NSF Award
2305729
Per- and polyfluoroalkyl substances (PFAS) are fluorinated organic chemicals that have been manufactured and used in numerous consumer products and industrial applications since the 1940s. PFAS are commonly referred to as “forever chemicals” due to their persistence, stability, and resistance to natural environmental degradation processes. In addition, PFAS have been shown to bioaccumulate in human tissues and aquatic organisms raising concerns about their toxicity and adverse impact on human and ecosystem health. During the last two decades, PFAS have been increasingly detected in groundwater aquifers which serve as sources of drinking water for many communities throughout the United States. In contaminated groundwater aquifers, PFAS are often found alongside other toxic chemicals such as chlorinated solvents including trichloroethylene (TCE) and tetrachloroethylene (PCE). The overarching goal of this project is to design, evaluate, and optimize a novel two-phase dark-light reactor (DRL) for the ex-situ treatment of groundwater contaminated by mixtures of PFAS and chlorinated solvents using magnetic and photochemically active nanomaterials. The successful completion of this project will benefit society through the generation of fundamental knowledge to advance the development and deployment of efficient and sustainable technologies for the treatment and remediation of groundwater aquifers contaminated by mixtures of PFAS and chlorinated solvents. Additional benefits to society will be achieved through student education and training including the mentoring of three graduate students at Southern Illinois University at Carbondale.<br/><br/>In groundwater aquifers and subsurface formations, PFAS contaminants are often commingled with toxic chemicals such as chlorinated solvents including trichloroethylene (TCE) and tetrachloroethylene (PCE). However, to date, limited research has been devoted to the treatment and remediation of groundwater aquifers contaminated by mixtures of PFAS and chlorinated solvents. In addition, there is a critical need for pilot-scale studies to demonstrate and validate the feasibility and field-scale applicability of promising PFAS groundwater remediation technologies that are being investigated in bench scale laboratory studies. The goal of this research is to develop, evaluate, and validate the field-scale applicability of an integrated sorption-photocatalytic process for the ex-situ treatment and remediation of groundwater contaminated by mixtures of PFAS and TCE/PCE. To advance this goal, the Principal Investigator (PI) and research team propose to design, evaluate, and optimize a two-phase dark-light reactor (DRL) that will utilize nanomaterials under darkness to sorb PFAS and partially destroy TCE/PCE followed by exposure of the nanomaterials to UV light to destroy the remaining sorbed PFS and TCE/PCE contaminants. The specific objectives of the research are to 1) synthesize and characterize nanoscale zero-valent iron/reduced graphene oxide nanohybrids using an innovative and scalable process ; 2) conduct bench scale lab studies to assess the impacts of environmental factors on the efficiency of the DLR to remove PFAS and TCE/PCE in contaminated groundwater using the nanomaterials that are synthesized in Objective 1, and 3) conduct pilot field studies to evaluate and optimize the effectiveness of the new DRL and nanomaterials for the ex-situ treatment and remediation of groundwater contaminated by mixtures of PFAS and TCE/PCE. To implement the educational and outreach goals of this project, the PI plans to leverage the Research Enriched Challenge (REACH) program at Southern Illinois University at Carbondale to recruit and mentor undergraduate female students to work on the project. In addition, the PI plans to engage with the US Geological Survey (USGS) and the Illinois Environmental Protection Agency (EPA) to share the results of the research and discuss potential field applications/demonstrations of the new two-phase dark-light reactor at contaminated sites in the State of Illinois.<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.
