Bulk-Water Experimental Research on the Effects Influencing the Formation of Trihalomethanes

Effects of formation of the disinfection by-products (DBPs), trihalomethanes (THMs), of chlorination were investigated through static bulk-water experiments. In this research, effects including organic matter, chlorine dosage, bromide, reaction time of chlorination, temperature, PH value and ammonia nitrogen were investigated. The results showed that all effects accelerated THMs formation except that of ammonia nitrogen; there is a good linear relationship between TOC, UV₂₅₄ and THMs, the correlation of UV₂₅₄ is better than TOC, and UV₂₅₄ can reflect changes of THMs formation better; when Cl₂/TOC<0.2, little THMs was formed; when Cl₂/TOC=0.2~2, chlorine decay was linearly related with THMs; when Cl₂/TOC>2, THMs increase was not distinct; bromide levels has great influence on the total formation amount of THMs. THMs increases with the increase of bromide levels, and chloroform decreases, while the other three kinds of bromo-halocarbon increased, especially bromoform. The conclusions of research would put forwards some suggestions to control and reduce THMs, ensuring safety water quality.