Control of disinfection by-products in drinking water by monochloramine disinfectant

Monochloramination could decrease the formation of dichloroacetic acid and richloroacetic acid compared with chlorination. The decrease of total haloacetic acid and trihalomethane is about 69.1% and 89%, respectively and no dibromochloromethane is detectable when the ratio of chlorine to ammonia is 4: 1. Increasing the pH value is beneficial to decrease disinfection by-products. There was no bromodichloromethane detectable and the amount of trichloromethane decreased about 82.3% when the pH value of water was increased from 7 to 8. The formation amount of dichloroacetic acid and trichloroacetic acid also decreased with the rising pH value and dichloroacetic acid decreased more evidently than trichloroacetic acid. Monochloramination could control brominated by-products very well compared with chlorination.