AWWA JAW57846

Formation of disinfection byproducts (DBPs) is a major concern for drinking water utilities. The addition of ozone can help minimize trihalomethane (THM) formation, but ozonation converts nonbiodegradable organic matter to biodegradable organic carbon, resulting in the formation of biodegradable organic matter and the potential for bacterial regrowth in the distribution system. Ozonation in drinking water treatment is typically used in combination with biofiltration. Yavich and Masten proposed and investigated a different approach, ozonation in combination with biological fluidized-bed treatment (FBT). This study was conducted using a continuously operated ozonation-FBT system with no pretreatment. Biofiltration and bench-scale ozonation systems were also used to compare the biodegradation efficiency of FBT and investigate the effect of ozonation on biodegradation efficiency. Results indicated that the combined ozonation-FBT process was effective in removing THM precursors and reducing turbidity. According to preliminary cost estimates, ozonation-FBT may be a practical and cost-effective alternative to conventional coagulation processes that require additional steps to control DBPs. For small water providers, the process represents a new option for reducing DBP and regrowth potential. Because of the system's small footprint and lack of sludge production, the ozonation-FBT process is also applicable for larger utilities with limited space for retrofitting or expansion. Includes 42 references, tables, figures.