Effect of chlorine dosage in prechlorination on trihalomethanes and haloacetic acids during water treatment process.

To identify the effect of chlorine dosage in prechlorination on the formation of disinfection by-products during drinking water treatment process, the relationship between chlorine dosage and concentrations of THMs and HAAs was analyzed. Furthermore, the variation about the ratio of THMs/HAAs was also analyzed. The results indicated that concentrations of THMs and HAAs would rise with the increase of chlorine dosage, and TCM was the main product of four THMs, while DCAA and TCAA were the primary products of five HAAs. Moreover, the ratio of THMs to HAAs rose with the chlorine dosage increase. Thus, chlorine dosage in prechlorination had a significant impact on THMs and HAAs and should be controlled effectively.