Reduction of chemical oxygen demand through electrocoagulation: an exclusive study for hazardous waste landfill leachate

Abstract

Leachate produced from hazardous waste landfills has been observed to exhibit very complex characteristics including the presence of a high amount of refractory organics and toxic elements which make it unfit for conventional treatment. This study is focused on the characterization and treatability of “hazardous waste landfill leachate” through electrocoagulation for the reduction of chemical oxygen demand (COD). Effect of different operating parameters, such as electrode material, interelectrode distance (IED), current density (CD), and electrolysis time (ET), has also been studied. For galvanized iron (GI) electrodes, a significant reduction in phenolic compounds, cadmium, lead, and zinc concentration was observed and more than 80% reduction in COD and color was achieved on a bench-scale reactor for a CD value of 41.64 A/cm2 at IED of 1.5 cm and for ET equating to 240 min. Substantiated by experimental results and statistical analysis like ANOVA and post hoc analysis, it appears that electrocoagulation is a proficient technology for the treatment of hazardous waste landfill leachate which has a huge potential for further research.