International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print),
ISSN 0976 – 6316(Online) Vol...
International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print),
ISSN 0976 – 6316(Online) Vol...
International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print),
ISSN 0976 – 6316(Online) Vol...
International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print),
ISSN 0976 – 6316(Online) Vol...
International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print),
ISSN 0976 – 6316(Online) Vol...
International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print),
ISSN 0976 – 6316(Online) Vol...
International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print),
ISSN 0976 – 6316(Online) Vol...
International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print),
ISSN 0976 – 6316(Online) Vol...
International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print),
ISSN 0976 – 6316(Online) Vol...
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  1. 1. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 3, March (2014), pp. 285-293 © IAEME 285 APPLICATION OF LEMNA MINOR L. ON REDUCTION OF CONTAMINANTS IN A TEXTILE INDUSTRY EFFLUENT D. Sivakumar*, A.N. Kandaswamy*, E. Arivoli*, V. Sesha Sayee* *Department of Civil Engineering, Vel Tech High Tech Dr.Rangarajan Dr.Sakunthala Engineering College, Chennai. ABSTRACT Textile industry processes are among the most environmentally unfriendly industrial processes, because they produce colour effluent that is heavily polluted the environment. Therefore, effluent from textile industry has to be treated before being discharged into the environment. In this study, experiments were performed using different process parameters like nutrient dosage, dilution ratio, pH and contact time to remove TDS and sulphate from the textile industrial effluent in constructed wetlands with the help of aquatic macrophytes Lemna minor L. From the experiments it was found that the maximum percentage reduction of various parameters in a textile industry wastewater by Lemna minor L. were obtained at an optimum nutrient dosage of 50 g, dilution ratio of 8, pH of 8 and contact time of 4 days. Similarly, the validation experiments results showed that the experiments were able to reproduce and the maximum removal percentage of sulphate in a textile industry effluent is 81.31 %, which is lesser than the removal of sulphate in an aqueous solution (84.62 %). Further, first order kinetic model was well fitted with the experimental data of this present study. Finally, this study was concluded that Lemna minor L. might be used for removing various parameters in any type of textile industry effluent. Keywords: Aquatic Macrophyte, Process Parameters, Textile Industry Wastewater. 1.0 INTRODUCTION Textile industries consume a large volume of water and chemicals for making various textile goods and as a result, large volume of effluent discharged on land with or without treatments. The quantities and characteristics of effluent discharged vary from mill to mill, which depends on the water consumption and the average daily product [14]. Many approaches have been taken to reduce water consumption by recycling the effluent comes from the textile industries. The raw materials particularly dyes used in the textile industry determine the volume of water required for production as well as wastewater generated [6]. The wastewater generated from the various processing units are INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND TECHNOLOGY (IJCIET) ISSN 0976 – 6308 (Print) ISSN 0976 – 6316(Online) Volume 5, Issue 3, March (2014), pp. 285-293 © IAEME: www.iaeme.com/ijciet.asp Journal Impact Factor (2014): 7.9290 (Calculated by GISI) www.jifactor.com IJCIET ©IAEME
  2. 2. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 3, March (2014), pp. 285-293 © IAEME 286 desizing, scouring, bleaching, mercerizing, dyeing, printing, and packing required huge amount of organic chemicals of complex structure [2, 11, 12]. The main parameters identified in the textile industry are pH, electrical conductivity (EC), chloride, sulphate, phenols, total dissolved solids (TDS), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) and other solution substances [18]. Therefore, wastewaters from the textile industry have to be treated before being discharged to the environment [16]. Various methods including aerobic and anaerobic microbial degradation, coagulation, chemical