Oxidative removal of stabilized landfill leachate by Fenton's process: process modeling, optimization & analysis of degraded products

In this study, the stabilized landfill leachate which has a BOD : COD ratio of 0.045 was treated using Fenton's process. The effect of process parameters like reaction time, pH, dose of FeSO4 and dose of H2O2 was estimated using One Factor At a Time (OFAT) and the linear, interactive and quadratic effects between the factors were studied using Face Centered Central Composite Design (CCF). In the OFAT approach, reaction time: 5 minutes, pH: 3.0, dose of FeSO4: 30 mM, and dose of H2O2: 30 mM were optimized. In CCF, the statistically optimized model shows maximum removal of organic substances at an FeSO4 concentration of 14.44 mM, pH 3.0 and 29.12 mM of H2O2. The regression co-efficient R2 = 0.9079, adj R2 = 0.854 and adequate precision = 14.676. The degradation of organic substances was assessed by measuring the Chemical Oxygen Demand (COD). Total Organic Carbon (TOC) and Gas Chromatography-Mass Spectroscopy (GC-MS) were investigated for the sample corresponding to the maximum COD reduction.