Electrochemical Treatment of PFAS-contaminated Groundwater using Novel Titanium suboxide Thin Film Technology

Tuesday, May 20, 2025

1:45 PM – 2:00 PM Alaska Daylight Time (AKDT)

Room: Room 5

Author(s)

Sunith Varghese

Graduate Research Assistant
South Dakota School of Mines & Technology, South Dakota, United States

Co-Author (not attending)(s)

Heidi Sieverding

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

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

Co-Author(s)

Lisa A. Kunza

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

Co-Author (not attending)(s)

Parthiba Karthikeyan Obulisamy

South Dakota School of Mines & Technology, United States
Bharat Jasthi

South Dakota School of Mines & Technology, United States
Ananth Kandadai

South Dakota School of Mines & Technology, United States

Co-Author(s)

Venkataramana Gadhamshetty

Professor
South Dakota School of Mines & Technology, United States

Abstract Submission: Per- and polyfluoroalkyl substances (PFAS) pose a potential environmental and human health threat due to widespread contamination of surface and ground water resources. Current remediation technologies often prove inadequate in destroying high concentrations of PFAS, necessitating the development of innovative and scalable solutions. This research addresses this challenge by focusing on the development of use-inspired, electrochemical remediation technologies to effectively treat fluorinated compounds from contaminated groundwater, subsequently preventing their migration into nearby water bodies. Electrochemical oxidation (EO) process used in the work herein is an emerging technology in PFAS treatment, which presents superior PFAS destruction efficiencies and a more environment-friendly approach compared to conventional methods. Thin film electrodes consisting of ~45 nm thick tetratitanium heptoxide (Ti4O7) deposited on inexpensive stainless-steel were developed and used to electrochemically destroy PFAS in water. Promising results were obtained using synthetic water based on 2500 ppb perfluorooctanoic acid (PFOA), 2500 ppb perfluorooctane sulfonic acid (PFOS) and 0.1 M sodium sulfate (Na2SO4). Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and ion chromatography (IC) measurements have yielded promising and reproducible results. Removal efficiencies of 60-75% were achieved for PFOA, PFOS, and perfluorobutane sulfonate (PFBS) in source water using electrochemical treatment (2.117 V for 180 min, vs Ag/AgCl), which were comparable to boron-doped diamond (BDD), an established industry standard for electrochemical PFAS mineralization. These results show promise in developing cost-effective electrodes for PFAS destruction and constitute a basis for subsequent field-scale demonstration of PFAS remediation.

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