AWWA WQTC71661

Recently, a higher quality of tap water has been required in terms of taste and odor, due to the sophistication of customers' needs. Therefore, the Bureau of Waterworks of the Tokyo Metropolitan Government set an original target of trichloramine, which causes strong chlorinous odor, and has carried out measures to reduce trichloramine. Trichloramine is one of disinfection byproducts and generated by a reaction of chlorine and ammonia ion. In the advanced water treatment, ammonia ion can be removed by biotical effect through the biological activated carbon treatment. However, the removal rate of ammonia ion becomes lower as temperature drops, and trichloramine is generated. Therefore, the study conducted research for measures to control trichloramine in a low temperature period. As a result, the study found that ammonia ion is constantly removed by breakpoint pre-chlorination without significant increase in the amount of trihalomethanes and haloacetic acids. Additionally, the study developed an automatic analysis device of trichloramine for more detailed monitoring. Includes 6 references, tables, figures.