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Resources, Conservation and Recycling 81 (2013) 1– 7

Contents lists available at ScienceDirect

Resources, Conservation and Recycling

journa l h om epa ge: www.elsev ier .com/ locate / resconrec

azardous process chemical and water consumption reductionhrough cleaner production application for a zinc electroplatingndustry in Istanbul

as ak Daylana,b,∗, Nilgun Ciliza,b, Aydin Mammodova,b

Bogazici University, Institute of Environmental Science, Hisar Campus, 34342 Bebek, Istanbul, TurkeySustainable Development and Cleaner Production Center, Hisar Campus,34342 Bebek, Istanbul, Turkey

r t i c l e i n f o

rticle history:eceived 19 January 2012eceived in revised form 3 September 2013ccepted 6 September 2013

eywords:etal finishing

inc electroplatingleaner productionounter current rinsinglosed loop cleaning

a b s t r a c t

The metal finishing industry consumes a range of chemicals that are considered hazardous to humanhealth and the environment. The technology and processes used in metal finishing operations such aselectroplating of metal parts and rinsing operations are the major sources of environmental pollution. Theaim of this study is to achieve a more efficient use of raw materials and water and to reduce the rinsingwater consumption and hazardous waste generation for the selected zinc electroplating plant. This canbe achieved through source reduction and material reuse and recovery that will lead to reduction in totalamount of waste, emissions and waste toxicity. The zinc electroplating process and its resulting envi-ronmental loads were investigated within the scope of the study, by considering the cleaner production(CP) opportunities. The proposed source reduction options include (a) closed loop cleaning system thateliminates hazardous chemical consumption as a technology modification and (b) counter current rinsingand drag-out tank application as an on-site reuse/recovery/recycling. The CP assessment methodologiesimplemented in the study cover on-site plant auditing and mass-balance analysis of zinc electroplatingprocess. In order to determine all involved inputs and outputs, measurements and data collection wereperformed for the related process flows as a part of the mass-balance analysis. The selected CP oppor-

tunities were evaluated in terms of their environmental benefits and economic feasibility. The results ofthe study indicate that implementation of the closed loop cleaning system prevents hazardous chemicalconsumption by utilizing aqueous cleaning solutions instead of toxic solvents resulting in 14.7% chemi-cal and 80% water consumption reduction during pre-treatment of metal parts while implementation ofcounter current rinsing application for the entire zinc electroplating process reduces the rinsing waterconsumption by 62% thus, decreasing the end-of-pipe treatment cost.

. Introduction

Cleaner production (CP) methodology is a preventive strategyirected at elimination or minimization of the impacts of produc-ion processes and products on the environment (Taylor, 2006). Inecent years, there has been an increasing interest in CP assessmenty industries, government authorities, non-governmental organi-ations (NGOs), consultants and the stakeholders in Turkey, sincepplication of CP methodology leads to the economic and envi-

onmental efficient products through sustainable use of energy,aw materials, chemicals and water in the production processesia process modification, input material substitution and on-site

∗ Corresponding author at: Bogazici University, Institute of Environmental Sci-nce, Hisar Campus, 34342 Bebek, Istanbul, Turkey. Tel.: +90 212 359 46 23;ax: +90 212 257 50 33.

E-mail address: basak.buyukbay@boun.edu.tr (B. Daylan).

921-3449/$ – see front matter © 2013 Elsevier B.V. All rights reserved.ttp://dx.doi.org/10.1016/j.resconrec.2013.09.002

© 2013 Elsevier B.V. All rights reserved.

reuse/recovery. CP methods also offer significant financial advan-tages along with environmental benefits on local and global scaledue to improvements in the competitiveness of the industry thoughincrease of revenues and decrease of inputs such as process waterand chemicals and non-product outputs such as hazardous wastes,wastewater and emissions to air (Ozbay and Demirer, 2007).Applied to a number of South African surface treatment companies,these methods have typically achieved reductions of the order of90% in water use and 50–60% in the use of chemicals and 55–60%in sludge generation (Telukdarie et al., 2006b).