oxidation, precipitation, filtration, membrane separation, electrochemical treatment [11] filtration, flotation, hydrogen peroxide catalysis, and reverse osmosis [3], ozonation [10] and biological techniques can be employed to remove various pollutant forms the textile industry wastewater [5]. However their costs are high and most of them are difficult to use under field conditions, hence such a condition there is an urgent need to study natural, simple, and cost-effective techniques for controlling pollution from industrial effluents and treating such wastewater, such as phytoremedation [7, 8]. Phytoremedation is the utilization of plants accumulation capabilities to remove contamination from water, wastewater, soil and air [4, 14, 17]. In recent years, considerable attention has been focused on absorption process using aquatic plants because, it has more advances than over conventional treatment methods include: low cost; high efficiency; minimization of chemical and biological sludge [15]. The application of phytoremediation technology by duckweed in wastewater treatment and management is quite interesting and revealing. Lemna minor L. known as common duckweed is a small, free floating aquatic plant fast growing, adapt easily to various aquatic conditions and play an important role in the extraction and accumulation of pollutants from waters and wastewaters [9, 13]. Thus, this study was conducted to remove the TDS and sulphate in a textile industrial effluent in constructed wetlands by using aquatic macrophytes Lemna minor L. using different process parameters. Further, the experiment results of TDS and sulphate in a textile industrial effluent is verified for their reproducibility with the separate experiments conducted to remove the same TDS and sulphate in an aqueous solution. Finally, kinetic model was developed to check the kinetics of experimental investigation of this present study. 2.0 MATERIALS AND METHODS 2.1 Collection of Lemna minor L. Lemna minor L. was collected from the local pond, which had no connection with any textile effluent discharge points. The collected Lemna minor L. (Fig. 1). was washed with deionized water and weighed. Further, the Lemna minor L. was initially subject to stabilization in small plastic tanks containing well water and the same were preserved for 15 days period. In addition, these plastic tanks were filled with gravel and wetland soil (collected from the local pond) up to five inches in height and maintained at normal temperature. Fig. 1: Photographic View of Lemna minor L.
  3. 3. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 3, March (2014), pp. 285-293 © IAEME 287 2.2 Collection of Textile Industry Effluent For the present study, textile industry effluent samples were collected from the final clarifier of textile industry effluent treatment plant of Chennai city, Tamil Nadu, India with the help of airtight sterilized bottles. Then, took the effluent samples to the Environmental Laboratory and then they were stored in refrigerator at a temperature of 278 K for analyzing total dissolved solid (TDS) and sulphate in later stages. In order to reduce the various parameters in a textile industry effluent, wetlands was constructed (plastic tanks) by using Lemna minor L. and conducted the removal study with various nutrient dosages, dilution ratio and contact time. 2.3 Absorption Experiments For the experiments, Lemna minor L., which maintained in the plastic tanks were collected, cleaned and introduced in the experimental tanks (constructed wetland). The experimental tanks also a plastic tank as similar to the plastic tank for preserving the Lemna minor L. Approximately, 100 g of Lemna minor L. was used in each experimental tank for this study. These experimental tanks were filled with textile industry effluent of 1000 ml. Triplicate of each experimental setup was maintained. In order to reduce the TDS and sulphate in a textile industry effluent, the experimental setup (constructed wetland) was examined for a period of 7 days by 1 day intervals by using aquatic macrophytes Lemna minor L. and conducted the removal study with various nutrient dosage (10, 20, 30, 40, 50, 60 and 70 g), dilution ratio (2, 4, 6, 8, 10, 12 and 14) and pH (4, 5, 6, 7, 8, 9 and 10). The nutrient used in this study was dried Cow dung, collected locally. The dilution ratio was used such that 1 part of effluent with various numbers of part of well water, thus, the ratio of 2, 4, 