ABSTRACT
Generally, few studies have reported a lab-scale use of electro-Fenton technology in continuous mode for the treatment of landfill leachate. For this reason, a continuous E-Fenton reactor was developed in order to validate this technique in landfill leachate treatment at lab scale. The effects of various operating factors on E-Fenton performance were evaluated to determine the optimal reaction conditions, such as voltage, Hydraulic Retention Time (HRT), H2O2/Fe2+ molar ratio, and H2O2/ initial COD (COD0) molar ratio. The results indicated that E-Fenton treatment was an effective way to degrade the refractory organics in biologically pretreated landfill leachate. The average removal efficiencies of COD and colority up to 85.58% and 100% were achieved with 40 min of the
1 INTRODUCTION
Landfill leachate is strongly polluted wastewater that contains complex pollutants including organic compounds, ammonia, heavy metals, inorganic salts, etc. (Wu, 2011). Conventional biological treatment is an economical way to remove biodegradable organic compounds in the leachate. However, mature landfill leachate contains significant amounts of recalcitrant organic compounds such as Humic Acid (HA), Fulvic Acid (FA), and hydrophilic fractions, which cannot be effectively removed by conventional biological treatment (Atmaca, 2009). Therefore, the effluent of biologically treated mature leachate usually contains considerable amounts of refractory organic pollutants, which may pose hazards to the environment. The biologically treated effluents then have to be properly treated before they can be discharged into the environment.
