Evaluation of the Different Fenton Processes Combined with Coagulation- Flocculation Pretreatment in Landfill Leachate Treatment

Advanced oxidation processes such as Fenton and photo-Fenton that have been applied effectively to oxide the persistent organic compounds in leachate and converts them to unharmful materials and final products. However, there are a few data about application of Fenton-like process in leachate treatment. Therefore, the aim of this study was to treat the municipal landfill leachate by above processes.. This study was an experimental study that was conducted with set up a pilot system. The used leachate collected from a municipal unsanitary landfill of Qaem-shahr city that located in Mazandaran province. All examinations and samples were analyzed according to Stndard Methods for the Examination of Water and Wastewater. The results showed that the conventional coagulation & flocculation process with chloride ferric removed about 45% of COD in optimum conditions. The combining of pretratment with AOPs significantly increased removal efficiency so that the removal efficiency COD for Fenton, photo-Fenton and modified fenton processes was 89, 85.45 and 81.82 percent in the same conditions, respectively. After all processes, the biodegradability (BOD5/COD ratio) of treated leachate compared to raw leachate was increased and the highest increasing of BOD5/COD ratio was in the photo-Fenton process. The efficiency of the Fenton-like process is less than Fenton and photo-Fenton processes. Instead, the Fenton-like process was done at the higher pH and will not have these problems.