6, 8, 10, 12 and 14 represents these parts of well water mixed with raw effluent. The pH was adjusted by using 0.1 M of NaOH and 0.1 M of HCl. The concentration of TDS and sulphate in a textile industrial effluent before and after treatment with Lemna minor L. were determined as per the standard procedure stipulated by APPA, AWWA and WEF [1]. The removal percentage of various parameters by Lemna minor L. was calculated by using the Equation (1): Percentage Removal = (1) in which C1 is the concentration of the parameter before treatment with Lemna minor L. and C2 is the concentration of the parameter after treatment with Lemna minor L. The initila concentration of TDS and sulphate in a textile industry wastewater is 2622 mg/l and 758 mg/l respectively. 3.0 RESULTS AND DISCUSSIONS The different process parameters like nutrient dosage, dilution ratio and contact time were selected for conducting the constructed wetland absorption study using Lemna minor L. to reduce the various parameters like TDS and sulphate in a textile industry effluent. 3.1 Effect of Nutrient Dosage Experimental investigations were conducted by changing the nutrient dosage from 10 g to 70 g with an increment of 10 g using Lemna minor L. and for the different contact time from 1 day to 7 days with an increment of 1 day. Fig. 2 indicates the percentage reduction of various parameters like TDS and sulphate in a textile industry effluent using Lemna minor L. against nutrient dosage (since, day 4 is the optimum contact time found from the study, the results obtained on the day 4 was presented and the results obtained from the day 1, 2, 3, 5, 6 and 7 were not presented in this study) with a contact time of 4 days, dilution ratio of 6 and pH of 7. The results revealed that the percentage removal of the selected various parameters is low by Lemna minor L. at the starting time of the experiment and then increases with contact time. This is
  4. 4. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 3, March (2014), pp. 285-293 © IAEME 288 because, the supplied nutrient could not be effectively utilized by Lemna minor L. for removing various parameters and thereafter as contact incrases, Lemna minor L. used nutrients effectively, results more removal of selected parameters. Up to nutrient dosage 50 g, the removal of various parameters in a textile industry effluent increased by Lemna minor L. steadily and for the nutrient dosage of 60 g and 70 g, the percentage removal results showed the resembles of the results obtained nutrient dosage 50 g. Hence, the optimum nutrient dosage found in this study for the maximum removal of TDS and sulphate in a textile industry effluent by Lemna minor L. is 50 g. The removal percentage for TDS and sulphate was not significant even the contact time and nutrient dosages were higher, it is more likely that an even sufficient contact time available, a significant portion of the available active sites remains undiscovered, leading to lower specific uptake for the nutrient dosage of 60 g and 70 g and for the contact time of 5, 6 and 7 days. Thus, the maximum removal percentage for TDS and sulphate in a textile industry effluent by Lemna minor L. against nutrient dosage is 64.35 and 68.14 % respectively (Fig. 2). Fig. 2: The Percentage Reduction of TDS and Sulphate in a Textile Industry Effluent using Lemna minor L. against Nutrient Dosage 3.2 Effect of Dilution Ratio Experimental investigations were conducted by changing the dilution ratio from 2 to 14 (effluent 1 : well water 2) with an increment of 2 using Lemna minor L. and for the different contact time from 1 day to 7 days with an increment of 1 day. Fig. 3 indicates the percentage reduction of TDS and sulphate in a textile industry effluent using Lemna minor L. against dilution ratio (since, day 4 is the optimum contact time found from the study, the results obtained on the day 4 was presented and the results obtained from the day 1, 2, 3, 5, 6 and 7 were not presented in this study) with a contact time of 4 days, the nutrient dosage of 50 g and pH of 7. The results revealed that the percentage removal of the selected various parameters is low at the beginning of the contact time and then increases later stages. In other words, the active sites in the Lemna minor L. could not be utilized effectively by the various parameters for their removal at the beginning and thereafter, absorbent sites of Lemna minor L. could be effectively utilized in later stages.
