DISINFECTION OF NATURAL WATER USING TITANIUM DIOXIDE

Abstract

Disinfection is practiced to kill pathogens and make water safe for drinking. Chlorine is the most widely disinfectant. Other disinfectants which have been used or are in use include ozone and ultraviolet radiation. Ozone and chlorine lead to disinfection by-product formation, which are carcinogenic. Considering these, use of nanomaterials as disinfectants is being explored. Therefore, it was considered worthwhile to study one of the nanomaterials. Titanium dioxide in the presence of UV light has sterilizing ability and can be used for water disinfection. This study focuses on the evaluation of disinfection efficiency of TiO2/UV for natural water with and without filtration. Titanium dioxide nanomaterial was synthesised and annular photo reactor was fabricated for conducting experiments. Disinfection of the Ganga canal, Krishni river and hand pumps water was done with (i)UV-C, (ii) chlorine (iii) TiO2 and (iv) TiO2 in the presence of UV-A. TiO2 was used both in slurry as well as in irnrnobilised form. Mechanism of disinfection and effect of natural organic matter on disinfection was also studied. Experiments were conducted both in batch and continuous mode. Disinfection efficiency increased with increase in irradiation time and decreased in the presence of impurities. Though, disinfection efficiency was highest in chlorination, disinfection by product formation potential was also higher.