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.

Impacts of particulate organic carbon and dissolved organic carbon on removal of polycyclic aromatic hydrocarbons, organochlorine pesticides, and nonylphenols in a wetland

“…Therefore, the removals or fates of organic contaminants in wetlands are the consequences of the two processes. Individual contaminants tend to interact with sediments, suspended particulates, water, and biota (transport processes) (Smit et al 2008;Weber et al 2006;Zhou and Maskaoui 2003) and be chemically and biologically transformed (Schulz et al 2003;Gross et al 2004) to different extents due to physicochemical properties such as vapor pressure, solubility, hydrophobicity, and biodegradability. Consequently, transport, transformation and fates of organic contaminants in wetlands greatly depend on their physicochemical properties.…”

“…This catchment has been known to have relatively constant concentrations of PAHs and OCPs in surface waters and sediments (Xue et al 2006;Huang et al 2005). Meantime, nonylphenol ethoxylates (NPEOs) and their degradation products which can cause endocrine disrupting effects have been found widely in wastewater effluents at relatively high concentrations (Gross et al 2004). …”

Evaluation of spatial and seasonal variations in surface water quality using multivariate statistical techniques

“…Rivers in watersheds with substantial agricultural and urban land use experience increased inputs and varying compositions of organic matter (Sickman et al, 2007) and excessive concentrations of phosphorus and other nutrients from fertilizer application and watershed releases (Easton et al, 2007). Natural and synthetic estrogens, other pharmaceuticals and disease-causing bacteria are entering streams through the release of wastewater from sewage treatment plants and effluent from septic systems (Gross et al, 2004;Kinzelman et al, 2003;Williams et al, 2003). Therefore, the effective, long-term management of rivers requires a fundamental understanding of hydro-morphological, chemical and biological characteristics (Shrestha and Kazama, 2007).…”

Harnessing Natural Attenuation of Pharmaceuticals and Hormones in Rivers

“…The river has a soft-bottom streambed and engineered sidewalls. Gross et al evaluated natural attenuation of selected pharmaceuticals, metabolites, and endocrine disrupters over a reach of 11 km of river flow, which corresponded to 7 h of residence time (17). The removal of these contaminants through an engineered treatment wetland during this flow was also quantified.…”