United States
Environmental Protection
Agency
Research and Development
Risk Reduction
Engineering Laboratory
Cincinnati OH 45268
EPA/600/S2-91/039 Oct. 1991
EPA Project Summary
Waste Minimization Opportunity
Assessment: A Photofinishing
Facility
EPA has developed a systematic ap-
proach to identify and implement op-
tions to reduce or eliminate hazardous
waste. The approach is presented in a
report entitled, "Waste Minimization
Opportunity Assessment Manuar (EPA/
625/7-88/003). To encourage use of this
manual, EPA is conducting a series of
assessment projects under the Waste
Reduction Assessment Program
(WRAP). This report describes the appli-
cation of the waste minimization (WM)
assessment procedure to a photofinish-
ing facility in Cincinnati, OH. This facility
volunteered to participate in the project
and provided technical support during
the study.
This Project Summary was developed
by EPA's Risk Reduction Engineering
Laboratory, Cincinnati, OH, to announce
key findings of the research project that
Is fully documented in a separate report
of the same title (see Project Report
ordering information at back).
Introduction
The purpose of this project was to dem-
onstrate the application of EPA's Waste
Minimization Opportunity Assessment
Manual to a retail photofinishing facility.
This manual provides a systematic planned
procedure for identifying ways to reduce or
eliminate waste.
This project was conducted in coopera-
tion with Accuphoto, a retail photofinishing
facility located in Cincinnati, OH. Accuphoto
volunteered for the project and provided
support throughout the effort. This facility
was selected for the project based on their
willingness to cooperate, the potential at the
facility for WM, and the fact that Accuphoto
is typical of facilities within this industry
segment.
The results of this project will be particu-
larly applicable to small and medium-sized
photofinishing facilities. The equipment and
processes used by Accuphoto are com-
monly employed by "minilabs," which repre-
sent a large portion of the photofinishing
retail industry. These WM technologies and
methodologies are generally low-capital
options that do not require extensive techni-
cal support to implement. Larger
photofinishing companies may find other
techniques to be more efficient and cost
effective and are more likely to use auto-
mated equipment and techniques that re-
quire monitoring by technical staff. Further,
larger firms can take advantage of econo-
mies-of-scale to increase the profitability of
waste minimization options.
Procedure
The WM assessment procedure is a sys-
tematic framework that can be used by a
facility's own employees to identify WM
opportunities. As a structured program, it
provides intermediate milestones and a step-
by-step procedure to (1) understand the
facility's processes and wastes, (2) identify
options for reducing waste, and (3) deter-
mine if the options are technically and eco-
nomically feasible to justify implementation.
These procedures consist of four major
steps: (1) planning and organization, (2) as-
sessment, (3) feasibility analysis, and (4)
implementation. This project completed the
first three steps of the procedures for the
various photofinishing processes used at
Accuphoto. Implementation of the recom-
mended options is at the discretion of the
host facility. The focus for this project was
on the film and print processing opera-
tions—processes for color and black and
white (B&W) films and papers.
Accuphoto staff participated in the survey
by providing background information and
data about the facility, and its equipment,
processes, operating procedures, waste
Printed on Recycled Paper
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generation, and WM options. They also
provided ideas for WM and input to the
ranking criteria used for evaluating WM
options. This information was used later in
the study to incorporate Accuphoto's pref-
erences in the evaluation process.
The key analytical datum with respect to
photographic waste is the silver concentra-
tion of spent process chemicals and wash
waters. Because silver is important in terms
of its economic value and also, as a com-
monly regulated pollutant, the silver con-
centration of each wastestream is important
in evaluating WM options and environmen-
tal impacts. Since wastestream data were
unavailable for this specific facility, they
were estimated using data from the litera-
ture.
The Accuphoto Fracility provides photo-
graphic processes forcolorfilm (C-41),color
paper (RA-4 and EP-2), black and white film
(T-max), and black and white paper. All
spent process chemicals and wash waters
are discharged into the sanitary sewer. The
B&Wfilm and paper processes and the EP-
2 process are plumbed directly to the sewer
drain. The RA-4 and C-41 processes dis-
charge to internal storage vessels that are
periodically drained into carboys. The car-
boys are emptied into a sink that discharges
to a sewer drain.
