The Indian Institute of Technology-Kharagpur has developed an ultra-low cost eco-friendly laterite based arsenic filter for providing safe drinking water.The innovation has won Sirshendu De, the head of chemical engineering department, the Innovation Award 2016 from the Indian Desalination Association (South Zone).
"In India and Bangladesh, it is generally agreed that arsenic contamination of groundwater is of geological origin and derives from the geological strata.The indigenous material developed by De is capable of adsorbing arsenic to the extent of 32mg per gram. "It is made from naturally occurring red laterite soil. This material has undergone chemical treatment to enhance its capabilities to adsorb arsenic. Moreover, an optimized design of a filter, with the material, has been formulated as well that enjoys a plethora of advantages
The ultra-low cost of the filter is more appropriate for the socio-economic conditions of our country, especially when the filter has no power requirement. The arsenic concentration of filtrate is always within the WHO drinking water permissible limit, independent of the ground water concentration. Also, the filter comparatively has extremely long life of about five years with no regeneration of the adsorbent (filter medium) required during its lifetime. The filter has facilities such as removal of arsenic (below 10 ppb), iron (below 0.3 ppm) and bacteriological contamination (more than 98%) together in a single unit.