbon Burning ..... 35
3.3.4 Solid Process Waste Losses ................ 36
3.3.5 PCB Concentration in Finished Product .......... 37
3.4 Monitoring Technology ...................... 37
4.0 COST DEVELOPMENT OF PCB REMOVAL FROM PAPER RECYCLING MILL EFFLUENT
STREAMS .............................. 39
4.1 Background ........................... 39
4.2 Plant PCB Wastewater Treatment ................. 42
4.3 Cost References and Rationale .................. 46
4.4 Cost Development ........................ 47
5.0 MODEL OF PCBs INVOLVEMENT IN THE PULP AND PAPER INDUSTRY ....... 55
5.1 Purpose and Objectives of Model Development ........... 55
5.2 First Order Model of Paper Industry ............... 56
5.2.1 Assumptions ............. -. ......... 56
5.2.2 Model Structure ...... ................ 58
5.3 Second Order Model of Paper Industry .............. 68
5.3.1 Industry Categorization for Second Order Model ...... 68
5.3.2 Equations ........................ 72
5.3.3 Quantitation and Exercise of the 2nd Order Model ..... 74
5.4 Discussion of Model Results ......... . ......... 80
6.0 CONCLUSIONS ............................. 82
APPENDIX I - INDUSTRY INTERVIEWS AND PLANT TRIPS
IV.
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OF TABLES
Table Nb. Page
2-1 . EPA Mill, classification 14
2-2 Water Usage in Paper and Allied Products Industries 21
2-3 Product Output and Recycle Rate 23
3-1 Representative Chemicals Used in Pulp & Papermaking 26
3-2 PCB Content of Paper and Paperboard 28
4-1 Sumiary of Distribution and Production of the Paper
Recycling Industry 40
4-2 Effluent Characteristics of the Paper Recycling Plants 41
4-3 Cost Analysis for a Representative Plant 48
4-4 Cost Analysis for a Representative Plant 49
4-5 Cost Analysis for a Representative Plant 50
4-6 Summary of Estimated Carbon Adsorption Treatment Cost at
Different Input PCB Levels 52
4-7 Stranary of Capital Investment of PCB Removal from Paper
Recycling Industry 53
4-8 Summary of Costs of PCBs Removal from Paper Recycling Industry . . 54
5-1 PCB Used in Carbonless Copy Paper 62
5-2 PCB Concentration in Product (ppm) 67
5-3 Annual Production for Industry Segments (106 tons) 71
v.
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LIST CF FIGURES
Figure No. Page
2-1 Generalized Schematic of Paper Production Process 20
3-1 Major Fiber and Water Routes in Paper Production 30
4-1 Pretreatment System Costs 43
4-2 Carbon Absorption Wastewater Treatment System Costs 44
4-3 Flow Diagram of Treatment System for Removal of PCS From
Wastewater 45
5-1 Schematic of First Order Model of Paper Industry 60
5-2 First Order Model with Differing Recovery Rate for Recycled Paper 65
5-3 Affect of Recycling Paper Other Than NCR Carbonless Paper on
PCS Content of First Order Model Production 66
o *
5-4 Schematic of Second Order Model 69
5-5 First Exercise of Second Order Model 78
5-6 Second Exercise by Second Order Model 79
VI.
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APPENDIX I
INDUSTRY INTERVIEWS AND PLANT TRIPS
1-1.0 OBJECTIVES OF INDUSTRY INTERVIEWS AND DISCUSSIONS
From previous efforts under Task I of Contract 68-01-3259, it was
apparent that the data available concerning PCBs in the paper industry were
sparse at best, and that extensive efforts would be required to gather suffi-
cient information for the model development and interpretation. The gathering
of such information was the major objective of all industry contacts during
this work; early in the program industry was made aware of the purpose of and
our approach to the work. Subsequent response and cooperation by the industry
were uniformly excellent.
Specific areas covered during the interviews and discussions included:
1) The level of awareness of the PCB problem within the industry;
2) Analytical data (on PCB levels in products and effluents) which
might be avail able or which might be obtained and made available
r
at a later date;
3) The possibilities and practicalities which bear on treatment of
mill effluents, or on internal water reuse and purification
systems;
4) Present trends in treatment technology as the mills prepare for
adherence to the 1977 and 1983 effluent quality criteria;
5) The standard practices of sampling and analysis which generate
the data base of PCB levels in the plants;
6) The similarities and differences found between production mills
operating under current bounds of raw material, energy, labor
and treatment costs; and '
7) PCBs transport within the plants.
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1-2.0 MEETINGS WTIH TRADE ASSOCIATIONS
1-2.1 Meeting with
In mid-July, 1976, a meeting was held in Washington, D. C. with
representatives of the American Paper Institute (API) , the Boxboard Research
and Development Association (BBDA.) , the National Council of the Paper Industry
for Air and Stream Improvement (NCASI) , senior staff members from several API
member companies, and the EPA Office of Solid Waste Management Programs
(OSVWP) . The approach to tiie program, and particularly the PCBs-industry
model, was outlined and discussed in detail. Cooperation and needed informa-
tion were solicited, and plans for the provision of available or anticipated
data were made. All areas noted under Section 1-1.0 were covered.
1-2.2 Meeting with Institute of Paper Chemistry (IPC)
On August 6, 1976 a meeting was held with staff members of the
IPC in Appleton, Wisconsin. John C. Wollwage, Vice President-Research; Dr.
H. S. Dugal, Director, Industrial and Environmental Systems Division; Dwight
5. Easty, Group Leader, Analytical Chemistry, Division of Natural Materials
and Systems; Mr. George Dubey; and Mr. Peter Parker (all of IPC) took part in
the discussions.
At that time the IPC was performing an in-house study aimed at
development of an improved procedure for PCS analysis in pulp and paper mill
matrices. They had attacked the question of PCS partitioning in mill flews and
found PCBs to be substantive to fiber, associating most notably with the small
particulate constituents (fines) of the pulp/water system. White water high
in f IT-IPS content is routinely recycled in order that as much of the fiber as
possible eventually become products since fines have a desirable effect on the
qualities of opacity and surface smoothness. Economical use of the raw fiber
requires a minimization of the fines loss. Such a procedure appears to pre-
ferentially associate the major portion of any PCBs .with the paper product.
It was also agreed that the PCB concentration in the waste sludge
might reasonably be assumed to be at the same concentration as in the product.
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m other words, if the PCB levels in paper product is in the low parts per
million range, PCB levels in the sludge will also be in this range. The
limited sludge data obtained supports this contention, and at the same time
shows paper mill sludges to be comparable to municipal treatment plant sludges
in PCB content (ranging up to 23 ppm) '.
The majority of PCBs introduced to papermaking as part of the
wastepaper input were believed by the IPC personnel to be still enclosed in
the gelatin-gum arabic microballoons. The microballoons (10 - 20 microns in
diameter) are known to be substantive to fiber. They release their PCB load
for analysis upon treatment with alcoholic KQH solution. It was not known
what fraction of the incoming capsules may break open, nor whether the pulping
and refining steps may cause breakage, but it was suspected that relatively
few of the microballoons would rupture during the papermaking process.
In addition, it was decided that PCBs in intact capsules would
not participate in evaporation as "free" or "wild" PCBs may be able to do.
Mass balances done by IPC on some paper mills have given an indication of a
possibility of evaporative losses, but not in large amounts, nor in amounts
which would jeopardize the overall, conclusions or credibility of the model
presented in Section 5.0 of this report.
During the analytical methodology work by IPC, small amounts of
PCB used to spike solutions showed significant evaporative losses. This has
resulted in a strong recommendation for the minimization of sample transfers
and handling in analysis for PCBs.
Present analytical capabilities at IPC show detection limits for
paper to be 0.1 ppm PCB and for solutions to be 0.1 ppb PCB. Both call for a
trained operator conversant with and practiced in routine PCB analysis.
Interferences on the chromatogram appear to be removed in good
part by oxidation of the sample with chromium trioxide. These interferences
seemed to be peculiar to the types of matrices found in pulp and paper proc-
esses. Attempts to simplify PCB analysis by perchlorination of all PCBs to
decachlorobiphenyl were found to give unsuitable results. This treatment
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appeared to have converted sane non-PCB components of carbonless copy paper
into a form which could be incorrectly identified as PCBs.
Other aspects of the problem and of the IPC program were dis-
cussed in detail. Many of these are discussed or referenced elsewhere in this
report. The results of this meeting served to solidify the approach to the
model and the selection of parametric values to be used in exercising the model.
1-3.0 PLRNT VISITS
Seven paper mi I la were visited during the program; four of these
utilized between 50 and 100 percent recycled material. The others either were
companies known to be very much aware of the PCBs problem and using some
recycled fiber or mills using only virgin fiber. Short summaries of the trip
reports for these plants are included below. As will be noted, some plants are
not named in these sunmaries.
1-3.1 Plant A - 100 Percent Recycled Raw Material,
General Description
Plant A employs approximately 300 people and has a Fdurdrinier,
two cylinder machines and a Printer Tinter. The raw material used is waste-
paper which has been sorted, graded, baled and marked by organized paper stock
dealers throughout the Midwest. The most important grades used are reclaimed
corrugated containers, mixed paper, newspaper and clippings trimmed from box
shops and converting plants. Much of the stock is picked up in large cities
by company trucks as return loads after delivery of the finished board. This
re-use of secondary fibre eliminates a large amount of paper tonnage being
sent to landfill or incinerated. In 1971 85,000 tons of wastepaper were re-
claimed through this plant.
The basic product manufactured from the wastepaper is paperboard.
This product is used for core stock, tube stock, wrapper, carton, paper box,
book bindings, and globe stock.
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r, Cleaning and Refining
The first step in converting paper stock to pulp is called
hydration; machines called hydropulpers axe used. These are large tubs with a
rotating disc in which the dry paper is mixed with warm or hot water. Chemicals
may be added to aid in the dissolving process and to destroy any bacteria which
may be present. Most of these machines operate on a continuous process. As
soon as the fibers are dissolved fine enough to be extracted through 1/8" holes
they are screened off.
The various cleaning and refining processes which follow pulping
are typically a spin-off to remove light particles of foreign material, and
settling to remove heavy dirt. In addition, there are several systems of
mechanical screening to remove coarse or undefibered bundles and dirt. Not the
least important is a treatment of high pressure - high temperature steam fol-
lowed by a refining process for the purpose of breaking down foreign materials
like pitch, wax, or asphalt which may be found in the wastepaper.
After the paper stock is cleaned and defibered, it is stored as a
liquid suspension in large chests. Before going to the paper machine the stock
is again refined or "brushed out" in machines called Jordans or Refiners, mixed
to an exacting consistency with water and screened one last time.
Papermaking
Plant A employs both Fourdriner and cylinder-type paper machines.
The latter employ cylinders covered with fine mesh wire to extract pulp from
the slurry stock onto the surface. The material is then deposited in thin
layers (one from each cylinder) to form the wet web. After all the cylinders
have deposited their contribution of fibers, the wet web of paper is pressed
to remove excessive water. Each pair of press rolls gradually increases the
pressure until the wet web is dry enough and strong enough to support its own
weight when it leaves the press section.
The Fourdrinier machine employs a long wire belt for formation
of the wet web. Paper stock is fed onto the moving wire through a sluice from
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a headbox, and, in contrast with a cylinder machine, the web is made up as a
contiguous single layer. Over a relatively short di stanoR enough water drains
through the wire by gravity and by passing over suction boxes that the mat can
leave the wire and pass onto a felt where pressing begins.
All machines employ a long section of many steam heated cylindri-
cal dryers. As the sheet leaves the wet end after all possible moisture has
been removed by mechanical pressing, the remaining excess moisture must be
removed by evaporation. The sheet of paper passes over ail of these dryers
which eventually produces a dry sheet to customer specifications.
The last step in the actual paper manuf acturing is calendering
or pressing for the purpose of obtaining a uniform finish and thickness. Also
at this station it is possible to apply surface sizing or other forms of coat-
ing or stain.
After passing through the calenders the paper is wound onto
reels to be rewound and trimmed to meet size orders. If the customer wants his
paper in flat sheets, it is run directly from the paper machine through a
sheeter. In either case, when the paper is finished it is banded, wrapped,
igbglgct, and weighed.
A substantial amount of the total production of Plant A is sent
to a converting plant for further processing. Most of this processing consists
of slitting wide rolls into narrow widths to be used for winding into cores
and tubes. This plant also performs cutting from rolls into sheets, precision
trimming of sheets, and laminating.
1-3.. 2 Plant B - 90 Percent Recycled Raw Material
General Description
This plant is a major manufacturer of tissue items, producing
800 tons of facial tissue, toilet paper, napkins and paper towels per day.
Approximately 90 percent of the raw material required is supplied by waste
paper, which is a slightly higher percentage than most other tissue mills.
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Plant personnel supplied a report on PCBs generated by them in
1975. The concern for effluent water quality dates back to the establishment
of a primary treatment'system in conjunction with the start-up of a deinking
process in the 1930's. The secondary treatment system was put into operation
several years ago, prior to the regulations governing suspended solids. A
tertiary process is in the development stage at the present time. PCS measure-
ments were begun in-house during 1975. Data on PCBs content of products prior
to 1975 have been obtained and are reported elsewhere.
Characterization of Raw Material
Although most of the raw material for this plant is wastepaper,
less than 50 percent of this is classed as post-consumer waste; in other words,
most of the returning paper stock has never been previously recycled. Office
wastepapers of the ledger grades are removed from the incoming stock, but a
quantitative screening of all returning paper stock is impossible from an
economic standpoint. As shown by industry data and the modeling effort in this
report, even a few sheets of the carbonless copy paper can have an observable
affect on PCS concentrations in a single day's output.
Office wastes in general do not make a desirable paper stock,
since many office paper products contain binders, colorants or other minerals
that are difficult to remove and cause problems in the papermaking process.
These wastes are purchased by the mill primarily to assist their paper dealers.
They do become more important during periods of short paper stock supply.
Effluent PCS Levels
PCB concentrations in clarified mill intake water were less than
0.1 ppb. Measurements of deinking, mill and combined effluents were reported
to range from 0.3 to 2.7 ppb.
In-Plant Vaporization Estimate
The plant has performed a water mass balance on its paper
machines. An average of 570 gal. per ton of product was lost. Assuming the
production of 800 tons per day and a water concentration of PCBs (excluding
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KBs bound to fines and assured nob to evaporate) of 0.1 ppb, evaporative losses
would be 0.00038 pounds of FOB per day or less than 0.15 Ibs/year. This is
probably an. undetectable loss if direct measurement was attempted.
1-3.3 Plant, C - 80 Percent Becycled Raw Material
Pulp Generation
Pulping is a batch process.at this plant. Wastepaper, accounting
for about 80 percent of the raw material, is added to pulpers 13 and #4 to-
gether with hot water and caustic soda. Steam jets raise the temperature to
about 185°P and deinking continues for about 1.5 hours. After deinking, the
stock fran both pulpers are dumped together yielding a stock slurry of about
7 percent consistency. From here the stock is passed through a one inch bar
screen that removes large contaminants such as string and rags. The pulp is
now punped to a holding chest.
Manually operated valves determine the quantity of stock dis-
charged from the holding chests through two 1/8-inch, screens. The accepts here
have a concentration of about 4.5 percent, and rejects from the screens are
trucked to a landfill. Accepts are stored in another holding tank.
Upon leaving this tank, the stock is diluted to about 0.7 per-
cent solids and run through centrifugal cleaning to remove fine contaminants.
Accepted stock is now directed to a screen with 0.010 inch slots. Accepted
stock from this screen pumped to two slope washers that have counter-stock flow
of water. These washers are arranged in series with the second one increasing
the stock consistency (solids concentration) to about S percent.
At this point the stock is pumped to two washers set up in
parallel. The washed stock, with a consistency of about 2 percent solids, is
pumped to a storage tank until the chlorination tank is ready for a new batch.
Water for the washers comes from the slope washers.
During chlorination, chlorine gas is pumped into a tank holding
the stock and allowed approximately five minutes retention to react. The stock
batch is then pumped towards a vacuum washer. However, before it is washed,
sodium hydroxide is afH^d which reacts with any residual chlorine to form
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sodium hypochlorite to augment the bleaching process; the final pH is 9. The
bleached stock is sent to retention tanks.
The stock pulp is sent to a vacuum washer to remove materials
made soluble by chlorination. This wash water originates from the paper machine
water supply, the white water. The filtrate from the washing process is pumped
to the slope washers which conditions the new batch for chlorination by reclaim-
ing the chemicals and also reduces the amount of water used. The stock pulp
now has a consistency of about 5.5 percent. Upon leaving the washers, the
stock pulp is pumped to high density storage tanks to await the papermaking
operation.
This mill also has a separate pulping system for virgin pulp and
pulp substitute. However, both virgin and substitute pulp are blended with
the wastepaper stock pulp. Here, chemicals are added to develop better fiber
bonding strength.
From the storage tanks the stock pulp is diluted to about a 0.3
percent consistency and pumped to the headbox. Prior to entering the headbox,
the pulp is rewashed, rescreened and run through a three stage centrifugal
cleaning system. Much of the water used in papermaking is recycled. Excess
white water is stared to be utilized in various operations in the mill.
The sheet is pulled through on a felt belt and dried. The speed
that it is pulled through regulates the strength of the product. Thickness is
governed by this speed and by slicing the sheet off the belt with a doctor
blade. Several plies are 1±en rolled together to produce a paper of desired
specifications.
