UNIST Unveils Revolutionary Technology to Permanently Remove PFAS from Water

Abstract
Advanced water treatment technologies must integrate material function with mechanistic understanding to achieve effective and sustainable contaminant remediation. Here, we introduce polyaniline (PANI) as an integrated amine-redox platform that enables reversible electrosorption of per- and polyfluoroalkyl substances (PFAS). By tuning its redox and protonation states, PANI switches between electrostatic and hydrophobic binding modes, allowing controllable capture and release. Spectroscopic analyses combined with molecular dynamics simulations uncover the mechanistic basis of this redox- and pH-dependent affinity: emeraldine states facilitate fast, reversible uptake via electrostatic interactions, whereas leucoemeraldine favors slower, irreversible hydrophobic binding. At the system level, a scalable flow-cell platform achieved >90% PFOA removal from 100 ppb feed solutions of both synthetic electrolyte and real wastewater. Within an adsorb–desorb–defluorinate strategy, reversible electrochemical capture and release concentrated PFOA 7.6-fold, generating an enriched stream suitable for downstream anodic oxidation. Subsequent treatment with a boron-doped diamond anode delivered an 88% defluorination ratio, nearly double that of direct oxidation, while reducing overall energy demand by more than 20-fold. These findings highlight the value of amine-redox materials that combine simplicity, reversibility, and mechanistic clarity, and demonstrate how electrosorption can bridge separation and destruction in energy-efficient treatment of dilute contaminants.

A research team, affiliated with UNIST has unveiled a novel method to tackle PFAS (Per- and polyfluoroalkyl substances), also known as the Forever Chemicals due to their resistance to natural degradation over hundreds of years.

Professors Kwiyong Kim (Department of Civil, Urban, Earth, and Environmental Engineering) and Byungjo Kim (Graduate School of Semiconductor Materials and Devices Engineering) at UNIST have created an electrochemical process using conductive polymers to adsorb, concentrate, and decompose low-concentration PFAS in water. This approach leverages the changing electrical states of the polymer to enable reversible adsorption and desorption, allowing selective removal with significantly reduced energy consumption.

When applied to wastewater, the system achieved over 90% removal of PFOA from solutions with just 100 parts per billion—operating at less than one-twentieth the energy of conventional methods. The team also developed an integrated system combining adsorption and electrochemical decomposition in a continuous process, simplifying treatment and making it more efficient.

Unlike traditional techniques that involve separating PFAS for incineration or landfilling—which merely isolate the chemicals—this technology allows for their complete breakdown, reducing environmental persistence.

Professor Kim explained, “Our conductive polymer-based system does not require chemical regeneration, making it a cost-effective and eco-friendly alternative for low-concentration wastewater. It can easily release captured pollutants without additional chemicals and streamline the entire treatment process.”

Molecular dynamics simulations further clarified how the polymers adsorb and release PFAS, providing insights for designing more effective materials.

Published in Environmental Science & Technology on January 13, this research was supported by the Ministry of Science and ICT, the National Research Foundation of Korea, and the Korea Institute for Industrial Technology.

Journal Reference
Sunghoon Doh, Sangmin Eom, Suk Soon Choi, et al., “Polyaniline as an Integrated Amine-Redox Platform for Reversible Electrosorption and Energy-Efficient PFAS Remediation: From Molecular Mechanisms to System Integration,” Environ. Sci. Technol., (2025).