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International Biodeterioration & Biodegradation xxx (2016) 1e5

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International Biodeterioration & Biodegradation

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Reuse of car wash wastewater by chemical coagulation and membranebioreactor treatment processes

Ida Alicia Rodriguez Boluarte a, Michael Andersen a, Biplob Kumar Pramanik b,Chia-Yuan Chang c, Steven Bagshaw a, Leanne Farago a, Veeriah Jegatheesan b, *, Li Shu b

a School of Engineering, Deakin University, Geelong Waurn Ponds Campus, VIC 3216, Australiab School of Engineering, RMIT University, GPO Box 2476, Melbourne 3001, Australiac Department of Environmental Engineering and Science, Chia Nan University of Pharmacy and Science, Tainan City 71710, Taiwan

a r t i c l e i n f o

Article history:Received 29 October 2015Received in revised form21 January 2016Accepted 21 January 2016Available online xxx

Keywords:Car wash wastewaterContaminantsMembrane bioreactorCoagulationOzonation

* Corresponding author.E-mail address: jega.jegatheesan@rmit.edu.au (V.

http://dx.doi.org/10.1016/j.ibiod.2016.01.0170964-8305/© 2016 Elsevier Ltd. All rights reserved.

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a b s t r a c t

Car wash wastewater contains significant concentrations of contaminants such as nutrients, organics,particulate matter, sand, oil, grease, diesel detergents and so on. A range of treatment processes such as amembrane bioreactor (MBR), coagulation and ozonation were investigated to treat car wash wastewater.Ozonation was effective in removing the chemicals and suspended solids; the removal efficiency wasgreater than the coagulation process. Once the MBR system was acclimatised, 100% of suspended solids,99.2% of COD, 97.3% of TOC and 41% of ammonia were removed. This study demonstrates that MBR is apotentially promising treatment system for recycling car wash wastewater which could be reused in thesame car wash station.

© 2016 Elsevier Ltd. All rights reserved.

1. Introduction

Water recycling provides a great opportunity to conserve one ofour natural resources that is essential for the survival of mankind.Reducing wastewater and being able to reuse it as resource iscritical in light of long term droughts. There are currently morethan 17.6 million motor vehicles registered in Australia (AustralianBureau of Statistics, 2014). All these vehicles need to be washedfrequently, either by a household car wash or by a commercial carwash service. The latter is a recent industry which is gainingpopularity due to its positive environmental impacts, comparing itwith the household car wash method. Car wash facilities usuallyhave two types of services (automatic and self-serve wash).Generally, 200 L of water are used in automatic wash every time acar is washed; and from 40 to 50 kL in a self-serve wash. Thus, carwash requires a big volume of water and also it generates a sig-nificant volume of wastewater containing various types of pollut-ants. Most of the time, the car wash wastewater is discharged intosewer systems without any treatment. For example, up to 10,000 Lof wastewater a day can be generated at a commercial car wash

Jegatheesan).

ez Boluarte, I.A., et al., Reusal Biodeterioration & Biodegr

station in Geelong, Australia. This equates to in excess of 3.5 millionlitres per annum of wastewater which is disposed of rather thanrecycled. If this is extrapolated across the more than 10,000 carwash facilities in Australia, it would represent over 35 billion litresof wastewater per annum. The current water price for businessessupplied by Barwon Water in the Geelong region is approximatelyAUD$2.21 per kilolitre. With a total volume of thirty-five billionlitres of wastewater being produced by car washes Australia wideeach year, the total value of the wastewater disposed of through thesewerage system is around AUD$77.35 million.

Chemical, biological and membrane processes have beenwidelyused in treating various kinds of industrial and municipal waste-water. Sabur et al. (2012) used coagulation processes for treating atextile wastewater and found that the removal efficiency of COD,total dissolved solids and turbidity was 90%, 74% and 93%, respec-tively. Amuda and Amoo (2007) reported that coagulation wascapable of removing 73%, 95% and 97% of chemical oxygen demand(COD), total phosphorus (TP) and total suspended solids (TSS),respectively, from beverage industrial wastewater. Moreover,membrane bioreactor (MBR) was highly effective in reducing thecontaminants from industrial wastewater. Hosseinzadeh et al.(2013) found that MBR led to a removal of 75%, 98% and 74%removal of COD, TSS and total nitrogen (TN), respectively, fromindustrial townwastewater. Cheng et al. (2015) studied the effect of

e of car wash wastewater by chemical coagulation and membraneadation (2016), http://dx.doi.org/10.1016/j.ibiod.2016.01.017

