Nanofilter System Can Deliver Clean Water to Rural Families for $2.50

Indian scientists have developed a filter system they say can provide clean water to rural families for less than $2.50 per year and help reduce incidences of diarrhea that cause tens of thousands of deaths in the developing world annually. Writing in the Proceedings of the National Academy of Sciences, researchers from the Indian Institute of Technology Madras (IITM) describe the filter, which contains a composite of nanoparticles, held within a sieve, that emit a stream of silver ions that eradicate water-based microbes. In producing the filter, the team used a material called aluminium oxyhydroxide-chitosan, which, because of its structure and the diameter of the silver nanoparticles, is optimal for releasing the silver ions at temperatures of between five to 35 degrees C. In addition, the material is widely available, and environmentally friendly, and it keeps concentrations of the silver ions below safe drinking water standards, lead author Thalappil Pradeep told ScieDev.Net. So far, the scientists have installed the filters in water treatment plants in West Bengal, but are now seeking a company to produce the devices for widespread use.