Monitoring and modeling of disinfection by-products (DBPs).

In the United States, the newly promulgated disinfectant/disinfection by-product (D/DBP) regulations force water treatment utilities to be more concerned with finished and distributed water qualities. In this study, monitoring of DBP formation was conducted from three French water treatment plants trying to assess DBP variations through time and space. Compared to the in-plant total trihalomethanes (TTHM) levels, TTHM levels in the distribution system increased from less than 150% to more than 300%. Significant variations for TTHM and bromate (BrO3-) levels throughout the seasons were also observed; generally higher levels in the summer and lower levels in the winter. Combining chemical DBP models (empirical power functional models) and hydraulic simulations, DBPs including TTHM and BrO3- were successfully simulated from the full-scale monitoring data, indicating that empirical DBP model can be a potential tool to access DBP formation in actual plants. This study also provides the protocols to assess DBP simulations in the water treatment systems.