The genotoxity of by-products by chlorination and ozonation of the river water in the presence of bromide ions

Abstract

This study focused on the evaluation of the genotoxic characteristics of chlorinated and brominated substances produced by ozonation and chlorination of the river waters containing bromide ions. The mutagenic activities of drinking waters and disinfected river waters were measured by Ames tests using S. typhimurium strains TA100 and TA98, and by chromosomal aberration test using cultured Chinese hamster lung cells (CHL/IU) in vitro. After flowing samples through CSP800 or XAD-2 resin column, absorbed substances dissolved in dimethyl sulfoxide, and submitted to the mutagenicity assays. Correlation was high between water qualities revealed by chemical analysis and mutagenic potentials. Mutagenic activities of the drinking waters produced by chlorination were observed to be higher than those by ozonation. Chlorinated waters highly increased in cells with the exchange- and chromatid-type of chromosomal aberrations compared with unchlorinated waters. The increase of mutagenic potentials was caused by by-products when bromide ions were substituted for chloride ions with various ratios.

Investigation of bromide ion effects on disinfection by-products formation and speciation in an Istanbul water supply

“…Recent epidemiological studies reported that brominated DBPs are more carcinogenic than their chlorinated analogs [17][18][19][20]. A recent study conducted in Istanbul showed that the lifetime cancer risk of THMs was highest in the Esenyurt district of Buyukcekmece water distribution system in Istanbul, and, dibromochloromethane (DBCM) contributed a higher cancer risk to Istanbul residents through a dermal route than did the other three THM compounds [21].…”

Evaluation of formation potential of trihalomethanes and mutagens due to chlorination of river water along the Kizu River in the Yodo River system in Japan

“…Generally, by-products of disinfection, such as trihalomethanes (THMs) and other hazardous compounds, produced in the chlorination of raw water in purification plants, are contained in drinking water (Meier 1988;Nobukawa and Sanukida 2000). The formation potential of these disinfection by-products in purification plants is dependent on the amount of organic material in the raw water (Rook 1974;Kito and Nakanishi 1987;Nakamuro et al 1989;Vartinen and Limatainen 1998;Nobukawa and Sanukida 1999).…”

Enhanced formation of bromate and brominated disinfection byproducts during chlorination of bromide-containing waters under catalysis of copper corrosion products

“…However, HOBr can react quickly with NOM to form brominated disinfection byproducts (Br-DBPs) (Cowman and Singer, 1996;Richardson et al, 2003;Zhao et al, 2012;Pan and Zhang, 2013), which are more carcinogenic than their chlorinated analogues (Nobukawa and Sanukida, 2000). Because copper ions can inactivate certain bacterial species (Feng et al, 1996), copper has been extensively used in water distribution pipes throughout the world.…”