Recent progress on electrocoagulation process for wastewater treatment: A review

Electrocoagulation (EC) is an established wastewater treatment method that has been widely explored for a broad range of wastewater pollutants due to its ease of operation, versatility, eco-friendly nature and low footprint. EC as a pretreatment process can significantly reduce the total energy usage, while also improving the quality of treated water. This review paper provides an in-depth assessment of the various operational parameters and electrode materials used during the electrocoagulation treatment of wastewater. The recent advancements in EC reactor designs and optimization studies have been reviewed. The effectiveness of combining the EC process with other water treatment techniques viz. membranes, oxidation, chemical and adsorption processes have also been validated in this review paper. Different combinations of EC process with microfiltration (EC-MF), ultrafiltration (EC-UF), nanofiltration (EC-NF), reverse osmosis (EC-RO), ozonation (EC-O3), peroxi-electrocoagulation (EC-H2O2) and electro-oxidation (EC-EO), have been elaborately discussed and summarized. The results are critically analyzed, and modifications have been suggested to improve the performance efficiency. Moreover, case studies regarding the application of the EC process from three different wastewater sources have been demonstrated. The economic aspects of the EC process and recommendation for its betterment is also made. Taken together, this review paper effectively illustrates the progress and current achievements in both standalone and hybrid EC process towards wastewater pollutant treatment, which can present new insights on improving the wastewater treatment scenario with promising environmental applications. The critical analysis and suggestions provided in this review paper will greatly enhance the scientific knowledge of the readers.