Optimizing the Fenton Based Pre-Treatment of Landfill Leachate Using Response Surface Methodology

Abstract

Mixing of xenobiotic substances with the household waste decreases the biodegradability of leachate generated from municipal landfill sites. In various parts of the world, where solar energy is pervasive, solar photo Fenton-based pre-treatment of municipal landfill leachate can be considered as a potential pre-treatment method to improve its biodegradability. Therefore, this paper reports a laboratory study conducted to compare the efficiency of Fenton and Solar Photo Fenton processes to pre-treat leachate from municipal solid waste landfill site of Chandigarh, India. The operating parameters such as pH and initial concentrations of reagents (i.e., H2O2 and Fe2+) were optimized using a three level multivariate Box-Behnken statistical approach in combination with response surface methodology. After 2 h of treatment, at the optimal conditions of pH 3.4, [H2O2] = 2.73 g/L and [Fe2+] = 63.71 mg/L, 86.21% degradation of Chemical Oxygen Demand (COD) was observed after solar photo Fenton-based treatment. On the contrary, the final COD removal obtained using Fenton process at the optimal conditions, pH 5, [H2O2] = 2.66 g/L, [Fe2+] = 47.29 mg/L, was 59.19%. Further, this study showed that the Fenton based pre-treatment can enhance the biodegradability of landfill leachate. After pre-treatment, the Biological Oxygen Demand (BOD5) to COD ratio of landfill leachate improved from 0.13 to 0.57 and 0.49 for solar photo Fenton process and Fenton process, respectively. Findings of this study will trigger the broader interest of the auditory comprising policy makers and scientists to treat the leachate using renewable sources and prevent contamination of groundwater.