The SCOPES Project is funded and supported by the Hinkley Center for Solid and Hazardous Waste Management (The Hinkley Center)
Why do they do?
The Solid Waste Management Act of 1988 created the center, to coordinate research, training, and service activities relating to waste management. Following a request for proposals (RFP) process, the Chancellor of the Board of Regents designated the University of Florida to be the Host Institution. The Center's primary funding comes from the Solid Waste Management Trust Fund, administered by the Florida Department of Environmental Protection (FL DEP).
TITLE: "Remediation of Perfluoroalkyl and Pharmaceutical Substances in Landfill Leachate via Solar Simulated Photocatalysis" FUNDING SESSION - 2019 PRINCIPAL INVESTIGATOR - "Sesha Srinivasan"
Research indicating the persistence of systems with multiple fluorine substituents, poly- and perfluoroalkyl substances (PFAS), have been conducted in animal and human populations, the food chain, water sheds, municipal drinking water and as a component of landfill leachate. Throughout the US, many landfills treat leachate through a wastewater treatment plant (WWTP). Therefore, any persistent chemicals have the potential to end up in water ways and ultimately, in the water supplied to municipal systems. The present proposal is aimed at the characterization of the distribution of PFAS in landfill leachate of various ages and the utilization of a new solar simulated photocatalytic oxidation approach to remediate these persistent species in landfill leachate. The proposed work is to utilize a novel, sustainable, synergistic process which is a combination of the nanotechnology involving development of novel catalysts capable of harnessing renewable solar energy for the treatment and remediation of landfill leachate contaminants such as PFAS. The patent pending methods developed as part of our leachate studies aimed at reducing chemical oxygen demand (COD) and nitrogen in landfill leachate uses a combination of photocatalysis and chemical oxidation. The methods will be aimed at the elimination of PFAS and their breakdown species in landfill leachate collected and fully analyzed on monthly intervals. The studies will use the synergistic advanced oxidation techniques by combining Earth abundant materials as photocatalysts with persulfate and peroxide oxidation to remediate PFAS in landfill leachate. Based on recent studies by us and others, the above combination has been shown to be economical and efficient at removing several contaminants from leachate. Our hypothesis is that this technique combined with either solar powered lamps or direct solar irradiation can be a viable means of eliminating the PFAS to the less harmful fluoride ion and carbon dioxide (CO2). The process design for specific destruction of the PFAS compounds 2 will be investigated with these sustainable approaches along with catalyst recycling studies aimed at reuse of photocatalyst. Photocatalyst tuning will be developed through TiO2 modification to match the optimum efficiency for destruction of the PFAS present in leachate. This includes incorporation of low toxicity and green heteropoly acid (HPA) catalysts as modifiers of titanium dioxide (TiO2) or nitrogen doped TiO2 or ZnO colloidal, photocatalytic nanoparticles. The HPA systems have been successful in degradation of small PFAS systems with products being ionic fluoride (F-) and CO2. HPAs have been easily incorporated into TiO2 and they have exhibited high potential for reuse and recycling. The proposed work will focus on demonstrating the feasibility of this approach to treat leachate containing PFAS to a level acceptable for safe discharge or at a minimum industrial reuse within legal standards. The EPA recommendation for total PFAS content in drinking water has been set at a level of 70 ng/L (parts per trillion). Overall, the proposed project will contribute critical knowledge regarding the remediation of these persistent PFAS compounds with the development of an efficient and sustainable approach to remediating landfill leachate and therefore address the Hinkley Center’s research 2019 research agendas 6, 11 and 12.
TITLE: "Remediation of Perfluoroalkyl Substances in Landfill Leachate via Solar Photocatalysis" FUNDING SESSION - 2021 PRINCIPAL INVESTIGATOR - "Dr. Sesha S. Srinivasan", Principal Investigator, "Dr. Scott L. Wallen", Co-PI
Polyfluoro- and perfluoroalkyl substances (PFAS) are persistence in the environment and they have been detected in harmful quantities in the food chain, watersheds, municipal drinking water, and as a component of landfill leachate. PFAS have been used for decades and although several have been banned, they continue to be found in thousands of current products that will eventually be landfilled. Throughout the US, many landfills treat leachate through municipal wastewater treatment plants (WWTP) and, therefore, the presence of any persistent chemical has the potential to end up in waterways and, ultimately, in the water supplied to municipal systems. The present proposal is aimed at the characterization of the distribution of PFAS in landfill leachate with respect to environmental conditions as well as the further development and demonstration of a new solar photocatalytic approach to remediate these persistent species in landfill leachate. The proposed work will utilize a novel, sustainable, solar initiated photocatalytic process involving a combination of recyclable, co-catalysts. The studies will focus on PFAS with less than eight carbons as current methods are incapable of remediating these smaller PFAS and they are often the byproducts of the remediation of larger PFAS. The studies will identify optimum pH, cocatalysts’, and oxygen concentrations necessary to remediate the PFAS systems to CO2 and fluoride ion (F- ). Additionally, aside from these targeted fluorinated products potential degradation byproducts not containing fluorine will be examined. Upon optimization of the process in model PFAS waste simulant systems, the developed approach will be aimed at real leachate samples collected on a quarterly basis from local landfills. Quantification of reaction products will be accomplished using fluoride ion selective electrode measurements as well as solid phase extraction followed by liquid chromatographic separation with triple quadrupole mass spectrometric detection to determine the pre- and post-treatment fluorinated species present, the overall efficiency of the PFAS remediation process, and the potential non-fluorinated byproducts that may be species of concern. The project will benefit various stakeholders including solid waste landfill operators, municipalities, and the residents of Florida by providing critical data on PFAS landfill leachate distribution and a method to efficiently and economically, remediate PFAS to innocuous CO2 and F-.
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