Discipline: Technology and Engineering
Subcategory: Chemical/Bimolecular/Process Engineering
Room: Exhibit Hall
Arleth Ortiz - University of Arizona
Co-Author(s): Anton Gomeniuc, University of Arizona, Tucson, Arizona; Jim A Field, University of Arizona, Tucson, Arizona; Jon Chorover, University of Arizona, Tucson, Arizona; Leif Abrell, University of Arizona, Tucson, Arizona; Jim Hatton, University of Arizona, Tucson, Arizona; Reyes Sierra-Alvarez, University of Arizona, Tucson, Arizona
PFAS, or per- and polyfluoroalkyl substances, are man-made chemicals commonly used in industrial applications and consumer products. These fluorochemicals are ubiquitous in the environment and are a concern due to their high toxicity, persistence, and bioaccumulation potential. PFAS concentrations exceeding EPA advisory levels have been observed in drinking water resources worldwide and even in rain and snow samples from diverse rural and urban areas. At present, sorptive approaches using granular activated carbon (GAC) or anion exchange resins are the most commonly used technologies for treating PFAS-contaminated water. However, these approaches are very costly and relatively inefficient at removing PFOA and shorter-length PFAS analogs. The aim of this project is to assess the feasibility of using two hydrophobic cationic polymeric adsorbents engineered in our lab (i.e., polyaniline (PANI) and poly-o-toluidine (POT)) to develop a cost-effective method for the remediation of PFAS contamination. Our hypothesis is that these polymeric materials will be effective PFAS adsorbents due to their ability to strongly retain PFAS through both hydrophobic interactions (i.e., between the hydrophobic polymer backbone and the fluorocarbon chain in PFAS) and electrostatic interactions (i.e., between cationic groups in the polymer and the anionic head group in many PFAS). Treatment of synthetic groundwater contaminated with a mixture of PFAS compounds (C4-, C7-, C8- and C9 perfluoroalkyl carboxylates; C4-, C6- and C8 perfluoroalkyl sulfonates, and 6:2 fluorotelomer sulfonate) was assessed in rapid small-scale column tests (RSSCT) packed with PANI and POT. Small-scale columns packed with a commercial GAC material were run in parallel to benchmark the performance of the polymeric adsorbents. Results obtained to date confirmed that PANI and POT have higher PFAS adsorption capacity compared to GAC even in the presence of high levels of natural organic matter (NOM), salts and/or organic co-contaminants. These results indicate the potential of the new cationic hydrophobic polymers for PFAS remediation of PFAS. Future research will investigate the performance of the polymeric adsorbents in small RSSCT experiments treating actual groundwater collected from a contaminated site.
Funder Acknowledgement(s): Dept. Chemical and Environmental Engineering and Dept. Environmental Science at the University of Arizona; JACOBS
Faculty Advisor: Reyes Sierra-Alvarez, firstname.lastname@example.org
Role: I was tasked with cleaning, maintaining, and calibrating the equipment used in the RSSCT experiment, and ensuring proper waste disposal. Every day, I would collect sample collections, and do pH readings and necessary calculations to produce solutions that were used in the experiment. I later helped run these samples through a centrifuge and filtered them so they may be analyzed using an analytical machine that would give us data and results of the RSSCT performance. After collecting enough information and data, I then summarized and presented our conclusions at the WAESO conference.