University of Wisconsin-Madison, PhD
EREF Scholar 2022
Permeable Sequestration Barriers for PFAS in Landfill Gas
Per- and polyfluoroalkyl substances (PFAS) have been observed in landfill leachates and gas, and while PFAS in landfill leachates have raised public concerns due to the potential toxicity of PFAS, less attention has been paid to PFAS in landfill gas.
Preliminary results in one of Yu’s current projects, demonstrates that composite landfill liners (geomembrane over a clay liner component) are effective in containing PFAS in leachate, and Yu aims to investigate effective strategies to manage PFAS in landfill gas. One possible solution is the use of permeable sequestration barriers (PSBs), following the concept of how permeable reactive barriers (PRB) are used for groundwater remediation. Horizontal PSB layers can be placed during waste filling to sequester PFAS in landfill gas while allowing the gas to flow freely for collection. Thus, PSBs should be permeable to release landfill gas but to be able to bind to PFAS capturing it from the gas. Successful application of PSBs will be controlled by the materials used in PSBs and the thickness of PSBs. Ideally, permeable waste materials that are effective PFAS sorbents can be identified that would normally be managed at a municipal solid waste landfill. These waste streams could then be used as inexpensive PSB media.
This research aims to evaluate the effectiveness of various PSB media in sequestrating PFAS, with an emphasis on waste materials as reactive media.
Yu Tan is a PhD student in Civil and Environmental Engineering at the University of Wisconsin-Madison (UWMadison), which he began in spring 2022. He earned a BS in the China University of Geosciences in Hydrology and Water Resources Engineering in 2015, and went to graduate school at Lanzhou University as a Master’s student (2015-2017) and then a PhD student (2017-2019). Prior to joining UW-Madison, he was a research scholar (2019-2021) at the University of Virginia. His research focuses on hydraulic barriers in environmental containment systems for containing solid, radioactive, and mining wastes.