Water Source and Effluent Treatment
Plant C uses municipal water which is believed to be relatively
low in PCBs. The intake volume is about 1.5 million gallons per day.
The discharges from Plant C enter a wet well from which the
wastewater is screened and sent to a ccmpany-operated treatment plant.
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Treatment consists of primary clarification and a two-stage activated sludge
system. Hie treatment plant effluent is discharged to the Fox River (mid-
stream) .
1-3.4 Plant D - 50 Percent Recycled Saw Ma^-Hai
Plant D is a major recycling operation. Six grades of wastepaper
(e.g., office and foodboard) are the major constituents of the raw materials
utilized to produce acceptable deinked pulp stock. This accounts for approxi-
mately 50 percent of the required pulp with the remaining being composed of
purchased virgin pulp and pulp substitute. There are essentially two pulping
systems - one for wastepaper and deinking and the other for the virgin and
substitute pulp.
Pulping and Fiber Recovery
Here, wastepaper is mechanically broken down with hot water
(about 190°F), caustic soda, surfactants and deinking chemicals by means of a
ribbed rotor at the bottom of the hydrapulper. Much of the heavy waste such
as metallic objects and plastic sheets are collected in traps at the bottom of
the pulper. At this point, the pulp stock has about a 6 percent consistency
(consistency being the percent solids to liquid).
The deinked pulp leaves the hydrapulper through perforated plates
and is pumped to blending chests for additional retention time and agitation.
The pulp now has about a 2.5 percent consistency. Upon leaving the chests, the
pulp is passed over a filter that recovers the cooking liquor in the filtrate.
The filtrate is reused in the pulper to recover the heat and residual chemicals.
Excess washer water is reused for other operation dilutions. Water is exten-
sibly recycled in the deinking operation.
The pulp is now sent to centrifflers, which are .centrifugal
cleaning devices for removal of pins, staples, and other heavy particles. The
accepted pulp has a 2 percent consistency and it is sent to a centrisorter
pressure screen. Accepted stock from the pressure screen goes on to washing
while rejects are passed through a deflaker and then across a screen for
further fiber recovery.
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The pulp then enters a four-stage counter-flow washing system.
The first stage consists of 2 cylinder washers, the second and third stages .
consist of sidehill washers, and the fourth is another cylinder washer. The
cleanest water is used for dilution at the fourth stage and the filtrate is
fed to the preceeding (third) stage. This filtrate is then used in the second
stage and its filtrate in the first stage, where the filtrate is discharged to
waste treatment. The water in the washing process originates from the dis-
charge of the paper machine water, white water, and the acid and alkaline
bleaching water.
Following washing, the stock is bleached with chlorine, followed
by treatment with caustic and then hypochlorite. The next treatment is a
three-stage pressure screen system. Accepted stock pulp from the first stage
pressure screen then goes to a five-stage centrifugal cleaner system for
removal of small heavy contaminants such as ink. Those fibers rejected are
replaced in the centrifugation scheme to concentrate the contaminants and
unacceptable pulp, and to reclaim as much of the shunted acceptable pulp as
possible. Following this is a four-stage system of centrifugal reverse
cleaners for removal of lightweight contaminants such as plastic fibers and
adhesives. After the cleaning system the stock goes to the final washer for
thickening and storage in high-density towers. The water removed by the
thickening process is reused in other washings and in the bleachery.
The above description for secondary pulp supplies 50 percent of
the materials required to meet the current demand of Plant D. The remainder is
composed of purchased virgin pulp and pulp substitute. Both are warehoused in
solid form and repulped in their respective hydrapulper, using recycled paper
machine white water. This pulp is then pumped to storage chests until needed.
From here, the pulp is sent to refiners for fiber shortening and fibrillation
to enhance greater bonding capacity-
From the refiners the pulp is discharged into a pipeline that
contains the secondary pulp for blending of the types. After sufficient time
to ensure homogeneity, components such as clay, titanium dioxide and alum, to
name a few, are added to the stock pulp as it moves to the paper machine.
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Papermaking
Stock taken from the high density storage tanks is diluted and
pumped to the papermaking system. Here the stock volume is controlled to
insure a constant head level. By operating under a known head, the texture of
die pulp sheet falling on the Fourdrinier remains the same throughout the
operation.
The endless mesh belt of the Fourdrinier effectively drains
enough water from the pulp slurry to permit the fibers to make a sheet called
the wet wab. Much water is recycled during papermaking operations. Since
this water is falling from the bleached product, the pulp imparts a white color
en the water and hence is called white water. Because water is continually
being added here, there is an excess overflow. This surplus water is stored
and used to supplement the water diluting the deinked stock. Several hundred
thousand gallons of water escape each day due to evaporation while the paper
is being pressed and dried. When the pulp leaves the headbox, it is 99 per-
cent water; after passing through the presses, it is about 60 percent water,
and after the driers, only about 5 percent moisture remains. This is the per-
cent moisture of the rolled product.
Intake Water and Wastewater Treatment
Since the product color and composition is highly important, the
water used throughout the operations necessarily should not contain any sus-
pended contaminants that are able to be removed. Therefore, this mill has a
treatment facility for intake water, utilizing flocculation with aim and lime,
addition of algacide, and filtration. The filter is composed of the following:
top layer - 8 inches of coal; middle layer - 2 feet of sand; bottom layer - 2
feet of crashed stone.
Currently, this mill only has primary treatment, a clarifier.
The present system has about 90 percent SS removal but only about 25-30 percent
CBD reduction. The effluent from this clarifier is being discharged to the
Fox River. The average flow for 1975 was 3.9 M3D. This volume can be broken
down as follows:
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2.5 M3D from deinking
.9 MCD from papermaking
.3 MGD from water plant
.2 MGD disposal plant and misc.
Under construction new at Plant D is a 2-stage activated sludge
system. Preliminary investigations on this type of treatment facility for pulp
and paper wastewater discharges indicates that this system is very effective
at further reducing the SS levels and greatly reducing effluent BOD.
Clarifier sludge contains 10 percent solids and is further con-
solidated in compaction tanks to a 12 percent solids level. The sludge is
furthered dewatered to 28 percent solids by lime addition and subsequent
vacuum filtering. The filtrate is returned to the primary clarifier and the
dewatered sludge is trucked to their private landfill..
Landfill Operations
The company has opened a new landfill which covers about 18 acres.
Preliminary geologic investigations revealed a solid bedrock foundation. The
area is encompassed by a man-made compacted day dike, effectively eliminating
any surface runoff from the landfill.
Concern for groundwater contamination resulted in the construction
of monitoring wells. There appears to be two layers of groundwater separated
by a clay table. When completely filled, the landfill will be slightly dome
shaped with a 2 degree slope.
1-3.5 Plant g - Less Than 50 Percent Recycled Raw Material
General Description
Plant E is basically self-contained, i.e., it produces in-house
nearly 50 percent of their filer requirement by cherai-inechanical treatment on
hardwoods. The remaining 50 percent is composed of purchased bleached kraft
pulp from Canada and other U. S. sites and such items as foodboard, cups, and
IBM cards. No carbonless paper is utilized. Production is between 300 and 400
tons per day.
1-13
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Product PCS levels f ran Plant E have consistently remained below
5 ppm proscribed by FDA. Effluent levels of PCBs are also apparently lower
than most of the industry using reclaimed fiber, probably because of efficient
removal of suspended solids in the waste treatment systems.
Pulping
Plant E "»?s gJTgnl-inec3Tlanic!a^ pulping/ virgin pulp from purchased
bleached kraft pulp, and secondary pulp from wastepaper. Each operation occurs
in a specific pulper and the stock is blended later according to product speci-
fications. The virgin pulp slurry is generated by only adding hot water while
the secondary pulp requires hot water plus caustic soda plus hypocnlorite bleach
ing powder. Both virgin and secondary stock pulp are not stored but directly
mixed with the <±emi-inechanical pulp stream. Plant E is a continuous operation,
and all grades of pulp are being used simultaneously but only that from the
chemi-mechanical system is allowed a detention.
Blending of pulp grades occurs in machine chests, each having a
different percentage of the grades depending on the eventual product. It is
just prior to these chests that other additives such as clay and other fillers
are added to provide the required paper characteristics.
Each pulp stream is passed through similar machines, with all
machines having an additional coating step. The stock pulp enters the Fourdriner
to produce the wet web, approximately 19 percent of the water content is voided
here (in other words the web's consistency increases from 0.5 to about 20 per-
cent) . The wet web is then drawn through a series of presses to further remove
the water. The majority of the remaining moisture is removed by drawing the
sheet through a series of dryers. Final moisture is about four percent.
Following the drying operation, the sheet is passed through
rollers to smooth it and produce a uniform thickness. It is then rolled,
trimmed, cut and warehoused. Some cut rolls are sent directly to a specification
cutting section for high-demand dimension consumer products (a sizeable fraction
of the total production is used for telephone books) .
1-14
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Waste Treatment
This plant utilizes two waste facilities; a fluidized bed incin-
eration for spent liquor in the pulp mill operation, and a wastewater treatment
plant for water used in the papermaking process plus excess wash water and
associated solids from the pulp mill.
The chemi-mechanical pulp mill effluent with a 6 percent solids
content is sent to an evaporator where -the solids content is increased to about
45 percent. The liquor, now a syrup, is placed in the incinerator operating at
approximately 1300°F, and the remaining moisture is flashed off allowing the
organics to be volatilized. At the bottom of the unit, air jets keep the ash
in motion (fluidized). Therefore, pulp mill activity is a closed system with
no effluent, and the excess ash is trucked to a landfill.
Wastewater currently receives only primary treatment in two
*
parallel clarifiers, but removal of approximately 96 - 98 percent of the sus-
pended solids is achieved with 40 - 50 percent BOD removal. A new secondary
treatment system will begin operations in the near future. Overflows from the
clarifiers will be combined and discharged to the secondary treatment reactor,
which is a closed, oxygenated, three-segment tank. Effluent from the reactor
is then sent to a settling tank and after a determined retention time the
supernatant liquid is discharged to the Fox Fiver. The new system is designed
to handle 6.5 mgd with a three hour retention. The mill has recently reduced
its water requirement from 8 mgd to 6.8 mgd in preparation for the secondary
system.
The sludge will be removed with some of it reused as seed in the
oxygenated reactor tank while most of it will be dewatered to about 22 percent
solids by a vacuum filter. This waste sludge is presently deposited on a land-
fill. There is no monitoring for groundwater contamination at this time.
Management is currently communicating with other mills that may
be able to use their sludge as it contains a high fiber concentration that can
be used for other paper products.
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1-3.6 Crown Zellerbach Research Laboratory and Catnas
A meeting with Dr. Herman R. Amberg, Director of Environmental
Services for Crown Zellerbach and members of his staff was held on June 29,
1976, at the Central Research Division in Canvas, Washington. Crown Zellerbach
has a number .of mills which range frcm total use of virgin fiber to complete
dependence on secondary fiber. Since most chemical analyses are done at the
Central Research location, it was felt that the question of analytical
accuracy could be de-emphasized and relative differences in PCB concentrations
assessed.
CZ analytical detection limits for PCBs in paper were routinely
1 ppm and are apparently dropping under continued attention to details of the
analysis. Some data had been taken as far back as 1971. A number of important
points were discussed:
1) No measurable PCBs had been found in virgin wood.
2) Exhaustive sampling and analysis had failed to identify
any PCB generation during the pulp bleaching stages.
3) Process chemicals were surveyed to identify any sources
of PCB and none were found.
4) Data would be made available through API.
A tour of the Camas Mill, which makes specialty papers, was taken.
This mill used virgin pulp, a snail amount of purchased pulp, sawdust and wood
chips frcm, surrounding gamniiis 35 its raw material. Inputs of PCB were there-
fore limited to that occurring in the intake water.
1-3.7 Weyerhauser Company
Cfc June 25, 1976, Dave Morris and Ted Ross of the Weyerhauser
Corporate Engineering Department at Taocma, Washington met with a Versar rep-
resentative. Mr. Ross had previously been involved with EPA contract work
which related to effluent guidelines for the pulp and paper industry and both
were following PCB-related matters.
1-16
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Vfeyerhauser's papermaking operations are based on a 100 percent
virgin fiber raw material. As a result, it was believed that this mill would
only encounter PCBs that ware associated with the intake water, or as a result
of internal PCB uses in transformers or capacitors. Contingency spill plans
were set up in every mill; transformers containing PCBs were rHVe*3 and
monitored for any signs of leakage.
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1.0 EXECUTIVE SUMMARY
1.1 Historical Background
In 1966, Soren Jensen reported the presence of PCBs (polychlorinated
biphenyls) in Swedish fish, and wildlife as a result of a study begun in 1964.
The Food and Drug Administration began, in 1967, a program to develop analytical
techniques for PCBs. During this period concern about PCBs in food and in the
environment of the United States was increasing. In 1969, FDA alerted its
Districts to expect PCBs in food samples, and to analyze for PCBs in foods
sampled for pesticide analysis. Findings of PCBs in fish, milk, eggs, and
poultry samples occurred throughout 1969 and 1970.
In August, 1971, a significant level of PCBs was found in a grain and
cereal composite of a Market Basket sample by FDA in their Total Diet Studies,
and the contamination was traced to the greyboard packaging of a cereal. According
to FDA (supporting data for Press Briefing by Dr. C. C. Edwards, September 29, 1971),
the highest PCBs level found in greybeard was 433 ppm. FDA met separately with
the American Paper Institute and with food manufacturers in September, 1971 to
inform them of the PCBs problem in foodboard and to discuss approaches to its
solution.
By the end of September, 1971, all concerned parties appear to have
agreed that the major source of greyboard contamination was recycled carbonless
copy paper which was known to contain PCBs. Production of this material had
ceased as of June 1, 1971, but recycling was continuing. In the same time frame,
Monsanto Industrial Chemicals Co., essentially the sole U.S. producer of PCBs,
announced cessation of sales for all but closed electrical systems (capacitors
and transformers) applications.
On July 6, 1973, the FDA issued its final rule-making document on
tolerance levels of PCBs in various foods and paper food-packaging material (10
ppm for paper food-packaging). By this time the paper industry had succeeded in
reducing PCB levels in food-packaging materials made wholly or partially from
recycled fiber to well below the FDA tolerance limit. This appears to have been
accomplished through, more judicious selection of recycled fiber for foodboard
manufacture, including:
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(1) Cessation of use of cutting scrap fron office form production
(where, carbonless copy paper content could be very high}; and
G2) Limitation or selectivity in the use of office waste for
foodboard production.
Levels of PCBs in foodboard have generally continued to decline since
1973 to a current level of less than one ppm, except for occasional "hot spots"
resulting in levels of up to five ppm, Ihese "hot spots1* are generally attributed
to the inclusion of significant quantities of outdated office files containing
carbonless copy paper. PCS levels in other paper products are also in the one
ppm or below range; those made from virgin pulp, of course, exhibit by far the
lowest FOB levels.
1.2 Carbonless Copy Paper
Aroclor 1242, a mixture of PCBs containing an average of 42 per cent
chlorine, was purchased from Monsanto and used in carbonless copy paper as an
ink carrier or solvent during the period 1957-1971. The total amount used for
this purpose was 44,162,000 pounds, approximately 28 per cent of the total
estimated Monsanto gales for plasticizer applications and 6.3 per cent of
Monsanto domestic sales of PCBs during 1957-1971. The average content of Aroclor
1242 in the carbonless copy paper was 3.4 per cent.
The National Cash Register Company (NCR) was the developer and sole
marketer of the PCB-containing carbonless paper, although Appleton Coated Paper
Co., Appleton, Wisconsin; Mead Corp., Dayton, Ohio; Combined Paper Mills,
Combined locks, Wisconsin; and Nekoosa-Edwards Paper Co., Port Edwards, Wisconsin,
at one time or other performed the actual production under license from NCR.
The Aroclor 1242 was used as a solvent for certain color reactants which
were encapsulated into microspheres producing aggregates 10-20 microns in diameter
and applied to one side of the paper during the coating process. The walls of the
microspheres were an aldehyde-gardened gelatin-gum arabic formulation which rupture
and released the dye under application of local high,pressures as from pens or
pencils. In 1971 alkyl-biphenyls were used as the dye carrier in place of
Aroclor 1242.
-2-
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It should be noted here that PCBs, primarily Aroclor 1254, were used
to a limited extent in printing inks. The total usage in this application is
estimated at 50,000 pounds, primarily in the 1968-71 time frame. No other actual
or potential usage of PCBs in paper product or usage besides the copy paper and
these inks has been definitely identified to date.
1.3 PCBs in Paper Mill Effluents
It has been recognized for several years that effluents from paper mills
contain environmentally significant quantities of PCBs. The PCBs in these waste-
water streams are generally more similar to Aroclor 1242 than to any of the other
Aroclors or to PCBs found in the general environment and biota (which tend to
exhibit chromatographic fingerprints corresponding to higher chlorine contents
than 1242). Thus, although introduction of PCBs into paper-making processes
through process water usage undoubtedly occurs (PCB levels at water intakes of
paper mills average about 0.1 ppb), the major source of process contamination by
PCBs appears to be carbonless copy paper contained in recycled wastepaper.