All solid wastes are collected by a city
solid waste contractor. Chemical contain-
ers are rinsed before being discarded with
other refuse. The costs of water and sewer
and solid waste disposal are included in the
cost of the Accuphoto's facility lease.
Results and Discussion
Eight options were considered to be po-
tentially applicable to Accuphoto.
Option 1. Wash Water Control
Wash water is currently used for the EP-
2 color film development process and the
B&W paper process. The wash water is
turned on each production day at approxi-
mately 7 a.m. and shut off at 7 p.m; water
use is therefore continuous during the day.
Production, however, is not continuous.
Because each developing process is typi-
cally used only 2 hr per day, water is wasted
for approximately 8 hr per day. However,
because of the semi-automated nature of
these production processes, operators are
not typically aware of exactly when the
process is complete. Further, operator con-
trol is generally not sufficient to provide
consistent water savings.
Option 1 includes the equipment needed
to automatically shut off water during non-
production periods. A simple way to achieve
this goal is installing a timer control system,
a switch, timer, and solenoid valve. In use,
the operator would push a button on the
switch, and the timer would be activated;
this would, in turn, activate the solenoid and
albw water to flow. After a preset time
period (user adjustable), the timer and sole-
noid would deactivate, shutting off the wa-
ter. The timer would be preset to the normal
or maximum production time depending on
the nature of the operation.
Further water reduction for these two
processes may be possible by evaluating
the water flow rate. The present flow of 2
gpm may be excessive, especially for the
EP-2 process, which has an efficient counter
current rinse arrangement. A silver test pa-
per could determine an acceptable flow
rate.
Option 2. Silver Recovery -
Metal Replacement Cartridges
Silver is present in the various spent
photographic chemicals and wastewaters.
The solutions themselves are not formu-
lated with silver; rather, silver is present in
the emulsion on films and papers as light-
sensitive silver halide. During processing,
the developer changes the exposed silver
halide to metallic silver. For B&W films and
papers, only the unexposed silver halide
(typically 80%) is removed from the emul-
sion during the fixer stage. The balance of
the silver remains on the paper or film. For
color films and papers, a dye is formed at
the sites of the developed silver. Then all
silver is removed during a bleach fix stage or
in subsequent washes and process solu-
tions.
The metal replacement cartridge (MRC)
is a device widely used in the photographic
industry for silver recovery, both as a stand-
alone method and in conjunction with other
recovery technologies. Metal replacement
cartridges are particularly popular with small
and mid-size laboratories because of the
associated low capital costs and the rela-
tively high silver recovery efficiency.
Option 3. Silver Recovery -
Electrowlnnlng
Option 3 is an equipment-related option
involving the use of an electrowinning de-
vice. With this technology, which closely
resembles electroplating, a direct electric
current is passed through a concentrated
silver solution from anodes to cathodes.
This causes the silver to plate out onto the
cathode in a nearly pure metallic form.
The selection from the wide range of
commercially available equipment depends
on the solution volume or flow rate, the
concentration of silver, and the level of
automation and design sophistication that
the user desires.
Option 4. Electrowinning with
MRC Tailing
With this option, based on the use of an
electrolytic unit described in Option 3, metal
replacement cartridges are used to polish
the effluent from electrowinning.
The recovery capability of Option 4 is
equivalent to Option 3 plus the removal of
silver from the effluent of electrowinning.
The average effluent will be desilvered from
500 mg/L to approximately 10 mg/L. By
using the same type of MRC described in
Option 2, only one 5-gal cartridge will be
consumed each year. Because of oxidation
of the steel wool, however, the units may
become fouled before they reach capacity,
and more frequent changes may be re-
quired.