Metal finishing industry (Standard Industrial Classification, SIC,3471) provides a broad range of surface finishing and conditioningservices to the medical, aircraft, construction, automotive, elec-tronics and energy industries. Metal finishing operations provide

modifications to the surface properties of metallic products in threemain process stages; surface preparation (cleaning and surface acti-vation), plating (electroplating, coatings, electroless plating, etc.),and post-treatment (chromating, passivating, etc.). Each stage is

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B. Daylan et al. / Resources, Cons

ollowed by a series of rinsing stages, leading to generation of higholumes of hazardous liquid and solid wastes mainly contaminatedith heavy metals and inorganic anions (Viguri et al., 2002). Over 11illion tons of zinc are produced annually worldwide and roughly

alf of it is used in electroplating industry for galvanizing to pro-ect steel against corrosion (IZA, 2011). Approximately 1% of theazardous waste in Europe is generated by the electroplating indus-ry (Fresner et al., 2007). Due to highly hazardous nature of solidnd liquid wastes generated by this industry and the regulatoryressures on discharge limits, the pollution prevention measuresave become important tools in achieving environmental and eco-omic improvements in metal finishing industry. Giannetti et al.2008) implemented a CP practice in a medium size gold-platingompany in order to reduce waste and pollution load of the plant.

35% reduction in water volume was achieved by manually con-rolling each rinsing tank and only opening the valve when theinsing water showed a certain turbidity controlled by the line staff.dditionally, 18% reduction in energy consumption was achievedy using polyvinyl chloride (PVC) balls in process bath to reducevaporation and heat loss. The volume of degreasing solution con-aining caustic soda, cyanides and hypophosphite was also reducedy 86% through prolongation of the bath life by tieing it up to theass of pieces degreased rather than replacing the solution at fixed

ntervals.The main objective of this study is to implement a CP audit

or the selected zinc electroplating plant through evaluation ofhe main characteristics and quantity of the generated waste anddentify the CP options that would lead to less wastewater and haz-rdous waste generation. A comprehensive on-site data collectionas performed to identify the CP opportunities for zinc electro-lating process. The economic benefits of these CP options wereonsidered along with the technical and environmental evaluation.

. The company profile and the methodology of CPssessment

The background information of the company and related envi-onmental aspects were assessed in the pre-assessment phasen order to develop the company profile. The selected zinc elec-roplating plant is a small and medium-size plant (SME) with20 personnel and production capacity of 6,000,000 dm2 elec-roplated metal parts per year. The company manufactures and

arkets racks, cabinets, wall-mount enclosures, subracks, mechan-cal assemblies, structural cabling products, fiber optic productsor domestic and international telecommunications, Internet, net-orking and electronics industries. Three main stages of the zinc

lectroplating process were considered within the scope of the CPudit; pre-treatment, zinc electroplating and post-treatment.

An environmental and technical analysis was carried out in thessessment phase to determine the process flow charts to identifyhe waste streams and their sources. Direct on-site measurementsnd data collection for the mass balance analysis were performedo quantify the raw material, water and chemical inputs and out-uts including waste and emissions from different process stages.n-site auditing of the existing production processes revealed highmount of chemical consumption with toxic properties and theesulting losses due to drag-out, particularly in zinc electroplatingnd passivation processes in addition to considerable wastewatereneration resulting from rinsing operations. 11,800 m3 water and4,200 kg process chemicals in total were consumed in the electro-lating processes in the year 2005.

Further information regarding available CP opportunities wasbtained through evaluation of previous case studies, literature andersonal communications with the CP expert team. After identifica-ion of CP options and their environmental benefits, the unfeasible

on and Recycling 81 (2013) 1– 7

CP scenarios were excluded by the joint decision of the companymanagers and the CP audit team members. Finally, prioritizedproduction processes and their corresponding CP options wereselected for further technical, economic and environmental analy-sis in the feasibility phase.

