State Water Resources Research Institute Program
Project ID: 2011SD199B
Title: Determination of Microbial Kinetics for the Degradation of Estrogens and Triclosan in Activated Sludge Systems
Project Type: Research
Start Date: 3/01/2011
End Date: 2/28/2012
Congressional District: SD First District
Focus Categories: Wastewater, Methods, Water Quality
Keywords: Microconstituents, Estrogen, Triclosan, Respirometry, Activated Sludge, Microbial Kinetics
Principal Investigator: Schmit, Christopher G
Federal Funds: $ 14,253
Non-Federal Matching Funds: $ 37,756
Abstract: Modern day analytical techniques have allowed scientists to determine the concentration of chemicals in the water at concentrations approaching parts per trillion. These new techniques have made scientists aware of numerous human pharmaceutical compounds (HPC) and endocrine disrupting compounds (EDCs) in the surface, sewer, and drinking waters throughout the world. In 1999 the USGS undertook a study to determine the presence of pharmaceuticals, hormones, and other organic contaminants in U.S. streams (Kolpin et al., 2002). The sampling of 139 streams throughout the U.S. found that 80% of these streams had some detectable level of one or more of these compounds.
There are two classes of compounds that have caused high concerns in terms of public health. These classes include the endocrine disrupting compounds (EDCs) and the anti-bacterial pharmaceuticals. EDCs are known to cause physiological changes in humans at low concentrations. Hormone therapy and ovulation control are two of the primary uses for EDCs. Hormone therapy contains many natural hormones including 17β-estradiol (E2). Ovulation control is accomplished through the synthetic hormone 17α-ethinylestradiol (EE2) and is practiced routinely throughout western civilization. Anti-bacterial pharmaceuticals include the popular chemical triclosan that is used in anti-bacterial products like soap and toothpaste. Scientists are concerned that these compounds are passing through wastewater treatment plants and impacting the environment. The concern of scientists with triclosan is that it passes through wastewater treatment plants and will eventually cause the mutation of a "super bug" that will resist our current methods for the treatment of bacterial infections. This research seeks to quantify the microbial kinetics for the biodegradation of the hormone 17β-estradiol (E2), synthetic hormone 17α-ethinylestradiol (EE2), and antibacterial chemical triclosan in municipal wastewater systems utilizing the activated sludge process. The kinetics will be determined by using extant respirometric methods with existing activated sludge mixed liquor from local wastewater treatment plants. Determination of growth rates, bacterial yields, and inhibition characteristics will be included as part of the respirometric method. Determination of these parameters would lead to optimization of treatment, which would improve water quality and mitigate the impact of these compounds on the environment.
Progress/Completion Report, 2011, PDF