Scientists have found that dirty water can be sterilized and made drinkable by filtering through a folded cotton sari and then exposing it to sunlight for less than an hour. Nandini Nimbkar and Anil Rajvanshi of Nimbkar Agricultural Research Institute (NARI), a non-profit institution in Phaltan, Maharashtra, demonstrated the Cloth Filtration process which is already a common practice in rural India.
Disinfection of water may be accomplished by chemical treatment like chlorination or by boiling the water. Chlorination may alter the taste and have side-effects while raising the water to boiling may not always be possible with sunlight and would require electricity or some other fuel.
NARI scientists have shown that disinfection could be achieved even at sub-boiling temperatures as low as 55ºc that can be reached using solar energy.