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Oral

Water, Wastewater & Stormwater

Bench-scale Test for the Removal of Per- and polyfluoroalkyl substances using Prefilter and GAC Systems

Tuesday, May 20, 2025
1:30 PM – 1:45 PM Alaska Daylight Time (AKDT)
Room: Room 5

    Author(s)

  • Damodar Poudyal

    Graduate Research Assistant, Department of Civil and Environmental Engineering
    South Dakota Mines, South Dakota, United States

    • Co-Author(s)

  • Kurt Chowanski

    Research Scientist III, Department of CBHS, Center for Sustainable Solutions
    South Dakota Mines, South Dakota, United States

  • Daniel Owens

    Assistant Prof, Dept of Chemistry, Biology, & Health Sciences, Center for Sustainable Solutions
    South Dakota Mines, South Dakota, United States

  • Heidi Sieverding

    Assistant Prof, Dept of Civil and Environmental Engineering, Center for Sustainable Solutions
    South Dakota Mines, South Dakota, United States

  • Lisa A. Kunza

    Associate Prof, Dept of Chemistry, Biology, and Health Sciences, Center for Sustainable Solutions
    South Dakota Mines, South Dakota, United States

Abstract Submission: Per- and polyfluoroalkyl substances (PFAS), commonly known as "forever chemicals" due to their persistence, pose significant challenges in water treatment. A 45-day bench-scale test was conducted using Prefilter and Granular Activated Carbon (GAC) systems with in-line canisters packed with media. Water contaminated with PFAS was continuously recirculated through Prefilter (12.2L) and GAC (20.2L) conduits, maintaining 1.5 m of hydraulic head. The test aimed to examine the clogging and biofouling potential for optimization within Prefilter and GAC systems. We overcharged the systems with silica flour, dissolved organic matter (DOM), and NPK fertilizer. Since pH can alter the solubility and mobility of PFAS contaminated water, we measured pH of water samples from both systems daily throughout the experiment (average temperature 200C). The average pH remained stable at 8.43 in GAC, while slightly increased to 8.76 in the Prefilter. Total organic carbon (TOC) levels in the Prefilter system (12-24.12 ppm) were significantly higher than those in the GAC system (0.21-2.18 ppm), indicating GAC's effectiveness in removing organic carbon. As the systems clogged, we utilized a backflush to restore the flow through the treatment systems. Our bench-scale tests will guide the design for a passive pilot scale treatment system.

Learning Objectives/Expected Outcome (Optional) : PFAS as emerging contaminants, bench-scale technique for the remediation of PFAS, etc.