Arsenic Mitigation from Contaminated Ground Water Through Chemical and Biological Processes: A Review

Arsenic contamination of groundwater has emerged as one of the global problems in the past few decades. A problem that was previously endemic to a few countries has now affected more than 300 million people of over 100 countries. Arsenic contamination typically results in characteristic dermatological complications (melanosis, keratosis) whereas chronic exposure may result in reproductive, neurological, cardiovascular, respiratory, hepatic, haematological, and diabetic effects in human. The abundance of arsenic in a plethora of natural forms poses a major challenge in its decontamination and removal. Numerous physico-chemical and biological techniques, including electrocoagulation, oxidation, coagulation-flocculation, adsorption, biological sorption, ion-exchange, membrane processes, and treatment with bio-organisms, have been extensively tested and reported by various researchers over the years for the removal of arsenic from groundwater. In this chapter, the currently available methods of decontamination of arsenic from ground water is discussed with emphasis on chemical and biological treatments, along with their advantages and drawbacks. An attempt to focus on the new state of the art technologies in this regard has also been made with discussions on future trends of research in this venture.