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MBR treatment for antibiotic wastewater treatment and found thatMBR could remove 92.5% of BOD, 96% of COD, 81.5% of suspendedsolids and more than 99.9% of selected antibiotics such as imipe-nem and cilastatin. Another study by Friha et al. (2014) found thataerobic submerged MBR could effectively treat the cosmeticwastewater with a removal of 98.13% of anionic surfactant and83.73% of COD. However, only a few studies have investigated carwash wastewater treatment with the aim of producing reusableeffluent. The car wash wastewater was extremely murky and thepresence of suspended solids was noticeable. Rubio and Zaneti(2009) found that flocculation column-flotation treatment couldeffectively reduce the turbidity and colour (>90% and 75%,respectively) from cash wash wastewater.

Lau et al. (2013) found that ultrafiltration and nanofiltration forcar wash water reclamation effectively reduced COD, TDS andturbidity. Kiran et al. (2015) compared the efficiency of modifiedpolyethersulfone and cellulose acetate membranes in the treat-ment of carwash effluent using ultrafiltration and found that themodified membranes performed better at removing COD, turbidityand maintaining stable flux than commercial polyethersulfone(PES) membrane. However, it is important to consider the costs ofimplementation, operation and maintenance along with the effi-ciency of the treatment process. Compared to conventional treat-ment technologies, MBR appears to be suitable for the removal ofall types of contaminants present in cash wash effluent since it hasthe ability to meet high permeate quality and small spacerequirement. Small footprint for space is required due to its limitedavailability in a car wash station and high effluent quality isrequired in order to reuse in washing cars. The objective of thisresearch was to investigate the impact of different treatment pro-cesses including MBR, coagulation and ozonation in treating carwash wastewater.

2. Materials and methods

2.1. Sample collection

The feed water was collected from Grovedale car wash in Gee-long, Australia. Car wash wastewater pre-treated in an oil andgrease separator was employed for this study. Samples were storedat 4 �C and brought back to room temperature (22 ± 2 �C) prior toall tests.

2.2. Treatment processes

2.2.1. MBR setupThe schematic of the laboratory-scale MBR experimental setup

is shown in Fig. 1. The system was constructed with five tanksincluding a 10 L feed tank, two 6 L anoxic reactors (AR1 and AR2), a10 L aerobic membrane bioreactor (AMBR) and a 10 L permeatetank. In order to increase the surface areawithin the anoxic reactorsto encourage bacterial growth, 75 polypropylene bio-balls (40 mmnominal diameter and 450 m2/m3 of specific surface area) suppliedby All Round Aquatics, Australia were placed in each anoxic reactor.A hollow fibre hydrophilic polyethersulfone (H-PES) membranemodule (pore size of 0.1 mm and effective membrane area of0.032 m2) from SENUOFIL Co., China was placed in the aerobicreactor. Hereafter, the entire system will be referred to as MBRsystem and the aerobic reactor with the membrane module will bereferred to as AMBR. The MBR system used activated sludge duringthe acclimatisation process for over 4 weeks, which was collectedfrom the Anglesea Wastewater Reclamation Plant situated closer toGeelong, Australia. Once the system was acclimatized with syn-thetic wastewater (C6H12O6 710 mg/L, CH3COONH4 200 mg/L,NaHCO3 750mg/L, NH4Cl 30mg/L, KH2PO4 30mg/L, K2HPO4 60mg/

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L, MgSO4.7H2O 50 mg/L, CaCl2.2H2O 30 mg/L, NaCl 30 mg/L),different ratios of carwash wastewater and synthetic wastewaterwere used as feed for the MBR process. Finally, 100% carwasheffluent was used and the performance of MBR system under thiscondition is reported in this study.

