Energy efficient removal of COD from landfill leachate wastewater using electrocoagulation: parametric optimization using RSM

In the present work, electrocoagulation method was employed using iron/aluminium electrodes for COD removal in the treatment of landfill leachate. The process was optimized with variables such as initial pH, applied current, initial COD and electrolysis time experimentally varied as per CCD design to know their influence on chosen response variables viz. COD removal efficiency and electrical energy consumption. The optimum conditions found were pH 5, applied current 0.5 A, initial COD concentration 5450 ppm and application time 9 min to achieve 64.25% efficiency with 0.59 W hour per gram removal of COD. The results prove that electrocoagulation process could be suitably used as an effective method for treatment of leachate. Operating cost of optimized condition was figured out as Indian rupee 0.211 (equivalent to 0.0028 US $) per gram of COD removed.