Fenton treatment of landfill leachate under different COD loading factors

The application of Fenton treatment technology for treatment of landfill leachate greatly depends on the optimum Fenton operating conditions for a specific leachate. Determining optimum Fenton conditions requires multiple experiments using variable reaction parameters (pH, temperature, and H2O2 and Fe2+ doses) and previous researches show a wide range of optimal operating conditions. In this study, the applicability of the dimensionless loading factor (L-COD); which is defined as the initial COD (COD0) of leachate with respect to available O-2 for oxidation, was examined to derive optimum Fenton oxidant dose using reduced set of experiments. The Fenton experiments were conducted using leachates with three different COD0 concentrations, 1092, 546, and 273 mg L-1, L-COD in the range of 0.25-1.0, and H2O2/Fe2+ 1.8 (w/w). The experimental data were analyzed to determine the correlation between the L-COD factor and selected feasibility parameters, amongst which were: (i) the COD removal kinetics, (ii) the total COD removal, (iii) the usability of H2O2 with respect to COD removal, (iv) leachate biodegradability, and (v) treatment cost incurred by chemical usage. The experimental COD removal with respect to the amount of O-2 supplied by H2O2 was compared with respect to the optimum COD removal efficiency by the equation: eta FPoptimum = 0.733L(COD) - 0.182 as developed by Singh and Tang (2013) and a L-COD of 0.75 was determined to be the optimum L-COD for leachate treatment. (C) 2013 Elsevier Ltd. All rights reserved.