Treatment of Leachate Wastewater with Fenton Process

Leachate wastewater produced from landfill areas contains high organic contents and heavy metals. Because of high concentration of organic materials and heavy metals, it can cause toxic effects on the environment. In addition, there is a possibility that leachate can reach to surface and ground water. The leachate wastewater cannot be treated easily by conventional treatment processes, discharge limits cannot be also achieved by these processes. For that reason, advanced treatment methods should selected to treat leachate wastewater and to discharge in limitations. Advanced oxidation processes can provide a suitable treatment for leachate wastewater due hydroxyl radical formation. The most appropriate advanced oxidation process is selected as Fenton Process in order to achieve high removal efficiency for the treatment of leachate wastewater to easily apply on chemical treatment process. The main objective of the study was to statistically determine the most favorable levels of the parameters for the treatment of leachate wastewater. The effects of H2O2 and ferrous ion concentrations and reaction time on the oxidation of leachate wastewater investigated by using a statistical design. In the Box-Behnken statistical experiment design method, Fe+2 and H2O2 concentrations and reaction time were selected as independent variables. As the dependent variables, TOC and color removal efficiencies were examined by keeping the pH constant at pH 3.5-4.0. Operating range for independent variable; H2O2 concentration was 5000-40000 mg/L (X1), Fe+2 concentration was 1000-3000 mg/L (X2), reaction time was determined as 30-60 minutes (X3). As a result of the experimental studies, the most appropriate reaction conditions according to TOC removal; H2O2 concentration was 5000 mg/L, Fe+2 concentration was 3000 mg/L, reaction time was 40 minutes and TOC yield was 50%. At these conditions, color removal efficiency was achieved as 84%.