Landfill Leachate Treatment through Electro-Fenton Oxidation

Abstract

Advanced Oxidation Processes (AOPs) have been employed to degrade biorefractory organic matters. This study investigates the combination of classical Fenton reaction with electrochemical oxidation, the electro-Fenton process, for the treatment of semi aerobic landfill leachate, collected from Pulau Burung Landfill Site (PBLS), Penang, Malaysia. The investigation has been carried out in batch reactors with aluminum electrodes to establish the optimal treatment conditions. The effects of applied current, pH, reaction time, electrodes separation distance, H₂O₂/Fe²⁺ molar ratio, and H₂O₂ and Fe²⁺ concentrations, significant process parameters by themselves, have also been investigated. According to the obtained results, electro-Fenton process is very efficient for the treatment of landfill leachate. Optimum oxidation efficiency has been achieved when neither H₂O₂ nor Fe²⁺ are overdosed, so that the maximum amount of OH radicals is available for the oxidation of organic compounds. The highest COD and color removals have been 92% and 93%, respectively; obtained at initial pH=3, H₂O₂/Fe²⁺molar ratio=1, applied current= 2A, treatment duration= 30 min, and electrodes separation distance= 3 cm. The current efficiency declines from 94% to 38% when the current rises from 0.5A to 2A.