United States
                 Environmental Protection
                 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
                  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).

                  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
                 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.

  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

 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-
   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

 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-
  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 -
  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-

 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
   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

 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
   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
   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
   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
   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
  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

                  Table 1. Summary of Waste Minimization Feasibility Analysis Phase
Waste Minimization Option
1. Wash water control
EP-2 bleach fix wash;
B&W paper process
fixer wash
Total Capital
Investment, $
Net Operating
Cost Savings,
Period, Yr
                 2. Silver recovery using
                    metal replacement
                 3. Silver recovery using
                 4. Silver recovery using
                   electrowinning with MRC
                 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

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
                 '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
 Center for Environmental
 Research Information
 Cincinnati, OH 45268
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