2.2.2. Coagulation and ozonation treatmentCoagulation was performed with a laboratory jar test apparatus

(Phipps and Bird, PB-700). Alum (Al2(SO4)3.18H2O) and Poly-Aluminium Chloride (PACl) coagulants were applied to 2 L carwash wastewater samples. Samples were mixed at 300 rpm for5 min and then mixed at 30 rpm for 30 min; samples were allowedto settle for 30 min after which the supernatant was collected foranalysis. The doses were 12.5 mL of 10% Alum and 10 mL of 5% PAClper 1 L of carwash wastewater. Both coagulants were testedwithout pH adjustment. Supernatant from the jar test conductedwith 10 mL of 5% PACl per L of wastewater was used for ozonation;the ozone dosage was 10 mg L�1 at 15e25 s of exposure.

2.3. Analytical methods

Conductivity, turbidity, dissolved oxygen (DO) and pH and of thewater samples were measured using a conductivity meter (WTWLF330), turbidity meter (2100p Hach), and DO meter (WTW ox-imeter 330), pH meter (WTW pH 330) respectively. Suspendedsolids concentration was analysed by using pre-dried GF/C filterpaper.

Total organic carbon (TOC) and TN concentration were deter-mined using a TOC-L Shimadzu analyzer. COD concentration of thewater samples were carried out using Spectroquant COD cell test kitand Thermo-reactor TR-320. The concentration of ammonium, ni-trate, nitrite, total phosphorus of the water samples were deter-mined usingMerck ammonium test kit (1.00683.0001, analogous toEPA 350.1), nitrate test kit (1.14773.0001), nitrite test kit(1.00690.0001) and phosphate cell test kit (1.14729.0001), respec-tively. Before these analyses were undertaken, all samples werefiltered through 0.45 mm filter.

3. Results and discussion

3.1. Performance of coagulation and ozonation

The characteristics of the car wash effluent before and aftercoagulation with Alum and PACl are shown in Table 1 (The valuesare average of two readings with a standard deviation lessthan ± 1%). The concentration of turbidity and suspended solids ofthe raw car wash wastewater was 1000 NTU and 4.2 mg/L,respectively. Etchepare et al. (2014) and Lau et al. (2013) reportedthat the concentration of turbidity of car wash wastewater was 229and 68.9 to 62.8 NTU, respectively. Clearly, the level of turbidity wassignificantly higher for this study compared to previous studiesbecause the Geelong region which is surrounded by rural areaswhere sand, mud, clay and other solids are available in largequantities and could easily get stuck onto the surface and tyres of acar. In addition, samples were mostly taken during the wet season,when turbidity increases because car bodies carry more dirt duringthat season. The removal efficiency of turbidity by coagulationwithalum or PACl was 99.5 and 99.6%, respectively.

The use of PACl as a coagulant resulted in a 65.25% COD removal,a result which could be attributed to the adsorption of organicmatter onto flocs and charge neutralization (Duan and Gregory,2003), as PACl coagulant is positively charged and it adsorbs thenegatively charged organic compounds in the coagulation process.There was a further small additional removal of COD (approxi-mately 2%) followed during ozonation. According to Hoign�e and

e of car wash wastewater by chemical coagulation and membraneadation (2016), http://dx.doi.org/10.1016/j.ibiod.2016.01.017

Fig. 1. MBR Set-up a) laboratory-scale MBR system b) Schematic of the MBR System.

I.A. Rodriguez Boluarte et al. / International Biodeterioration & Biodegradation xxx (2016) 1e5 3

Bader (1976), organic compounds can be oxidized via two mecha-nisms in the ozonation process: reaction with molecular ozone(direct pathway) or reaction with hydroxyl radical (HO�) (indirectpathway).

Nitrate concentration was reduced by 55, 65 and 52% after

Table 1Carwash wastewater quality after coagulation (with alum and PACl) and ozonation.

