ScholarWorks@중앙대학교

초록

The removal of ppm-level Hg2+ from wastewater via adsorption has emerged as an energy-efficient approach for water purification. Zeolites have garnered considerable attention for this process due to their low cost and high chemical stability; however, they traditionally suffer from low adsorption capacity and limited selectivity for Hg2+. In this study, we propose a strategy to design zeolites tailored for the selective, high-capacity capture of Hg2+ from wastewater. Our initial findings reveal the arrangement of Hg2+ in FAU zeolites: when adsorption is performed with a 50 ppm Hg2+ solution, Hg2+ primarily resides at the ion-exchange sites within the sodalite cages, with negligible presence in the supercages. To enhance capture capacity, we grafted aminoethanethiol (AET) onto the supercage walls through dynamic acid-base interactions between the amine moiety and bridging oxygen, which introduced free thiol groups capable of strongly binding Hg2+ via Hg-S bond formation. The AET-grafted FAU zeolite outperformed all previously reported zeolite adsorbents, achieving a partition coefficient of 9.26 mg/g ppm−1. Additionally, this zeolite demonstrated high selectivity, effectively removing Hg2+ from aqueous solutions containing multivalent ions without a decrease in removal efficiency. This protocol has the potential to be extended to various zeolite systems, making it suitable for the rapid and selective removal of Hg2+ in harsh purification environments. © 2025 Elsevier B.V.

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