Chemical Sciences

Terafil red clay is a low cost and sustainable water purification media (disc/candle) for efficient treatment and filtration of turbid and high iron containing drinking water. Pores in the Terafil disc are separated from one another by a ultrafine sintered clay membrane, but are connected through capillaries in the clay membranes whose openings are within 200 nm diameter; much smaller than iron colloids, turbid particles and most of the pathogens. Complete removal of iron and suspended particles from water is achieved along with significant removal of pathogens through this medium without clogging its core. The architecture of the disc (prepared by sintering a mixture of sand, red clay and wood saw dust) ensures a high rate of filtration and long operational life of 3-5yrs. Quality of filtered water falls within BIS limits, especially for turbidity and iron. Average rate of filtration is 13ml/hr per unit area (cm2) with input water having 50 NTU turbidity and 250mm water head. Fitted with food grade plastic or stainless steel containers it serves a point of use water filter for domestic purpose (50 litre/day). A battery of discs can be fitted to water tanks for community usage (1000-100,000 litre/day).