Episodic trihalomethane species and levels in tap water at a start of operation of advanced treatment in Osaka Prefectural water supplies.
Dramatic changes in trihalomethanes of tap water caused by decreasing the chlorine dose from to break-point to zero at a pre-chlorination could be found during several years from starting the advanced treatment in Osaka Prefectural water utilities (from 1998 to 2002). In 1998 (break-point chlorination), chloroform was predominant (an average of 14.3 microg/L) and bromodichloromethane (5.96 microg/L), dibromochloromethane (4.19 microg/L) and bromoform (1.06 microg/L) were in the decreasing order. In contrast, in 1999 (chloramination), dibromochloromethane and bromodichloromethane were abundant trihalomethanes (6.61 and 5.72 microg/L) and followed by chloroform (4.14 microg/L) and bromoform (1.41 microg/L). Trihalomethane distribution in 2002 (non-chlorination) was almost the same as that in 1999.
Yamamoto
Kohji
K
Osaka City Institute of Public Health and Environmental Sciences, Osaka 536-0026, Japan. ko-yamamoto@city.osaka.lg.jp
Mori
Yoshiaki
Y
D002725:Chloroform / Q000032:analysis*; D006842:Hydrocarbons, Brominated / Q000032:analysis*; D007564:Japan; D022882:Trihalomethanes / Q000032:analysis; D014874:Water Pollutants, Chemical; D014881:Water Supply / Q000032:analysis*
D006842:Hydrocarbons, Brominated; D022882:Trihalomethanes; D014874:Water Pollutants, Chemical; C025191:bromodichloromethane; D002725:Chloroform; C015044:bromoform; C027947:methylene bromide