Electrocoagulation (EC) technology for wastewater treatment and pollutants removal

Abstract

During the last few years, environmental sector has shown a largely growing interest in the treatment of different types of wastewater by electrocoagulation (EC). It has recently attracted attention as a potential technique for treating industrial effluent due to its versatility, treatment efficiency, low cost, and environmental compatibility. This technique uses direct current source between metal electrodes immersed in the effluent, which causes the dissolution of electrode plates into the effluent. The metal ions, at an appropriate pH, can form wide range of coagulated species and metal hydroxides that destabilize and aggregate particles or precipitate and adsorb the dissolved contaminants. Therefore, the aim of the present study is to review the mechanism, factors responsible, and application of the EC technology for the treatment of industrial wastewater and removal of pollutants from surface and potable waters. Study found that performance and treatment efficiency of EC depend on various factors, i.e., choice of electrode materials, electrode distance, arrangement of electrode, operating current density, electrolysis time, pH of the solution, temperature, and the design of reactor. It is also evident from the study that recently, EC technology has been successfully employed for the treatment and removing pollutants from municipal wastewater, industrial wastewater, i.e., textiles, tanneries, pulp and paper, food processing industry, and oily wastewater. This technology also used for the heavy metal and inorganic ions removal and potable and surface water treatment. In addition, this paper presents an overview of the optimum process conditions, i.e., current densities, treatment time, pH and removal efficiencies, its advantages, challenges, and future prospects of EC technology.