2.1. Pre-assessment phase: evaluation of the zinc electroplatingprocess

The selected zinc electroplating process starts with a pre-treatment stage that consists of cleaning and degreasing opera-tions. Metal surfaces contaminated with oil or grease lubricants,dust, soil matter, metal fines, particulates and oxidation productsare cleaned in this stage (Randal, 1998). While the cathodic andanodic cleaning baths are used to remove oil, grease and particles,acid washing (pickling) is applied for the removal of metal oxidesfrom the surfaces being plated (Erol and Thming, 2005). After thepre-treatment stage, metal parts are plated with an alkaline zincelectroplating process. Zinc plating provides a homogeneous sur-face and corrosion resistance to the metal object. The activationand passivation processes (electro-polishing) of the post-treatmentstage, consist of application of hot concentrated acid that yieldsstainless steel mirror sheen parts and enhances the corrosion resis-tance of the finishing material. The use of nitric acid and trivalentchromium solution as cleaning agents in these stages results in pro-duction of highly acidic and heavy metal containing wastewater.Each chemical bath is followed by an overflow rinsing bath in thezinc electroplating process.

Rinsing operations were the primary source of wastewater inthe selected zinc electroplating process. Almost 88% of the waterwas used for the rinsing operations and the rest was used for thechemical bath replacement and cleaning of the chemical baths.The rinsing operations are necessary for the removal of the drag-out from racks and parts after being drawn out from the processbaths. The chemical and metal loss through drag-out from processbaths pollutes the rinsing water. Depleted process baths are alsoperiodically discharged and added to the wastewater volume. Inorder to comply with effluent discharge regulations, the selectedzinc electroplating plant had an end of pipe treatment plant whichgenerated sludge that required further disposal.

Due to outdated equipment and poor maintenance there wereexcessive levels of waste generation and unnecessarily large quan-tities of water consumption from these processes. According tothe STS BREF, efficient process control methods such as measuringand controlling process parameters (flow rate, pressure, tempera-ture, composition and quantity) and development of a maintenanceprogram were suggested to the company management (STS-BREF,2007). Since there were no scheduled training programs for work-ers, informational seminars and workshops were conducted duringthe pre-assessment phase on the topics of occupational health andenvironmental safety for the plant managers, administrators, tech-nicians and workers in order to efficiently implement the CP plan.

2.2. Assessment phase: input and output evaluation of selectedprocess

A detailed site audit was performed during the assessmentphase to identify the quality and quantity of raw materials,water and chemicals consumed and wastewater produced sinceno recorded data was available for the plant. The process massbalance was established to determine the amount of raw mate-rials, products, byproducts, wastes and emissions for the zinc

electroplating process (Fig. 1). In order to determine all inputsand outputs, chemical concentration and replacement periods ofprocess baths, input water type (recycled water or tap water) ofprocess baths, tank volumes, inlet/outlet points of rinsing tanks

B. Daylan et al. / Resources, Conservation and Recycling 81 (2013) 1– 7 3

Table 1The generated CP option categories for the selected processes.

CP option Advantages

(A) Technology modificationClosed loop cleaning system application in the pre-treatment unit of metal parts Reduction of water consumption and elimination of hazardous chemicalsLonger drainage time implementation in the zinc plating for drag-out minimization More chemical drips back to process tank, leading to chemical reduction in

rinsing waterWetting agent application in vertical chemical baths for drag-out minimization Reduction of drag-out up to 50%, but in the meanwhile, foaming problems

can occurDrag-out tanks application for drag-out minimization Recovery and reuse of drag-out lossesDrain board installation in zinc plating baths for drag-out minimization Drag-out reduction up to 40%Counter current rinsing application in rinsing baths of alkaline zinc electroplating line Reduction in rinsing water consumptionSpray rinsing application in rinsing baths of production lines Reduction in rinsing water consumption

(B) On-site recycle/reuse/recoveryReverse osmosis application in rinsing water baths Recovery and reuse of rinsing water with up to 90–99% efficiencyDeionized rinsing water reuse in first rinsing baths Reuse of first rinsing water in plating bath as evaporated water make-up.