Option 5. Recovery of Silver -
Ion Exchange
Ion exchange is a silver recovery tech-
nique applicable to large volumes of low
concentration solution such as wash wa-
ters. Photofinishing shops using this tech-
nique either (1) have sufficiently large vol-
umes of dilute wastewaters such that silver
recovery from these streams is economical,
and/or (2) must reduce an effluent to a low
silver concentration to meet a discharge
limitation.
Typically, an ion exchange unit consists
of a canister or column that holds the ion
exchange resin; regeneration equipment;
and auxiliary items such as pumps, valves,
filters, controls, and instrumentation. Dur-
ing operation, the wastewater is pumped
through the column and the silver is re-
moved onto the ion exchange resin. When
the capacity of the resin is reached, the
silver is stripped from the resin in a concen-
trated form using a regeneration solution.
Option 6. Recovery of Fixer
To recycle the fixer, electrolytic recovery
can desilver the spent fixer. This method
does not add contaminants to the fixer;
however, electrolysis will produce some
changes in the fixer. Two changes that have
been identified are 1) sulfite is consumed
and 2) the fixer pH is lowered. Sulfite con-
sumption will eventually breakdown the thio-
sulfate complex to form sulfide. Sulfide af-
fects the ability of the fixer to remove silver
and also hinders the plating capability of the
electrolytic unit. Significant changes in pH
may also affect the fixer quality and the
silver recovery process.
To recover fixer, a dedicated electrolytic
unit is needed—one used only for recycling
fixer because the recovery process must be
done on a continuous basis rather than as a
batch operation. Batch treatment of fixer
would result in an inconsistent chemical
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composition, and control of the photographic
process would be hampered. Further, dur-
ing batch recovery of silver, it would be
necessary to constantly monitor the silver
concentration and current density. If too
much current is used or the recovery unit is
left on too long, the thiosulf ate in the fixer will
break down to form sulfide ion and silver
sulfide.
A continuous recovery system can re-
duce fixer replenishment up to 75% by
maintaining approximately a 500 mg/L sil-
ver concentration in the fixer. In this mode,
silver recovery can be enhanced by using a
metal replacement cartridge to recover sil-
ver from the blow-down of the electrolytic
recovery process.
Option 7. Recovery of Bleach
Fix
Bleach fix can be recycled using a con-
tinuous electrolytic system as described for
fixer recovery. The chemical composition of
bleach fix makes electrolytic silver recovery
difficult to control, however, and the pro-
cess is generally inefficient.
The method most commonly recom-
mended for bleach fix recovery is the three-
step desilvering process with metal replace-
ment cartridges: 1) silver recovery, 2) a
ferrous-EDTA complex oxidized back to
ferric-EDTAto restore bleaching ability, and
3) chemicals lost through carry-over with
the film or paper added to bring the solution
up to replenisher strength.
The silver recovery step should be per-
formed using two metal recovery cartridges
in series. The second unit will protect against
excessive silver carryover when the first
unit approaches exhaustion. During silver
recovery, ferric-EDTA is converted to fer-
rous-EDTA. Because the primary bleach
reaction involves ferric-EDTA, the solution
can be aerated to oxidize ferrous-EDTA
back to ferric-EDTA. Folbwing aeration, the
solution can be returned to the holding tank
for reuse.
Option 8. Recovery of
Developer
Ion exchange can be used to recover
color developer. This technology removes
bromide ions and decomposition products
that cause the developer to become spent.
Recovery has been successful with the use
of a strong-base anion-exchange resin. The
ion exchange resin has been traditionally
regenerated with the use of sulfuric acid,
and, in a few cases, with sodium hydroxide.
Experimentally, a new regenerant system
composed of 1.0 M sodium chloride fol-
lowed by 0.5 M sodium bicarbonate has
been successfully used. The advantage of
this system is the non-corrosive nature of
the regeneration wastestreams. Because
of the high capital investment required for
ion exchange equipment, the recovery of
developer is only applicable to large
photofinishing facilities.
Conclusions and
Recommendations
The technical feasibility evaluation ini-
tially determines the nature of the WM op-
tions, either equipment-related, personnel/
procedure-related, or materials-related. For
each of the three types of WM options,
specific information and data are required.
