To study the formation potential of trihalomethanens (THMs) due to anthropogenic sources and effect of various precursors on the potential of THM formation, surface raw water samples were collected from Ganga Barrage Water Treatment Plant, Kanpur (India) from January to June 2009. The concentration of THMs and THMFP (Trihalomethane formation potential) at different chlorine dosages were below the WHO GV. THMFP values in May and June were found to be three times higher than those in January. Chloroform levels were found higher than DBCM (dibromochloromethane), DCBM (dichlorobromomethane) and BF (bromoform) in all the seasons. The seasonal variation of chloroform concentrations reported the level lower than WHO GV. THM formation rate was found to be very fast in first 24 h compared to that of exceeding reaction time. The higher the reaction time leads to the higher THM concentrations which was very prominent at higher chlorine dosages. Values of THMFP increased as TOC (total organic carbon) increased from Jan to Jun with exception of February. On temperature increase, THMFP values showed increase.
Ganga, Trihalomethanes, Raw water, Anthropogenic, Seasonal variation