Optimization of Fenton and photo-Fenton-based advanced oxidation processes for post-treatment of composting leachate of municipal solid waste by an activated sludge process

In the present study, the application of advanced oxidation processes (AOPs) for the treatment of composting leachate by an activated sludge process was investigated. The efficiency of Fenton process and photo-Fenton process for treatment of high Chemical Oxygen Demand (COD), color and turbidity removal was investigated using Response Surface Methodology (RSM) under Central Composite Design (CCD). Optimal removal efficiencies were achieved 55.91% and 75.53% in Fenton process and 69.64 and 84.09% in a photo-Fenton process for CODCr and color removal, respectively at initial pH 4.5, hydrogen peroxide dosage 1 ml/L, iron sulfate dosage 0.75 g/L and Ultra-Violet (UV) contact time 78 min. Furthermore, results indicated that the BOD5/COD ratio was increased from 0.2 to 0.52, which in turn increases wastewater biodegradability. Results showed that initial pH in the photo-Fenton process had an enormous effect on CODCr removal efficiency. In consequence, the photo-Fenton process was more efficient process in CODCr and color removal for composting leachate.