For equipment-related options, the informa-
tion requirements relate to the state of the
technology, availability of equipment, per-
formance specifications, testing, space and
utilities, production effects, and training. For
personnel/procedure-related options, the
required information relates to training and
operating instruction changes. For materi-
als-related options, the required informa-
tion relates to production impacts, storage
and handling, training, and testing. The WM
options evaluated during this project were
all equipment-related options.
Based on the results of the assessment
phase, five WM options were selected for
further evaluation in the feasibility analysis
phase. The technical and economic results
of the feasibility analysis phase are summa-
rized in Table 1. This table indicates the
total capital investment, the net operating
cost savings, and the payback period (total
capital investment/net operating cost sav-
ings) for each option.
The results of the study indicate that the
fastest payback would be realized from
Options 1 and 7. Option 1 involves conserv-
ing water by installing wash water controls;
Option 7 involves recycling bleach fix and
recovering silver with the use of MRCs.
Bleach fix recovery will require some tech-
nical evaluation by Accuphoto. If Accuphoto
decides not to recycle bleach fix (Option 7),
then the fastest payback for silver recovery
is Option 2 (use of MRCs). If production
increases significantly in the future, the
payback period for electrowinning (Options
3 and 4) becomes increasingly attractive.
For example, if a 2.3 multiple increase in
production (this factor relates to the capac-
ity of the selected electrowinning unit) is
assumed, the payback periods for Options
3 and 4 is 1.1 yr and 0.9 yr, respectively. The
payback period for Option 7 (bleach fix and
silver recovery) reduces to 0.3 yr. Using the
same production increase, the Option 2
payback period reduces at a slower rate to
0.4 years. A more in-depth cash flow analy-
sis over the life of a project considering
equipment depreciation, tax rates, loan
rates, and other factors not evaluated dur-
ing this study could be performed by
Accuphoto.
The full report was submitted in fulfillment
of Contract No. 68-C8-0061, Work Assign-
ment 2-05, by Science Applications
International Corporation under the spon-
sorship of the U.S. Environmental Protec-
tion Agency.
•&U.S. GOVERNMENT PRINTING OFFICE: 1991 - 548-028/40095
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Table 1. Summary of Waste Minimization Feasibility Analysis Phase
Waste Minimization Option
1. Wash water control
Applicable
Wastestreams§
EP-2 bleach fix wash;
B&W paper process
fixer wash
Total Capital
Investment, $
$675
Net Operating
Cost Savings,
VYr
$1,436
Payback
Period, Yr
0.47
2. Silver recovery using
metal replacement
cartridges'
3. Silver recovery using
etectrowirmingt
4. Silver recovery using
electrowinning with MRC
tailingf
7. Recycle of bleach fix
and silver using MPCsf
C-41 bleach, fixer and $1,071
stabilizer; RA-4 bleach
fix and stabilizer; EP-2
bleach fix and bleach fix
wash; T-Max fixer wash;
B& W paper process fixer
wash
C-41 bleach and fixer; $3,510
RA-4 bleach fix; EP-2
bleach fix; T-Max fixer;
B& W paper process fixer
C-41 bleach and fixer; $3,667
RA-4 bleach fix; EP-2 fix;
T-Max fixer; B&W paper
process fixer
RA-4 bleach fix; EP-2 $ 1,571
bleach fix
$1,325
0.81
$1,414
$1.757
$2,508
2.48
2.08
0.63
'Streams with 5 troy oz or greater par year.
rStreams with a stivet concentration >500 mg/L.
(Spent bleach fix solutions.
§Wastes association with color fHm process C-41, color paper processes RA-4 and EP-2, ftS W film process T-Max, andB& W paper process
This summary was prepared by staff of Science Applications International Corp.
McLean, VA 22102.
Mary Ann Curtan is the EPA Project Officer (see below).
The complete report, entitled "Waste Minimization Opportunity Assessment: A
Photofinishing Facility " (Order No. PB-91 231 530/AS; Cost: $26.00, subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental
Research Information
Cincinnati, OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
EPA/600/S2-91/039
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