CAREER: Piezoelectric Mechanocatalytic Destruction of PFAS in Solid Matrices at Ambient Conditions: An Integrated Research and Education Plan

Per-and polyfluoroalkyl substances (PFAS) are synthetic chemicals that have been manufactured and used in numerous consumer products and industrial applications since the 1940s. PFAS are among the most stable chemicals ever produced. During the last two decades, increasing detection of PFAS in various environmental media has raised significant concerns about their persistence, stability, and adverse impact including toxicity to living organisms and humans. With the gradual phase-out of PFAS from consumer and industrial products, stocks of obsolete PFAS chemicals are becoming solid wastes. In addition, large quantities of PFAS solid wastes are increasingly being generated including wastewater sludge, contaminated soils, and spent granular activated carbon (GAC) and ion exchange (IX) media used to remove PFAS from contaminated drinking water sources. Currently, thermal processes such as incineration and pyrolysis have emerged as the most effective for treating and destroying PFAS laden solid wastes at industrial and commercial scales. However, PFAS thermal treatment processes require high temperatures (150-900 °C) and often generate gaseous streams containing toxic intermediates and products of incomplete combustion (PICs) that require additional treatment to mitigate their releases into the environment. The overarching goal of this CAREER project is to lay the foundation for the development and validation of a novel piezoelectric material (PZM)-assisted ball milling (BM) process capable of treating and destroying PFAS solid wastes at room temperature and ambient pressure. To advance this goal, the Principal Investigator proposes to explore the activation of mixtures of catalytic piezoelectric materials (PZMs) and PFAS chemicals/solid wastes using a BM reactor to generate high electric potentials to decompose and mineralize PFAS into benign inorganic products. The successful completion of this project will benefit society through the generation of new fundamental knowledge and the design and synthesis of reactive PZMs to advance the development of more effective and sustainable technologies for the treatment and destruction of PFAS solid wastes. Additional benefits to society will be achieved through student education and training including the mentoring of one graduate student and one undergraduate student at Clarkson University. PFAS solid wastes are pervasive in the environment. They include obsolete PFAS chemicals, manufacturing wastes, contaminated soils, municipal solid wastes, and spent granular activated (GAC) and ion exchange (IX) media used to remove PFAS from contaminated drinking water sources. The overarching goal of this CAREER project is to advance the development of an innovative mechanochemical process that could treat and convert PFAS solid wastes to benign products at ambient temperature and pressure. The core guiding hypothesis of the proposed research is that the collisions between steel balls and catalytic piezoelectric materials (PZMs) in a ball milling (BM) reactor loaded with PFAS solid compounds/wastes can generate transient high electric potentials to degrade and destroy the PFAS. The specific objectives of the research are to (1) optimize the BM collision energy required to carry out the PFAS mechanochemical degradation process, (2) maximize the reactivity and catalytic activity of the PZMs via rationale design of crystal structure and heterojunctions, (3) use advanced in-situ and ex-situ characterization tools to probe and unravel the mechanisms and pathways of PFAS degradation, and (4) evaluate the cost-effectiveness of a PZM assisted BM process in the treatment and destruction of PFAS solid wastes. The successful completion of this project has the potential for transformative impact through the generation of new fundamental knowledge to advance the design and demonstration of a PZM-assisted ball milling (BM) process and reactor for the treatment and remediation of PFAS solid wastes at room and ambient pressure. To implement the educational and training goals of this CAREER project, the Principal Investigator (PI) proposes to leverage established programs at Clarkson University to (i) engage and mentor undergraduate students to work on the project research activities, (ii) promote K-12 STEM literacy, and (iii) provide PFAS related workforce training. To promote STEM literacy for K-12 students, the PI proposes to develop and deliver science courses and hands-on laboratory exercises based on the project research activities. In addition, the PI plans to collaborate with the accredited PFAS analysis center at Clarkson University to prepare training materials and host virtual seminars in PFAS analysis and treatment for the environmental remediation workforce. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.