Optimization of Printing-ink Wastewater Treatment by Fenton Oxidation Using Response Surface Methodology

Fenton oxidation was employed to treat the printing-ink wastewater.Initial pH value,H2O2 dosage and FeSO4 dosage were selected as independent variables,and removal rate of COD of wastewater as the response value.Box-Behnken Design method was employed for the experimental design,of which an experimental matrix of three-factorial,three-level experimental design consisting of 17 experimental runs was obtained.Experimental results were simulated and analyzed by response surface methodology.A quadratic polynomial equation was established for describing the relationship between COD removal rate and three independent variables.The analysis of individual and interactive effects of the three variables on responses was conducted in accordance with the simulated equation.Response surface analysis results demonstrate that the selected factors had significant correlation with the removal rate of COD of printing-ink wastewater.The optimum conditions of Fenton oxidation were determined to be initial pH value 2.7,H2O2 dosage 779 mg/L and FeSO4 dosage 806 mg/L.The removal rate of COD of wastewater was up to 84.2% under the optimal conditions.The experimental values agreed with the predicted values of the model equation with 1.66% deviation only.