The occurrence of pharmaceuticals, nonylphenol ethoxylate metabolites, and other wastewater-derived contaminants in surface waters is a potential environmental concern, especially since the discovery of contaminants with endocrine-disrupting properties. The present study investigated the discharge of emerging contaminants into the Santa Ana River (CA, USA) and their attenuation during river transport and passage through a constructed wetland. Contaminants studied included pharmaceuticals (gemfibrozil, ibuprofen, naproxen, ketoprofen, and carbamazepine) and their metabolites, hormones, the metabolites of alkylphenol polyethoxylates (APEMs), N-butyl benzenesulfonamide (NBBS), and chlorinated tris-propylphosphates (TCPPs). The APEMs included alkylphenols (APs), short-chain AP polyethoxylates (APEOs), AP polyethoxycarboxylates (APECs), and carboxylated APECs (CAPECs). In wastewater treatment plant effluent, APECs and CAPECs represented the dominant APEM fraction (1.8-18.7 microg/L), whereas APEOs and APs contributed only small amounts to the overall APEM concentrations (0.10-0.92 and < or =0.1 microg/L, respectively) except where the effluent was infiltrated into soil (5.2 microg/L). In effluents, ibuprofen and its metabolites, TCPPs, and NBBS were detected regularly (<0.5 microg/L), and the other pharmaceuticals were detected occasionally. Transport in the Santa Ana River for 11 km resulted in the significant attenuation of all contaminants, from 67% for gemfibrozil to 100% for others. Wetland treatment (residence time, 2-4 d) resulted in partial removal of ibuprofen, gemfibrozil, and TCPPs and transformed APEOs to APECs.

As water reuse becomes increasingly important to satisfy water demand, ensuring the quality of recycled wastewater becomes ever more vital. Pharmaceuticals (PhACs) and alkylphenol polyethoxylates (APEOs) metabolites are two groups of chemicals that are commonly present in treated effluent and have received attention for their demonstrated or potential biological effects. In this paper we present data on the effects of river transport, wetland treatment, and groundwater recharge on the attenuation of these emerging chemicals. Using data from three advanced water treatment plants, we also report on the efficiency of microfiltration, reverse osmosis and ultraviolet oxidation in removing these compounds from advanced treated effluents. With respect to natural attenuation processes, decreases in pharmaceutical concentrations during river transport were likely attributed to sediment sorption and chemical and biological degradation or transformation. Wetland treatment was less efficient when compared to river transport. Groundwater recharge appeared to be an effective removal process (> 99% attenuation) for PhACs and APEO metabolites, although trace levels of the latter can travel substantial distances in the subsurface. With regards to the engineered treatment options, reverse osmosis was capable of almost complete rejection of all PhACs and APEO metabolites analyzed, whereas the performances of microfiltration and UV treatment were much less efficient and consistent.