(C) Good housekeeping measuresBath concentrations optimization Reduction in chemical consumptionBath filters installation Extension of bath life

wauolMreatts

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Increase in bath temperature

ere considered by evaluating the pre-treatment, electroplatingnd post-treatment bath preparation data sheets. Flow meters weresed to identify the amount of rinsing water consumption. Drag-ut and evaporation losses were adopted as 1.5 mL/dm2 from theiterature for the wastewater generation calculations (EPA, 1998;

editerranean Action Plan, 2000). The annual and monthly dataecords of the accounting and purchasing departments were alsovaluated. Since, there was no energy consumption data collectionnd calculation system at the company for the selected processes,he annual energy consumption inventory and related cost calcula-ions for the selected product groups could not be included in thistudy.

The material balances were evaluated to identify the amountsf the inputs, outputs and identified losses. The environmen-al performance indicators for the involved unit processes wereeveloped from the material balance data sheets by dividing theuantity of a raw material input or waste stream by the sur-ace area of the electroplated metal part produced over the sameeriod (Barbiroli and Raggi, 2003; Fresner, 1998; Gurbuz et al.,004). According to the environmental performance indicator cal-ulations, 1.97 kg water and 4 × 10−3 kg process chemicals wereonsumed to electroplate 1 dm2 sheet steel (Fig. 1). The 1.97 kg/dm2

ater consumption is significantly higher than the limit value of.03–0.2 kg/dm2 described in the STM-BREF, Chapter 3 “currentonsumption and emission levels for the surface treatment of met-ls and plastics”-, and thus, the pollution prevention efforts were

Zinc Ele

Chemical consu mption ;

Elo ctrol yti c oil c leane r: 2 60 kg /yea r Hot oil cleaner: 420 kg/year HCl: 11,325 kg/year Electro lyti c Z n anode: 4,190 kg /year NaOH: 2,550 kg/ year Zn-polisher 1,410 kg/year HNO3: 3,65 5 kg/ year Triv alent Chromiu m sol ution : 390 kg/ year

Water consumption:

Water f or pr ocess bat hs:18x 105 kg/year Rins ing water:1 0x1 06 kg/yea r

Fig. 1. The mass balance analysis o

Minimization of drag-out loss

focused on the reduction of the process water consumption (STM-BREF, 2006).

2.3. Generation of cleaner production options

The CP options were developed based on the process informa-tion gathered from the company and literature survey. Evaluationand mass balance assessment of inputs and outputs had led toidentification of the processes with excessive resource consump-tion (Koefoed and Buckley, 2008). Development of the CP optionsthat include process changes and product improvements leadingto reduced environmental impacts and economic benefits throughresource conservation and recycling were carried out in coopera-tion with the company managers. The generated CP options weregrouped under (a) technology and process modification, (b) on-siterecycle/reuse/recovery and (c) good housekeeping practices cate-gories and the list of generated CP options were given in Table 1.Once all possible CP options and their benefits were identified,the prioritized CP opportunities were defined and further evalu-ated.

2.4. Prioritization of focus points

Production processes with the most severe environmental pol-lution potentials were considered in the identification of focuspoints. Among those, the closed loop cleaning system for the

ctroplating

Product:6x1 06 dm2/year elect ropl ated sheet steel (SS)

Emission produ ced : Wastewate r: 1.7x106 kg/yea r

f zinc electroplating process.

4 B. Daylan et al. / Resources, Conservation and Recycling 81 (2013) 1– 7

Table 2The selected and prioritized CP options.

Existing process Proposed process Benefits

Technology modificationConventional pre-treatment (anodic

and cathodic cleaning)Closed loop cleaning system Elimination of hazardous solvents, recovery and reuse of the cleaning

solution, reduction of water consumption, sludge productionminimization

rag-o

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On-site recycle/reuse/recoveryRinsing operations of zinc plating Two stage counter current rinsing and d

tank application

re-treatment of metal parts as a technology modification andounter current rinsing and drag-out tank applications as on-siteecycle/reuse/recovery were selected since these options had thereatest effect on the recovery of cleaning and plating chemicals as

ell as process rinsing water consumption. The selected CP options

ummarized in Table 2 were evaluated in detail in the feasibilityhase.