Car wash wastewater 5% PACl (10 mL/L of wastewater) 10% Al

pH 8.5 7.01 4.16SS (mg/L) 4200 9.5 6Turbidity (NTU) 1000 4.46 3.99COD (mg/L) 433 150 e

NH4þ (mg/L) 2.2 4.95 4.5

Nitrite (mg/L) 0.77 0.65 0.09Nitrate (mg/L) 2.0 0.9 0.7TN (mg/L) 11.73 1.32 0.64TP (mg/L) 25 0.4 1.7

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treatment by PACl, alum and ozonation, respectively. There was asignificantly greater removal of TN after alum treatment (94%) thanPACl (88%) or ozonation (78%). We have calculated the increase inNH4

þ concentration due to the decrease in pH during coagulation(see the supplementary document for additional information). But

um (12.5 mL/L of wastewater) Ozonation of supernatant coagulated with PACl

7.3893.73

1414.050.070.952.590.4

e of car wash wastewater by chemical coagulation and membraneadation (2016), http://dx.doi.org/10.1016/j.ibiod.2016.01.017

Fig. 2. Removal of colour by coagulation/flocculation and ozonation processes. Fromleft to right (i) raw carwash wastewater, (ii) carwash wastewater after coagulation,flocculation and sedimentation (10 ml of 5% PACl is applied to 1 L of carwash waste-water), (iii) carwash wastewater after coagulation, flocculation and sedimentation(10 ml of 5% PACl is applied to 1 L of carwash wastewater) followed by ozonation (2.5 L/min ozone applied for 23 s).

I.A. Rodriguez Boluarte et al. / International Biodeterioration & Biodegradation xxx (2016) 1e54

further increase in NH4þ concentration needs investigation. It is

found that PACl was more efficient in removing TP than alum. Themechanism of TP removal by coagulation was described by Persson(2011) who stated that positively charged coagulant ions forminsoluble precipitates which could reduce the phosphorus con-centration by sedimentation or flotation. The removal of colourfrom the carwashwastewater through coagulation and ozonation isshown in Fig. 2.

3.2. Performance of the MBR system

The characteristics of the car wash wastewater quality atdifferent stages of the MBR system are shown in Table 2. Thecharacteristics of the car wash water were different in Tables 1 and2 as samples were collected at different times and one was used forcoagulation study (Table 1) and the other was used for MBR study(Table 2). The MBR system operated under the following condi-tions: (i) the hydraulic retention time (HRT) of anoxic reactor 1(AR1), anoxic reactor 2 (AR2) and the AMBR were 1.5, 2.5 and 2.5days respectively, (ii) the permeate suction through the membranefrom the AMBRwas carried out on a 10min on and a 2min off cycle.Thus the flux through the membrane was 6.5 L/m2 h (iii) therecirculation ratio (¼ return flow rate from the AMBR to AR1 orAR2/feed flow rate) was 2.5.

The pH of the AMBR was 8.0 while the pH in permeatedecreased to 7.63. The removal efficiency of COD was approxi-mately 99.2%. This was attributed to the degradation of oxygen-demanding organic compounds in anoxic reactors and AMBR, andthen the remaining oxygen demanding chemicals were rejected by

Table 2Carwash wastewater quality at different locations of the MBR system.

Car wash wastewater In anoxic reactor 1

pH 7.63 7.70DO (mg/L) 2.47 0.08TSS (mg/L) 307 5190EC (mS/cm) 713 910TOC (mg/L) 198.72 36.84COD (mg/L) 776 e

NH4þ (mg/L) 3.5 1.75

Nitrite (mg/L) 1.2 0.535Nitrate (mg/L) 6.75 5.45

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the membrane. Similar to the COD removal, there was a highremoval of TOC (97.3%).

The overall removal of ammonium by the MBR was 41%. Therewas a 49.2% removal of nitrite within the AMBR. Denitrificationoccurs in the anoxic tanks and nitrification occurs in the aerobic(MBR) tank. The recirculation helps the nitrified water to returnback to the anoxic tank from the aerobic tank. Therefore a goodreduction in NH4

þ can be seen in the anoxic tank compared to theinfluent. However, since the rates of removal could affect theoverall efficiency, the effluent emerging from the MBR containsNH4

þ that is higher than the anoxic tank. But, there is an overallreduction in NH4

þ by the entire system as stated above.