  5. 5. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 3, March (2014), pp. 285-293 © IAEME 289 Fig. 3: The Percentage Reduction of TDS and Sulphate in a Textile Industry Effluent using Lemna minor L. against Dilution Ratio Up to dilution ratio of 8, the removal of various parameters in a textile industry effluent by Lemna minor L. increased steadily and in the dilution ratio 10, 12 and 14, the percentage removal results showed the resembles of the results obtained for the dilution ratio 8. Hence, the optimum dilution ratio found in this study for the maximum removal of various parameters in a textile industry effluent is 8. Further, at low dilution ratio, the removal of TDS and sulphate in a textile industry effluent were not absorbed easily by the Lemna minor L. and high dilution ratio, the removal of TDS and sulphate in a textile industry effluent were absorbed more by the Lemna minor L. This is because, the high dilution ratio, the ions freely move within the solution results easy to absorb more on to the minor L. active sites. The removal percentage for various parameters was not significant even the contact time and dilution ratio were higher, it is more likely that an even sufficient contact time available, a significant portion of the available active sites remains undiscovered, leading to lower specific uptake for the dilution ratio 10, 12 and 14 and for the contact time of 5, 6 and 7 days. Thus, the maximum removal percentage for TDS and sulphate in a textile industry effluent by Lemna minor L. against dilution ratio is 72.53 and 75.22 % respectively (Fig. 3). 3.3 Effect of pH Experimental investigations were conducted by changing the pH from 4 to 10 with an increment of 1 using Lemna minor L. and for the different contact time from 1 to 7 days with an increment of 1 day. Fig. 4 indicates the percentage reduction of TDS and sulphate in a textile industry effluent using Lemna minor L. against pH (since, day 4 is the optimum contact time found from the study, the results obtained on the day 4 was presented and the results obtained from the day 1, 2, 3, 5, 6 and 7 were not presented in this study) with a contact time of 4 days, the nutrient dosage of 50 g and dilution ratio of 8.
  6. 6. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 3, March (2014), pp. 285-293 © IAEME 290 Fig. 4 The Percentage Reduction of TDS and Sulphate in a Textile Industry Effluent using Lemna minor L. against pH The results revealed that the percentage removal of TDS and sulphate is low in acidic pH and then high with pH increases. This is because, in a slight alkaline to alkaline condition, the active sites in the Lemna minor L. could be effectively utilized for removing TDS and sulphate in a textile industry effluent than in acidic condition. Up to pH of 8, the removal of various parameters in a textile industry effluent by Lemna minor L. increased steadily and for the pH 9 and 10, the percentage removal results showed the resembles of the results obtained for the pH 8. Hence, the optimum pH found in this study for the maximum removal of various parameters in a textile industry effluent is 8. The removal of TDS and sulphate in a textile industry effluent on day 7 and for the pH 9 and 10, the removal percentage for TDS and sulphate was not significant, even contact time and pH were higher, it is more likely that an even sufficient contact time available, a significant portion of the available active sites remain undiscovered, leading to lower specific uptake for the pH of 9 and 10 and for the contact time of 5, 6 and 7 days. Thus, the maximum removal percentage of TDS and sulphate in a textile industry effluent by Lemna minor L. against pH is 78.27 and 81.31 % respectively (Fig. 4). 3.4 Verification Experiment In order to validate the above experiments in reducing the various parameters in a textile industry effluent, a separate experiment has been performed with an optimum nutrient dosage (50 g), dilution ratio (8), pH (8) and contact time (4 days) for the removal of sulphate in an aqueous solution. The maximum removal percentage of sulphate in a textile industry effluent and in an aqueous solution by Lemna minor L. is shown in Fig. 5. The initial concentration of sulphate in an aqueous solution is similar to the initial concentration of sulphate in a textile industry effluent. The results (Fig. 5) showed that the maximum removal percentage sulphate in a textile industry effluent by Lemna minor L. is about 81.31 %, which was lesser than the removal of sulphate in an aqueous solution, where the removal rate is 84.62 %. The maximum removal rate in an aqueous solution is due to there were no competitive ions present in an aqueous solution than in a textile industry effluent. Based on the results, it may be concluded that Lemna minor L. may be used for removing any other parameters in any type textile industry effluent for an identified optimum values of selected parameters.