Wa ter: 3,200 m3/yea r (rinsing bath3 -4)

Shee t s teel

Re cycle d Wa ter: 3,200 m3/yea r

a. The ex

1,2 (rins

Sheet Steel

b. Two st

Chemical Bath 1. Rinsing

Original S

Proposed Sy

Chemical Bat h Drag -out tank

Drag -out retur n

Zinc: 27 kg/year Triv alent solution :

102 kg/year

Fig. 2. The mass balance analysis of (a) the overflow rinsing a

ut Minimization of rinsing water consumption, recovery and reuse ofprocess chemicals

3. Results and discussion

3.1. Feasibility analysis of the CP options

Cost estimation and environmental assessment of the proposedCP options were performed in the feasibility phase in order toevaluate applicability of the prioritized CP options. The calculated

Water: Wa ter: 3,200 m3/year 3,600 m3/yea r (rin sin g bat h 8-9) (r insing bath 12-13)

Sheet Stee l

Re cycle d Wat er: Re cycle d Wa ter: 3,200 m3/year 3,600 m3/year

isting over flow rins ing

:retaW:retaW:retaW63 m3/year 1,263 m3/year 1,263 m3/year

ing bath3-4) (rinsing bath 8-9) (rinsing bath 12-13)

Shee t St eel

Recycled Water: Recycled Water: Recycled Water 1,263 m3/year 1,263 m3/yea r 1,263 m3/yea r

ag e coun terc urre nt rins ing

Bat h 2. Rinsing Bat h

ystem

stem

Counter Curre nt rinsing

Fresh water

nd (b) the counter current rinsing with drag-out tank.

B. Daylan et al. / Resources, Conservation and Recycling 81 (2013) 1– 7 5

Table 3The Summary of the economic evaluation of counter current rinsing and drag-out tank application.

Parameter Before After SavingTwo stage over flow rinsing Two stage counter current rinsing

On-site recycle/reuse/recovery (counter current rinsing and drag-out tank application)Rinsing water consumption m3/year 10,000 3789 6211

EUR/year 5900 2234 3666Zinc recovery kg/year – 27 27

EUR/year 158 158Trivalent solution recovery kg/year – 102 102

EUR/year 357 357Saving from chemical recovery EUR/year 515

Saving from water recovery EUR/year 3666Total annual saving EUR/year 4181

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Capital investment cost EUR 2000Payback period Months 6IRR value for 5 year % 208

nnual savings, internal rate of return (IRR) values and pay-backeriods were used as indicators of the economic viability of theptions (Barbiroli and Raggi, 2003). The comparison of the plant’snvironmental and economic performance before and after imple-entation of a given CP option served as a basis for its subsequent

mplementation. The overall results were expressed as net environ-ental impacts, in the units of pollution intensity indices, such as

ilogram of water and chemical used per unit of product describedurther below (Howgrave-Graham and Berkel, 2007).

.1.1. Counter current rinsing and drag-out tank in zinclectroplating

The existing rinsing operations were operated by the skip rins-ng technique that used the same rinsing tanks for different stagesf plating and cleaning processes in the selected zinc electroplatingrocess and consisted of four rinsing baths (Mediterranean Actionlan, 2000; UNEP, 1998a). Overflow rinsing 1 and 2 are used afteroth anodic cleaning and acid washing and overflow rinsing 3 and

are used after both cathodic cleaning and zinc plating whicheads to increase of the hazardous waste load of rinsing water andccumulation of sludge residues, as the quantity of the sludge isroportional to the concentration of metal in the waste rinsingater (Park et al., 2000).

The two stage overflow rinsing was used in the existing zinclectroplating process as shown in Fig. 2. Each tank had its ownnlet point for fresh water with 200 L/h capacity. In the recom-

ended counter current rinsing, only the last rinsing bath has annlet point for fresh water and the excess water goes to preceding

insing bath. The excess wastewater from the first rinsing bath isent to the reverse osmosis (RO) system and recycled through theinsing system. Additionally, a drag-out tank filled with deionizedater is recommended after zinc plating and passivation tanks for

able 4he summary of the economic evaluation of closed loop cleaning system.