3.3. Mass balance

In this section, the kinetics of MBR system are discussed usingmass balance computations. The retention time in anoxic reactor 1,anoxic reactor 2 and AMBR were 32.4, 32.4 and 54 h respectively.Also the feed COD:TOC ratio was 3.91. Further, the average TOCvalues of the feed, in the anoxic reactor 1, anoxic reactor 2 andAMBR were 198.7, 36.8, 30.1 and 28.7 mg/L respectively. Theaverage COD of the feed was 776 mg/L and assuming that theCOD:TOC ratio is maintained at 3.90 throughout the above threebiological reactors, the COD values in anoxic reactor 1, anoxicreactor 2 and AMBR would be 143.7, 117.6 and 112.1 mg/L respec-tively. However, the measured COD of the effluent from AMBR was5.0 mg/L which indicates the contribution of hollow fibre mem-brane in removing COD. Thus, the corresponding COD loads to AR1,AR2 and AMBR were 0.57, 0.11 and 0.05 g/L.d, respectively. Underthese COD loadings, the COD removal in those reactors was 81.5, 3.4and 0.7% respectively. Another 13.8% removal of COD was gaineddue to the retention of COD onto the membrane submerged in theAMBR. As discussed in a similar work by our research group withdye wastewater (Rondon et al., 2015), the possible reason for theremoval of COD by the membrane can be the biofilm that generallyforms on the surface of the membrane. This biofilm will assist indegrading part of the organic matter passing through it. Thus thetotal COD removal by the above system was 99.4%.

The above COD removal percentages were computed withrespect to the average feed COD concentration of 776 mg/L. If theCOD removal percentages were computed with respect to the CODconcentrations of the solution that enters each biological reactor,then the COD removal percentages in each biological reactor (AR1,AR2 and AMBR) would be 81.5, 18.2 and 4.7% respectively. In thiscase, the contribution of the membrane in removing COD would be95.5%. The average MLSS values in AR1, AR2 and AMBR were 5190,6100 and 3250 mg/L respectively and corresponding food tomicroorganism ratios (F/M) were 0.10, 0.01 and 0.02 (g-COD/d)/(g-MLSS) respectively. This indicates that this MBR system could befurther optimised by increasing the COD loading and correspond-ingly the F/M ratio. A system similar to the one used in this studywould be very useful in treating carwash wastewater for the

In anoxic reactor 2 In aerobic MBR Permeate

7.61 8.08 7.630.06 5.05 3.71

6100 3250 0.00901 883 84330.12 28.69 5.42

e e 51.5 2.4 2.050.60 0.61 2.3658.85 13.45 14.45

e of car wash wastewater by chemical coagulation and membraneadation (2016), http://dx.doi.org/10.1016/j.ibiod.2016.01.017

I.A. Rodriguez Boluarte et al. / International Biodeterioration & Biodegradation xxx (2016) 1e5 5

purpose of reusing the treated carwash wastewater in the carwashstations.

3.4. Practical implication

When considering the results of this research from a practicalperspective, coagulation is not suitable to treat carwashwastewateras it decreased the pH of the treated supernatant to acidic levelwhich may have some effect on car paint. Moreover, coagulationproduces a large quantity of sludge, which requires additionaltreatment. Although MBR was not very effective in removingnitrogenous compounds compared to coagulation or ozonation, itwas very effective in reducing oxygen demanding chemicalsincluding suspended solids from the car wash effluent.

According to Li et al. (2007), the BOD, COD, suspended solids,turbidity and pH of the carwash water should be 10 mg/L, 50 mg/L,5 mg/L, 5 NTU and 6.5e9.0 respectively. However higher values forBOD (<25 mg/L), COD (<125 mg/L) and suspended solids (<60 mg/L) have been recommended in EU standards (Boussu et al., 2007).Further, in order to be used in high pressure pumps to performwash cycle, treated water should not contain particles more than10 mm size (Brown, 2000). The MBR used in this study effectivelyreduced all types of contaminants and met the car wash waterquality guidelines stated by Li et al. (2007). The MBR permeatecould be reused in the carwash stations in order to improve envi-ronmental practices and to gain financial benefits.

4. Conclusions

This study demonstrated the efficiency of the coagulation,ozonation and MBR in removing both solids and chemical con-taminants from a car wash wastewater sample. Coagulants, alumand PACl, reduced all types of contaminants from car washwastewater. Ozonation was an effective method to remove partic-ular contaminants of car wash wastewater compared to coagula-tion. The quality of the permeate produced by the MBR wasextremely high. It is anticipated that the outcomes of this studyfromMBR may have significant implications for the water industry,the community and the environment. The use of MBR systemsheralds a new direction relating to the conservation of water incommercial facilities and new cost saving initiatives for industriesand businesses. However, a major drawback in the operation ofMBR is fouling, therefore future work to investigate the character-istics and control of fouling may be worth considering for its

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sustainable application.

