Arsenic Removal in Drinking Water—Impacts and Novel Removal Technologies

Abstract

Arsenic contamination of surface and subsurface waters has been reported in many parts of the world; the problem is particularly severe in Bangladesh. In view of epidemiological problems of arsenic ingestion, it is imperative to look for an effective technology for removal of arsenic in drinking water. Column studies were conducted at the University of Regina using manganese greensand to remove arsenic from drinking water. Iron addition was found to be necessary to achieve effluent arsenic level of 25 μg/L in manganese greensand filtration system. In view of the possible regulatory requirement to achieve arsenic levels of less than 5 to 10 μg/L, further studies were conducted using iron oxide-coated sand (IOCS). Batch studies with IOCS showed that effluent arsenic level could be achieved below 5 to 10 μg/L levels. High adsorption capacity (136 μg/g) of the IOCS showed that the media could be effectively used for achieving less than 5 μg/L of effluent arsenic level in the treatment systems, particularly in small water utilities. A preliminary study was conducted to remove arsenic from drinking water using rusticles containing bacteria, and bacterial growth in arsenic solution was also studied.