Despite notable advancements in water treatment, addressing contaminants of emerging concern, such as perfluorinated compounds, endocrine disruptors, pharmaceuticals, and pesticides, remains a challenge for conventional processes. This seminar will explore creative approaches to rethink water treatment technologies, emphasizing both effectiveness and sustainability. Specifically, I will discuss my lab's advancements, focusing on the development of novel, multifunctional membranes and three innovative processes for treating per- and polyfluoroalkyl substances (PFAS). To begin, I will present our research on aggregation-resistant, 'crumpled' graphene oxide (CGO) based nanocomposites that enable unique membrane functionality for water treatment. As-synthesized, core-shell nanostructured CGO composites exhibit significantly enhanced aqueous stability and optimized reactivity due to tunable composite geometry and surface chemistry - along with ease of encapsulating secondary functional particles (e.g., photocatalysts). As a self-assembled film, CGO nanocomposites provide high water flux while efficiently rejecting and/or (photo)degrading model aqueous pollutants. Further, CGO assemblies can be designed to have regenerative (and exceptional) antimicrobial properties. Lastly, these CGO-nanocomposites uniquely allow for a novel, in situ fouling management strategy via magnetic-based separation and self-(re)assembly. The second part of the presentation will focus on newly developed PFAS treatment technologies with promising application potential. First, I will present our research on ultra-high capacity, multifunctional nanoscale sorbents designed and optimized for low-energy PFAS separation and recovery. I will then discuss an environmentally friendly pathway to covalently transform PFAS, particularly perfluorooctanoate (PFOA), into insoluble esters. Finally, I will introduce unique photocatalyst-based composites capable of broad, complete, and rapid PFAS defluorination under UV light at room temperature and pH-neutral conditions.

Bio: John is Professor in the Department of Chemical and Environmental Engineering at Yale University. His research program is focused on developing and advancing water-related technologies and understanding/engineering interfacial processes, typically at the nanoscale, as they relate to environmental-based health, security, and energy challenges. John held postdoctoral fellowships at the Swiss Federal Institute of Technology in Zurich (ETHZ) and Rice University as a U.S. Intelligence Community (IC) fellow. He obtained his B.S. from Texas A&M University and Ph.D. from Rice University in environmental engineering.