Iron oxide waste to clean arsenic-contaminated water

Abstract

Serious cases of arsenic toxicity of people drinking water have led to the development of water purification methods. For instance, arsenic can be removed from water by adsorption on natural iron oxides. The use of iron oxide from waste could decrease the cost and recycle iron. Here, we studied arsenic removal from contaminated water using iron oxide wastes from a pickling unit of a steel plant. This iron oxide was reduced to magnetic iron oxide in a fluidised bed reactor. We tested arsenic removal from As-spiked solutions and from contaminated waters from West Bengal. Results showed more than 90 % arsenic removal within 10 min. The arsenic concentration of contaminated waters was decreased from 0.010–0.018 to 0.002–0.008 mg/L. We also found that the occurrence of SO42- and PO43- decreased arsenic adsorption. Iron oxide waste is therefore a new low-cost and effective arsenic adsorbent to clean water.