A review on decontamination of arsenic-contained water by electrocoagulation: Reactor configurations and operating cost along with removal mechanisms

Abstract

Pollution of water resources by arsenic (As) that originates from both natural and anthropogenic sources is a serious matter causing health problems to millions of people worldwide due to the toxic effects of this ionic pollutant. To attain conformity with strict Maximum Contaminant Level (MCL) of As (10 mu g/L), electrocoagulation (EC) is considered as an advantageous process for the removal of As because of high removal efficiency, simplicity, cost-effectiveness, feasibility of small scale operations and lower chemical requirement in comparison with other treatment processes. In this regard, this review discusses the applications and performance results of EC process for arsenic removal, taking into account the drawbacks and limitations of EC technologies. The mechanism and theoretical aspects of arsenic removal by EC was reviewed with details. The effects of operational parameters on the efficiency of EC process, including current density, charge loading and initial pH, as well as reactor configurations and operating cost of the process were reviewed. The amount of sludge produced during EC process, characterization and disposal methods were investigated and the simultaneous removal of As with other contaminants from water presented. Furthermore, examples of pilot and full-scale applications of EC for the removal of arsenic were provided. Concluding remarks and outlook of this field of study with respect to new areas of research are also discussed. (C) 2019 Elsevier B.V. All rights reserved.