Study on Haloacetic Acids Content in Municipal Water Supply System of Tianjin

The concentration and variation of haloacetic acids(HAAs) in the municipal water supply system of Tianjin were investigated.The results show that the dichloroacetic acid(DCA) and trichloroacetic acid(TCA) contents in the finished water of every waterworks and the pipe network water are far lower than the limited values in the Sanitary Standard for Drinking Water(GB 5749-2006).During the whole process from raw water entering waterworks to reaching end users(water taps),the concentrations of DCA and TCA firstly increase rapidly,then keep stable and lastly decrease rapidly.The HAAs concentrations in the filtered water are most close to or reach the peak value.Using prechlorination process can promote the formation of HAAs,and the water temperature is positively correlated with the formation of HAAs.