AWWA JAW64053

Traditional chloramine practice involves the addition of ammonia and chlorine nearly simultaneously, minimizing the presence of free chlorine. However, many drinking water treatment plants are not practicing traditional chloramination; they now have a significant period of free chlorine exposure that can accentuate disinfection byproduct (DBP) formation. This article investigates the effects of treatment, pH, and prechlorination on dihaloacetic acid (X₂AA) formation kinetics. The data obtained and subsequent conclusions drawn provide new insight into X₂AA formation and control during chloramination to help ensure that chloramination remains a viable treatment option. With many utilities facing a balancing act regarding chlorine, chloramines, and concentration times time requirements, a better understanding of X₂AA formation kinetics with chloramines is essential input in the complicated decision-making process of weighing disinfection requirements against DBP formation. Includes 37 references, tables, figures.