CAREER: Sorption and Biodegradation Processes for Removal of Pharmaceutical Compounds in Biological Systems

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

Harper 0546388 The focus is biodegradation and sorption of pharmaceutical compounds (PhACs) in engineered bioreactors. Intellectual Merit. These research results are expected to be an important part of the foundation needed for understanding fate of PhACs in both engineered and natural systems. The use of FED modeling for predicting biological transformations has not been done before, and may provide the missing, conceptual framework needed for a more complete understanding of transformation pathways. The proposed sorption studies will establish the basic thermodynamic properties of PhAC sorption and will fully uncover the connection between particle size and hysteresis. The expected results have potential to make fundamental scientific contributions, while also making direct connections to design and operating strategies for water quality professionals. The research uses basic scientific concepts from quantum chemistry and thermodynamics, and the experimental tasks utilize modern analytical techniques and computational software. The four key research hypotheses are: 1) The biological oxidation of PhACs and their metabolites will occur at the location where the frontier electron density (FED) is highest. FED may be established as an organizing principle for predicting biologically-mediated PhAC transformation. These results may impact the understanding of PhAC mass transport in bioreactors, surface waters, and sediments. 2) PhAC sorption is entropy-driven, endothermic, and diffusion-controlled. Establishing the thermodynamic baseline for PhAC sorption to activated sludge biomass will help to understand available data in a meaningful way. 3) Sorption hysteresis is more pronounced as the particle size distribution shifts toward larger sizes. The results could produce a fundamental understanding for how sorption hysteresis is affected by activated sludge particle size. 4) PhACs or their metabolites located within the interior of larger floc particles are more persistent. When both biodegradation and sorption occur simultaneously, PhACs and their metabolites may become trapped within the interior of activated sludge floc particles, where biological activity is lower. Education and outreach. The integrated education and outreach activities will enrich the environmental engineering program at Auburn University with new course elements that enhance learning, promote diversity in engineering through collaboration with the Auburn University BellSouth Minority Engineering program (BMEP), and promote environmental literacy among middle school students. The new course elements include using the cooperative learning strategy and interdisciplinary design projects. BMEP activities faculty mentoring, problem-solving labs, and direct involvement in the research project. I also propose to promote environmental literacy in young people by incorporating a 1 hr environmental learning module in Auburn University annual interactive learning conference for middle school students. Broader Impacts are expected that at the successful completion of this project will help place the members of my research group near the center of the international, interdisciplinary dialogue concerning the proliferation of PhACs in the environment. I further expect that the curriculm at Auburn University will be strengthened through new course elements, diversity in engineering will be enhanced, and local middle school students will become more environmentally literate.