Water purification
A product called NanoCeram, developed by the Argonide Company with backing from the US National Aeronautics and Space Administration (NASA), is said to filter bacteria and even viruses out of water, not by forcing it through tiny holes but by using a positive charge to attract these negatively charged viruses and bacteria, which measure in the range of 20 to 100 nm. In NanoCeram, active component is an alumina (AlOOH) fibre two nanometers in diameter. Seldon Laboratories of Vermont has developed a “nanomesh” fabric made of fused carbon nanotubes that it says can filter out all bacteria, viruses, and other waterborne pathogens to US Environmental Protection Agency (EPA) potable water standards. The mesh also removes lead, arsenic, and uranium. Researchers at Rensselaer Polytechnic Institute (US) and Banaras Hindu University (India), working in collaboration, claim to have devised a simple method of producing carbon nanotube filters that remove microscale to nanoscale contaminants from water remove 25nm sized polio viruses from water, as well as larger pathogens such as E. coli. Nanosized particles of iron hydroxide have been proved by Bayer researchers to be a highly effective adsorbent. At the heart of the system is a fixed bed of granular ferric oxide (Bayoxide® E33) through which arsenic contaminated water flows and which adsorbs the arsenic. The SORB 33 adsorption process is currently proving its worth in more than 15 commercial water treatment plants in the UK.