Optimization of the process variables for landfill leachate treatment using Fenton based advanced oxidation technique

Abstract

The efficacy of Fenton based advanced oxidation technique for landfill leachate treatment was statistically assessed and the optimum operating conditions were determined. This process was optimized using response surface methodology (RSM) coupled with four-factor (five-level) central composite design (CCD). The process variables; pH, reaction time, Fe2+ and H2O2 dosages were used to study the response, chemical oxygen demand (COD) removal. A significant quadratic regression model was obtained to fit the experimental data and all the factors were statistically significant. The model accounted for the response within permissible error. The coefficient of determination was found to be equal to 0.95. The adequate precision ratio was obtained as 22.133. The optimized COD removal of 61% was obtained at 3.1 pH, the reaction time of 36 min, Fe2+ dosage of 0.04 mol L−1 and H2O2 dosage of 0.075 mol L−1. Response surface plots suggested that higher pH values are not favourable and increasing the chemical dosage might not always lead to higher COD removal efficiency. The results obtained were in agreement with the various past studies, thus, approving the accuracy of the model obtained.