A number of paper mills, in response to the need for improvement of water
quality, have installed or are now installing waste treatment processes which are
expected to greatly reduce the PCB levels in their effluents. However, these
levels may still be typically above the one ppb level proposed by EPA on July 23,
1976 as an effluent standard for capacitor and transformer manufacturers, and the
quantities of wastewater from paper mills are generally much larger than from such
equipment manufacture. In addition, sludges or concentrates from paper mill
water treatment may be sufficiently high in PCBs as to warrant concern about pro-
per disposal. "
The magnitude of the PCB control problem is illustrated by the existence
of 230 paper mills producing pulp completely derived from recycled wastepaper and
550 other facilities utilizing some fraction of secondary fiber in their pulp
production (typically 10 to 15 per cent). Recycled wastepaper amounts to
about 13 million tons per year as a pulp source, third in importance to pulpwood
and forest product wastes.
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1.4 Purpose and Objective of the Beported Work
The purpose of the work reported herein was to bring together all
relevant information and data concerning PCBs in the paper industry, and to
interpret these data with regard to present and future environmental significance.
Specifically, the report addresses the sources, transport and release of PCBs
throughout the paper industry; the historical perspective and projected future
impact of PCBs usage in carbonless copy paper; and a preliminary account of
technology and costs associated with abatement of PCBs in paper mill effluents.
The data obtained on intake and effluent PCB levels, on paper recycling statistics,
etc., from industry and other sources are also discussed.
There appears to be general agreement that the entry of PCBs into the
paper industry was completely unintentional, that the industry responded well to
the need for reduction of PCB levels in food packaging, and that waste treatment
systems for suspended solids removal (albeit installed for purposes other than
PCB control) will significantly reduce PCB discharges from the industry. Never-
theless, continuing and increasing concern by the public and by state and federal
agencies regarding environmental and human health effects of PCBs, including con-
tamination of food packaging materials as well as PCBs in wastewater, have repeated
focused attention on the paper industry, much to the concern of that industry.
The objective of this report is to present the actual situation, as accurately as
possible, in order to serve those who must make regulatory decisions potentially
affecting a valuable resources recovery industry.
The concern of the industry was reflected in their excellent cooperation
with the project. Cooperation and support from federal and state agency personnel
were also uniformly excellent. However, it should be noted that, in general,
there was a scarcity of data in several relevant areas, particularly historical
data prior to 1975; this was the major limitation to the accuracy and completeness
of the results obtained. Results of industry visits are presented in Appendix I.
1.5 Major Results of the Study
Since 1971, when NCR carbonless copy paper was no longer manufactured wil
a PCB dye solvent, PCB concentrations in paper products, effluents and sludges
-4-
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have shown a precipitous decline. The former are now in the 0-1 ppm range for
most products tested. Effluents have dropped as the. result of better suspended
solids removal in compliance with. BPCTCA and approaching BATEA requirements.
Sludges seem to have approached the range of <1 to 24 ppm PCS common for municipal
treatment plants. The driving force has been the reduction in NCR carbonless
forms being recycled, and the final disposal by incineration or landfilling of a
large annual fraction of the paper industry's output. The present 19% recycling
rate shows that 81% of the annual production is not available to be recycled and
carries its PCB load to the landfill or the atmosphere (via incineration of wastes).
A search for evidence of "pulses" of PCB as old files are recycled failed
except on a one-mill/one-day basis. The 40 million pounds of PCB put into the
carbonless copy paper has been routed through the wastepaper stream each time
losing 80% of the previous year's mass, and being further diluted by virgin wood
pulp and forest product residue pulps. As of 1976 the average product concentra-
tion as well as influent and effluent levels had all fallen to the point where
.the sensitivity and detection limits of the analytical methods for measurement
required improvement. The FDA reported a decrease from 15.3 ppm in recycled
(food packaging) paperboard in 1972 to 1.4 ppm in the same material in 1974.
As the introduction of PCB has decreased in the recycled waste paper
stream, the fraction of product PCB arising from the input water has increased,
but this contribution does not appear to be significant at present. For a 0.1 ppb
intake water concentration, total removal to the pulp will produce (in a paper
requiring 13,000 gallons per ton) a PCBs concentration of 0.005 ppm. As an
example of just how directly the effect of the carbonless copy paper acts, the
same concentration (0.005 ppm) would result from the PCBs found in 0.14g of copy
paper ... less than one 8 x 10 inch piece.
The historical perspective shown by our mathematical model, and validated
by the available data, show PCBs in paper mill effluents and product to have passed
a maximum in the 1970-1971 period and to be continuing down to pre-1957 levels under
the influence of declining amounts of PCBs in the recycled waste paper stream and
the low effective concentrations found for intake waters.
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CH-site measurements and laboratory experiments have shown the PCS to
be substantive to fiber; that is, preferentially associated with, the fibers rather
than the water in which, they are carried. Highest PCS concentrations in fiber
slurries are associated with the smallest fiber particles, the "fines". Economical
utilization of the fiber requires it to be exhaustively recycled in attempts to
associate it with, the paper being manufactured. Fines control porosity, surface
finish, and affect brightness of the product. Discharge of PCB from a typical
mill thus appears to be primarily by way of the suspended solids. Removal of
suspended solids accomplishes PCB removal, and a consideration of the high surface
to volume ratio of the smaller particles shows why they are the ones that need
to be removed for a low PCB effluent.
A continued trend of increased water recycling is exhibited by the
industry, for the purpose of minimizing external treatment costs as well as re-
covering chemicals, heat and raw material fron process streams. This has culminate
in the design and construction of a totally process-effluent free bleached kraft
pulping mill in Canada. Only non-contact cooling water will be discharged.
New end-of-pipe treatment systems, such as the Zurn-Attisholz 2-stage activated
sludge system installed by Wisconsin Tissue Mills, offer promise of significant
reductions in BCD and suspended solids/PCBs. Cost estimates for carbon absorption
treatment (end-of-pipe) range from $886 to $1227 per pound of PCB removed.
Seme data exists to show net removal of PCB from an intake water as
evidenced by a lower concentration in the effluent. The paper-making process in
such a case is withdrawing the PCBs from the environment and stabilizing them in
the much less mobile paper phase. Of course, numerous routes whereby these PCBs
can become remobilized (in air or water) are available.
It is believed that essentially all of the Aroclor 1242 used in carbon-
less copy paper has been released to the environment (assuming negligible degrada-
tion) . At the present time more than half can be attributed to landfills and the
remainder dissipated. In a sense, these PCBs were mobilized upon the initial
production of the paper, and their passage through, paper mills merely resulted in
partition between the accepting media (water, air, solid wastes, products).
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2.0 PROCESS TECHNOLOGY OF THE PULP AND PAPER INDUSTRY
3'
2.1 Background
Pulp and paper manufacturing consists of two distinct processes.
Pulping is the reduction of whole wood or waste paper into a semi-liquid
fibrous mass, while papermaking consists of forming discrete fibers into paper
sheet or paperboard. There can also be ancillary operations which provide
special features such as coloring, coating and backing.
The processes require four basic raw materials: fiber, water, energy
and chemicals. In contrast to the earliest mills, newer mills may be located
some distance from their fiber source, especially in the case of recycling-
oriented mills where proximity to fiber means an urban center rather than a
forest. The water requirement is definitely being reduced in magnitude as
recycling methods are being developed within the industry. The recycling has
the benefit of assisting in meeting more stringent discharge criteria as well
as recovering chemicals from process waters and meeting energy needs by re-
covering energy from organic wastes.
The wood used in pulp and paper manufacturing is called pulpwood. It
can be either hardwood from deciduous broad leaf trees, or softwood from con-
iferous or needlebearing trees. This categorization reflects the proportion of
cellulose to lignin (the substance which holds the fibers together). The supply
arrives at the pulping facility as logs, chips made fron roundwood, as sawdust,
slab or chip residues from saw mills.
In traditional logging practice, the central portion of the tree was
utilized in the pulping mill requiring a removal of the bark from the log.
Mschanical debarking or hydraulic means are used with the bark often collected
and burned as an energy source.
2.2 General Pulping Techniques
Regardless of the type of process involved, the basic objective of
pulping is to reduce the wood to non-woody fibrous materials by rupturing the
bonds between the fibers of wood. This task entails either cooking the pulp-
wood (using suitable chemicals) in a digester under controlled conditions of
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time, temperature, and pressure or reducing the wood to fibers by mechanical
or semichemical means.
2.2.1 Mechanical Pulping
Mechanical pulping, sometimes called "the groundwood process,11
operates by mechanical means, generally using either a large grindstone or a
machine called a "refiner". The present methods of manufacture do not differ in
principle from that of 1867, though the size, capacity and form of the grinders
have undergone much change. In all equipment the logs of wood are pressed against
the face of a rapidly revolving grindstone in such a way that the length of the
log is parallel to the shaft holding the stone. In the older grinders, logs two
feet long were placed by hand in pockets attached to the grinder frame, and were
forced against the stone by pressure plates operated hydraulically . Usually there
were three pockets on each stone so that one could be opened, filled with wood,
and put back into operation without shutting down the entire grinder.
Modern grinder installations are very different in appearance
fron these old ones, and operate much more efficiently. Continuous magazine
grinders have been developed, in which the logs are fed into the grinder on one
floor and dropped down through the magazine to the pockets of the grinder on the
floor below. Such grinders are usually installed in pairs driven by a motor which
may rate as high as 4000 horse power and have a turning speed fron 3,500 to 5,000
The increasingly popular disk mill method uses a refiner to shred
and grind groundwood chips between counter-rotating metal shearing disks. Refiner-
ground wood, which usually has longer fibers, is preferred over stoneground wood
since it yields a stronger paper.
Both types of mechanical pulpers are generally used in an inte-
grated papermaking facility, in which the resultant fiber is thickened by removal
of water and stored as slush pulp rather than being formed into flat sheets for
sale as market pulp. Characteristically, groundwood pulping requires high power -
over 32,000 kw to operate a 500 ton per day groundwood mill.
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Unlike chemical pulping, groundwood pulping entails considerable
fiber damage. It produces a relatively weak paper that discolors easily on
exposure to light. On the other hand, groundwood processes have the advantage
of converting about 95 percent of the dry weight of wood into pulp, compared to
about 50 percent for chemical processes. The strength problem may be overcome
by adding long-fibered chemical pulp to groundwood pulp between the pulping and
papermaking stages.
Groundwood pulp constitutes 70 to 80 percent of newsprint by
weight. Groundwood plants are principally located in Canada and the southern
U.S., where the supply of softwood and electricity is ample.
2.2.2 Chemical Pulping
Chemical pulping is the process of cooking wood with suitable
chemical reagents to dissolve and degrade the lignin, the cementing material
*-
between the wood fibers, and allow the fibers to be easily separated. The
diversity of pulping processes is increasing in response to the availability of
improved technology, the need to improve productivity, and the requirement to
curb pollution. Currently, two major chemical techniques and one semichemical
technique of widespread caiiiiercia] importance are employed.
The most significant chemical processes are the sulfate or kraft
process, the acid sulfite process, and the neutral sulfite process. In the kraft
and the acid sulfite processes, the debarked and chipped wood is loaded into a
large metal digester along with the appropriate chemicals in an aqueous solution.
Heat is applied and cooking is continued, usually at high temperatures and pres-
sures, until the desired degree of delignification and purification is obtained.
Cooking transforms lignin, some carbohydrates, resins, and mineral matter into
soluble compounds that can be removed by washing. For most pulp grades, over 95
percent of the lignin is eliminated. Because the cooking liquid also attacks and
removes some desirable hemicellulose and cellulose from the wood, relatively poor
yields are inherent in chemical pulping.
The type of process and products involved determines the necessary
cooking conditions. The important variables are the si2e and physical properties
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of the chips, the liquor composition .^nd concentration, and the time, pressure,
and temperature of cooking. The liquor concentration is the roost important
variable since it affects the reaction rate and cooking time; a large initial
concentration increases the reaction rate but decreases the yield since the
stronger liquor removes or weakens more of the desirable cellulosic materials.
From an economic standpoint, the most important variables in cooking are the
chemical composition and the thermal energy requirement. The industry is con-
centrating on improved methods of recovering and recycling the chemicals and
of reducing energy inputs.
The acid sulfite process, discovered in 1874 and well established
commercially by 1890, remained the most important chemical process until it was
overtaken by the kraft process in 1937. Here, the cooking liquor is made at the
mill by burning sulfur in a/iV to form sulfur dioxMe and reacting the gas with
limestone to produce a cooking acid of the desired composition and concentration.
for years the only base used was inexpensive calcium, but sodium,
magnesium, and ammonia-based sulfite liquors have come into use recently,
especially in Scandinavia and North America, for various reasons: reduced cooking
time, easier recovery of cooking chemicals, reduced stream pollution, more market-
able by-products, fewer required screenings subsequent to cooking, and greater
brightness. However, the soluble bases other than calcium cost four to five times
more per ton of pulp and their advantages in yield, reduced cooking time, and
improved pulp quality alone, without the possibility of spent liquor recovery and
before the advent of stringent pollution'controls, would not have warranted in-
dustry use.
Since the spent liquor in the calcium-based process is uneconomic^
to recover and presents a major water pollution control problem, most plants will
abandon the process unless an economical way can be found to recover or dispose of
the spent liquor. Spent liquor has been variously used, e.g., as a road binder or
in the manufacture of yeast, vanilla, alcohol, fertilizers, insecticides, tanning
agents, and inks. It can also be burned in concentrated form to produce power and
steam; the heat value of the dried sulfite waste is about two-thirds that of
industrial coal, but much of the energy produced must be used to evaporate and con-
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centrate the liquor in preparation for burning. Even this limited recovery is
likely to become more attractive as energy prices rise.
Despite such, efforts to find alternative uses for the spent
liquor, most mills have continued to dispose of it as a waste product. Recent
water pollution control requirements might alter this trend.
The kraft Csometimes called the sulfate) process is now pre-
dominantly used in pulping. The name "sulfate"' (derived from the sodium sulfate
used as the make-up chemical in the chemical recovery process) is misleading since
the active cooking agents are mostly sodium hydroxide and sulfide.
As in the sulfite process, wood in chip form is cooked in large
steel digesters in the presence of a cooking liquor and under conditions of
elevated temperatures and pressures. The cooked chips are then defiberized in a
blow tank and screened as necessary before washing and bleaching. The prepared
pulp may be either pressed and dried into flat sheets for sale or shipment to
another facility or retained in a slurry form for use at an adjoining paper or
paperboard plant.
The kraft process has various advantages: it can be used on al-
most any species or quality of wood; its cooking times are short; it entails no
pitch problems; recovery of the spent liquor is relatively easy; and it yields -
valuable by-products. The pulp produced has great strength and can be bleached
to high levels of brightness. The efficient chemical recovery system is especially
advantageous and economical since the sodium hydroxide used in the kraft process
is a very effective but relatively expensive chemical.
The principal disadvantages of the process are its high capital
costs, high cost of bleaching, and discharge of several highly malodorous waste
gases {e.g., hydrogen sulfide). Fegulations requiring controlled discharge are
thus significantly affecting the economics of the kraft process. Electrostatic
precipitators and scrubbers are being used to reduce odor by precipitating dust
particles to which the odor producing particles cling. Unfortunately, since the
wastewater from these cleaning operations cannot be used for pulp washing be-
cause the odor is imparted to the pulp, this deodorizing method merely substitutes
a liquid waste problem for a gaseous one.
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2.2.3 Semichemical Pulping
Semichemical pulping, which combines mechanical and chemical
pulping features, chemically treats the wood to achieve partial softening and
then uses mechanical refining to conplete the fiberization. Semichemical pulp-
ing offers several advantages over both chemical and groundwood processes. The
yield is from 65 to 90 percent of the weight of the wood because only part of
the lignin and hemicellulose is removed. This is considerably better than the
straight chemical process. The chemical pretreatment reduces the amount of
power necessary for the subsequent mechanical reduction, increases the average
fiber length, and enables the process to be used effectively with hardwoods.
In addition, since sgnichemical pulping uses fewer chemicals than the pure
chemical processes and requires a lower capital investment, it lends itself to
use in smaller plants. One drawback is that semichemical pulping only works
well for hardwood and is not used for softwood species.
The two most important types of semichemical pulping are the
neutral sulfite semichemical and the cold caustic processes. The more widely
used neutral sulfite process treats the wood with a solution of sodium sulfite
which, during cooking, is buffered to about pH 7 with a buffering agent such as
sodium bicarbonate. The physical characteristics of the neutral sulfite process
pulp make it particularly well suited for use as a corrugating medium. The
neutral solution produces a pulp with high yield, about 65-80 percent, strength,
and brightness without offensive odors.
The cold caustic process, which employs caustic soda (sodium
hydroxide) to produce coarse pulps for corrugating and some finer pulps for
printing papers, is particularly useful with high density hardwoods that cannot
be used in the groundwood process. Efficient use of chemicals and reduction of
the mechanical energy required for subseqent refining make this process lower
in operating costs than either groundwood or other semichemical processes. The
pulps produced are inferior to kraft pulps in physical properties but stronger
than or equal to groundwood pulps made from softwoods.
Qiemical recovery in semichemical mills, unlike in the kraft
system, can use a number of chemical processes. For the semichemical process
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using caustic soda, a recovery process similar to that used to recover sodium
hydroxide in the Rraft process may be used. Most of the remaining techniques
involve either combustion of cross-recovery (using the kraft mill recovery
system).
