Arsenic removal in drinking water by reverse osmosis

Abstract

Arsenic is widely distributed in nature in the air, water and soil. Acute and chronic arsenic exposure by drinking water has been reported in many countries, especially Argentina, Bangladesh, India, Mexico, Mongolia, Thailand and Taiwan. There are many techniques used to remove arsenic from drinking water. Among them reverse osmosis is widely used. Therefore the purpose of this study is to find the conditions favorable for removal of arsenic from drinking water by using reverse osmosis techniques. The experiments were conducted with two types of arsenic (III, V) in tap water up to arsenic concentration of 400 μg/l. We were applied different production water flow rates and pH for removal of arsenic from drinking water. We conclude that in this experiment 99% removal efficiency was achieved for arsenic (III) and arsenic (V). Arsenic (V) is very efficiently removed by reverse osmosis and arsenic (III) removal efficiency depends on water pH. Practical processes can be developed with reverse osmosis to remove all major species of arsenic from water.