| Abstract |
| In the chlorination process, aquatic organic matter serves as a precursor to the formation of potentially harmful disinfection by-products(DBP) such as trihalomethanes (THMs), haloacetic acids (HAAs), and total organic halides(TOX). Formed THMs are chloroform, bromodichloromethane, dibromochloromethane, and bromoform. the formed HAAs are monochloroacetic acid (MCAA), dichloroacetic acids (DOM), trichloroacetic acids (TOM), monobromoacetic acids (MBAR), and dibromoacetic acids (DBAA).The formation of disinfection by-products(DBPs) is one of the major issue for drinking water quality control. Whenever raw water or organic compounds extracted from natural water are chlorinated, significant concentrations of THMs and HAAs are produced. With recent advances in the analysis of chlorination by-products and their health effects, numerous organic halides HAAs, THMs, haloacetonitriles, etc have been identified at low level. In this study, the distribution profiles of disinfection by-product(DBP) formation by the chemical reactivity with chlorine was investigated among the water treatment plants(WTP)-HMWTP, DSWTP, and MJWTP-located at lower basin of the Nakdong river. The raw waters used were river water for HMWTP and DSWTP and lake water for MJWTP. As a results, the distribution of THMs and HAAS speciation in the finished water of the water treatment plants showed in the order: for the formed THMs, CHCl₃ of 49~62%, CHCl₂Br of 26~27%, CHCIBr₂ of 10~20%, CHBr3 of 1~5%, and for the formed HAAs, DCAA of 41 -51%, TCAA of 23~38%, DBAA of 18~30%, MBAR of 2~5%, MCAA of 0%, which showed the dominant compounds were CHCl₃ and CHCl₂Br for THMs and DCAA and TCAA for HAAs, respectively. Configuration of DBPs with the raw water used evealed the CHCI₃ concentration of THMs were higher in both HMWTP and DSWTP than in MJWTP, and TCAA of HMs were higher in both HM and DSWTPs than in MJWTP. Based on the results of the batch experiment to evaluate the function of sand filter on DBPs removal, HAAs could be seen to be removed by the biodegradation by the microorganism grown in the sand filter. The concentrations of THMs and HAAs in distribution system were 1.3~1.6 and 1.4~2.1 times higher than in final water of the WTPs, respectively, so it indicates that the concentrations of them increases with the increase of pipeline distance from the WTPs. |
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| Key Words |
| disinfection by-products, DBP, trihalomethanes, THMs, haloacetic acids, HAAs, chloroform, bromodichloromethane, dibromochloromethane, bromoform, monochloroacetic acid, MCAA, dichloroacetic acids, DCAA, trichloroacetic acids, TCAA, monobromoacetic acids, M |
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