Pukyong National University Develops Technology for Adsorption and Decomposition of Cancer-Causing "Forever Chemicals" PFAS

Professor Kim Geonhan's Research Team:
Ultrafast Adsorption, Regeneration, and Repeated Use Achieved
Eco-Friendly Adsorbent Expected to Benefit Water Environment Industry
Published in "Advanced Materials"

The research team led by Professor Kim Geonhan (Department of Materials Engineering) at Pukyong National University has developed a technology that can rapidly adsorb and decompose per- and polyfluoroalkyl substances (PFAS)-organic pollutants that threaten the water environment-in water, and can also regenerate the material for repeated use.

PFAS are widely used in frying pan coatings, waterproof treatments, and semiconductor processes. However, due to their hydrophobicity and persistence, they remain in soil and water systems and are known to cause cancer, liver damage, and reproductive toxicity in humans, earning them the nickname "forever chemicals."

Currently, methods such as activated carbon and ion-exchange resins used to remove PFAS from soil and water systems have limitations, including low adsorption capacity, slow reaction rates, and the generation of secondary waste.

Professor Kim Geonhan's team overcame these limitations by synthesizing copper-aluminum layered double hydroxide intercalated with nitrate (Cu2Al-NO3 LDH) with high crystallinity.

The developed material demonstrated excellent anion exchange rates due to Al-Al defects (basal-plane disorder).

Experimental results using this material as an adsorbent showed that the maximum adsorption capacity for a representative PFAS pollutant, perfluorooctanoic acid (PFOA), was 1,702 mg/g, and the reaction rate constant was 13.2 h-1-more than 10 times faster than conventional activated carbon. The material cost was also lower than existing options.

Notably, the research team demonstrated that when the PFOA-saturated adsorbent is heat-treated with calcium carbonate (CaCO3) at 500°C, about 54% of the adsorbed PFOA is converted into non-toxic calcium fluoride (CaF2). Furthermore, the structure can be restored through a "memory effect," allowing for repeated use.

The team named this the "Capture-Thermal destruction-Regeneration (CTR) process," and proposed it as a core technology for sustainable water treatment.

In continuous fixed-bed column experiments, a treatment performance of 720 mg/g was achieved under an empty bed contact time (EBCT) of 7.5 minutes. Stable performance was also demonstrated under influent and effluent conditions at actual water purification and sewage treatment plants, confirming its potential for field application. Especially, the material showed selective adsorption depending on the PFAS chain length under various mixed conditions, indicating its effectiveness for removing not only single but also complex pollutants.

Professor Kim Geonhan stated, "This technology is a PFAS remediation platform with low cost, high efficiency, and regenerability, capable of replacing expensive activated carbon and ion-exchange resins. It offers a new solution to environmental problems that have remained unsolved until now," adding, "We expect it will make significant contributions to sustainable water management, the protection of human health, and related industries in the future."

This research was led by first author and corresponding author Professor Kim Geonhan, as well as Dr. Jung Younggyun, a postdoctoral researcher at Rice University (co-first author), Professor Michael S. Wong's research team, Professor Kang Seoktae's research team at Korea Advanced Institute of Science and Technology, and international collaborators from the University of Oxford, Lawrence Berkeley National Laboratory, and the University of Nevada.

The research paper, "Regenerable Water Remediation Platform for Ultrafast Capture and Mineralization of Per- and Polyfluoroalkyl Substances," was published online on September 25 in a world-renowned journal in the field of materials science (IF 26.8).

This study was supported by the Basic Research Program of the Ministry of Education and the National Research Foundation of Korea, the Grand Challenge Convergence Research and Development Program of the Ministry of Science and ICT, and the Sejong Science Fellowship.

Schematic diagram of PFAS removal and mineralization process (CTR process) using copper-aluminum layered double hydroxide intercalated with nitrate.

This content was produced with the assistance of AI translation services.