전기응집/부상 공정에서 반응표면분석법을 이용한 TiO2 수용액의 탁도 처리조건 최적화

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

The removal of turbidity from TiO2 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 TiO2 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 s urf ace model. T he a pplication o f RSM y ielded t he f ollowing r egression e quation, w hich i s an empirical relationship between the turbidity removal efficiency of TiO2 wastewater and test variables in uncoded unit: Turbidity removal (%) = 69.76 + 59.76Current + 11.98NaCl + 4.67pH + 5.00Current × pH − 160.11Current2− 0.34pH2. The optimum current, NaCl dosage and pH of the TiO2 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.