Efficient Removal of Cs+ and Sr2+ Ions by Granulous (Me2NH2)4/3(Me3NH)2/3Sn3S7•1.25H2O/Polyacrylonitrile Composite

The need to effectively and selectively remove radioactive Cs-137 and Sr-90 from nuclear waste solutions persists to mitigate their environmental mobility and high radiotoxicity. Because it is difficult to effectively remove them from acidic environments that degrade most sorbents, new sorbent materials are highly desirable. Here, efficient removal of Cs+ and Sr2+ is achieved by the composite of layered tin sulfide (Me2NH2)(4/3)(Me3NH)(2/3)Sn3S7 center dot 1.25H(2)O (FJSM-SnS) and polyacrylonitrile (PAN) (FJSM-SnS/PAN). The granulous composite possesses regular particle morphology and good mechanical strength as an engineered form. It shows excellent acid-base and.-irradiation resistance, high maximum adsorption capacities (q(m)) of 296.12 and 62.88 mg/g for Cs+ and Sr2+ ions, respectively, and high selectivity even in the presence of excess Na+ ions or using lake water. Impressively, q(m)(Cs) of FJSM-SnS/PAN reaches 89.29 mg/g under even acidic conditions (pH = 2.5). The column loaded with FJSM-SnS/PAN granules exhibits high removal rates (R) toward low-concentration Cs+ and Sr2+ ions under both neutral and acidic conditions. Moreover, the composite can be recycled and reused with high R-Cs and R-Sr. This work highlights the great potential of metal sulfide ion-exchangers in engineered form for the efficient removal of Cs+ or Sr2+ ions, especially under acidic conditions, for radionuclide remediation.

Automated summary

The composite of layered tin sulfide (FJSM-SnS) and polyacrylonitrile (PAN) shows efficient removal of Cs+ and Sr2+ ions with high selectivity, even under acidic conditions. It has high maximum adsorption capacities and can be recycled and reused while maintaining high removal rates for low-concentration Cs+ and Sr2+ ions.