title: Occurrence and fate of pharmaceuticals and alkylphenol ethoxylate metabolites in an effluent-dominated river and wetland.
abstract: 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.
authors.affiliation: Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305-4020, USA.
authors.forename: Birgit
authors.initials: B
authors.lastname: Gross
authors.forename: John
authors.initials: J
authors.lastname: Montgomery-Brown
authors.forename: Anneke
authors.initials: A
authors.lastname: Naumann
authors.forename: Martin
authors.initials: M
authors.lastname: Reinhard
mesh_terms: D002140:California; D045166:Estradiol Congeners / Q000032:analysis; D005019:Ethyl Ethers / Q000032:analysis* / Q000378:metabolism; D005411:Flame Retardants / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000378:metabolism; D010636:Phenols / Q000032:analysis* / Q000378:metabolism; D010968:Plasticizers / Q000032:analysis; D011092:Polyethylene Glycols / Q000032:analysis* / Q000378:metabolism; D045483:Rivers / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D045166:Estradiol Congeners; D005019:Ethyl Ethers; D005411:Flame Retardants; D004364:Pharmaceutical Preparations; D010636:Phenols; D010968:Plasticizers; D014874:Water Pollutants, Chemical; C023354:alkylpolyethoxylates; D011092:Polyethylene Glycols