Application of low-cost adsorbents for arsenic removal: A review

Abstract

The presence of arsenic in waters, especially groundwater, has become a worldwide problem in the past decades. The current regulation of drinking water standard has become more stringent and requires arsenic content to be reduced to a few parts per billion. There are numbers of arsenic removal methods, which include coagulation followed by precipitation, membrane separation, anion exchange, etc. The use of low-cost adsorbent obtained from an environmentally friendly materials, has been investigated as a replacement for the current expensive methods of removing arsenic from solution. Natural materials or waste products from certain industries with a high capacity for arsenic can be obtained, employed, and disposed of with little cost. Modification of the adsorbents can also improve adsorption capacity. The aim of this article is to review briefly arsenic chemistry and previous and current available technologies that have been reported in arsenic removal. The technical feasibility of various low-cost adsorbents for arsenic removal from contaminated water has been reviewed.   Key words: Arsenic speciation, methods of arsenic removal, low-cost adsorbents, wastewater.