Optimization of the Turbidity Removal Conditions from TiO2 Solution Using a Response Surface Methodology in the Electrocoagulation/Flotation Process

전기응집/부상 공정에서 반응표면분석법을 이용한 TiO2 수용액의 탁도 처리조건 최적화

  • Kim, Dong-Seog (Department of Environmental Science, Catholic University of Daegu) ;
  • Park, Young-Seek (Department of Health & Environment, Daegu University)
  • 김동석 (대구가톨릭대학교 환경과학과) ;
  • 박영식 (대구대학교 보건환경)
  • Received : 2009.10.09
  • Accepted : 2009.11.25
  • Published : 2009.12.31


The removal of turbidity from $TiO_2$ wastewater by an electrocoagulation/flotation process was studied in a batch reactor. The response surface methodology (RSM) was applied to evaluate the simple and combined effects of the three main independent parameters, current, NaCl dosage and initial pH of the $TiO_2$ solution on the turbidity removal efficiency, and to optimize the operating conditions of the treatment process. The reaction of electrocoagulation/flotation was modeled by use of the Box-Behnken method, which was used for the fitting of a 2nd order response surface model. The application of RSM yielded the following regression equation, which is an empirical relationship between the turbidity removal efficiency of $TiO_2$ wastewater and test variables in uncoded unit: Turbidity removal (%)=69.76+59.76Current+11.98NaCl+4.67pH+5.00Current${\times}$pH-160.11$Current^2-0.34pH^2$. The optimum current, NaCl dosage and pH of the $TiO_2$ solution to reach maximum removal rates were found to be 0.186 A, 0.161 g/l and 7.599, respectively. This study clearly showed that response surface methodology was one of the most suitable method to optimize the operating conditions for maximizing the turbidity removal. Graphical response surface and contour plots were used to locate the optimum point.


electrocoagulation/flotation;response surface methodology (RSM);Box-Behnken method;$TiO_2$;optimization


  1. Gao, P., Chen, X., Shen, F., Chen, G. : Removal of Chromium (VI) from wastewater by combined electrocoagulation-electroflotation without a filter. Separation and Purification Technology, 43, 117-123, 2005
  2. Cho, I. H., Chang, S. W., Lee, S. J. : Optimization and development of prediction model on the removal condition of livestock wastewater using a response surface method in the photo-Fenton oxidation process. Journal of Korean Society of Environmental Engineers, 30(6), 642-652, 2008
  3. Mansour, L. B., Ksentini, I., Elleuch, B. : Treatment of wastewaters of paper industry by coagulation-electroflotation. Desalination, 208(1-3), 34-41, 2001
  4. Balasubramanian, N., Kojima, T., Srinivasakannan, C. : Arsenic removal through electrocoagulation: Kinetic and statistical modeling. Chemical Engineering Journal, 155(1-2), 76-82, 2009
  5. Lim, Y. B., Park, S. H., Ahn, B. J., Kim, Y. I. : Practical design of experiments, Seoul, Free Academy, 1-15, 2008
  6. Kim, D. S., Park, Y. S. : Effect of coagulation and homogenization on the dissolved air flotation and sedimentation of bulking sludge. Journal of Environmental Health Sciences, 33(1), 68-74, 2007
  7. Golikova, E. V., Rogoza, O. M., Shelkunov, D. M., Chernoberezhskii, Y. A. : Electrosurface properties and aggregation stability of aqueous dispersion of TiO$_{2}$ and ZrO$_{2}$. Colloid Journal, 57(1), 25-29, 1995
  8. Cho, I. H., Park, J. H., Kim, Y. G., Lee, H. K. : Optimization of photocatalytic degradation conditions for dying wastewater using response surface method. Journal of Korean Society on Water Quality, 19(3), 257-270, 2003
  9. Kim, D. S., Park, Y. S. : Sewage sludge thickening using electroflotation. Journal of the Environmental Science, 16(9), 1085-1090, 2007
  10. Lee, S. B. : Design of experiments of focused on exercise using Minitab 15 version, Seoul, Ire Tech. Inc., 233-240, 2008
  11. Song, W. Y., Chang, S . W. : The study o f statistical optimization of NDMA treatment using UV-process. Journal of Korean Society on Water Quality, 25(1), 96-101, 2009
  12. Lee, S. H. : Engineering statistics data analysis using Minitab, Seoul, Ire Tech. Inc., 715-732, 2008
  13. Shin, M. S., Lee, K. H., Kim, D. J., Han, M. Y. : A study on the removal characteristics of TiO2-containing wastewater by electroflotation. Journal of Korean Society of Environmental Engineers, 24(1), 71-78, 2002
  14. Kim, D. J., Lee, K. H., Kwon, A. Y., Han, M. Y. : Optimum operation conditions for TiO2 wastewater treatment by electroflotation. Journal of the Korean Society of Water and Wastewater, 15(1), 34-39, 2001
  15. $\"{O}$lmez, T. : The optimization of Cr(VI) reduction and removal by electrocoagulation using response surface methodology. Journal of Hazardous Materials, 162(2-3), 1371-1378, 2009
  16. Hur, J. M., Park, J. A. : Performances of anaerobic sequencing batch reactor for digestion of municipal sludge at the conditions of critical solid-liquid separation. Korea Journal of Environmental Health Society, 28(5), 77-85, 2002
  17. Mathur, S., Singh, P., Moudgil, B. M. : Advanced in selective flocculation technology for solid-solid separations. International Journal of Mineral Processing, 58, 201-222, 2000
  18. Wang, J. P., Chen, Y. Z., Ge, W. Y., Yu, H. Q. : Optimization of coagulation-flocculation process for a paper-recycling wastewater treatment using response surface methodology. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 302(1-3), 204-210, 2007
  19. Burns, S. E., Yiacoumi, S., Tsouris, C. : Microbubble generation for environmental and industrial separation. Separation and Purification Technology, 11, 221-232, 1997
  20. Aleboyeh, A., Daneshvar, N., Kasiri, M. B. : Optimization of C.I. Acid Red 14 azo dye removes by electrocoagulation batch process with response surface methodology. Chemical Engineering and Processing, 47, 827-832, 2008