Researches on Formation of Haloacetic Acids in Chlorination of Drinking Water by a Novel Technique

Haloacetic acids（HAAs） are formed during the chlorination of drinking water,which are harmful to people′s health due to their carcinogenic and mutagenic effects. In the present study,a detection method combining methyl tert -butyl ether（MtBE） extraction with acid catalysis and gas chromatography coupled with an electron capture detector（GC/ECD） was developed for determining HAAs. The detection limit of this method（MDL） and relative standard deviation（RSD） were below 0.37 μg/L and 6.2%,respectively. The laboratory chlorination experiments were conducted with the purpose of investigating the influences of reaction time,temperature,UV 254 ,bromide and ammonia-nitrogen on the formation of HAAs. The results show that the formation amount of HAAs increases with increasing reaction time and temperature,respectively;and there exists a linear relationship between the formation of HAAs and UV 254 . The formation amount of HAAs decreases first and then increases as the bromide ion concentration increases,and adding NH +4 is a possible way to control the formation of HAAs.