Integrated Heterogeneous Electro-Fenton Process and Constructed Wetland for the Treatment of Stabilized Landfill Leachate

Treatment of stabilized landfill leachate is a great challenge due to its poor biodegradability. Present study made an attempt to treat this wastewater by combining electro-Fenton (E- Fenton) and constructed wetland (CW). E-Fenton treatment was applied prior to Constructed wetland process to enhance the biodegradability of leachate, which will be beneficial for the subsequent biological process. This study also investigates the efficiency of Magnetite (Fe3O4) nanoparticles as a heterogeneous catalyst in E-Fenton process. The objectives of this study are to synthesize chitosan to obtain magnetite nanoparticles via iron ions assembly and to characterize the synthesized nanoparticles using SEM, XRD and FTIR analysis to assess its nature. The effects of initial pH, catalyst dosage, applied voltage and electrode spacing on Chemical Oxygen Demand (COD) removal efficiency were analysed to determine the optimum conditions. Heterogeneous E-Fenton process gave 84.29% COD removal at catalyst dosage of 50 mg/L, pH 2, electrode spacing 3 cm, voltage 5 V and electrode area 25 cm2. The proficiency of utilizing eggshells as a media in constructed wetlands was evaluated for the treatment of wastewater previously subjected to electro-Fenton treatment. And it was found that combined E-Fenton and biological treatment (CW) resulted in overall COD removal of 95.79%, bringing down the final COD to 292 mg/L. Thus, the combination of the E-Fenton process followed by a biological process is efficient for complete mineralization with lower operational cost.