AWWA ACE63219

Wastewater treatment plants (WWTPs) are a potential source of disinfection byproducts (DBPs) and DBP precursors (i.e., effluent organic matter [EfOM]) in many watersheds through the U.S. and the world. The presence of wastewater discharges in watersheds impacts drinking WTPs (DWTPs) that rely upon those watersheds for drinking water supplies. Therefore, the fate of DBPs and DBP precursors in watersheds is important to understand. Although several biogeochemical processes (i.e., sorption to sediment, volatilization, hydrolysis, biodegradation, photolysis) could potentially reduce the levels of DBPs and DBP precursors in receiving waters, upon careful review of the literature and based on modeling efforts, it was concluded that for most DBPs and DBP precursors that biodegradation and photolysis of these materials would dominate their fate in receiving waters with short residence times between WWTP discharges and DWTP intakes. Of course, for some DBPs (i.e., trihalomethanes [THMs]) volatilization would be significant. However, for many of the "emerging" DBPs of potential health concern, they are more polar than THMs and, hence, have very low Henry's Law constants and would not be very volatile. The purpose of this paper is to examine the change in regulated and emerging DBPs (THMs, haloacetic acids [HAAs], nitrosamines, haloacetonitriles [HANs], haloketones, haloacetaldehydes, and halonitromethanes) and changes in DBP formation potential (FP) (i.e., DBP precursors) during kinetic biodegradation and sunlight photolysis experiments. In addition, the impact on the EfOM was followed by measurements of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and ultraviolet absorbance (UVA) at 254 nm. Includes tables, figures.