CAREER: Leveraging the multifunctional redox properties of pyrogenic materials to enable biological transformations of aqueous organic contaminants

North Carolina State University, Raleigh NC

Investigators

Abstract

Pollution from past releases of toxic organic contaminants continue to plague the Nation’s water, soil, and sediment. While various technologies and approaches have been developed to remediate these legacy pollutants, they continue to present challenges for communities around the country. The overall goal of this CAREER project is to address these challenges and protect human and the environmental health by developing treatment technologies that more completely degrade toxic organic pollutants in a cost-effective manner. The basis for this technology is a hybrid microbial-material process. In this approach, microorganisms provide the driving force to enable reactions on the surface of materials that degrade the organic pollutant. While this process has shown great promise, there are many gaps in our knowledge of how this process occurs. The fundamental insight gained will permit the informed design and optimization of materials that can degrade specific pollutants. These materials can then be applied to engineered systems such as water and wastewater treatment plants. The integrated education plan will have significant and broad impacts and will reach a diverse audience of K-12 teachers and students through a mentoring program for underrepresented high school students in partnership with the NC School of Science and Mathematics. These efforts will increase the scientific literacy of the Nation and help develop the STEM workforce of the future. The overall goal of this CAREER project is to study the fundamental mechanisms of how microbial-driven electron transfer from redox-active materials transform organic contaminants. Conventional methods for the biological treatment of organic contaminants like chlorinated solvents rely on the activity of specific bacteria. These bacteria are often low in abundance and sparsely distributed in the subsurface, and materials that harness the activity of these bacteria can greatly enhance and sustain contaminant removal. Geobacter, a group of bacteria that are present in water, soil, and sediment are extremely metabolically versatile in their ability to utilize insoluble electron acceptors such as pyrogenic carbonaceous materials (PCMs). Geobacter use PCMs such as activated carbon and biochar to shuttle electrons through the material to abiotically degrade contaminants on the material surface. The PI will combine the tools of electrochemistry, microscopy, spectroscopy, and molecular biology to address knowledge gaps in our understanding of these interactions at microbial-material-contaminant interfaces. Three complimentary goals in the proposed program will be pursued: (1) Determine the role of PCM properties on microbial and contaminant reactivity, (2) Assess the role of contaminant adsorption on reaction kinetics and toxicity to the microorganisms, and (3) Determine the effect of environmental matrix components on the resiliency of reactions mediated by PCMs. With this information, a new generation of materials can be designed to degrade organic pollutants in applications including drinking water, stormwater, and bioremediation systems. The research objectives will be integrated with innovative education initiatives. K-12 teachers in biology will learn advanced microscopy and experiment kits to introduce students to environmental microbiology. Collaboration with the Friday Institute for Educational Innovation will leverage these activities to reach hundreds of K-12 teachers and students through existing school partnerships with the annual NC Science Teachers Association Conference. A multi-level mentoring program for underrepresented high school students will be piloted at the NC School of Science and Mathematics to provide research experiences to help students pursue careers in STEM. Finally, a new undergraduate-level lab on PCM microbial reactivity at will be developed at NCSU. 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.