NSF Award
2307222
Antibiotic resistant bacteria ("superbugs") are considered one of the greatest challenges facing humanity in the 21st century. In the U.S., more than 23,000 deaths per year are associated with antibiotic resistant bacteria, and approximately $55 billion is spent annually to combat antibiotic resistance. The spread of antibiotic resistant bacteria is causing global concern that we may be returning to a pre-antibiotic era. Resistance to antibiotics is carried by the genetic materials of bacteria called antibiotic resistance genes. These emerging contaminants are being rapidly transmitted in built environments such as wastewater treatment plants. Recent studies are exploring the feasibility of using new approaches and materials, such as carbon nanomaterials, to remove antibiotic resistance genes. Despite the great potential, previous studies consistently report inefficient removal due to a lack of in-depth understanding of the interactions between antibiotic resistance genes and carbon nanomaterials. The goal of this project is to understand the fundamental chemistry when antibiotic resistance genes interact with carbon nanomaterials. Based on the knowledge gained from this project, a robust carbon nanomaterial-membrane system can be developed and applied to wastewater treatment plants to combat antibiotic resistance. The system is also expected to be broadly applicable to the treatment of various emerging contaminants that are difficult to remove using conventional technologies. In addition to advancing engineering applications and fundamental chemistry, this project will provide educational opportunities for highly motivated, low-income high school students. Undergraduate students from groups traditionally under-represented in STEM will also be involved in the research. This early exposure to research is expected to be transformative in broadening the horizons and academic/career goals of participating students.<br/><br/>Antibiotic resistance genes are considered an emerging contaminant and can spread rapidly in the built environment such as municipal wastewater treatment plants. One of the promising approaches to combat antibiotic resistance is the use of carbon nanomaterials to adsorb and degrade antibiotic resistance genes. However, because the effects of their nanoscale properties on adsorption and degradation are not well understood, inefficient removal is consistently reported in the literature. The goal of this project is to develop a mechanistic understanding of the interactions between antibiotic resistance genes and carbon nanomaterials. This goal will be achieved by pursuing three interrelated objectives: 1) understand the interactions with membranes coated with reduced graphene oxide; 2) enhance the electrostatic adsorption of antibiotic resistance genes on the modified membranes; and 3) enhance the electrochemical degradation of antibiotic resistance genes by the modified membranes. By immobilizing carbon nanomaterials on membranes, the interactions are expected to be readily tuned and enhanced with pressure-driven filtration. In addition, the membranes can act as a support layer for carbon nanomaterials to be electrically charged, allowing electrostatic adsorption at anodic potentials as well as reactive oxygen species-induced degradation at cathodic potentials. Alternation of the electrical potential will also result in synergistic interactions. This project is expected to provide insight into the design of nanostructured materials and heterogeneous nanosystems for water and wastewater applications. The "trap-and-zap" strategy (i.e., adsorption followed by degradation) developed in this project is expected to be applicable to the treatment of emerging contaminants in heterogeneous environments. A major benefit of this project will be addressing the societal need for alleviating the ever-growing energy demand for water and wastewater treatment. This project will promote teaching, training, and learning by supporting \high school, undergraduate, and graduate students in research. The principal investigators have been and will continue working closely with the Society of Women Engineers, the National Society of Black Engineers, and the Society of Hispanic Professional Engineers to engage students from groups traditionally under-represented in STEM in research.<br/><br/>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.
