Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic organofluorine chemicals that are known as “forever chemicals” due to their resistance to thermal, chemical, and biological degradation. PFAS have been used worldwide to make nonstick cookware, food packaging, water-proof clothing, grease-resistant paper, firefighting foams, and many other consumer products. Because of their widespread use and high stability, these forever chemicals have been frequently found in soil, air, water, and food. Moreover, most people in the world have been exposed to some level of PFAS. Exposure to certain PFAS may lead to detrimental health impacts including reproductive effects, developmental effects, increased risks of cancers, weakening of the immune system, and endocrine system disruption.
Plant Uptake and Mitigation of PFAS Associated with Sewage Effluent and Biosolids Application in Tile-Drained Fields
Application of sewage effluent and biosolids in agricultural fields is a win-win practice for providing nutrients and organic matter to improve soil health and reduce chemical fertilizer use. However, sewage effluent and biosolids are being considered as substantial PFAS sources. The use of these organic wastes in agricultural fields facilitates the introduction of PFAS into soils, where these emerging contaminants may subsequently be taken up by plants and enter food chains. Principal investigator (PI) Wei Zheng and colleagues from the University of Illinois, University of California, Riverside, Metropolitan Water Reclamation District of Chicago, and Illinois Farm Bureau received a nearly $1.6 million grant from the U.S. Environmental Protection Agency (U.S. EPA) to deal with this issue.
In this project, they will conduct a series of laboratory and field experiments to explore PFAS uptake and accumulation in plants grown in subsurface tile-drained fields irrigated with rural sewage effluent, investigate the physical and molecular mechanisms that govern PFAS uptake and accumulation in plants grown in biosolids-amended soils, and develop innovative and efficient techniques to mitigate PFAS plant uptake, and thereby reduce their entry into the food chain. The successful completion of this project will provide information to assess the potential risks of using rural sewage effluent for irrigation of agricultural fields, contribute science-based knowledge to state or local regulators to determine whether biosolids for agricultural use could result in soil contamination and plant uptake, and offer mitigation approaches to reduce the loading of PFAS into food crops from organic wastes, thus increasing U.S. water and food security.
This project starts in October 2024 and will be funded through September 2027.
PFAS in land-applied biosolids in agricultural settings: a mechanistic understanding on fate and mitigation
Wei Zheng, Ph.D., is a co-PI collaborating with a professor at the University of Utah to conduct another PFAS project. In this project, Zheng will be responsible for developing a most promising, practical, and cost-effective technique to mitigate PFAS contaminants through derived biosolids. His group will design special biochars to reduce the mobility and bioavailability of biosolids-associated PFAS and thereby prevent their leaching and plant uptake. This technology will help municipal wastewater treatment plants to overcome their challenges: how to properly handle PFAS-containing sewage sludge.
The U.S. EPA is funding this three-year $1.6 million project.