Pukyong National University

PKNU, Develops Eco-Friendly Technology to Adsorb and Degrade Carcinogenic ‘Forever Chemicals’ (PFAS)

-Professor Kim Geon-Han’s research team achieves ultra-fast adsorption with regenerable, reusable materials

-Eco-friendly solution expected to transform water treatment industry … Published in <Advanced Materials>

A research team led by Professor Kim Geon-Han (Department of Materials Science and Engineering) at Pukyong National University has developed a new technology that can rapidly adsorb and decompose perfluoroalkyl substances (PFAS) in water, with the added benefit of being reusable through regeneration.

PFAS, commonly used in non-stick cookware coatings, waterproof treatments, and semiconductor processing, are known as “forever chemicals” due to their hydrophobic and non-degradable properties. These substances persist in soil and water systems and are linked to serious health issues such as cancer, liver damage, and reproductive toxicity.

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

To overcome these challenges, Professor Kim Geon-Han’s team synthesized a highly crystalline copper-aluminum layered double hydroxide (Cu₂Al？NO₃ LDH) with inserted nitrate ions. This new material demonstrated excellent anion exchange kinetics due to basal-plane disorder caused by Al？Al defects.

When used as an adsorbent in experiments, the material achieved a maximum adsorption capacity of 1,702 mg/g and a reaction rate constant of 13.2 h？¹ for perfluorooctanoic acid (PFOA)―a common PFAS pollutant―exhibiting a performance over ten times faster than conventional activated carbon, while also being more cost-effective.

In particular, the research team demonstrated that when the PFAS-saturated adsorbent was thermally treated at 500°C with calcium carbonate (CaCO₃), approximately 54% of the adsorbed perfluorooctanoic acid (PFOA) was converted into non-toxic calcium fluoride (CaF₂). Moreover, the material’s structure could be restored through a “memory effect,” allowing it to be reused. 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, the new material achieved a treatment capacity of 720 mg/g under an empty bed contact time (EBCT) of 7.5 minutes. It also showed stable performance under real-world conditions, such as influent and effluent water from water purification and sewage treatment plants, confirming its practical applicability. Notably, the adsorbent exhibited selective adsorption based on PFAS chain lengths even under mixed contaminant conditions, suggesting its effectiveness in removing not only single pollutants but also complex mixtures.

Professor Kim Geon-Han stated, “This technology is a PFAS purification platform with low cost, high efficiency, and reusability―an alternative to expensive activated carbon and ion-exchange resins. It offers a new solution to long-standing environmental issues.“ He added, “We expect this achievement to make significant contributions to sustainable water management, public health, and related industries.”

This research was led by Professor Kim Geon-han as both the first and corresponding author, and jointly conducted with Dr. Jeong Young-kyun (Rice University, co？first author), Professor Michael S. Wong’s team (Rice University), Professor Kang Seok-tae’s team (KAIST), as well as international collaborators from the University of Oxford, Lawrence Berkeley National Laboratory, and the University of Nevada.

The research findings were published online on September 25 in the world-renowned journal <Advanced Materials> (IF 26.8), under the title “Regenerable Water Remediation Platform for Ultrafast Capture and Mineralization of Per- and Polyfluoroalkyl Substances.”

This work was supported by the Basic Research Program of the Ministry of Education and the National Research Foundation of Korea (NRF), as well as the Challengeable Future Problem-Solving Research Program and the Sejong Science Fellowship under the Convergence R&D Program for National Strategic Challenges funded by the Ministry of Science and ICT.