Acknowledgements

The authors are grateful to the owner of Grovedale Car Wash,Mr. Joe Pongrac for initiating this research by providing backgroundto problems faced due to carwash wastewater and supplyingwastewater samples to conduct this research.

References

Amuda, O.S., Amoo, I.A., 2007. Coagulation/flocculation process and sludge condi-tioning in beverage industrial wastewater treatment. J. Hazard. Mater. 141,778e783.

Australian Bureau of Statistics, 2014. Motor Vehicle Census. Jan 2014 ed. Australia,2013. http://www.abs.gov.au/ausstats/abs@.nsf/mf/9309.0.

Boussu, K., Kindts, K., Vandecasteele, C., Van der Bruggen, B., 2007. Applicability ofnanofiltration in the carwash industry. Sep. Purif. Technol. 54, 139e146.

Brown, C., 2000. Water Conservation in the Professional Car Wash Industry, first ed.Washington, USA: International Car Wash Association.

Cheng, S.-F., Lee, Y.-C., Kuo, C.-Y., Wu, T.-N., 2015. A case study of antibioticwastewater treatment by using a membrane biological reactor system. Int.Biodeterior. Biodegr. 102, 398e401.

Duan, J., Gregory, J., 2003. Coagulation by hydrolysing metal salts. Adv. ColloidInterface Sci. 100e102, 475e502.

Etchepare, R., Zaneti, R., Azevedo, A., Rubio, J., 2014. Application of flocculatione-flotation followed by ozonation in vehicle wash wastewater treatment/disin-fection and water reclamation. Desalin. Water Treat. 1e9.

Friha, I., Karray, F., Feki, F., Jlaiel, L., Sayadi, S., 2014. Treatment of cosmetic industrywastewater by submerged membrane bioreactor with consideration of micro-bial community dynamics. Int. Biodeterior. Biodegr. 88, 125e133.

Hoign�e, J., Bader, H., 1976. The role of hydroxyl radical reactions in ozonation pro-cesses in aqueous solutions. Water Res. 10, 377e386.

Hosseinzadeh, M., Bidhendi, G.N., Torabian, A., Mehrdadi, N., 2013. Evaluation ofmembrane bioreactor for advanced treatment of industrial wastewater andreverse osmosis pretreatment. J. Environ. Health Sci. Eng. 11, 1e8.

Kiran, S.A., Arthanareeswaran, G., Thuyavan, Y.L., Ismail, A.F., 2015. Influence ofbentonite in polymer membranes for effective treatment of carwash effluent toprotect the ecosystem. Ecotoxicol. Environ. Saf. 121, 186e192.

Lau, W.J., Ismail, A.F., Firdaus, S., 2013. Car wash industry in Malaysia: treatment ofcar wash effluent using ultrafiltration and nanofiltration membranes. Sep. Purif.Technol. 104, 26e31.

Li, T., Xue-jun, T., Fu-yi, C., Qi, Z., Jun, Y., 2007. Reuse of carwash wastewater withhollow fiber membrane aided by enhanced coagulation and activated carbontreatments. Water Sci. Technol. 56 (12), 111e118.

Persson, P.O., 2011. Cleaner Production: Strategies & Technology for EnvironmentalProduction. Royal Institute of Technology e Industrial Ecology, Stockholm.

Rondon, H., El-Cheikh, W., Rodriguez Boluarte, I.A., Chang, C.Y., Bagshaw, S.,Farago, L., Jegatheesan, V., Shu, L., 2015. Application of enhanced membranebioreactor (eMBR) to treat dye wastewater. Bioresour. Technol. 183, 78e85.

Rubio, J., Zaneti, R.N., 2009. Treatment of washrack wastewater with water recyclingby advanced flocculation-column flotation. Desalination 8, 146e153.

Sabur, M.A., Khan, A.A., Safiullah, S., 2012. Treatment of textile wastewater bycoagulation precipitation method. J. Sci. Res. 4, 623e633.

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