One of the grand challenges for Environmental Engineers in the 21st century is designing a future without pollution and waste. In this talk, I will discuss my group’s efforts in interfacial chemistry to develop reactive adsorbents and sensors for environmental remediation and pollutant monitoring. First, I will discuss the critical role of pyrogenic carbonaceous matter (PCM; e.g., biochar and activated carbon) in promoting a broad range of chemical and microbial synergies, from affecting redox-active elements' global biogeochemical processes to influencing environmental remediation and water treatment. However, due to PCM's inherent chemical heterogeneity, it is difficult to identify what critical properties contribute to its reactivity. We have developed a tunable PCM-like polymer (PLP) network through controlled polymer synthesis. This allows us to delineate the contribution of individual properties (e.g., functional groups, porosity) to PCM's reactivity, particularly in accelerating the surface-enhanced hydrolysis of nitroaromatics. Understanding these critical properties is crucial for designing reactive adsorbents that can concentrate and destroy contaminants, reducing material replacement costs. In the second part, I will discuss our progress in developing a novel molecularly imprinted polymer (MIP) that is both conductive and redox-active for electrochemical detection of per- and polyfluoroalkyl substances (PFAS) in water. We created three MIPs via an electropolymerization approach. Our MIPs showed high selectivity, stability, reusability, and low detection limit (below pg L-1), providing an innovative sensor platform for rapid PFAS detection and laying the groundwork for monitoring other pollutants.

 

Dr. Wenqing Xu is a professor in the Department of Civil and Environmental Engineering at Villanova University, PA. Currently, she is on sabbatical and works as a UPS Foundation Visiting Professor at Stanford University. The central focus of her research program is to better understand the various ways that nature detoxifies contaminants by the integration of chemical, biological, and material sciences approaches to (i) attenuate pollutant transport and thereby protect source water and (ii) degrade contaminants with novel materials to provide safe drinking water. Dr. Xu has served as a principal and co-principal investigator of projects funded by the department of Defnese (DoD-SERDP), the National Science Foundation, the National Institute of Environmental Health Sciences, and the Environmental Protection Agency on research involving the development of reactive adsorbents for pollutant abatement, such as chlorinated solvents, pesticides, munitions constituents, per- and poly-fluoroalkyl substances (PFAS), and disinfection byproducts (DBPs). She has taught undergraduate courses such as Introduction to Environmental Sciences and Engineering, Water and Wastewater Treatment, Capstone Design, and graduate courses such as Aquatic Chemistry and Physicochemical Processes. She is a recipient of various awards, including the NSF CAREER award (2018) and the University Scholarly Achievement Award (2020). She is active in several professional engineering associations and is the associate editor of the journal Environmental Engineering (ASCE). She is also an award committee member for the Franklin Institute in Philadelphia. She received her B.S. and M.S. degrees in environmental engineering from Nankai University in China (2007) and Johns Hopkins University (2009), respectively, and a Ph.D. degree in environmental engineering from Yale University (2014).