2.2.4 Secondary Fiber Pulping
Secondary fiber, derived from wastepaper, is a principal source
of pulp for some papermaking facilities around the large metropolitan areas.
Secondary fiber accounts for about 20% of the fiber used for pulp today. Al-
though the rising cost of fiber will undoubtedly induce the industry to increase
use of secondary fiber (especially recycled paper, the highest-quality waste-
paper used for making pulp today), such increases may be less than is popularly
anticipated. Rising energy costs, the difficulty of separating wastepaper from
other trash, and the lack of captive supplies may limit the growth in use of
wastepaper as a fiber source. Mills that use wastepaper generally have little
control over their secondary fiber supply, although firms are increasingly
seeking long-term wastepaper supply arrangements.
2.2.5 Dissolving and Special Pulps
Variations of the basic sulfate and sulfite processes which
produce pulps for paper and paperboard are used to produce a special type of
pulp called dissolving pulp. This segment of the pulp industry has becone so
specialized that it operates much as a separate industry. To generate dis-
solving pulp, pulps produced by kraft or sulfite processes are chemically
purified to remove all semi-cellulose and to extract pure cellulose. The pure
cellulose is then used as a raw material to produce rayon, cellophane, and cel-
lulose derivatives used in such diverse products as explosives, detergents,
lacquer, food product thickeners, hand lotions, and automobile accessories.
Dissolving pulp is also used to make glassine paper (the paper that forms the
clear window in window envelopes). Dissolving pulp facilities are frequently
located adjacent to kraft and sulfite mills so that the pulp can be delivered
in slush form without drying.
-13-
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2.3 EPA Classification of Mills by Pulping Method
It is af the pulping stage that the process schemes allow for dif-
ferentiation between plants. In compliance with certain sections of FWPCA of
1972, EPA has established the following sub-categories of pulp, paper and paper-
board operations for the purpose of establishing effluent guidelines:*
Table 2-1 EPA Mill Classification
1. Bleached Kraft: Dissolving Pulp
2. Bleached Kraft: Market Pulp
3. Bleached Kraft: Fine Papers
4. Bleached Kraft: B.C.T. Papers
5. Papergrade Sulfite
6. Papergrade Sulfite Market Pulp
7. Low Alpha Dissolving Sulfite Pulp
8. High Alpha Dissolving Sulfite Pulp
9. Soda
10. Groundwood: Oierai-inechanical (CMP)
11. Groundwood: Thermo-mechanical (IMP)
12. Groundwood: Fine Papers
13. Groundwood: C.M.N. Papers
14. Deink
15. Non-Integrated Fine Papers
16. Non-Integrated Tissue Papers'
17. Non-Integrated Tissue Papers (fwp)
EPA defines each class of mill as follows:
1. BLEaCHED KRftFT; DISSOLVING PULP means that production of a highly bleached
pulp by a "full cook" process utilizing a highly alkaline sodium hydroxide and
sodium sulfide cooking liquor. Included in the manufacturing process is a "pre-
cook" operation termed prehydrolysis. The principal product made by mills in
this subcategory is a highly bleached and purified dissolving pulp which is used
principally for the manufacture of rayon and other products requiring the virtual
absence of lignin and a very high alpha cellulose content.
* Reference No. 1; further industry and process descriptions, including waste-
water characterization, can also be found in this and associated references.
-14-
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2. BTFACHED KRAFT; MARKET PULP means the production of bleached pulp by a "full
cook" process utilizing a highly alkaline sodium hydroxide and sodium sulfide
cooking liquor. Included in this subcategory are mills producing papergrade
market pulp as the only product.
3. BT.F.ACHED KRAFT; FINE PAPERS means the production by integrated pulp and paper
by a "full cook" process utilizing a highly alkaline sodium hydroxide and sodium
sulfide cooking liquor. The principal products made by mills in this subcategory
are fine papers which include business, writing, and printing papers.
4. PLFACHED KRAFT; B.C.T. PAPERS means the production by integrated pulp and
paper mills of bleached pulp and paper by a "full cook" process utilizing a highly
alkaline sodium hydroxide and sodium sulfide cooking liquor. The principal
products made by mills in this subcategory are papers of low filler content
including paperboard (B) , coarse papers (C) , and tissue papers (T) .
5. PAPERGRADE SULFITE means the production by integrated pulp and paper mills of
pulp and paper, usually bleached, by a "full cook" process using an acidic cooking
liquor of bisulfites of calcium, magnesium, ammonia, or sodium containing an excess
of free sulfur dioxide. The principal products made by mills in this subcategory
are tissue and fine papers.
6, PAPERGRADE SULFITE MARKET PULP means the production of pulp, usually bleached,
by a "full cook" process using an acidic cooking liquor of sulfite of calcium,
magnesium, ammonia, or sodium containing an excess of free sulfur dioxide. The
principal product made by mills in this subcategory is papergrade market pulp.
7. LCW ALPHA. DISSOLVING SULFITE PULP means the production of highly bleached and
purified pulp by a "full cook" process using very strong solutions of bisulfites
of calcium, magnesium, ammonia, or sodium containing an excess of free sulfur dioxida.
The pulp produced by mills in this subcategory are viscose, nitration, or cellophane
grades and are used principally for the manufacture of rayon and other products
requiring the virtual absence of lignin.
8. HIGH ALPHA. DISSOLVING SULFITE PULP means the production of highly bleached and
purified pulp by a "full cook" process using very strong solutions of bisulfites of
calcium, magnesium, ammonia, or sodium containing an excess of free sulfur dioxide.
-15-
-------
The pulp produced by m-nig in +MJ3 subcategory is principally acetate grade and
the principal uses are for the manufacture of rayon and other products requiring
the virtual absence of lignin.
9. SOD& means the production by integrated pulp and paper mills of bleached pulp
and paper by a "full cook." process utilizing a highly alkaline sodium hydroxide
cooking liquor. The principal products made by mills in this subcategory are
printing, writing, and business papers.
10. GROCNDWJODt CHEMI-MECHaNICaL means the production by integrated pulp and paper
mills of pulp and paper, with or without brightening, utilizing a chemical cooking
liquor to partially cook the wood followed by mechanical defifaration by refining
at atmospheric pressure. The principal products made by mills in this subcategory
are fine papers, newsprint, and molded fiber products.
11. GROUNEWOOD: THEiK>MBCHaNICaL means the production by integrated pulp and paper
mills of pulp and paper, with, or without brightening, by a brief cook utilizing
steam, with, or without the addition of cooking chemicals such as sodium sulfite,
followed by mechanical defibraticn by refiners which are under pressure. The
principal products made by mills in this subcategory are fine papers, newsprint,
coarse papers, and tissue products.
,#
12, GRDCNDWDOD: FINE PAPERS means the production by integrated pulp and paper mills
of pulp and paper, with or without brightening, utilizing only mechanical defibra-
ticn by either stone grinders or refiners. The principal products made by mills
in this subcategory are fine papers which include business, writing, and printing
papers.
13. GROUNDWOOD; C.M.N. PAPERS means the production by integrated pulp and paper
mj-T-ig of pulp and paper, with or without brightening, utilizing only mechanical
defibraticn by either stone grinders or refiners. The principal products made by
mills in this subcategory are papers of low filler content including coarse
papers (C), molded fiber products (M), and newsprint (N).
-16-
-------
14. DEINK means the production of pulp and paper visually brightened or bleached
from recycled waste papers in which an alkaline treatment is used to remove
contaminants such as ink and coating pigments. The principal products made by
mills in this subcategory are printing, writing and business papers, tissue papers,
and newsprint.
15. EO^INTEGRATED FINE PAPER means the manufacture of fine papers by non-
integrated mills from wood pulp or deinked pulp prepared at another site. The
principal papers made by mills in this subcategory are printing, writing, business,
and technical papers.
16. ^OI-IMTEGRaIED TISSUE PAPER means the manufacture of tissue papers by non-
integrated mills from wood pulp or deinked pulp prepared at another site. The
principal products made by mills in this subcategory are facial and toilet papers,
glassine, paper diapers, and paper -bowels.
17. NC^INTEGRATED TISSUE PAPERS (FRCM WASTE PAPER) means the manufacture of
tissue papers by non-integrated mills from recycled waste papers (fwp). The
principal products made by mills in this subcategory are facial and toilet papers,
glassine, paper diapers, and paper towels.
The effluent limitations and standards for the above subcategories are
based upon on-site manufacture of all of the pulp (including deinking of waste
paper) used to produce the final products (i.e., no supplementary fiber source
such as purchased pulp or waste paper was included in the determination of the
effluent limitations or standards). The exception to this is the Groundwood:
CMN Papers and Groundwood: Fine Papers subcategories which were based upon ground-
wood mills manufacturing papers from pulp produced on-site and from purchased
pulp used as supplementary fiber. Of particular interest frcm the standpoint
of PGBs and waste paper recycling are categories 14, 15, 16 and 17.
2.4 Papermaking Processes
2.4.1 Background
Far most paper and paperboard products, the papermaking machine
receives prepared paper stock containing about 199 pounds of water for every pound
-17-
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of dry material, passes it through a series of operations to form it into a
continuous web and to remove the excess water, presses the wet sheet to remove
still more water and to make the sheet still more dense, dries it over heated
driers and finally reels it up into large rolls. This change from stock con-
taining almost ten tons of water per 100 pounds of dry matter to a sheet of
paper which seldom contains over 5 pounds of water in 100 pounds of dry paper
takes place in just a few minutes according to the speed of the machine. A
schematic of the overall process is shown in Figure 2-1.
Although many mechanical variations and improvements have been .
made over the years, only two basic types of paper machines, the fourdrinier
and the cylinder, are used today. Both were invented over a century ago. These
machines differ significantly in the method of forming the fiber web.
The fiber stock is subjected to a series of refining and clean-
ing stages prior to its introduction to the paper machine. These stages are
chosen to produce the desired fiber characteristics to meet the product's needs.
The fiber stock is mechanically refined in heaters or continuous refiners to
fray or "brush" the individual fibers. The frayed fibers will have a tendency
to mat together and the degree of matting will produce the required, strength in
the final paper. In fine papers where a compact, tight mat is required the
stock may also be pumped through a fordan which will cut the fibers to the re-
quired length with a limited amount of brushing.
2.4.2 Fourdrinier Paper Machine Process
In the fourdrinier, the refined stock is pumped to a headbox
which controls the amount of stock flowing to the paper machine "wire" and thus
maintains the paper at the desired consistency. The carefully diluted stock
(~ 0.5% solids) is then spread evenly on the "wire" (a woven brass or bronze
cloth, the mesh of which differs in type and size of opening according to the
paper being made) to form the paper. Water drains through the wire, and is
squeezed from below to assist in the drainage. The transfer of the sheet to
presses is accomplished with a suction pick-up roll. The sheet leaves the "wet-
end" of the machine at a consistency of 35 to 40% solids and is passed through
heated, hollow iron or steel drum dryer rolls in the dry end. Because of its
higher output speed and greater versatility the fourdrinier is more canton than
the cylinder.
-18-
-------
Figure 2-1 gives a schanatic process flow diagram for the
fourdrinier paper machine. Of special interest is the recycling loop of both
water and fiber from the fourdrinier section back to the rich white water tank,
saveall and filtered white water tank. This stream is the major inplant carrier
of fines-related PCBs, and is shown to be repeatedly passed through the fourdrinier
to incorporate as much of the fiiaer and fines load as possible in the product
paper.
2.4.3 Cylinder Paper Machine Process
In the cylinder machine, the headbox and wire found in the four-
drinier are replaced by a wire-covered cylinder mold which is partially iamersed
in the prepared stock.
The principle of the cylinder machine differs from that of the
fourdrinier in several respects. Instead of the sheet being formed on an endless
belt of woven wire through which the water drains, leaving the fibrous stock on
its surface, the cylinder mold revolves while partially iitmersed in a vat of the
dilute stock and the^ sheet is fozmed on the surface of the wire-covered mold.
This is accomplished by maintaining the water level within the cylinder lower
than that outside so that the water drains into the cylinder leaving the stock
on its surface. The web of paper fonned by the revolving cylinder is removed off
the top of the cylinder by a felt. Usually a cylinder machine consists of several
cylinder molds and vats supplied with stock entirely independeltly, and as the
felt passes over each cylinder in turn it picks up the sheet from each, thus
making a sheet of multiple layers. This makes it possible to form sheets with
surface layers differing from those within the sheet, either in color, kind or
fiber or both.
The same basic flow process is associated with cylinder machine
as the fourdrinier shown in Figure 2-1; however, as mentioned above, the final
product may be multi-layered, requiring a parallel stock flow through each
cylinder machine.
-19-
-------
PURCHASED
PULP
SLUSH PULP
FROM INTEGRATED
PULP MILL
1 1 PROCESS
| 4 WATER
Dili DCD __.._! Ir.
T
*
1 _..__
PULP
CHEST
B FILTERED
fr TANK . "
REFINERS
t
| ALTERNATE
MACHINE LFIBER| SAVEALL
CHEST f* 1 5»AVtAL1-
l< t
*K 1
CENTRIFUGAL
CLEANERS
RICH WHITE
WATER TANK
1 L -4 HH
1 1 ^
MACHINE
SCREENS
COUCH PIT
AND
WIRE PIT
I L 'L _J
I
FOURDRINIER
SECTION
'
"i
<
PRESS
SECTION
SIZE 4-K-i 8
PRESS -*jn |
Jl
DRYER
SECTION
DRYER «*J U 3
CALENDER
1
PAPER
PRODUCT .
^1
H20
Vapor
t
;. SPWPR
. LEGEND:
. Main Process
Secondary Process
Process Waste Lin<
Figure 2-1
GENERALIZED SCHEMATIC OF PAPER PRODUCTION PROCESS
-20-
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2.5 Paper Industry; Size and Distribution
2.5.1 Water Usage
Census Bureau data shows that Paper and Allied Products had a
1973 water intake of 2,415 billion gallons. Gross water usage was estimated
to be 8,126 billion gallons. The ratio gross/intake shows how much water re-
use is occurring. The historical trend is shown on Table 2-2.
Table 2-2
Water Usage -in Paper and Allied Products Industries
Gross Water Intake Water
Year (billion gal) (billion gal) Gross/Intake
1973 8127 2415 3.36
1968 6522 2252 2.89
1964 5491 2064 2.66
1959 5046 1937 2.60
1954 4242 1786 2.38
Between 1954 and 1973 water intake increased by 35%. In the
same period, total paper and paperboard production rose 106%. The trend to
internal water recycling is well documented and continuing. A report by Rapson^ '
describes the processes to be used at the bleached kraft mill of Great Lakes
Paper Co., Ltd. at Thunder Bay, Ontario. This mill will start up in late 1976
and will recycle virtually all of its water, emitting only low temperature heat
in uncontaminated cooling water. Projections indicate this to be at a lower
cost than use of external treatment. One major reason will be the conservation
of heat in the counter current washing of the bleached pulp.
Allowing for a 5% water loss associated typically with product
moisture, about 2.2 trillion gallons of water was discharged to U.S. waterways
in 1973. Average runoff for the continental U.S. is given by Todd(3) as 655
trillion gallons. A simple division indicates that the paper and allied product
discharge is 0.33% of the total continental runoff. Since the discharge is not
evenly distributed over the rivers, the water quality of even large streams can
be strongly affected by the effluent loads from paper mills.
-21-
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2.5.2 Production History
There is much potential for confusion in the utilization of
data from the pulp and paper industry because over the years for which, infor-
mation has been retained, new products as well as new processes have appeared.
As a result, the categorization of the output of the industry is constantly
changing. While the categories are relatively stable over a short term period,
they have changed noticeably during the long term. The general overall trend
has been one of production increase, underlain with a use of recycled waste
paper which has varied with world economic and political conditions. Table 2-3
shows the information on production and secondary fiber usage obtained from
Bureau of Census, American Paper Institute and other sources for the 1957-1974
period.
According to the last column of Table 2-3, the rate of recycling
has remained virtually constant at about 20% since 1968. Even with the emphasis
on re-use and conservation of natural resources, little change can be seen.
(4)
Lingla states that paper constitutes 31% by weight of municipal solid wastes
going to disposal. Of that paper, 29% is corrugated containers, newspapers and
printing papers are each 20%, and packaging and the other categories make up the
balance. Slightly more than half of all paper wastes are from residences with
the rest originating in commercial or institutional locations.
Source separation is a basic part of most collection systems
focusing on recycling. Newspaper bundling in residential areas and compacted
corrugated carton collection from commercial establishments are examples of
such source separation schemes. This is required so that a paper mill utilizing
recycled paper in its furnish (raw material) can be assured that the proper
type of fiber is going into its process.
The type of catch-all waste which emanates from offices, govern-
ment and commercial firms is termed "mixed waste". While it can be utilized by
segments of the paper industry, there exists the chance in this waste stream for
the carbonless copy paper which contains PCBs.
-22-
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-23-
-------
3.0 TRANSPORT OF PCBs IN TEE PAPER INDUSTRY
3.1 PCS Sources to the Industry
3.1.1 Influent Waters
A representative value for PCBs concentration in the intake
waters of paper mills was deemed necessary for several aspects of the work. This
value, which was determined to be 0.1 ppb, was derived from several sources as
shown below.
