Progress 07/01/23 to 06/30/24

Outputs
Target Audience:The target audience of this research include agricultural producers, private well owners, public drinking water managers, local public health agencies, watershed managers and environmental regulators. Agricultural producers were a particular focus of this research because of recent reports of PFAS contamination of several categories of agricultural commodities including dairy and meat products. Beyond the concern over chemically tainted food products, PFAS contamination of public drinking water resources has become a primary focus of environmental regulators. On April 10, 2024, the EPA published maximum contaminant levels (MCLs) for six PFAS compounds detected in drinking water. MCLs are legally enforceable PFAS concentration limits permitted in public drinking water supplies. The over 150,000 public drinking water systems in the United States must come into full legal compliance with the new national PFAS regulatory limits by no later than April 10, 2029. Our new portable PFAS detection technology will lower the cost and therefore enhance the ability of our target audience to monitor the level of PFAS in rural drinking water resources. By lowering the cost and time required to assess PFAS concentrations in rural water supplies, our technology will allow water quality stakeholders to take actionable decisions that immediately reduce the overall public health risk associated with exposure to these contaminants. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided workforce development across principal investigators, postdoctoral, doctorate and undergraduate levels. All participants in the project, including those at CEL, SUNY-ESF and TCU, collectively participate in monthly project status meetings to disseminate recent scientific and project development progress. These meetings provide all parties with an opportunity to practice and improve communication/presentation skills, expand their scientific understanding of the concepts of the project and gain a broader perspective from both academic and business viewpoints. Direct support from this project has enabled the participation of one full-time postdoctoral research, one graduate student and two undergraduate students. Selected preliminary data was presented at the American Chemical Society (ACS) Conference Spring 2024. Additionally, this project allowed for the continuing education at the Workshop "Advances in PFAS: Challenges and Opportunities" organized by NYS Center of Excellence, Healthy Water Solutions. Such participations at workshops and conferences helped to develop a strong professional network and expand collaboration opportunities. How have the results been disseminated to communities of interest?The results were disseminated to communities of interest on multiple occasions. First, results were presented at the Workshop "Advances in PFAS: Challenges and Opportunities" organized by NYS Center of Excellence, Healthy Water Solutions. There, policy makers, industry professionals, and researchers met to discuss the most recent advances in PFAS-related research. We had an opportunity to communicate to the decision makers by using our research results and our future research plans. Second, our research team had an opportunity to attend the New York State Innovation Summit 2023. There, we had the opportunity to showcase our project to various companies, startups, and researchers at the forefront of emerging technologies in State New York. While presenting at the American Chemical Society (ACS) Conference Spring 2024 (Healthy Water Solutions 2nd Annual Meeting 2024), our research team had a chance to communicate with nationally- and internationally recognized professionals and researchers from various fields including those in PFAS research and drinking water treatment. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Major accomplishments related to each of these goals are as follows: The effect of pyrolysis conditions were explored and the produced lignin-based biochar was characterized by means of infrared (IR) spectroscopy and scanning electron microscopy (SEM). Lignin-derived porous biochar was fabricated from lignin oil through a nano casting method using a silica (SiO2) nanoparticle with an average size of 100 nm synthesized by the Stöber method. The composite was heated to 900 °C under N2 at a heating rate of 100 °C/h and maintained at 900 °C for 4 h. To remove the silica template, a 2 M NaOH aqueous solution was added to the composite. The prepared biochar was applied to FTO glass substrate as electrodes. Based on the morphology and surface analysis, we concluded that the surface area and distribution of pore volume are important factors affecting conductivity and redox reactions. The modified biochar-based macroelectrode was produced and characterized using various characterization techniques, such as IR spectroscopy, SEM imaging, water droplet contact angle measurement, cyclic voltammetry, and electrochemical impedance spectroscopy. Investigation of the biochar surfaces by FT-IR spectroscopy before and after treatment with the FMA (fluorinated molecular acceptor) coatings demonstrated the successful deposition of the FMA by the presence of functional group of the FMA which was absent for the untreated biochar surfaces. Water droplet contact angle measurements showed a clear contrast between FMA coated and uncoated biochar surfaces. The contact angle measurements indicated that the uncoated biochar electrodes present a strongly hydrophobic interface and treatment with the FMA establishes a substantially more hydrophilic interface. Electrochemical study of the biochar surfaces paralleled these results where substantial interfacial charging effects were observed for the uncoated surfaces whereas the FMA coated electrodes provided substantially reduced background currents and improved electrochemical stability attributed to decrease oxidation/reduction of the biochar surface. Preliminary data demonstrates the affinity of the surface towards specific PFAS. Selectivity of the macroelectrode depends on the surface and chemical properties of the introduced modification. The electrochemical response of FMA coated and uncoated biochar-based electrodes have been analyzed using aqueous solutions containing perfluorooctanoic acid (PFOA) concentrations of 1 to 10 parts per million (ppm). This result suggest that effective surface capacitance is most sensitive to changes in the solution PFOA concentration. Given these observations, our work is now focused on refining our methodological determination of the effective surface capacitance and determining the optimum applied potential and AC frequency range to extract this information. A current challenge in the area is the poor reproducibility in terms of the observed electrochemical response of redundantly fabricated electrodes. We are refining both our electrochemical measurement protocol, chemical design of the FMA, and electrode fabrication methodology to try and improve reproducibility. Efforts to address this objective have focused on the fabrication and synthesis of the critical chemical and material components of the biochar electrodes as well as proof of concept electrochemical studies. The design and conceptualization of portable device remains as an objective for future STTR Phase II work.

Publications