Electrochemical Oxidation of Landfill Leachate: Investigation of Operational Parameters and Kinetics Using Graphite-PVC Composite Electrode as Anode

The preparation of a new carbon composite electrode constructed from graphite-polyvinyl chloride (graphite-PVC) compressed mixtures was used for the first time to treat landfill leachate in Malaysia under electrochemical oxidation. The electrochemical oxidation of landfill leachate was studied on graphite-PVC and Pt electrodes as anode and cathode, respectively, with the presence of NaCl electrolyte in a batch electrochemical reactor. The highest chemical oxygen demand (COD) and color removals of 87% and 97%, respectively, were achieved at pH 3, 0.58% (m/v) + 2078 mg L-1 electrolyte concentration, 15 V applied voltage, and 105 min electrolysis time. To confirm electrochemical oxidation, a field emission scanning electron microscopy (FESEM) was used to evaluate the surface of graphite-PVC electrode before and after treatment. The constant rate in terms of pseudo-first-order kinetics increased from 0.0015 min(-1) to 0.0186 min(-1) at 5 and 20 V applied voltage. The graphite-PVC composite exhibits favorable qualities as an electrode material because of its mechanical resistance, low cost, simple preparation, and easy renewal of the electrode surface.