Parameter Before

Convent

Technology modification (substitution of the conventional pre-treatment of zinc platinWater consumption m3/year 7550

Chemical consumption kg/year 680

EUR/year 713

Wastewater production m3/year 732

Cost of treatment EUR/year 772

Recycled water production m3/year 6776

EUR/year 4140

Running costs EUR/year 5625

Total annual saving EUR/year 3855Capital investment cost EUR 13,000Payback period Years 3.3IRR value % 15

the recovery of plating metal and passivation chemicals (Koefoedand Buckley, 2008; Reeve, 2007; Telukdarie et al., 2006a). A chem-ical metering pump is used to return the drag-out from this tank tothe plating tank. The pumps are controlled by level sensors placedin the process tanks (Roy and Shapiro, 1999).

Counter current rinsing in metal plating provide over6200 m3/year water saving which corresponds to 62% reduction incompany’s total water consumption (Table 3). The pollution inten-sity index as kilogram of water per unit of product is decreased to0.6 kg water/dm2 SS from 1.7 kg water/dm2 SS for rinsing opera-tions. The recommended option leads to 4181 D saving on annualbasis with a short payback period of 6 months. Moreover, drag-out bath application provides 515 D /year worth process chemicalrecovery. This option was considered in 2-year middle term appli-cation plan starting from the year 2007, due to its relatively highIRR value (208%) and short payback period.

3.1.2. Closed loop cleaning system for zinc platingThe recommended closed loop cleaning system that replaced

conventional pre-treatment system as illustrated in Fig. 3, workswith aqueous cleaning solutions instead of cathodic (electrolytic oilcleaner) and anodic (hot oil cleaner) cleaning solvents. In this sys-tem, naturally occurring microorganisms digest and metabolize oilsand greases by enzyme action and convert them into carbon dioxideand water (Groudeva et al., 2001; Reeve, 2007; UNEP, 1998b).

In the recommended system, the aqueous cleaner is constantlyreplenished and returned back to the tank in the optimum con-dition for a steady-state operation. The benefits of the system

include energy saving due to low operating temperature, minimaltank residue generation that eliminates costly hazardous sludgedisposal, continuous replenishment of chemicals, safer workingenvironment, moderate pH and simple operation. Since this is a

After Savingional pre-treatment Closed loop cleaning

g with the closed loop cleaning system)1263 6287630 501152 −439– 732– 7721260 5516618 35221770 3855

6 B. Daylan et al. / Resources, Conservation and Recycling 81 (2013) 1– 7

a. Conventional Pr e-trea tment

b. Closed Loop Cleaning

Original Syst em

Proposed Sys tem

Electro lyti c Water: Hot oil Water oil cleaner: 4000 m3/year clea ner : 3,550 m3/year 260 kg/ year 420 kg /year

Sheet ste el Sheet steel

Waste wa ter: Rec ycled wate r 732 m3/year 6,776 m3/year

CathodicCleaning

Anodiccleaning

Overflow rinsing

Overflow rinsing

Bio -soak Bio -water: Bio -plus: 430 kg/year 80 kg/year 70 kg/year

Sheet steel Sheet stee l

Re cycled wa ter: 1,250 m3/yea r

Bio-cleane r tank

Bio filte r

nal pr

ctv

esarroct8acctv1ra

Fig. 3. The mass balance analysis of (a) conventio

losed loop system and contains only aqueous cleaning solutions,here is no toxic fume release which is a serious concern in open-ertical baths (Veglio et al., 2003).