During the early months of 1976, EPA instructed its Regional
Offices to conduct a sampling program aimed at identifying point sources of PCBs
to the environment. This Regional Surveillance Program reported in excess of
2,400 data points. Of these, 106 could be unambiguously categorized as having
come from a natural body of water. With the elimination of a few samples suspected
of being contaminated, the average value of these "natural water" samples is 2.3
ppb. However, the choice of sampling sites was usually contiguous to a facility
which was already a potential PCS emitter, so that this value is probably more
representative of a high use, industrially developed stream rather than an environ-
mental background. The intake PCS concentrations for paper mills might therefore
be expected to be somewhat less than this 2 ppb average. Paper mills faced with
suspended solids in their intake water will usually perform a clarification clean-
up prior to use. Such treatment would be expected to remove up to 90 per cent of
the PCBs from the water (retained on removed particulates).
Dennis obtained STOHET data for PCBs in major U.S. drainage
basins and showed a range of median values for each basin from ND (not detectable)
to 0.3 ppb in his tabulation for 1974.
Data on intake water PCB concentrations from the Institute of
Paper Chemistry for eight Wisconsin paper mills showed three mills reporting un-
detectable levels and the other five reporting an average of 0.2 ppb PCBs.
On the basis of the above considerations, the representative PCBs
level of the water used in paper mills was taken to be 0.1 ppb.
-24-
-------
3.1.2 Process Chemicals
Table 3-1 gives a typical listing of sane of the major kinds of
chemicals used in pulp and paper making. The amounts used on a per unit ton basis
vary frcm trace quantities to 280 Ibs. for some pulping liquor constituents.
Both Crown Zellerbach and Institute of Paper Chemistry researchers
have tested process chemicals for PCBs. None have ever been detected except for
one specialty chemical reported by IPC. A rough calculation shows that to produce
a 2 ppn KB concentration in a product which uses 8 Ibs. of trisodium phosphate
per ton of pulp (assuming a complete extraction of PCS by the fiber) , 2 grams of
PCB would have to come in with the detergent. Its concentration in the detergent
would be 5500 ppm, easily detected. Even an increase of 0.1 ppm in the product
from this source would require a concentration of 27.5 ppm in the phosphate.
Present analytical capabilities allow monitoring at 1 ppm and below, so that PCB
inputs from process chemicals would have been easily noticed.
3.1.3 Inks
The National Printing Ink Research Institute at Lehigh University
was contacted for details on present and past usage of PCBs in printing inks. The
major use reported was the NCR encapsulation procedure used in the carbonless copy
paper. A small number of patents do exist for PCB use as part of some inks
sensitive to ultraviolet light. However, they date from the very early seventies
and had not gotten into widely marketed use by the time the PCB use in carbonless
copy paper was stopped. To the best knowledge of NPERI, none of these inks reached
commercial production and no;present day formulations utilize PCBs as a constituent.
Subsequent conversation with a representative of the Sun Chemical
Co.* indicated that PCBs were used for several years prior to 1971 in "flexographic"
inks used on flexible packaging. It was estimated that the production of such inks
during 1970 was about 20 million pounds, of which about five per cent of the pro-
duction would have contained PCBs at a two per cent by weight concentration. Thus,
the estimated use of PCBs for this purpose, apparently the maximum, was 20,000
pounds in 1970. The historical trend for this application is not known, but based
*Personal Conrnunication with Mr. William Rusterhaltz, Sun Chemical Co., October, 1976.
-25-
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TBBLE 3-1
CHEMICALS USED IN PULP & PAPEFMRKENG
Oiauical Synbol
smme, sa2sn3
Sodiun Acid
Sulfite
Surfactants
Oodecylpheool of
ethylene
Cbeids bases
Dioxide SO.
Sulfuric Acid
chloride
Sodium
Anoint
/Ion
90-120
2-4
10
4-a
pulping
ttttric
Pitch dispersaot far
salfite pulp
for
140-230
Salt caka", Kraft
for
control
Gooicin?
sul£i.^8
pi] ping
Palp
, 'soda ash"
lfl-13
4-a
of waste paper
TOC
MaCH
3,4.4 aacbJxsocarbanilida
Hydrochloric pn
n^iiiiijt^j/iiTw c,H. Cl,
aospboric flcid
£br
Alun zeplaceoent
, dainking,
soda"
Bactariostat (microbiological
coitczol) substantive to
caJ-lulosa
pH adjust, cl (wring agent
daaning 9ol\nsit far felts
Brighterar, pracipitataa Ca,
a phosphate
A Large aonber of special
pirittri* additives; sweeteners
lite sacchrin, odorants like
ethyl vanillan, and so on.
-26-
-------
on a five-year period of usage and linear growth during that period, it is
estimated that the total usage of PCBs in such inks was about 50,000 Ib.
The above figure is roughly 0.1 per cent of total PCBs usage in
carbonless copy paper. In addition, flexible packaging materials typically were
plastic or contained plastic adhesives which render them unattractive for re-
cycling. Thus, it appears unlikely that the PCBs usage in flexographic printing
inks' has contributed significantly to PCBs inputs to the paper industry.
3.1.4 Recycled Waste Paper
As was indicated in Section 1.0, the major source of PCBs entry
into the paper industry appears to have resulted from the use of Aroclor 1242 in
carbonless copy paper during 1957-71 and subsequent recycling of a fraction of this
product. To some-extent, PCBs contamination has spread from this source through-
out paper products because of the affinity of paper for PCBs. A summary of avail-
able data on PCBs levels in various types of paper products, by year, is presented
on Table 3-2. The recycling of these products tends to perpetuate the contamination.
3.1.5 Other Potential Uses or Sources of PCBs in Paper Mills
Although paper mills utilize askarel-filled (PCB) transformers and
capacitors, and may have utilized PCB-filled hydraulic or heat transfer systems,
PCB-oontaining lubricants, paints, etc., it is considered unlikely that such
activities would be causing release of significant quantities of PCBs to either
effluent streams or product streams.
Similarly, it is also considered highly unlikely that PCBs are
produced in the practice of wastewater chlorination in the paper industry. Biphenyl
has not been identified as a waste stream constituent from this industry, although
very small amounts could conceivably enter via recycling of packing materials
(typically for fruit) which have been treated with biphenyl as a fungicide.
3.2 PCB Content of In-Plant Streams and Reservoirs
Data on PCB levels of in-plant process streams are almost completely non-
existent for three apparent reasons. First, at the observed low concentrations,
PCBs have no effect on product quality, so that internal monitoring is not required.
-27-
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TABIE 3-2
FCB CONTENT OF PAPER AND PAPEKBOARD
1968
Prior to
1970
1971
1972
1973
1973
1974
1975
1976
'DLscoun
,
Virgin pulp
Recycled* wastepaper
input
Recycled^ ' wastepaper
input (1970-1972)
Recycled paperboard
Virgin pulp
P.-_ ..i- -, -uvl
3pe'Jj|oaJTl
Virgin newsprint
Recycled newsprint
Virgin bond paper
Recycled bond paper
Bleacfagd kraft pulp
Bleached kraft iiri^-r board
Publication paper
ppryrfl far} pf^-fxr^raff^
Recycled U) wastepaper
input
Virgin pulp
Paperboard
Virgin pulp
PapgrfoVWCl
Cereal liner
/Vi-in uu-u-ra l.-ojl Iru-LmruT
opLCjetjcAueci ooarcL
Waxed paper
Spec, twist
Lantin. grade
Bookstock-.
Recycled* ' wastepaper
input
No. of
Samples
2
13
24
200
2
100
3
3
7
2
4
1
3
115
5
2
4
6
-
-
-
-
-
138
tina known sanoles of NCR carbonless copy
PCS Content
-------
Second, most plants, especially the older ones, are not planned with specific
capability for sampling in-plant flows, so any sampling done is more by opportunity
than by design. Thirdly, commercial PCS analyses cost from $60 to $100 per sample,
and a sampling program without a clear goal of compliance with regulations or
product improvement is generally considered a poor investment. A PCB analytical
system would require capital costs in the range of $15,000 to $20,000 and annual
expenditures for trained personnel, lab space, and operation of up to $50,000.
3.2.1 PQBs in Deinking and Pulping Process Water
The deinking process water is typically not a recycled stream,
although in many cases it represents a significant fraction of the total water
usage for a recycling mill. Deinking procedures and conditions depend on the
product qualities desired (white or natural or color, etc.). Although some of
the PCBs associated with recycled paper will probably be stripped from the fibers
during deinking, this should represent only a minor fraction of the total PCB load
of the reclaimed material.
During the pulping process the cellulose fibers are separated, and
this process should also release the PCBs or PCB-containing micro-balloons held
within the mat. PCBs already released from microballoons would then be able to
distribute themselves- between the fibers and the water. Since evaporation and other
' losses of PCBs during pulping should be small, the above appears to be the situa-
tion when the slush pulp enters the paper mill.
3.2.2 Distribution of PCBs in the Papermaking Process
In the papermaking process (see Figure 2-1), most of the PCBs
entering with the pulp exit with the product. These would include most of the PCBs
in intact microballoons and most of the PCBs associated with fibers. In the drying
and calendaring sections/ the vaporization of excess water would be expected to
codistill free (not encapsulated) PCBs at or near the surface. This is the major
opportunity for vaporization loss in the process.
In a typical plant, much of the water in the papermaking process
(white water) is recycled as shown in Figure 3-1. White water from the fourdrinier
or cylindrical machines contains dissolved and suspended PCBs. The fibers present
-29-
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SLUSH
PULP
$ -
'PULP
CHEST
1
PROCESS
WATER
t 1
REFINERS
»
F
MACHINE
CHEST
3
FILT
WHITE
TA
i
4
«
4
*
FIBER
*
ERED
WATER
NK
k
M
»
k
»
1
SAVEALL
CENTRIFUGAL
CLEANERS
i
t
k
k
RICH WHITE
WATER TANK
: L - 4
r
MACHINE
SCREENS
=
*
::
t-
COUCH PIT
AND
WIRE PIT
t L ^
F
FOURORINIER
SECTION
.
I
PRESS
SECTION
::Wh
II 1 1 Wd
ite
ter
.j
- .
T
Figure 3-1
Major Fiber and Water Routes in Paper Production
-30-
-------
are relatively sttall, with high surface area per unit weight, so that the ratio
of PCBs to solids by weight may be as large as or greater than the PGBs content
of the product. Much of the PCBs in suspended form is added back to the main
process with the short fibers, in order to conserve fiber. The liquid phase from
the "save-all", a separator unit, is filtered to father remove fiber (which goes
back into the process) and the filtrate is discharged. This clarified save-all
yield can be one of the major coiiponehts"of~the discharge from the plant.
If we assume a 1 ppm PCS concentration (typical of product PCB levels
using recycled pulp) in the fiber portion of the clarified save-all yield (at
120 mg/1 solids), the PCB concentration of that flow is 0.12 ppb which is effective-
ly the same as the intake value selected as representative, and near the lower
working limit of present analytical techniques. About 95 per cent of the PCBs
entering the save-all appear to be directly recycled back into the paper on the
PCBs first pass through the white water system. Thus, it appears that most of
the PCBs (and the solids) in the effluents arise from unit processes other than the
save-all.
Since it appears that most of the PCBs in paper mill effluents are
associated with the fiber solids (either encapsulated or adsorbed PCBs), the
major route of PCBs entry into wastewaters must then be via solids entry. On
Figure 3-1, this occurs primarily in the aqueous discharges from the centrifugal
cleaners, machine screens, and press section. Fiber loss at these points is
sufficient to cause solids levels up to several grams per liter in the raw waste-
water.
3.2.3 Fate of PCB-Oontaining Microspheres
The hardened gelatin-gum arabic walls of the ink-carrying micro-
balloons used in the NCR carbonless copy paper are considered essentially stable
under conditions typically encountered in the use of secondary fiber. Thus, most
of the microballoons should proceed through the process intact. Most would be
expected to be incorporated into the product, because of the manner in which fiber
is collected in to product (essentially a filtration process).
-31-
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Based on the above, the PCBs content of the plant effluent should
consist of those microspheres not retained in the product and a fraction of that
released by breakage (through usage of the paper, during collection and transport
of wastes, and in the recycling and papermaking processes). The remainder of that
released by breakage could remain on the product, be vaporized, or removed from
the stream in various other ways.
This line of reasoning leads to the conclusion that most of the
PCBs in paper products and wastepaper is still encapsulated. Discussions with
paper industry representatives have supported this view, especially discussions on
the comparison of analytical results between procedures in which the microballoon
walls have and have not been definitely destroyed. PCS levels resulting from
destruction of the microsphere walls with alcoholic potassium hydroxide solution
are much higher than those obtained using conventional extraction procedures.
However, this could be grossly misleading since the same treatment is necessary to
separate the individual fibers to release for analysis PCBs (in whatever state)
trapped within the mat.
The actual proportion in paper products and effluents of PCBs in
intact microballoons is not known and could be ascertained only with difficulty.
Cne of the items of future work proposed by the Institute of Paper Chemistry in
a recent report is to determine the amount and effect of PCBs present in pro-
ducts and effluents within intact microballoons.
3.3 PCS Losses from the Pulp and Paper Industry
3.3.1 Wastewater
The PCBs content of microballoons in plant effluents can be
removed by solids removal; similarly, PCBs sorbed onto suspended solids in the
effluent can likewise be removed. Solubilized PCBs, either in true solution or
present in or on very small particulates, will be very difficult to remove from
effluents.
The partition coefficient for PCBs between cellulose and water is
not expected to be anywhere near as large as those between lipids or carbon (for
example) and water, based on the relatively slight accumulation in woody plants
-32-
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and scanty general information available on this subject. Unpublished data
obtained fron the Institute of Paper Chemistry concerning a series of experiments
in which- one per cent fiber slurries in water were doped with. PCBs Cup to 100 ppb),
shaken and allowed to settle, and then filtered and analyzed, indicated partition
coefficients ranging from 800 to 1700. These values are hot sufficiently high to
allow removal of dissolved PCBs with, suspended solids in mill wastewaters as
described below.
At a partition coefficient for PCBs between cellulose and water
of 500, and a suspended solids content of two gm/liter, about one-half of the
"free" PCBs would be expected to be adsorbed onto the fiber. However, recent
industry experience has indicated that removal of over 90 percent of the suspended
solids from the wastewaters will also remove over 90 percent of the PCBs, with
resulting PCS concentrations in the range of 0.1 ppb to several ppb, well below
the reported solubility level of Aroclor 1242. In the absence of-Other infor-
mation, this appears to indicate that 'relatively little of the PCBs in the waste-
water is present as dissolved PCBs.
Three alternative explanations for the above appear to be
possible:
(1) The partition coefficient between water and the solids present is
very much greater than a few hundred;
(2) Most of the PCBs present are encapsulated in microballoons and
are thus removed in this form along with the other solids; or
(3) Organic solids added to or present in wastewater treatment systems
serve to separate the PCBs from the water. .
Alternatives (2) and (3), or a combination of these, appear to
be more likely than alternative (1). In all paper mill wastewater treatment
systems of which we are aware, polymeric flocculation aids are added in primary
treatment and/or the water is subjected to activated sludge secondary treatment.
It is well-known that biological sludges exhibit a strong affinity for PCBs and,
although the sorptive.activity of the polymeric agents for PCB relative to water
(and cellulose) is not known, it may be surmised that these agents are better
scavengers of PCBs than cellulose. However, alternative (2) (most PCBs still
encapsulated) remains a strong possibility until proven otherwise.
-33-
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The KB leyels in raw wastes from recycliiig plants vary widely
but are typically in the range of 10 to 100 ppb. With, current waste treatment
practices, this is reduced to a typical range of less than 0.5 ppb to several ppb,
with occasional excursions. As a consequence of the recent experience showing PCS
removal concomitant with suspended solids removal, compliance with BPCTCA (1977)
and BAIEA (1983) should result in continuation of the downward trend in effluent
PCB levels.
3.3.2 Vaporization losses
3.3.2.1 losses During
Available information indicates that there may be
measurable losses of PCB during the removal of moisture from the paper in
the dryer^section, ofthe machine. This conclusion was reached- on the basis
of mass balance studies done on a number of cooperating Wisconsin mills.
We are dealing here with a PCB concentration in a typical
paper of only 1 gram per ton. Since the qualitative assessment of the vapor-
ization loss was that it was a few percent of the PCBs present, the loss will
not pose a health hazard, nor will it have a significant effect on the con-
clusions reached in the model of the industry.
3.3.2.2 losses from Effluent Treatment Ponds
A significant amount of the treatment of papermill
effluent occurs in systems open to the atmosphere. Such choices as aerated stabiliz
tion basins, ditch aeration, and rotating biological surfaces are designed to provic
a greater supply of atmospheric oxygen to the effluent for the purposes of lowering
BCD. At the same time an opportunity arises for PCBs to exchange across the solid-
liquid and liquid-gas interfaces. No definitive data on these processes for PCB
loss are available, but there may be the possibility of exchange mediated by the
partitioning of the PCBs in the complex systems.
One expects some exchange based on previously published
descriptions of apparent losses from natural water systems such as Lake Michigan^
as well as demonstrated losses from 1 per cent pulp fiber/distilled water slurries
-34-
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in experiments carried out at the Institute of Paper Chemistry, The latter case
showed up to 30 per cent losses from solutions spiked to the. 100 ppb concentration.
Quantitative assessment of the evaporative losses from
actual treatment facilities will require application of field sampling techniques
for airborne PCBs which are still in the development stage.
