Electrocoagulation as a revived wastewater treatment method-practical approaches: a review

This review paper aims to demonstrate electrocoagulation (EC) as a revived technology and introduce recent steps of advanced configurations, along with hybrid approaches for the efficient electrochemical treatment of multi-sourced wastewaters. A brief theoretical background is also provided. Moreover, the practical applications of the process are presented, while no previous research has ever attempted to do so. Through online-based data research, it was found that there are 75 manufacturers of EC systems internationally. Industrial case studies reveal actual process conditions and economical data. America holds 33% of global EC systems' manufacturing share and it is considered the leader in EC innovative designs with a percentage of almost 59%. In America and Europe, composite schemes are nearly equivalent to EC autonomous systems, with respective percentages of 41% and 47%. The performance of a two-stage process combining electro-coagulation (EC) and electro-oxidation (EO) has been proven to be the most successful combination in industrial wastewater treatment, representing 54% of hybrid systems available globally. Most of the commercialized EC systems are of small-medium sizes, accounting for 88% of all systems available worldwide. The latest trends on new reactor and electrode configurations are also presented. EC has great potential for further improvement as there is strong academic background to support water treatment companies for industrial scale ups. Cylindrical type reactors tend to dominate due to the ease of their use and maintenance; meanwhile, hybrid systems of EC with EO, membranes and/or adsorption will continue to expand on the market due to the mature level of these technologies and their ease of adaptation. (c) 2021 Society of Chemical Industry (SCI).