| The potable reuse of wastewater treatment plant (WWTP) effluents has been discouraged due to the potential health risks associated with the quality of such waters. Non-potable reuse is currently practiced throughout the world, and increasing water resource demands make the potable reuse of wastewaters inevitable in the future. Important questions concerning the potential public health impacts of wastewater reuse, are addressed by this research.;Residual organic matter present in wastewaters after treatment, or effluent organic matter (EfOM), can be problematic during additional treatment prior to distribution to the general public. Organic matter, either natural (NOM) or EfOM, consists of a heterogeneous mixture of numerous organic compounds that present an oxidant demand and form regulated by-products (DBPs) during drinking water disinfection.;A suite of isolated NOM samples (primarily hydrophobic acids) were provided by the United States Geological Survey in order to establish a database of physical-chemical as well as oxidant-reactive properties to compare against EfOM. A wide range of oxidant demand and DBP formation was observed during the chlorination of these samples in controlled aqueous matrices.;EfOM was isolated from three different WWTPs during four isolation campaigns using nonionic macroporous resins and nanofiltration. Compared to NOM isolates, EfOM samples are enriched in elemental sulfur and nitrogen, while exhibiting a substantially lower ultra-violet light absorbance (UVA) per milligram of carbon and lower weight-averaged molecular weight. The aromatic, aliphatic, and carboxylic carbon contents of EfOM samples were similar to those of NOM isolates.;During chlorination, EfOM isolates formed quantities of DBPs comparable to NOM isolates studied. As EfOM isolates exhibited lesser chlorine demands compared to NOM isolates, the EfOM isolates formed more brominated trihalomethanes in the presence of bromide. Trends were observed between physical-chemical characteristics and oxidant-reactive properties; chlorine demand and differential UVA spectroscopy provided the best indicators of DBP production. Ozonation of EfOM formed by-products previously observed during the ozonation of NOM, yet correlations between these compounds and physical-chemical properties were not observed. |
