Generation characteristics of disinfection by-products (DBPs) by chlorination in sewage effluent

This study was performed to investigate the disinfection efficiency and the generation characteristics of disinfection by-products (DBPs) in the sewage effluent. In the case of total coliforms, disinfection efficiency higher than 99%, the required contact time was 30 min at chlorine dose of 0.5 mg/L, 20 min at 1.0 mg/L, and 10 min at 1.5 mg/L, respectively. When the sewage effluent was disinfected with chlorine dose of 0.5 mg/ L for 10 min, the maximum generation concentration of trihalomethanes (THMs), haloacetonitriles (HANs) and haloacetic acid (HAAs) were 32.2 mu g/L, 2.97 mu g/L, and 16.29 mu g/L, respectively. The concentration of chloroform was 28.4 mu g/L corresponding to 88.1% of the THMs. The concentration of HANs and HAAs were found to be inconsiderable. The average residual chlorine concentration of sewage effluent was 0.4 mg/L, the generation concentration of THMs was maximum 1.72 mu g/L and average 2.79 mu g/L. HANs and HAAs were under the detection limit by GC/MSD.