Process Uses Plastic Bottles To Remove Arsenic from Drinking Water

U.S. researchers say they have developed a simple, inexpensive process that uses common plastic bottles to remove arsenic from drinking water, a problem facing nearly 100 million people in developing nations. In the process, pieces of plastic soda or water bottles are coated with cysteine — an amino acid found in dietary supplements and foods — and dropped into arsenic-contaminated water. After the mixture is stirred, the coated plastic bits grab hold of the arsenic like a magnet, stripping significant levels of the contaminant from the water, said Tsanangurayi Tongesayi, a professor of analytical and environmental chemistry at Monmouth University and leader of the study. During tests, researchers found that they could reduce arsenic levels from 20 parts per billion — or nearly twice the U.S. safe drinking standard — to 0.2 parts per billion. Also, Tongesayi said, the simplicity of the method makes it especially advantageous in regions that do not have access to expensive purification methods. In many parts of the world, arsenic enters drinking water supplies from natural deposits in soil and rock. A 2010 study found that one in five deaths in Bangladesh is associated with exposure to arsenic in the drinking water.