Biodegradation of Potential Wastewater Micropollutants by Ammonia-oxidizing Bacteria

Approximately 80% of US streams (108 out of 139 US streams<br />surveyed) were contaminated with a wide range of wastewater<br />micropollutants, including bisphenol A (BPA, a plasticizer), triclo-<br />san (5-chloro-2-(2,4-dichlorophenoxy)-phenol, an antimicrobial<br />agent), and ibuprofen (a non-steroidal anti-in？ammatory drug)<br />(Kolpin et al., 2002).<br />Triclosan is a synthetic, broad-spectrum antimicrobial agent<br />that has been widely used in the United States since the 1960s<br />(Jungermann, 1968). As an antimicrobial agent and preservative,<br />triclosan has been incorporated into a broad array of personal care<br />products (e.g., hand disinfecting soaps, medical skin creams, dental<br />products, deodorants, toothpastes), consumer products (e.g., fab-<br />rics, plastic kitchenware, sport footwear), and cleaners or disinfec-<br />tants in hospitals or households (Singer et al., 2002). Between 1992<br />and 1999, over 700 consumer products contained antibacterial<br />properties, and the vast majority of the products contained triclo-<br />san (Schweizer, 2001). The disposal of the triclosan-containin