In this paper, a new ferric chloride-(polyvinylpyrrolidone-grafted-polyacrylamide) hybrid copolymer was successfully synthesized by free radical polymerization in solution using ceric ammonium nitrate as redox initiator. The hybrid copolymer was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Response surface methodology (RSM), involving central composite design (CCD) matrix with two of the most important operating variables in the flocculation process; hybrid copolymer dosage and pH were utilized for the study and for the optimization of the wastewater treatment process. Response surface analyses showed that the experimental data could be adequately fitted to quadratic polynomial models. Under the optimum conditions, the turbidity and chemical oxygen demand (COD) removal efficiencies were 96.4% and 83.5% according to RSM optimization, whereas the optimum removals based on the genetic algorithm (GA) were 96.56% and 83.54% for the turbidity and COD removal models. Based on these results, wastewater treatment using this novel hybrid copolymer has proved to be an effective alternative in the overseeing of turbidity and COD problems of municipal wastewater.
References
[1]
Wang, J.P.; Chen, Y.Z.; Ge, X.W.; Yu, H.Q. Optimization of coagulation–flocculation process for a paper-recycling wastewater treatment using response surface methodology. Colloid. Surf. A 2007, 302, 204–210, doi:10.1016/j.colsurfa.2007.02.023.
[2]
Zheng, H.; Zhu, G.; Jiang, S.; Tshukudu, T.; Xiang, X.; Zhang, P.; He, Q. Investigations of coagulation–flocculation process by performance optimization, model prediction and fractal structure of flocs. Desalination 2011, 269, 148–156, doi:10.1016/j.desal.2010.10.054.
[3]
Devi, R.; Dahiya, R. COD and BOD removal from domestic wastewater generated in decentralised sectors. Bioresour. Technol. 2008, 99, 344–349, doi:10.1016/j.biortech.2006.12.017.
[4]
Duan, J.; Gregory, J. Coagulation by hydrolysing metal salts. Adv. Colloid Interface Sci. 2003, 100, 475–502, doi:10.1016/S0001-8686(02)00067-2.
Yang, W.; Qian, J.; Shen, Z. A novel flocculant of Al(OH)3-polyacrylamide ionic hybrid. J. Colloid Interface Sci. 2004, 273, 400–405, doi:10.1016/j.jcis.2004.02.002.
[7]
Tang, H.; Shi, B. The characteristics of composite flocculants synthesized with inorganic polyaluminium and organic polymers. In Chemical Water and Wastewater Treatment VII, Proceedings of the 10th Gothenburg symposium 2002, Gothenburg, Sweden, June 17–19, 2002; IWA Publishing: London, UK, 2002; pp. 17–28.
[8]
Kasiri, M.; Khataee, A. Photooxidative decolorization of two organic dyes with different chemical structures by UV/H2O2 process: Experimental design. Desalination 2011, 270, 151–159, doi:10.1016/j.desal.2010.11.039.
[9]
Omar, F.M.; Rahman, N.N.N.A.; Ahmad, A. COD reduction in semiconductor wastewater by natural and commercialized coagulants using response surface methodology. Water Air Soil Poll. 2008, 195, 345–352, doi:10.1007/s11270-008-9751-7.
[10]
Woon, S.; Querin, O.; Steven, G. Structural application of a shape optimization method based on a genetic algorithm. Struct. Multidiscip. Opitm. 2001, 22, 57–64, doi:10.1007/s001580100124.
[11]
Mason, R.L.; Gunst, R.F.; Hess, J.L. Statistical Design and Analysis of Experiments: With Applications to Engineering and Science; Wiley-Interscience: Hoboken, NJ, USA, 2003; Volume 356752.
[12]
Yang, Y.; Li, Y.; Zhang, Y.; Liang, D. Applying hybrid coagulants and polyacrylamide flocculants in the treatment of high-phosphorus hematite flotation wastewater (HHFW): Optimization through response surface methodology. Sep. Purif. Technol. 2010, 76, 72–78, doi:10.1016/j.seppur.2010.09.023.
[13]
Pretsch, E.; Bühlmann, P.; Badertscher, M. Structure Determination of Organic Compounds: Tables of Spectral Data; Springer: Berlin, Germany, 2009.
[14]
Ghafari, S.; Aziz, H.A.; Isa, M.H.; Zinatizadeh, A.A. Application of response surface methodology (RSM) to optimize coagulation–flocculation treatment of leachate using poly-aluminum chloride (PAC) and alum. J. Hazard. Mater. 2009, 163, 650–656, doi:10.1016/j.jhazmat.2008.07.090.
[15]
Sharma, P.; Singh, L.; Dilbaghi, N. Optimization of process variables for decolorization of Disperse Yellow 211 by Bacillus subtilis using Box–Behnken design. J. Hazard. Mater. 2009, 164, 1024–1029, doi:10.1016/j.jhazmat.2008.08.104.
[16]
Wantala, K.; Khongkasem, E.; Khlongkarnpanich, N.; Sthiannopkao, S.; Kim, K.W. Optimization of As(V) adsorption on Fe-RH-MCM-41-immobilized GAC using Box-Behnken design: Effects of pH, loadings, and initial concentrations. Appl. Geochem. 2011, 5, 1027–1034.
[17]
Tripathi, P.; Srivastava, V.C.; Kumar, A. Optimization of an azo dye batch adsorption parameters using Box–Behnken design. Desalination 2009, 249, 1273–1279, doi:10.1016/j.desal.2009.03.010.
[18]
Ahmadi, M.; Vahabzadeh, F.; Bonakdarpour, B.; Mofarrah, E.; Mehranian, M. Application of the central composite design and response surface methodology to the advanced treatment of olive oil processing wastewater using Fenton’s peroxidation. J. Hazard. Mater. 2005, 123, 187–195, doi:10.1016/j.jhazmat.2005.03.042.
[19]
Trinh, T.K.; Kang, L.S. Response surface methodological approach to optimize the coagulation–flocculation process in drinking water treatment. Chem. Eng. Res. Design 2011, 89, 1126–1135, doi:10.1016/j.cherd.2010.12.004.
[20]
Stephenson, R.J.; Duff, S.J.B. Coagulation and precipitation of a mechanical pulping effluent—I. Removal of carbon, colour and turbidity. Water Res. 1996, 30, 781–792.
[21]
Tan, B.H.; Teng, T.T.; Omar, A. Removal of dyes and industrial dye wastes by magnesium chloride. Water Res. 2000, 34, 597–601, doi:10.1016/S0043-1354(99)00151-7.