  7. 7. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 3, March (2014), pp. 285-293 © IAEME 291 Fig. 5: The Percentage Reduction of Sulphate in a Textile Industry Effluent and in an aqueous solution using Lemna minor L. against Optimum Nutrient Dosage (50 g), Dilution Ratio (8), pH (8) and Contact Time (4 days) 3.5 Model Development In this study, the experimental data are fitted with first order kinetic model. The first order model is given by (2) on integration the Eqn.1 becomes (3) where C0 is the initial concentration of TDS and sulphate in mg/l, C is the concentration of TDS and sulphate in mg/l at time ‘t’, ‘t’ is degradation time, days and ‘k1’ is the first order rate constant, days- 1 . The negative sign indicates as time increases the rate constant decreases. The first order rate constant was calculated from the slope of the straight line by least square fit (Fig.6). The rate constant k1 and R2 values are presented in Table 1. Table 1: The kinetic parameter and the regression equation for the parameters TDS and sulphate in a textile industry effluent at an Optimum Nutrient Dosage (50 g), Dilution Ratio (8), pH (8) and Contact Time (4 days) Sl.No. Parameters k1 R2 1 TDS, mg/l -0.2799 0.9699 2 Sulphate, mg/l -0.3183 0.9811
  8. 8. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 3, March (2014), pp. 285-293 © IAEME 292 Fig.6: First order Kinetic Model for TDS and Sulphate in a Textile Industry Effluent for the Optimum Nutrient Dosage (50 g), Dilution Ratio (8), pH (8) and Contact Time (4 days) The R2 value for TDS and sulphate respectively is 0.9699 and 0.9811 respectively (Table 1) and indicate that the ability of the first order kinetic model in describing the kinetics of the present work. In other words, the model is fitted well with the experimental data. Thus, from the kinetic studies, it was found that the reduction of TDS and sulphate in a textile effluent follows the first order kinetic model. 4.0 CONCLUSION In the present study, the experiments were conducted to find out the ability of Lemna minor L. in removing TDS and sulphate in a textile industry effluent. The ability of Lemna minor L. for removing TDS and sulphate in a textile industry wastewater by various nutrient dosages, dilution ratio, pH and contact time were monitored. The maximum percentage reduction of TDS and sulphate in a textile industry wastewater by Lemna minor L. were obtained at an optimum nutrient dosage of 50 g, dilution ratio of 8 pH of 8 and contact time of 4 days. From the validation experiments, it was found that the experiments were reproduced at an optimum values found from the experiments conducted for the removal of TDS and sulphate in a textile industry effluent. The first order kinetic model is fitted well with the experimental data obtained from textile industry effluent. From the results of removal of TDS and sulphate, Lemna minor L. might be used for removing various parameters in any type of textile industry effluent. 5.0 REFERENCES 1. APPA, AWWA, and WEF, “Standard methods for the examination of water and wastewater,” 20th ed., APHA Publication, Washington D.C., 2005. 2. Bisschops, I. and Spanjers, H., “Literature review on textile wastewater characterization,” Environmental Technology, Vol. 24, pp. 1399-1411, 2003 3. Cooper, P., “Removing color from dye house wastewaters-a critical review of technology available,” J. Soc. Dyers Colorists, Vol. 109, pp. 97-100, 1993. 4. Demirezen, D., and Aksoy, A., “Accumulation of heavy metals in typha angustifolia (L.) and potamogeton pectinatus (L.) living in Sultan Marsh (Kayseri, Turkey),” Chemosphere, Vol. 56, pp. 685-696, 2004.