3.3.3 Incineration Losses
Destruction of PCBs by high temperature incineration is generally
regarded as requiring a 2 to 3 second exposure to 2,000°F for "complete" combustion.
Shorter contact times or lower temperatures will not allow complete elimination of
these stable compounds. Specially designed incinerators have been operated by
Monsanto and other firms for the proper decimation of PCB-containing liquid wastes,
but typical municipal and industrial incinerators will not destroy PCBs completely.
3.3.3.1 Bark Burning
In those mills which practice barking, the bark is often
utilized as a hog fuel in mills which generate sufficient bark to use it to fire a
boiler for steam generation. Smaller producers of bark may simply incinerate it
along with unsalvageable fiber from other parts of the operation. Like the virgin
wood, bark has a PCS content which is essentially nil and results in an extremely
tiny emission to the atmosphere under these conditions.
3.3.3.2 Sludge, Spent Liquor and Carbon Burning
On an industry-wide basis there has been a drastic decrease
in incineration of these materials. The price of fuel necessary to mix with them
has risen to the point where alternative disposal schemes cost less.
Sludge is dewatered and generally landfilled. Its PCS
content usually ranges from 4 to 25 ppn, the same range exhibited for municipal
(14)
treatment plants. As such, it should be subject to the same careful handling
as other PCS wastes.
Spent liquor of all types is being internally recycled
and refined to reduce the amount of make-up chemical required in the pulping stages.
More and more opportunities are being discovered for converting spent liquors into
-35-
-------
salable by-products or for conversion -bo other uses inside the plant. -These
reasons have led to a great overall reduction of liquor burning throughout the
industry.
Charcoal burning has been used in a few instances for
the production of carbon. But the extent is not great and one would expect
volatilization of any POBs to have taken, place prior to such an activity. As in
bark burning, actual measurements of such potential losses are not available.
3.3.4 Solid Process Waste Losses
The industry exhibits an average process loss of 2 to 5 per cent.
That isf of the pulp entering the paper machine, 2 to 5 per cent of the fiber by
weight does not get incorporated into the product paper. This amounts to 40 to
100 pounds of solids per ton of product that will be incorporated into the sludge.
As mentioned in the previous section, the few data for paper mill sludge KB con-
tent shows it to be in the same range exhibited by municipal treatment plant
sludges. These considerations predict that an average mill with 100 ton daily
production might landfill between 2 and 120 grams of PCBs per day (0.004 - 0.26 Ibs.
The effective mobility of PCBs in the landfill situation is not
well described. The EPA Regional Surveillance Program generated 75 samples describe
as leachates. These were gll samples where ground water was determined to have had
the opportunity to percolate prior to sampling.
Eliminating three samples known to be directly associated with
highly contaminated industrial sites, the average value for the 72 remaining sample
is 2.8 ppb. It is only 2.8 times the 1 ppb detection limit specified in the EPA
40 CRP PT.136 standard analytical method.
Assuming that landfills are about 40 to 50 per cent paper, neither
the paper or the sludge would appear to be mobilizing large quantities of PCBs.
In fact, the leachate PCB concentration is indistinguishable from that of industrial
intake waters reported by the Regional Surveillance Program and described in
Section 3.1. The binding of the PCBs to the fiber may be similar in stability
and strength to their association with soil or sediment particles. PCB mobility
in sediments is reported to be very low. ^15'1 '17' This is thought to be due to
the availability of organic material with which PCBs preferentially associate.
-36-
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3.3.5 PCS Concentration in Finished Product
Product concentrations are referred to elsewhere. In general,
PCS levels of current products made with recycled fiber range up to one to two
parts per million. This material appears to be almost entirely due to use of
Aroclor 1242 in NCR carbpnless_copy paper_prior _to_the spring of 1971. _ Levels in
products_appear to be consistently decreasing since the 1971-72 time frame.
3.4 Monitoring Technology
The study of PGBs within the pulp and paper industry is naturally based
on the data generated by the analytical procedure. At the present time, just as
in the analysis of natural waters for PCBs, there is no standard method for the
analyses of pulps or effluents which take into account the peculiarities of the
matrices involved. For example, in the analysis of pulp or paper, it is absolutely
essential to remove the PCBs from the fiber quantitatively so that, eventual extraction
into an organic solvent such as hexane may be accomplished. Removal procedures such
as treatment with alcoholic potassium hydroxide have been used. Application of
surfactants such as Triton X-100 is also practical. Having removed the PCBs from the
fiber, it is then necessary to make sure that both forms, the free PCB and the
encapsulated PCB from NCR carbonless copy paper, are extracted into the solvent.
There exists a definite problem with storage of samples prior to extrac-
tion and analysis. Apparently, the organic activity of the bacterial population
immobilizes PCBs in slimes deposited on container walls and fiber. An attempt to
control such losses has been to add formaldehyde to the samples, killing all biotic
(18)
activity. This has proven successful in lake and stream waters.v
EPA researchers recommend that the extraction step be performed on a vortex
mixer in the original container. This is to give the solvent the maximum opportunity
to react with any of the analyte bound to the container walls. It also will assist
in reducing volatilization losses already shown to be potentially large by the
(12)
Institute of Paper Chemistry. Similarly, it has been recommended that all
transfers of material during the pre-analysis manipulations be kept to an absolute
minimum.
-37-
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Limited intercalibrations have shown the drastic effects on precision
and accuracy which, the small differences in sample handling and storage can have.
One IPC study showed 3 laboratories reporting 21.5 ppb, 102 ppb and 180 ppb on a
split effluent sample. But while other samples showed as large percentage
differences, there was no regularity in the laboratories reporting high or low on
a given sample. IPC and others are working in the vicinity of a 0.1 ppb detection
limit in effluent samples. Most of these intercalibraticns took place at concentra-
tions far above the detection limits so noise in the analysis is small compared to
irregularities introduced by storage and handling.
Quantitation of the chronatogram is a difficult process for the complex,
multi-peaked plots given by PCBs. Paper mill effluents often show interfering
peaks caused fay non-PCB materials. Eecourse to mass spectroscopy analysis, is some<-
times necessary to separate these interferents. Some removal is accomplished by
sample oxidation with chromium trioxide, but many peaks can remain and a qualitative
assessment of the chromatogram by a trained person must be employed. The possibility
of mis-identification is real, but the alternative use of the GC-mass spectrometer
is often too expensive to be considered for routine use.
The continuing decline in PCS concentrations in effluent, sludge and
product will require a continuing improvement in detection limits and sample treat-
ment techniques.
A detailed treatment of analytical techniques for PCBs in paper products
and paper mill effluents is presented in Reference (12).
-38-
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4,0 COST DEVELOPMENT OF PCB REMOVAL ERDM PAPER RECYCLING MILL
EETTLUENT STREAMS
4.1
The inajor apparent cause of PCBs in this industry is the use,
until 1972, of Aroclor 1242 in carbonless copy paper. A significant por-
tion of this paper has gone through at least one recycle resulting in the
PCB contamination of the effluents emanating from these facilities.
Three inajor types of paper recycling mills currently exist
in the U.S. They are:
(1) Mills producing paper products with deinking process;
(2) Mills producing paperboard from wastepaper; and
(3) Non-integrated mills producing tissue paper from
wastepaper without deinking.
A number of mills in the paper recycling industry are so-called
complex mills, i»e., mills which produce multiple paper grades. The basis
used for classifying complex mills is the product and process which account
for the largest dally production capacity. Table 4-1 summarizes the
distribution and the production of the paper recycling industry in the U.S.
The general process used in the paper recycling industry is
pulping and deinking (only for deink mills) , pulp washing, bleaching (not
for paperboard mills) , screening and cleaning, and papermaking. PCBs can
be released from the recycled paper in any or all of the above process
steps. The water usage of a deinking plant is large and can amount to 65
percent of the total usage of the entire mill. Water used in pulp washing
is generally done, in a counterf low system which allows maximum potential for
water reuse. Some characteristics of the effluent streams are shown in
Table 4-2. Data on the PCBs level in the effluent streams for this industry
are discussed in Section 3.3.
Technologies for the removal of PCBs from industrial waste-
waters were evaluated and described in a previous report. '^ Carbon
adsorption in conjunction with pretreatmant (equalization and multimedia
-39-
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filtration) was recommended as the best current candidate for the removal
of PCBs from, the. wastewaters to the 1 ppb level or below. Cost information
generated in this report for the treatment of paper recycling mill effluents
is based upon the pretreatraent and carbon adsorption cost curves of Figures 4-1
and 4-2 which were taken from that report. ^^
In the analysis which, follows, we have taken the general view that
sufficient PCBs will be present in solution in the wastewater to warrant considera-
tion of carbon treatment down to the one ppb level. As was discussed previously,
it is conceivable that a sufficient fraction of the PCBs present will be removed
with, the solids during filtration so that the one ppb can be reached without
resort to further treatment by carbon or any other technique Cuv-ozone, etc.).
Similarly, we have assumed, for the purpose of cost estimation, an end-of-pipe
treatment without regard to any treatment (to reach BPTCA, etc.) already in place.
In essence, then, the following should represent a worst-case situation.
4.2 Plant PCS Wastewater Treatment
The treatment system designed to remove PCBs from wastewater
is capable of handling all possible contaminated flows. A schematic flow
diagram for this treatment system is given in Figure 4-3. ^Since there
can be a wide variation existing in these flows, a flow equalization basin
is necessary to provide a near constant flow downstream to any downstream
treatment unit operation.
In the equalization basin, suspended oils and immiscible sol-
vents will separate and rise to the surface. Suspended solids will either
rise, -fell or remain suspended depending on their densities and particle
size. It has been found that suspended solids will absorb PCBs on their
surface and these are removed either in the equalization basin or by the
subsequent filtration. Any heavy material collected from the bottom of
the basin would be drummed and sent to an incinerator for decomposition
of PCBs. The floating liquids would be removed by a belt skimmer and
drummed for subsequent incineration, since these oils could contain high
concentrations of PCBs. It is assumed that PCBs will enter the equaliza-
-42-
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tion basin at an unknown concentration and leave it at 200 ppb, and that filtra-
tion will reduce the PCBs level to 50 ppb. Subsequent terminal treatment
systems, i.e., rgqfr"" adsorption will reduce this PCBs concentration
to 1 ppb or less. Plants which already have treatment for suspended :.
solids and discharge less than 50 ppb of PCBs in their effluent streams
may install the carbon absorption system only.
4,3 Cost References and Rationale
The basic assumptions and rationale employed in developing the
wastewater treatment costs in the paper recycling industry for PCS
can be gM'UHJ" i flp*3 as follows:
(1) Costs are developed for "representative plants" rather
than any actual plant. "Representative plants" are
defined to have a size, age, and wastewater flow
agreed upon by a substantial portion of the manu-
facturers in this category. In the absence of such
information, the arithmetic average of production
size and wastewater flow for all plants is used.
It should be noted that the unit costs to treat
wastes at any given plant may be considerably
higher or lower than the representative plant
because of individual circumstances. Extra-
polation of these costs to the entire industry
would very likely be unrealistic.
(2) Ihe costs for the end-of-pipe treatment for PCBs
are assumed to be essentially proportional to the
volumetric flow rate of the wastewater. Ihe treat-
(19)
ment costs developed in the previous report * '
for PCB removal "are reassembled and presented
in Figures 4-1 and 4-2.
-46-
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(3) Very linri-Nad amounts of information are available
from this industry concerning the PCS concentration
in the effluent and the kinds of treatment presently
employed. Therefore, the estimated total annual
cost for PCB wastewater treatment of a representative
plant is based on the "worst case" conditions. It
was assumed that "representative plants" employed no
terminal treatment for PCBs removal and practiced no
segregation of wastewaters containing PCBs from other
in-process use waters.
(4) Costs are developed separately for the pretreatment
(equalization and multimedia filtration) and the
carBon adsorption treatment of PCBs.
(5) The capital cost is based on 8 percent interest over
a period of ten years. If the supply of waste paper
with substantial PCB content stops before the ten-
year period is up, the capital recovery cost will
increase substantially.
4.4 Cost Development
Three major categories are identified within the paper-
recycling industry (see Section 4.1). The costs of wastewater treatment
are developed for each individual category. Costs for pretreatment and
carbon adsorption for each category are shewn in Tables 4i-3 through
4,5. The capital costs, operating and maintenance costs (excluding
power}, and power costs are taken .directly from Figures 4-1. and 4-2
at given wastewater flew rates. Throughout the analysis represented by
Tables 4-3 _ through. j4-5j_annual capital recovery costs were calculated
based upon a ten-year lifetime and an 8 percent interest rate, consistent
fl9)
with the earlier reference. ' The capital recovery factor was thus
estimated to be 0.15. All cost estimates contained in this report are
based on 1976 dollars.
-47-
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A summary of cost estimates for PCB removal at different in-
in Table 4H5T^_A suOTnary_of total_capital _ invest^
inent cost information for PCBs from paper recycling mill ef fluent is given
in Table 4-7. Basedljpon the informatign_ooni-ajned in this table , this
industry, as a whole, would have to invest up to an estimated maximum of
$366,700,000 to achieve a PCB limitation of 1 ppb in their wastewaters.
There is also an anticipated $94,120,000 of annual treatment cost for the
mant cost of PCB removal. The estimated annual treatment costs correspond
to a three to five percent increase in the selling prices of products from
this industry.
Depending on the amount of pretreatment required to decrease
the suspended solids to a point where fouling of the charcoal beds could be
avoided, costs could escalate, severely. Such, would be the case for effluents
from deinking operations where fines loading can be heavy and particle sizes
quite small.
-51-
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TABLE 4-6
OF ESTIMKIED CARBON ADSOEPTIGN
TREATMENT COST AT DIFFERENT INPUT PCS LEVELS
[PCB] Input
(PPb)
50
40
30
20
10
5
Estimated Annual Carbon Adsorption Costs
$/kg of PCB Removed ($/lb)
Deink
1,870(850)
2,350(1,070)
3,160(1,430)
4,820(2,190)
10,200(4,620)
22,900(10,400)
Paperboard
2,330(1,060)
2,930(1,330)
3,940(1,800)
6,020(2,730)
12,700(5,770)
28,600(13,000)
Tissue
2,730(1,240)
3,430(1,560)
4,610(2,090)
7,030(3,190)
14,800(6,740)
33,400(15,200)
-52-
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TABLE 4-7
OF CAPITAL INVESTMENT OF PCB
REMOVAL HOI PAPER RECYCLING INDUSTRY
Deink
Paperboard from
wastepaper
Ncn-integrated
tissue paper fron
wastep^er without
deink
Total
Total. Capital Investment
, l Dollars
Pretreattnent Carhdn adsorption Total
78,200,000 14,600,000 92,800,000
247,500,000 6,440,000 253,900,000
17,200,000
2,800,000
20,000,000
342,900,000
23,800,000 366,700,000
all plants in each category have production rates similar to
tiie representative plants.
-53-
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-54-
-------
5.0 MODEL OF PCBs INVOLVEMENT IN THE PULP AND PAPER. INDUSTRY
5.1 Purpose and Objectives of M3del Development
Although it is generally agreed that the major input of PCBs into the
paper industry has been through, recycling of NCR carbonless copy paper (and this
view is strongly supported by evidence presented previously in this report),
there are a number of questions concerning PCBs in this industry which have not
been answered:
d) How long will PCBs from NCR paper continue to cause
significant product levels of PCBs?
(2) How long will paper mill effluents continue to exhibit
PCS levels of significance?
(3) What are the chances for "hot spots" of PCB levels in
products and effluents due to locally high concentrations
of NCR paper in recycled fiber?
C41 Are PCB levels in intake water significant at present in
comparison to levels from NCR paper, with regard to
product and effluent levels?
The purpose of developing and exercising a model of PCBs involvement
in the paper industry was to obtain the best available answers to the above
questions. By necessity, the model takes a simplistic material balance form;
the major limitation of the utility and accuracy of the results obtained arises
from the almost complete lack of data on process stream PCB levels and the extremely
limited set of data concerning effluent and product concentrations of PCBs.
However, the model does appear to be consistent with available information and
does predict the PCB concentrations in various paper products and in the effluent
water from paper processing plants in terms of the amount of input PCB accepted
with the raw material and contained in the intake waters.
The effluent prediction is based on a constant distribution factor be-
tween the product and the effluent. Data available on sludge, effluent and pro-
ducts place this distribution coefficient in the vicinity of 1:1000, effluent
-55-
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to product. The actual PCS concentration in the. effluent entering the receiving
stream will reflect the treatment process at a given site,' With a more rigorous
approach to the distribution coefficient, one would be able to narrow the limits
of predictability considerably. We have aimed at the center of the array in. order
to maintain a tie to "average1* conditions.
At all times it is realized that the model is only a general one; no
attempt has been made to apply it to a particular mill. A simple mass balance
with known PCS inputs, water flows and production outputs would be a
straightforward task, for a given site.
The model does show that a mill which accepts NCR carbonless copy or
converter scrap, has poor suspended solids removal and has a high PCS level in
its intake water might be capable of producing a high PCB effluent as a local
"hot spot". Present values for recycled wastepaper _indicate this likeli- __
hood to be continually decreasing. However, the expected frequency or severity
of hot spots cannot be fully addressed because of lack of data.
5,2 First Order Model of Paper Industry
5.2.1 Assumptions
The model is based upon the following assumptions:
11 The two primary sources of PCB to the paper industry
are:
a) NCR carbonless copy paper made between 1957 and
1971 and its associated converter scrap at 3.4%
FCBs by weight; and
b) The PCB load of the intake waters, taken to
average 0.1 ppb.
