A.W. Carpenter, J. Darcy, W. Storm
Keywords: PFAS, nanomaterial, sensor, water, contaminant
Summary:Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants of concern impacting water quality throughout the United States. PFAS are used in a variety of commercial products and fire-fighting foams, which can lead to ground and surface water contamination, and eventually impact drinking water. As of January 2021, the Environmental Working Group has identified PFAS contamination at 2,337 locations across 49 states. Often, municipal drinking water supplies with known PFAS-impacts, influent and effluent are sampled weekly to inform when an emergency treatment system should be “turned-on”. Current sampling methods are expensive and have a two week turn-around, meaning community PFAS exposure can occur while awaiting sample analysis. An on-site, low-cost screening methods that could more quickly warn of exposure would have significant human health impact. Early estimations of the PFAS treatment market are at $3.1Bn, with testing representing a key revenue driver. To meet this need, AxNano is developing a nanomaterial-enabled PFAS sensor that utilizes hyperspectral imaging (HSI) to provide a high-throughput, lower-cost, more accessible alternative for qualitative and quantitative analysis of PFAS targets. We have preliminarily tested our technology with two of the most common PFAS: perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). This presentation will demonstrate our ability to select between water with PFOS, with PFOA, and with a mixture of PFOS+PFOA based on observing spectral changes of the nanomaterial. Ongoing work is aimed at determining the sensitivity, selectivity, and limit of detection of nanomaterials with a broader range of PFAS, as well as integration into a prototype HSI system. Based on current regulatory limits, the goal is to detect PFAS in the ppb down to ppt range.