Effect of routine water treatment technology on concentrations of MX and mutagenicity of drinking water

ObjectiveTo study the effect of routine water treatment technology on contents of 3-cloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone(MX)and total organic carbon(TOC)in drinking water,as well as mutagenicity of the non-volatile org anic extracts from drinking water for providing scientific bases for optimization of the drinking water treatment technology.MethodsWater samples includingraw water,water from treatment steps of coag ulative precipitation after prechlorination,precipitation,filtration and chlorination disinfection,and tap water were collected.GC/MS and TOC-Analyse were used to determine the concentrations of MX and TOC.The pH value and turbidity of water were also determined.The mutagenicity of non-volatile organic extracts from water samples was evaluated by means of Ames test.ResultsMX and TOC concent rations showed the same variation during the process of drinking water treatment.Compared to raw water,MX and TOC levels in water were increased after prechlorination and chlorination disinfection and decreased after precipitation.MX levels were signinficantly cor related with TOC levels,but not with pH value and turbidity.There were higher mutagenic activities of water after chlorination disinfection and tap water than that of raw water.ConclusionFor drinking water treatment technology,chlorination and precipitation were impo rtant procedures affecting concentrations of MX and TOC.Chlorination enhances formation of MX and mutag enic activity of drinking water.