The recommended system eliminates consumption of 680 kglectrolytic oil cleaner, a highly corrosive and strong oxidizingolution, per annum and substitutes acidic cleaning solvents withqueous cleaners (Table 4). The closed loop system not onlyeduces the wastewater generation but, also provides recovery andeuses opportunities for the cleaning solution with 1–1.5 yearsf cleaner bath life and as a result, reduces the consumption ofleaning chemicals by 14.7%. The closed loop cleaning systemogether with the counter current rinsing application results in0% of rinsing water saving. The closed loop system is also suit-ble for workers’ environment as it prevents hazardous solventonsumption and air mist generation. The water and chemicalonsumption indices were reduced from 0.7 kg water/dm2 SSo 0.2 kg water/dm2 SS which is within the range of the limit

alue of 0.03–0.2 L/m2 described in the IPPC Directive and from.13 × 10−4 kg chemical/dm2 SS to 1.05 × 10−4 kg chemical/dm2 SSespectively (STM-BREF, 2006). This system, with 15% IRR valuend 3.3-year payback period, was considered in 5-year long term

e-treatment and (b) closed loop cleaning system.

action plan by the plant management starting from the year2006.

4. Conclusions

The input–output evaluation method based on flow andmaterial balances was implemented to reveal the possible CPapplications in the selected zinc electroplating plant. Water andchemical unit indices were calculated using material flows relatedto the selected processes. The CP assessment method was employedfor the modification of the existing processes by providing alter-native technologies that lead to manufacture of the products ofequal quality. In the feasibility phase, technical, environmental andeconomic performances of the prioritized CP options were evalu-ated. The closed loop cleaning system as a technology modificationoption and counter current rinsing and drag-out tank application asan on-site recycle/reuse/recovery option have constituted the focus

points of the CP assessment in the zinc electroplating process.

The rinsing water consumption can be reduced from10,000 m3/year to 3789 m3/year in the whole metal finishingline after application of the counter current rinsing method,

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B. Daylan et al. / Resources, Cons

hich corresponds to 62% reduction in water consumption. Theecommended counter current rinsing option has a high 5-year IRRalue (208%) and short payback period of 6 months. Additionally,he drag-out recovery prevents the carriage of process chemicalso the rinsing bath, resulting in 515 D /year saving due to reductionn chemical consumption. 680 kg/year hazardous solvent con-umption is prevented in the closed loop cleaning system withpplication of aqueous cleaning solution in the pre-treatmenttage and rinsing water consumption is reduced by approximately0%. Hazardous chemical load of the wastewater treatment plant

s also reduced since a cleaner bath solution is recovered andeused with bio-filter unit for up to 1–1.5 years. The system has

15% 5-year IRR value and 3.3 year payback period and wasonsidered for a 5-year long term implementation by the companyanagement. Although the total process water consumption index

s decreased from 1.97 kg/dm2 to 0.96 kg/dm2, it is still higher thanhe limit value set by the IPPC Directive since the CP options weremplemented in only four out of seven different unit processessed in the electroplating plant.

CP application does not end with process modifications andechnical alterations of the existing processes and requires changesn worker attitude and adoption of responsible environmental

anagement practices. The CP audit conducted in this study wouldave been incomplete without considering the socio-culturalspects of the whole production process. As previously mentioned,he educational level of the workers was low and thus series ofeminars and on-site workshops were conducted in order to famil-arize the working personnel with the technical and environmentalspects of the proposed CP options. Since, an integrated CP devel-pment requires the engagement of employees at every level ofhe organization, additional seminars were held with the company

anagers for the continuous promotion of the proposed CP con-ept.

In this study, none of the recommended CP options interfereith each other, and thus, can be implemented together in the

elected plant. The technical, environmental and economic eval-ation of the CP options indicates that the proposed CP optionsre feasible alternatives for the old production processes andead to minimal electroplating metal, chemicals and rinsing wateronsumption. The preventive business strategy provided in thistudy conserves resources and promotes greater overall efficiencyhrough improved production technologies and will be useful tohe companies that aim to improve the economic performance andnvironmental safety of the electroplating process.

cknowledgments

The authors are thankful to Mr. Can GUR, Canovate Group CEO,or his great support to conduct this study, Mr. Gun Evren GOREN,he Deputy General Manager and Mr. Erol YENICI, the Produc-ion Manager, for their tolerance, valuable technical expertise and

now-how transfer as well as to all employees who have shownontinued cooperation for the successful execution of the project.

e would also like to thank Ms. Cigdem CENGIZ for sharing herxperience and technical information.

n and Recycling 81 (2013) 1– 7 7

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