Publication

Abstract : In the present study, laboratory experiments were conducted for determining effectiveness of various disinfectants against inactivation of Total Coliform and Fecal Coliform of water samples collected from different sites of Jadavpur University. Chlorine (sodium hypochlorite and bleaching powder), silver, copper, solar radiation, ultraviolet rays and boiling was facilitated; samples were intermittently tested with respect to contact time (CT) following most probable number technique (MPN/100 ml) and bacteriological H2S strip tests. After chlorination, chlorine demand and residual-free chlorine was obtained using modified Horrocks method. Effective CT sufficient to lower down the viable counts, by various mode of treatment are as follows: boiling-1 min < chlorination-30 min < UV treatment-1 h < SODIS- 6 h < silver wire-8 h < copper wire-8–10 h. Samples were passed through ultraviolet rays at different flow rates; it was very effective against lower contamination. However, it did not show good disinfection against higher contamination, suggesting a need for providing proper contact. Silver and copper disinfection requires low operational cost nonetheless takes longer time for disinfection. SODIS may be encouraged in rural areas though a weather-dependent process. Boiling is efficient and faster compared to other methods, chlorine disinfection is a standard process to treat large volume of contaminated water; though should be avoided as its byproducts are very harmful for human health.