Treatment of landfill leachate using integrated continuous electrocoagulation and the anaerobic treatment technique

Abstract

In this study, an electrocoagulation method as a pretreatment step followed by an anaerobic treatment of landfill leachate are investigated. The electrocoagulation was performed at different operating conditions using a specially designed spiral iron electrode in continuous mode. Initial pH 5, current density 50 mA/cm2, and retention time of 54 min with no electrolyte addition was found to provide the maximum removal efficiency 69%. The effluent of the electrocoagulation was then treated anaerobically and the process was optimized using full factorial design method as two factors at three levels for wastewater concentrations of 50, 75, and 100% and cosubstrate concentrations of 2, 1.5, 0.5 g/L. The maximum COD removal for the anaerobic treatment was 74%. The combined system showed an overall COD removal efficiency of 92% by reducing the COD from 6400 mg/L to 516 mg/L. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 1668–1676, 2018