2} A secondary source is PCBs already existing in recycled
paper due to la and Ib above.
3} The routes of PCBs out of the paper industry are limited
to:
-56-
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a) Product
b) Effluent
c) Sludge and other solid wastes" (or process^loss)
d} Evaporation
4} Most of the PCBs in the paper industry remain associated
with, the fUber, either as product or as sludge. This
appears to be due to the presence of PCBs in microspheres
used in the NCR paper plus the low solubility of PCBs in
aqueous solution and its preferential association with
surfaces and organic rich interfaces. In sane cases PCBs
found in industrial effluents are almost quantitatively
associated with the suspended solids.
51 Evaporative losses of PCS will depend to a great deal on
the integrity of the capsular form. Industry experts have
been quite unanimous in their agreement that capsular
breakage would be small. The evaporative losses intimated
fay some of the mass balances attempted at the Institute of
Paper Chemistry are very small compared to the amounts of
PCB moving through the systems. As a result, we have
chosen to neglect evaporative losses in the treatment of
the model since any assessment would be fragmentary at best.
6) Contributions of PCB by inks or adhesives are negligible
and not considered to be large enough to affect even a
locate distribution. Based on the estimation presented
in Section 3.1, the upper bound of PCBs into paper products
other than the NCR paper appears to be on the order of
50,000 to 100,000 pounds, much less than one percent of
the total PCBs usage in the NCR papar during the same
time frame. Thus, non-NCR PCBs should be negligible with
regard to the model.
-57-
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7} Prior to 1957, when NCR carbonless copy paper was intro-
duced, the PCB content of paper products would have been
controlled by the PCBs carried with, the intake water. The
effluent would have been cleaned by the passage of PCBs
from the water to the fiber during the pulping and paper
making process. Total transfer for a typical process would
have produced a paper with a PCB concentration of 0.02 ppm.
Based on this consideration, and the realization that pre-
sent day detection limits for PCB in paper are in the
vicinity of 0.1 ppm, the model has been exercised neglecting
the intake water contribution.
8} The two routes for PCB return on NCR paper are:
a) As part of the recycling waste paper stream in
"mixed" or deinked grades of paper stock.
bl As converter scrap purchased by mills that use
it as furnish Craw material) .
Other assumptions or specific decisions made in developing the
model will be indicated at the point where the information is used or the
5.2.2 Model Structure
The first order model is an overview of the industry as a whole.
Mass balance considerations are utilized to develop a "one-box" representation.
Such a treatment avoids the complexity of the actual recycling web, and applies
the limited data on PCB concentrations of waters, product and sludge to produce
a first look at the time rate of change of PCB levels in average product as a
result of the growth and eventual cessation of NCR carbonless copy paper in the
recycled waste stream. This admittedly simple approach serves as a foundation
upon which to further divide the industry, as well as providing a qualitative
validation of many of the accepted descriptions of PCB occurrence within the
industry.
-58-
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Figure 5-1 shows a schematic representation of the first order
paper industry model, where:
ECt) - evaporative losses of PCS. These losses are yet to be assessed on
an industry wide scale, but early indications are that they are
not dramatic. Any such losses would have the effect of lowering
product, effluent and sludge FOB concentrations, but would not
change the relationship between these.
VCt) - input of virgin wood pulp. Virgin wood has been found to be
relatively free of PCBs, but may pick up some front the water used
in the pulping stages.
W. (t) - intake water. Census Bureau data for total water usage are relied
on. The typical intake water PCS concentration is taken to be 0.1
ppb. This value is probably an upper bound on a natural water
and nonetheless turns out to have only a small effect on KB con-
centrations found in the paper industry.
SCtl - sludge output. This is the amount of process loss going to sludge.
It is inferred that sludge output is proportional to the production
rate and has the same concentration of PCBs as the product.
R(t) - amount of paper stock being recycled. The average lifetime of paper
products is taken to be 1 year before recycling. Hence the concentra-
tion of PCBs in the paper stock is assumed to be that of the previous
year's product.
WQut(t) - effluent water. It is generally held that PCBs in the effluent are
strongly associated with the suspended solids. In the present case
the effluent can be considered what might typically ronain after
primary treatment, removal of settleable solids and sane suspended
solids. How much removal occurs in an actual mill will depend on
the type and amount of treatment available. It has been assumed
here that the effluent PCB concentration is proportional to the pro-
duct concentration. The constant of proportionality would depend
on the treatment system efficiency for solids removal. But in
-59-
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-60-
-------
any case., the effluent cxsncentration predicted by the model gives
an idea of the KB which, might escape into the. environment with-
out further consideration and treatment.
P(t) - annual production of the industry.
N(tl - FCBs introduced to the paper industry as a result of NCR carbon-
less copy converter scrap and recycled used sheets. While NCR
production figures for carbonless copy paper and its PCS content
are known, the amount recycled from, office and other commercial
institutions or from converting operations can only be guessed
at. Converter scrap varies between 10 and 15% (15% was the figure
used in an A.D. Little Paper Industry study) for printing and
writing grades/20' However, much of this scrap was recycled
in-plant, back into NCR carbonless forms - this amount could not be
estimated by personnel at Mead (the manufacturers for NCR). Shade
Information Systems, Inc., a converter of carbonless and a supplier
of post-consumer office waste, in testimony before the Department
of Natural Resources in Wisconsin, estimated that 10% of all office
waste is presently recycled, that of this recycled paper, 10% came
frcra old files and 90% from yearly usage, and that the average life-
time for files is three years.^21^
According to Mr. Ed Nastar of the International Business Forms
Association, the major uses for carbonless paper are in invoices and
customer statements with tax forms using a lesser amount. If one
extends the Shade estimates to include commercial establishments like
stores with offices then one can use the same estimates for carbon-
less paper: 10% of each years production is eventually recovered with
90% of that recovered coming from, the previous year and the other 10%
coming from old files with a three year half life. These estimates
are used in the model. (To show the sensitivity of the model to the
NCR recovery rate a 20% figure will be presented). Table 5-1 shows
NCR production from 1957-1971.
-61-
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TSble 5rl.
*m «M*» «^M«W««»
Year
1957
1958
1959
I960
1961
1962
1963
1964
1965
1966
1967
1968
1961
1970
1971
1972
1973
1974
1975
*h** -**+*****tr*r»^***tf^rm* ^^**P_£ ^ ^^^^iixa
PGB in NCR Paper Manufactured
OLQ Pounds^
58,7
77.9
101.9
114.9
164.3
195.3
228.1
270.5
348.9
424.6
435.5
580.1
627.8
661.1
126.6
0
0
0
0
-62-
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Since the amount of old NCR carbonless recycled into the in-
dustry can only be estimated and few measurements on other than recycled box-
board exist by which to validate the figures, the exact levels 'predicted by the
model should be regarded with caution. Nonetheless, the model does reflect the
trends and dynamics of PCS involvement in the industry.
The PCB mass balance equation for the First Order Model is
written:
P Ct) Cp (t) +S (t) Cp (t) -W (t) Cwout (t)
where:
Cp(t) = PCBs concentration in product for year t.
Cw. = PCBs concentration in input water (taken to be 0.1 ppb)
Cw . (t) = PCBs concentration in effluent = X CpCt) where X is a
constant dependent on the level of suspended solids.
In EPA data ' "* the suspended solids are shown to range fron 500 ppm in
non-deinked paper mil Is to 1700 ppm in deinking effluents. Considering that the
best available technology is not uniformly used now or in the past, 1000 ppm is
assumed for a suspended solids load, and the model is exercised with X at IQQQ»
From John Strange Paper Co. data a X of - was obtained while Ft. Howard informa-
tion indicated X at to
and: S(t) , the sludge output is taken to be proportional to P(t) . That is:
S(t) £(t), where £ is the proportionality constant.
A value of 4.5% was chosen for 5, based on previously reported data for
process losses.
Rewriting the previous equation,
R(t)CpCt-l) + NCt) + 10~10W. Ct) = Cp(t) [0.955 PCt) + 10~3W . Ct)]
Ul < i, ^ > v-» OUt
-63-
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As a simplistic first exercise - assume A = 0, i.e., all PCS is
retained by the product. Let the NCt) assume three cases:
A_ - 10% recovery
AJ.J - 15% recovery (10% recycle + 5% converter scrap)
A_ ' - 25% recovery (20% recycle + 5% converter scrap)
Figure 5-2 shows the PCS concentration in the product for these three different
recovery rates. The NCR production is also plotted as a reference to show the
roll-off of the curves.
Immediately obvious is the direct and quantitative relation
between the NCR recovery and PCBs in the product. Product levels rapidly fall
below the 1 ppm level by 1973 or 1974, so that input water concentrations (W
appear to be conpletely dominated by the NCR contribution.
Further insight is gained if the data of A-.. (15% recovery) are
plotted again with R(t) = zero; that is, if there was no recycling of product back
into the paper stock input. Figure 5-3 shows the result of this exercise. For th
overall industry under these conditions, 15% NCR recovery appears to be responsibl
for about 83% of the PCS in the product. However, if broken down further, specifi
segments of the industry which utilise a large proportion of wastepaper in their
furnish would be expected to exhibit a larger dependence on the PCBs recycling to
the paper stock input.
The effect of process loss to sludge is easily demonstrated in a
tabular format. Table 5-2 shows the 15% NCR recovery data now allowing R(t) to
operate (i.e., recycling to paper stock) and X> values of 0 (plotted in Figure 5-2
10~"3, and 2 x 10~3. According to the data on Table 5-2, a X of 10~3 (ratio of
PCBs level in effluent to TSS level in effluent) decreases the PCBs levels in the
product by only about ten percent from those at zero PCBs in the effluent (X - 0).
A further reduction of six to ten per cent in product PCB levels results from
application of X = 2 x 10~3. As further internal reuse schemes for white water
proliferate a continuing decrease would be expected in both suspended solids and
X. All peripheral factors point to a continuing association of the majority of
PCBs introduced into the system with the product.
-64-
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-65-
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-66-
-------
Table 5-2
Year
1957
1958
1959
1960
1961
1962
1963
1964
19-65
1966
1967
1968
1969,
1970
1971
1972
1973
1974
1975
X=0
0.48
1.58
2.15
2.66
3.20
3.96
4.58
5,04
5.68
6.76
7.69
.8.08
9.18
10.20
8.03
2.83
0.86
0.45
0.33
A=1(T3
0.43
1.41
1.93
2.39
2.88
3.58
4.15
4.59
5.28
6.21
7.04
7.42
8.46
9.40
7.40
2.61
0.80
0.42
0.30
u vffr«U.
A=2xlO~3
0.39
1.27
1.75
2.16
2 62
* UA*
3.26
3 79
w / ^
4 20
* * * v
4 85
* * ww
5 72
*» * / ^
6 49
w * ^ j
6.86
7.85
8 72
v / A>
6.86
V W U
2.43
T*^
0.74
0 39
\J W«/
0.28
-67-
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This general overall look at PCBs demonstrated the following:
a) A 1970-71 peak in product PCS concentrations corresponding
to maximum PCS usage in NCR paper plus a one-year or less
delay in reaching maximum KB levels in the recycling stream.
bl With, the cessation of NCR product-inn the drop off in pro-
duct PCS was rapid. Different specific industry segments
would show a different drop off rate (this is investi-
gated with, the second order model).
c) Using reasonable choices for the adjustable constants,
the major source of PCB is the NCR carbonless paper's
direct input to the industry. Farther recycling of
paper contaminated by recycled NCR input has a relatively
.small effect on the concentration observed in the paper
product.
d) It is difficult to assess the quantitative effects of
such, industry responses to the PCBs problem as elimina-
tion of deinking grades as furnish for food board. There
is no doubt that within a specific segment of the in-
dustry such activity was beneficial. In the overview
of the first order model, however, these effects cannot
be separated out. The model as developed exhibits an
overWielming response to the NCR carbonless recovery
rate which would inundate any analysis of a finer internal
structure.
5.3 Second Order Model of Paper Industry
5.3.1 Industry Categorization for Second Order Model
The obvious industry categorization useful to a more detailed
industry analysis is paperboard;- paper; and construction paper and board. The
latter segment includes portions which use 100% recycled paper stock (construction
paper) and others which use little, if any, recycled paper stock (construction
board) and can be further subdivided on this basis. Figure 5-4 shows schematicall
-68-
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""I
_. A w.
News y vi
25% Nj
W:
ii M*) Ik
| I Evaporation
1 E^'W
PAPER
% Sludge S(1)(t)
-.,
Water Wn'(t) out
I
120%
| f^%
______ _ ___________ |
|
i!:
15%
1 ' ff
LL. i p
News
25%
A vin<2'(t)
N- *2'(t)
in
Win(2)(t)
II Evaporation
" I E<2»(t)
COMBINATION BOXBOARD
AND CHIPBOARD
1
1 ^
, H
tsiudge's(2>(t)
Wator W*2)/*l nut
i
-1
MOO
u
News
25%
F*Z
%
^ Vin<3'
|V. Evaporation
1 E<4Mt)
CONSTRUCTION PAPERS
AMD nTHPR
MIML/ u i ncn
(CONSTR. PAPER; TUBE; CAN & DRUM;
MACHINE; GYPSUM)
__/
W
% Sludge S(4>(t)
ater t out
V. CONSTRUCTION BOARD
Sludge S(5>(t)
Figure 5-4. SCHEMATIC OF SECOND ORDER MODEL
-69-
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the five categories selected and the flews of products returning to these industry
segments in recycled waste streams as well as other inputs, products, and dis-
charges. Figure 5-4 is thus essentially a schematic diagram of the second order
model. Annual production data, front 1957 through. 1974 for each of the five
industry segments are presented on Table 5-3,
Segment I, paper, has a product output approximately equal to
the sum of segments II, in, and IV. This should be remembered when one assesses
the total load of PCS associated with the production of a given segment. The
load will be PCB concentration times the output.
Segment II, combination boxboard and chipboard, is based on a
raw material which is 100% recycled. Historical PCB data (back to 1971} exists
for combination boxboard. Almost all of the deinked paper stock (ledger grades)
went into box production prior to 1971; also, most of the mixed grades and pulp
substitutes went into box production. As a result, most NCR paper entering the
general area of paperboard would probably wind up associated with combination
boxboard and chipboard. Chipboard is included since sufficient data were avail-
__ _ _ __ _ ___ _______ . __ _______ __ . __ _ _____ . __ _ _____ __ ___ ,____
able on this category, ^ ' but chipboard is less than io% of this segment's
total output.
Segment III contains those items which are primarily made from.
virgin wood or recycled product from Segment III.
Segment V, construction board, uses all virgin wood and is not
recycled.
Segment IV is a composite segment, the components of which have
the following characteristics:
a) All use a high percentage of mixed waste which could
contain NCR sheets.
b) Many products are used in building applications which
precludes their entry into the recycled waste stream.
c). The tube, can and drum, component is not likely to be
recycled, though 'it has an open usage different than
the building materials.
-70-
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Table 5-3
Annual Production for Industry Segments (10s tons I
Year
1957
1958
1953
1960
1961
1962
1963
19£4
1965
1966
1967
1968
1969
1970
1971
19.72
1973
1974
I
Paper
13.6
" 13.5
15.0
15.4
15.7
16.5
17.3
18.2
ia.2
20.7
20.9
22.4
23.6
23.6
23.8
25.4
26.5
26.9
II
Combination
Boxfaoard
&
Chipboard
3.9
4.0
4.2
4.2
4.3
4.3
4.4
4.5
4.7
5.0
4.1
4.4
4.3
4.1
3.8
3.9
4.0
3.5
III
Containerboard
8.9
8.8
9.8
10.3
10.9
11.6
12.2
13.4
14.4
15.9
16.5
18.4
20.0
19.7
20.3
22.4
23.3
22.2
IV
Construction
Papers and
Others
2.7
2.8
3.1
2.8
3.0
3.1
3.2
3.4
3.5
3.3
3.1
3.5
3.5
3.5
4.0
4.3
4.3
4.2
-71-
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5.3.2 Equations
The. same definitions of mathematical terms hold for the second
order model as for the first order model Csee Sec. 5.2.2} , applied on a segment-
by-segment basis. In addition, the second order node! uses superscripts to
denote association with, a, particular industry segment. Other symbols used are:
C^ Ct) = KB concentration of virgin wood in industry segment 1.
ce Ct) = KB concentration in aqueous solution of effluent, from segment 1.
The following are based on our assumptions:
cva) Ct) = cvc21 (t) = cv(3) Ct) = cvC4) ct) = cv(5) (t) = o
Ct) - C Ct) - C (t) = C (t)
Ea) Ct) = EC21 Ct) =» EC3) Ct) - EC4) Ct) = EC5) Ct) 3 0
and,
c *
Smut
where X's are constants.
Since newsprint contains little if any FOB,
NC3) (t) a 0
N(5) (t) = 0
Prior to 1957,
After 1957 one has these 5 unknowns, and the following 5 equations
-72-
-------
01 Nai(tI-h{.70Rai-CtlCaiCt-l}+0.05Ra) Ct}CpC3lCt-ll+.25Rai Ct) CO)
p p
(t) + s (t) + xW(1) (t)]c(1) (t)
(21 N(2) (t)-l- [0.15RC21 Ct)C C21 Ct-l)+0.20R
-.t21
C31Ct-ll+0.25RC2)Ct)CO}j
(This holds until 1971 at which time the paperboard segment greatly decreased their
usage of recycled paper. Thus, the coefficient of 0.20 for the paper portion of
the paper stock input is taken to be zero for years after 1971.)
