Dr. Wenqing Xu, associate professor of Civil and Environmental Engineering, has been awarded $657,137 as part of a $1.467 million National Institutes of Health grant (R01) for a five-year collaborative project between Villanova University and the University of Iowa. "Elucidating mechanisms for enhanced anaerobic bioremediation in the presence of carbonaceous materials using an integrated material science and molecular microbial ecology approach” reflects Dr. Xu’s work on the bioremediation of legacy pollutants and emerging contaminants frequently encountered at Superfund sites.
While anaerobic reductive dehalogenation by organohalide-respiring bacteria (OHRB)—a common bioremediation strategy for halogenated pollutants in groundwater and sediments—has proven effective, these strategies are often incomplete in field applications. A newer remediation strategy involving amendment of pyrogenic carbonaceous matter (PCM, e.g., activated carbon) to the subsurface has been shown to promote synergistic interactions among OHRB and improve efficacy, however, the underlying mechanisms of how PCM properties best support microbial network interactions, and thereby enhance OHRB performance and contaminant biodegradation remain unknown. Dr. Xu says, “These unknowns limit our ability to optimize OHRB performance in bioremediation strategies where PCM is used.” This project is aimed at closing these knowledge gaps.
The central hypothesis, Dr. Xu explains, is that “key PCM properties will shape microbial community structure and drive the expression of metabolic functions associated with reductive dehalogenation processes.” Identifying positive impacts between PCM and OHRB will allow for the development of tailored PCM that foster synergistic microbial network interactions and facilitate more effective and sustainable bioremediation. Dr. Xu adds, “The proposed research is both innovative and interdisciplinary because we will use a tunable platform to change material surface properties and employ advanced molecular microbial ecology tools to assess the impacts of these properties on microbial community structure, function and activity including OHRB.”
The outcomes of this project will benefit human health and realize economic benefits by reducing human exposure to halogenated pollutants in the environment and demonstrating the potential for more effective and sustainable remediation approaches that combine tailored PCM and OHRB.
Dr. Xu’s impressive body of work has earned her numerous federal awards and grants, including a 2018 NSF CAREER award for “Transforming the Synergistic Interactions between Pyrogenic Carbonaceous Matter (PCM) and Sulfur Species into Solutions for Contaminant Detoxification” and a 2019 Department of Defense grant worth $1.46 million to lead a multi-institutional research project to address explosive residuals at military training sites. In recognition of her scholarship, in 2020, Villanova University presented her with its prestigious University Scholarly Achievement Award.
Dr. Xu directs Villanova Engineering’s Environmental Interfacial Chemistry Group. The central focus of her research program is to understand the various ways that nature detoxifies contaminants and use this knowledge to design engineered systems to better retain and/or degrade them. In addition to leading her own research agenda, she has collaborated across departments and institutions to solve interdisciplinary challenges. Results from these research activities have translated into 12 peer-reviewed articles in prestigious journals including Environmental Science & Technology. Two PhD students, three master’s students, and one undergraduate student were involved as first or co-authors on these papers and have since graduated from Villanova. Dr. Xu is also frequently invited as a seminar/conference speaker and has delivered 18 invited talks domestically and internationally.