Ecological Engineering To Promote the Degradation of Estrogen in WastewaterEPA Grant Number: FP916409
Title: Ecological Engineering To Promote the Degradation of Estrogen in Wastewater
Investigators: Falk, Michael
Institution: University of California - Davis
EPA Project Officer: Carleton, James N
Project Period: January 1, 2004 through December 31, 2006
Project Amount: $100,779
RFA: STAR Graduate Fellowships (2004) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Fellowship - Environmental Engineering , Engineering and Environmental Chemistry
In recent years, trace contaminants are frequently recognized as important constituents within water affecting public health and system ecology. Steroidal estrogenic compounds, in particular, have emerged as potential threats as a result of their ability to disrupt the endocrine system of animals at low levels (e.g., ppt). The steroidal estrogenic compounds are not eliminated during passage through conventional wastewater treatment plants and frequently are detected in the aqueous environment. Finding a viable alternative treatment configuration and/or treatment is of pressing concern in promoting sustainable development. The objective of this research is the use of a novel technology, membrane bioreactors (MBRs), to systematically investigate the microbial degradation of the synthetic estrogen 17α-ethynylestradiol (EE2), the primary active constituent of the birth control pill. EE2 will serve as a model compound for endocrine disrupting agents because of its endocrine disrupting potential and its elevated loading rates from humans compared to the other steroidal estrogenic compounds. I postulate that the microbial communities and associated processes in MBRs are fundamentally different from those in conventional wastewater treatment systems and lend themselves to successful removal of low concentrations of trace contaminants. This may be accomplished by the increased retention of biomass indicative of an MBR unit, leading to starvation physiology, increased production of extracellular enzymes, and selection for different microorganisms.
The research will involve a side-by-side comparison of MBR and conventional activated sludge treatment configurations. The studies addressing the process conditions leading to and affecting degradation of EE2 will be combined with detailed microbiological and molecular analysis of the microbial communities that develop in the respective bioreactors. The working hypothesis states that certain process conditions selecting for specific microbial communities will accomplish microbial degradation of EE2. Microbial fingerprinting, such as terminal restriction fragment length polymorphism (T-RFLP), will be applied to study population dynamics in different reactors. In addition, community members will be identified in detail by cloning and sequencing to establish an inventory of microbial diversity. The presence of individual bacterial groups and species will be verified and quantified by fluorescent in situ hybridization (FISH) and real time polymerase chain reaction (PCR). I also plan to monitor, optimize, and compare the ability of each respective reactor to comply with the regulations specified by the State of California and the federal government. Ensuring that the state and federal regulations are met should facilitate the growth of this novel technology.