(31 (a01 Ct)cpC3) Ct-1)] =[pC31cW3>ct)«3wout»>(t)] cp(3)(t)
C41 NC4) (tH-[o.35RH) Ct)C (1) (t-l)+0.40RC4) (t)C (3) (t-l)+0.25R(4) (t) (0)]
(51 o - [ PC) Ct)+sC5) CW+AjW^,.'51 (t) J c(5) CO
Motes:
(a) Fran equation (5) C (5) Ct) = 0 for all (t) .
(b) From equation (3). C (3) (t) = 0 for all (t) .
(c) All X's are from .001 to .002. This allows us to ignore X terms since they
are so much smaller than the P(t) and S(t) terms.
-73-
-------
Substitution yields:
Fran equation CD
Na) Ct)0.70CpC1) Ct-l)R(1) (t) =[pa) Ct)+Sa) Ct}] Cp (t)
Fran equation (2)
NC2) Ct)+[o.20Cp(1) Ct-l)+0.15Cp(2) (t-lj] R(2) Ct) =[p(2) Ct)+S(2) (t)] Cp(2) (t)
(The 0.20 constant drops to 0 after 1971 as noted above)
Fran equation (4)
NC4) Ct)+0.35R(4) Ct)C (1) Ct-1) = [p(4) Ct)+S(4) (t)]c (4) (t)
Equations (3) and (5) are negligible, based on Notes (a) and (b) above.
5.3.3 Quantitation and Exercise of the 2nd Order Mxlel
MsLenahan's study of 1969-1970 paper stock usage was used as the
(23^
basis for quantitating the model. v ' This extensive study accounted for over 90%
of the wastepaper stock usage. It also tabulated the paper stock by type and
associated that with its end use. A number of other studies have since been based
on these figures; utilization of these data thus keeps the model on a somewhat
parallel footing for comparison with the other studies.
The second order model is a good deal more complex than its
predecessor in Section 5.2. To explore the effects of recycling on specific
segments of the industry it was necessary to subdivide the industry into identifi-
able sectors. This necessitated developing a reasonable set of criteria for
routing the recycled paper between these sectors.
-74-
-------
The following additional assumptions were made;
1) Paper products produced one year are considered to be recycled the next,
2) The paper stock percentages of various inputs were taken to be constant
over the period 1957 to 1974, except in the combination boxboard and chip-
board category after 1970. In this category/ industry reaction to PCB in
food packaging and the eventual FDA 10 ppn limit is reflected.
3) Each segment's percentage of the overall paper stock usage is constant
from 1957 to 1974 using the 1969 percentage. The model is quite in-
sensitive to changes in this parameter.
41 Recycled newsprint is considered to be PCB free. Newsprint is produced
primarily from virgin fiber, and the only paper stock used in newsprint
is other newsprint. Consequently, no PCB from NCR paper should be intro-
duced into this segment. Measurements by Hazleton Laboratories in 1972
confirm low background values of PCBs in newsprint.' '
Since newsprint is only a small percentage of paper output it was not set
aside as a separate category. However, newsprint is a sizeable fraction
of the recycled waste stream and here it was accounted for separately.
5) Containerboard uses very little paper stock, and what it does use is old
containers or container clippings. (This excludes gypsumboard, chipboard,
and recycled tube, can and drum segments). Ws therefore approximated
paper stock in this subcategory to be 100% container. This implies that
containerboard will be PCB free.
6) As before, process loss to sludge was assumed to have the same PCB con-
centration as the product. The process loss estimates are those previously
published for 1970. <22>
7) Bureau of Census data was used to obtain values for total paper stock
recycled.
8) The model is very sensitive to the total amount of NCR carbonless copy paper
recycled into the industry, and to its distribution within the industry. Un-
certainties in these affect the details of the model, but not the general
trends.
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9) Virgin wood contains negligible PCB.
10} PCB concentration of input waters is taken to be 0.1 ppb.
111. Evaporative losses are not considered for the reasons given for the first
order model exercise in Section 5.2.
12} The "mixed" category of waste paper includes #1 and #2 mixed, super mixed,
boxboard clippings and mill wrappers. The amounts of each going into "mixed"
in 1969 was investigated by other workers. ' Paper stock dealers inter-
viewed indicated that "mixed" paper was usually office waste with the follow-
ing approximate composition:
Chosen for
Range (%) Model
Old Corrugated Cartons 0-15 10
Newsprint 10-25 20
High-Grade Printing & Writing 60-90 70
13} The loss of PCBs in solution in effluent waters is assumed to be negligible
compared to PCBs associated with the suspended solids.
The model is exercised for two distribution schemes for NCR paper as follows:
a} The NCR received in a given year is assumed to be 5% of the converter scrap
from that year's production and 10% of the post consumer wastepaper. Of the
post consumer waste 9/10 came* from the previous production year and 1/10 cane
from years prior to that.
(A three year half-life with exponential decay is postulated for the post
consumer waste NCR paper which is recycled more than 1 year after being
produced. This assumption is significant only after 1971.)
All of the 5% NCR converter scrap is assumed to go into the paper segment
of the industry. The combination boxboard segment rejected it due to a
discoloration problem.
The recovered post consumer NCR was distributed according to the percentage
of printing and writing paper being recycled within each segment. 70% of
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the mixed category was taken to be printing and writing paper except
within boxboard paper stock where it is estimated that 50% of the mixed
was actually boxboard clippings. About 2/3 of the deinking category is
taken to be printing and writing paper. The final breakdown of NCR in
the paper stock for each segment thus becones:
PAPER - 5% converter scrap
3% post consumer
OOMBINATICN BOXBC&RD AND CHIPBQARD - 3.5% post consumer
CCNSTKJCTICN PAPER - 3.5% post consumer
After 1970 the combination boxboard segment drastically reduced the use of
ledger grade papers and some pulp substitutes. This was industry's response
to eliminate NCR from inadvertently contaminating the foodboard grades. In
the model, the NCR entry figures for that segment are adjusted to reflect this
industry action. The NCR going into the paper segment may have increased its
percentage of NCR received as a result. Though this is not entirely clear, it
has been included in the second exercise of the model.
Figure 5-5 shows the response of the model. The rapid decrease in segment II
PCB levels after 1970 is evident. Concomitant reductions occur in segments I
and IV. While the latter two reflect the loss of the NCR carbonless copy
paper production, the former shows cessation of PCBs usage by NCR as well as
additional reduction caused by the industry action.
A second exercise of the model, shown on Figure 5-6, is made on the assumption
that 10% of the returning NCR is sent to the paper and boxboard segments
based on the use of deinking stock. The paper segment has not used mixed
grades and boxboard officials state that their product has not used mixed grades,
(20 23)
although several references indicate some usage. ' The second exercise is
performed with the assumption that the boxboard segment (II) does not use mixed
grades, other than boxboard clippings.
10% recovery of wastepaper is calculated at 9% the year after production, and
1% thereafter based on the 3 year half-life described earlier.
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The post-1970 reduction, of NCR into the combination bcodboard segment is
included. The reduction in ledger grgyfe' usage, by boxboaid is assumed to
have been by half in 1971 and complete stoppage thereafter. If the ledger
stream might have diverted to the paper segment upon its rejection by the
boxfaoard (segment U), the effect this would have had on the paper PCB is
shown by a dotted plot from 1971 on in Figure 5-6.
Overall, we see the same general trends in both exercises
(Figures 5-5 and 5-6). The routing chosen for the returning PCB in the NCR paper
effects the details of the product concentrations, as does the relative size of
the production output within each segment.
In each scenario, the primary removal of PCB containing NCR fra
production allowed a return of every segment to pre-1957 PCB levels in the produc
by 1374 or 1975. This trend is reflected in the decreases shown by available dat
in Table 3-2. The decreases documented are of the same general magnitude as prod
by the model. Data on "recycled wastepaper input" (6) has reflected a drop to 0.1
ppm in 1976, which is near the detection limit of the analysis for PCB in paper
products.
5.4 Discussion of Model Results
The results obtained from exercising the model show clearly the over-
whelming dependence of PCB levels in both product and effluents upon the NCR pape
content of recycled fiber. According to these results, product levels of PCBs
resulting from the NCR paper should be less than one ppm by the present time (197
with the possible exception of the combination boxboard and boxboard segment, and
of course, excepting localized hot spots caused by inclusion of small amounts of
NCR paper in the fiber recovery stream. This result agrees with recent analytica
results on PCB levels in paper industry products. Product levels, effluent level
and frequency and severity of hot spots should continue to decline slowly as the
PCBs in paper products are diluted further with virgin and less contaminated
secondary fiber.
The ratio of PCBs concentration to TSS in the effluents had little ef f
on product levels, as would be expected. Values of this ratio in the range of
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0.001 to 0.002 appear to be consistent with available data on both effluents and
products. This result indicates that most of the PCBs entering the process exit
in the product and thus generally agrees with the analysis of Section 3.
The overall, agreement of the results obtained with the model tend to
support the various assumptions made. Agreement is reflected by comparison with
avail able data on both product and effluent PCB levels. Thus, the model as pre-
sented does appear to represent a reasonable and consistent material, balance for
PCBs around the paper industry.
A distribution for incoming PCBs between product, effluent, and waste
treatment sludge can be calculated based on the results of the model. Using
the following values:
(1) PCBs level on product = 1 ppm of solids
(2) PCBs on solids in wastes = 2 ppm of solids
(3) 90 percent removal of solids and PCBs in wastewater treatment
(4) 135 ppm suspended solids in final effluent
(5) 0.27 ppb PCBs in final effluent
(6) Zero loss through vaporization
The results obtained are:
Plant Percentage of Inccming Weight of PCBs Level Solids
Stream PCBs Contained Therein Stream* in Stream Content
Product 75-80 1 kkg 1 ppn 95-96%
Sludge 18-20 0.6 kkg 0.4 ppm 20-30%
Effluent 2-3 100 kkg 0.27 ppb 135 ppm
* Based on one kkg of product.
The results obtained indicate that on the order of 75 percent of the
PCBs entering a paper mill exit associated with the product. The values
selected probably represent more of a "best case" situation for a recycling
plant than a typical situation within the industry. The PCBs distribution should
vary from plant to plant and from, product to product, but should not be nearly so
widely variable as suspended solids or PCBs concentrations, which are known to
fluctuate widely from day to day in a given plant.
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6.0 CCNCUJSICNS
The following conclusions are based on the evidence presented in this
report:
(1) The recycling of NCR carbonless copy paper was and still is the
only major source of PCBs into the paper industry.
(2) KB levels in paper products have been decreasing since 1972 and
apparently will continue to decrease under the influence of con-
tinued dilution of PCBs from recycled NCR paper.
(3) PCS levels in effluents fran paper Trills utilizing reclaimed
fiber have been decreasing in recent years/ and will continue to
decrease, due to decreased PCB levels in reclaimed fiber plus
application of wastewater treatment technology.
(4) PCB levels in sludges resulting from wastewater treatment may
be as hirh. as 10 - 20 ppm. Disposal of such material should be
performed with care.
(5) application of carbon adsorption as an end-of-pipe method for
PCBs removal from wastewater in the paper recycling industry
could increase product prices as much as three to five percent.
(6) The proportions of PCBs present in intact nrLcrcballoons in paper
products and in paper industry wastewaters are not known. General
indications are that more PCBs in the industry are encapsulated
than are "free" (released from micrcballoons plus other sources).
(7) The model generated to define PCBs involvement in the paper
industry represents a reasonable and consistent material balance
of PCBs input and output in this industry.
(8) According to the model, PCB levels in products and effluents are
sensitive only to the parameters associated with recycle of NCR
carbonless copy paper containing PCBs.
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(9) The product PCS levels obtained fron exercise of the model agree
well with available data; the results indicate a steep drop-off
following cessation of PCBs usage by NCR and a continuing, but
less steep, decrease thereafter. Current product levels are in
the one ppm range (recycled fiber).
(10) Within the limitations and assumptions of the model, on the order
of 75 percent of the PCBs entering the papermaking process exit
associated with the products.
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1. Environmental Protection Agency. Developnent Document for Interim Final
and Proposed Effluent Limitations Guidelines and Proposed New Source Perfor
mance Standards for the Bleached Kraft, Gpoundwood, Sulfide, Soda, De-ink
and Non-Integrated Paper Mills Segment of the Pulp, Paper and Paperboard
Mills Point Source Category. Vols. I and II. Washington, D.C.: U.S. Cover
ment Printing Office, 1976.
2. Rapson, W.H. "Pulp and Paper Technology: The Closed-Cycle Bleached Kraft
Pulp Mill." Chemical Engineering Progress (June 1976), pp. 68-71.
3. Todd, O.K., Editor. The Water Encyclopedia. Water Information Center, 19"
4. Lingle, Stephen A. (U.S. Environmental Protection Agency), "Paper Recyclir
in the United States." Waste Age, (November 1974), pp. 6-10.
5. Dennis, D.S. in Conference Proce*a^'''ngs - National Conference on Polychlor-
inated Biphenyls (November 19-21, 1975).Washington, D.C.: EPA, March 1976
6. DeFries, Myron, and McKay, Edward. "Plant Visit to Ft. Howard Paper
Company." (Versar Trip Report), August 9, 1976.
7. Luey, A.T. (Boxboard Research and Development Association). Letters to
Ms. E. Campbell (FDA), August 1974-January 1976. Concerning PCS levels in
paper intended for food packaging uses.
8. Thomas, G.H.; and Reynolds, L.M. "Polychlorinated Terphenyls in Paperboarc
Samples." B"lTetin of Environmental Contamination and Toxicology, X (1973)
pp. 37-41.
9. Shahied, S.I.; Stanovick, Richard P.; Mclntorff, David E.; and Missaghi,
Ecnil. "Determination of Polychlorinated Biphenyl (PCBs) Residues in Grade;
of Pulp, Paper and Paperboard." Bulletin of Environmental Contamination
and Toxicology, X (1972), pp. 80-96.
ID. Pound, Charles. (Technical Director of Connecticut Paperboard Corp.) Lett
to Bennett Ryan, Versar Inc., concerning results of PCB tests. June 14, IS
11. Institute of Paper Chemistry. Summary of IPC Questionnaire on Polychlori-
nated Biphenyl (Aroclor 1242) in Pulp and Paper Mill Environments. August
1976.
12. Institute of Paper Chemistry. Polychlorinated Biphenyls in Pulp and Paper
Mills, Part I, Analytical Methodology. Project 3295, Report Cne, A Progre
Report. Appleton, Wisconsin: September 31976.
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13. Versar Inc. PCBs in the United States; Industrial Use and Environmental
Distribution (NTIS Publication FB-252-012), Springfield, Va.;National
Technical Information Service, 1976.
14. Furo, A. Keith; Lawrence, Alonzo W.; Tong, Steven S.C.; Grandolfo, Marian C.;
Hofstader, Robert A.; Backe, Gail A.; Gutenmann, Walter H.; and Lisk,
Donald J. "Multielement and Oilorinated Hydrocarbon Analysis of Municipal
Sewage Sludges of American Cities," Environmental Science and Technology,
X (July 1976), pp. 683-687.
15. Tucker, E.S.; Sitschgi, W. J.; and Mees, W.M. (Monsanto Co.). "Migration
of Polychlorinated Biphenyls in Soil Induced by Percolating Water."
Bulletin of Environmental Contamination and Toxicology, XIII (1975) ,
pp. 86-93.
16. Achari, R.G.; Sandhee, S.S.; and Warren, W.J. "Chlorinated Hydrocarbon
Residues in Ground Water." Bulletin of Environmental Contamination and
Toxicology, XIII (1975), pp. 94-96.
17. Bellar, T.A.; and Lichtenberg, J.J. "Some Factors Affecting the Recovery
of Polychlorinated Biphenyls (PCBs) from Water and Bottom Samples," Water
Quality Parameters, ASTM STP 573, Jtoerican Society for Testing and Materials,
(1975), pp. 206-219.
18. Bellar, T.A., and Lichtenberg, J.J. "Some Factors Affecting the Recovery
of Polychlorinated Biphenyls (PCBs) from Water and Bottom Samples." Pre-
sented at the Chemical Institute of Canada -.Canada Centre for Inland
Waters, Symposium on Water Quality Parameters, Burlington, Ontario,
November 19-21, 1973.
,*
19. Versar Inc. Final Report - Assessment of Wastewater Management, Treatment
Technology, and Associated Costs for Abatement of PCBs Concentrations in
Industrial Effluents - Task II, Contract No. 68-01-3259.Springfield,
Va.: February 3, 1976.
20. Arthur D. Little, Inc. Analysis of Demand and Supply for Secondary Fiber in
the U.S. Paper and Paperboard Industry, Vol. I, II, III, Contract 68-01-2220.
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to Review and Receive Public Comment upon Proposed Administration Rules
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Waters of the State." Madison, Wisconsin: August 28-29, 1975.
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Institute). Paper Recycling - The Art of the Possible 1970-1985. Kansas
City, Missouri: American" Paper Institute, 1973.
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1969 and 1970," Tappif LV (November 1972), pp. 1605-1608.
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