Arsenic contamination, effects and remediation techniques: A special look onto membrane separation processes

In many countries, arsenic (As) concentrations above acceptable standards for drinking water have been found, which is bringing awareness and becoming a worldwide concern. As occurs in the environment naturally, but anthropogenic activities such as mining, fossil fuels burning, pesticide and herbicide application have been playing a major role in the As occurrence in groundwater and drinking water. The two inorganic arsenic ions As(III) and As(V) are ubiquitous in natural waters and pose significant health risks to humans even at low concentrations, for example, lung cancer, cirrhosis and myocardial infarction. Therefore, there is an increasingly search for technologies that have high removal efficiency, simplicity, cost-effectiveness, feasibility and lower chemical requirements. In this regard, this paper reviews the occurrence, exposure pathways, effects and removal technologies such as oxidation, flocculation, coagulation, adsorption, ion exchange and particularly membrane separation processes (MSP), with attention to the disadvantages and limitations of these technologies. Furthermore, integrated approaches between MSP and others are discussed. Lastly, emergent technologies in MSP such as forward osmosis, membrane distillation and electrodialysis were discussed and their efficiency and performance towards As retention was presented. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.