Disinfection By-Product (DBP) Formation and Control in Potable Reuse Applications

摘要

Decades of research has elucidated the precursor characteristics, formation mechanisms, and control strategies for regulated disinfection by-products (DBPs) and some unregulated DBPs in conventional water treatment plants (WTPs). However at potable reuse facilities, the prevalence and type of precursors, formation mechanisms, and control strategies can all be different than at conventional WTPs. The impact of ozonation is a good example. At conventional surface WTPs, ozone degradation of chloramines-reactive n-nitrosodimethylamine (NDMA) precursors tends to result in a net reduction of finished water NDMA concentrations. In contrast, NDMA formation hypothesized to be via ozone-catalyzed nitrosation reactions results in increased NDMA concentrations at advanced water treatment plants for potable reuse applications. Data from three potable reuse studies illustrates the importance of carefully assessing DBP concentrations in purified water, factoring in proposed treatment, blending strategies, and chlorination conditions to accurately anticipate resulting DBP concentrations and any required adjustments for regulatory compliance and to meet site-specific water quality goals.