  9. 9. International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 3, March (2014), pp. 285-293 © IAEME 293 5. Guendy, H.R., “Treatment and reuse of wastewater in the textile industry by means of coagulation and adsorption techniques, Journal of App. Sci. Res., Vol. 6, no. 8, pp. 964-972, 2010. 6. Irina-Isabella, S., and Romen, B., “Wastewater characteristics in textile finishing mills,” Environmental Engineering and Management Journal, Vol. 7, no. 6, pp. 859-864, 2008. 7. Ismail, Z, and Beddri,A., “Potential of water hyacinth as a removal agent for heavy metals from petroleum refinery effluents,” Water Air Soil Pollut., Vol. 199, pp. 57-65, 2009. 8. Ji, G.D., Sun, T.H. and Ni, J.R., “Surface flow constructed wetland for heavy oil – produced water treatment,” Bio. Techno., Vol. 98, pp. 436-441, 2007. 9. Kaur, L., Gadgil, K. and Sharma, S., “Effect of pH and lead concentration on phytoremoval of lead contaminated water by lemna minor,” .American–Eurasian J.Agric.and Environ.Sci., Vol. 7, no. 5, pp. 542-550, 2010. 10. Lin, S.H., and. Lin, C.M., “Decolorization of textile waste effluents by ozonation,” J. Environ. Syst., Vol. 21, pp. 143-153, 1999. 11. Lin, S.H., and Peng, C.F., “Treatment of textile wastewater by electrochemical method,” Water Res., Vol. 28, pp. 277-283, 1994. 12. Lin, S.H., and Peng, C.H., “Continuous treatment of textile wastewaters by combined coagulation, electrochemical oxidation and activated sludge,” Water Res., Vol. 30, pp. 587-593, 1996. 13. Naphi, I., Dalu, J., Ndamba, J. and Gijzen, H., “An evalution of duckweed based pond systems an alternative option for decentralization treatment and reuse of wastewater in Zimbabwe,” Water Sci.Technology, Vol. 48, no. 11, pp.115-122, 2003. 14. Patel, D., and Kanungo, V. , “Phytoremidation potential of duckweed (lemna minor l: atiny aquatic plant) in the removal of pollutants from domestic wastewater with special reference to nutrients,” The Bio sci., Vol. 5, no. 3, pp. 355- 358, 2010. 15. Roy, R., Fakhruddin, A.N.M., Khatun, R. and Islam, M.S., “Reduction of COD and pH of textile industrial effluents by aquatic macrophytes and algae,” Journal of Bangladesh Academy of Sciences, Vol. 34, no. 1, pp. 9-14, 2010. 16. Sawyer, C.C., and McCarty, P.L., “Chemistry for environmental engineers,” McGraw Hill, New York, pp. 331-514, 1978. 17. Shaikh Parveen, R. and Bhosle Arjun, B., “Bioaccumulation of chromium by aquatic macrophytes hydrilla sp. & chara sp.,” Advances in Applied Science Research, Vol. 2, no. 1, pp. 214-220, 2011. 18. Sofia, N., Haq, N. and Khalil-Ur-Rehman, “Physico-chemical characterization of effluents of local textile industries of Faisalabad–Pakistan, Int. J. Agri. Biol., Vol. 2, no. 3, pp. 232-233, 2000. 19. S.K.Agrawal, R.K.Watile, P.V.Mohata and S.C.Makwana, “Utilization of Textile Apparel Waste in Clay Brick”, International Journal of Advanced Research in Engineering & Technology (IJARET), Volume 4, Issue 7, 2013, pp. 48 - 52, ISSN Print: 0976-6480, ISSN Online: 0976-6499. 20. Mukherjee. S., Bhattacharya A. K. and Mandal. S. N., “Mitigation of Colour and Cod from Textile Wastewater by HMS, Polymeric Coagulants and Aids – Including Longitudinal Study”, International Journal of Civil Engineering & Technology (IJCIET), Volume 4, Issue 5, 2013, pp. 33 - 41, ISSN Print: 0976 – 6308, ISSN Online: 0976 – 6316. 21. R Radhakrishanan and A Praveen, “Sustainability Perceptions on Wastewater Treatment Operations in Urban Areas of Developing World”, International Journal of Civil Engineering & Technology (IJCIET), Volume 3, Issue 1, 2012, pp. 45 - 61, ISSN Print: 0976 – 6308, ISSN Online: 0976 – 6316.

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