Treatment of Landfill Leachate via Electrocoagulation and Electro-Fenton Processes: A Comparative Study

This study aims to compare the effectiveness of ElectroCoagulation (EC) and Electro-Fenton (EF) processes in the treatment of high-strength storage leachate. The effect of operating parameters, including initial pH, contact time, and mass ratio of COD: H2O2, on Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) removal efficiencies of leachate was investigated. For this purpose, a jacketed reactor in which the electrochemical process is performed using monopolar-bonded iron electrodes is designed. As a result of the experimental studies, the optimum operating parameters of the EC process were determined as follows: pH 7, current density 150A/m2, and reaction time 30 minutes. Under these conditions, 37.87% COD and 47.36% TOC were removed respectively. Due to the lack of expected results in the treatment of this wastewater in the EC process, treatability studies were carried out with the EF process. As a result of the study, optimum conditions were found to be pH 3, current density 150 A/m2, H2O2= 500 mg/L (KOI: H2O2@1), and working time 10 min. A higher COD (71.7%) and TOC removal (90.87%) have been obtained with the EF process under optimum conditions. The operating costs of electrocoagulation and electro-Fenton processes under optimum conditions were calculated as 2.26 and 1.78 €/m3, respectively. Experimental findings revealed that, unlike the EC process, the EF process can be a good option for landfill leachate treatment in terms of providing less treatment time, less sludge, more cost-effectiveness, and necessary discharge limits.