Pharmaceuticals and Steroid Hormones: Extending Knowledge and Mitigation Strategies.

The widespread occurrence in watersheds of emerging contaminants, including pharmaceutical and personal care products (PPCPs) and steroid hormones, has been recognized as a critical environmental issue. Effluents from sewage treatment plants (STPs) and reuse of wastewater from concentrated animal feed operations (CAFOs) have been identified to be the major sources discharging these emerging contaminants into the surrounding water bodies. Using these waters for agricultural irrigation may introduce wastewater-associated PPCPs and hormones to the receiving fields. In this study, an isotopic dilution method was developed for simultaneous analysis of trace levels of emerging contaminants in a variety of environmental samples. With the developed methods, we identified and quantified PPCPs and steroid hormones in a municipal STP, evaluated the removal efficiency of these emerging contaminants in the treatment processes, and monitored their occurrence in the surrounding watershed. Results showed that the STP could effectively remove parts of the emerging contaminants, but many PPCPs and one hormone were still detected in the effluents at ng/L levels. To evaluate the environmental fate of wastewater-associated PPCPs and hormones, we also investigated their degradation and sorption in water-soil systems and proposed degradation pathways based on the identified metabolites. In addition, two pollution prevention strategies were started. First, a medicine take-back program was implemented across the state of Illinois to minimize loading of pharmaceutical contaminants into the environment. Second, we developed an on-site oil-sequester treatment approach to capture PPCP and hormone contaminants from STP effluent or CAFO wastewater before their release into the environment.