Rapid and efficient removal of Sr2+ ions by the easy-to-operate and environmentally friendly KInSnS4@collagen fibers aerogel

Abstract

It is still a challenge to capture radioactive 90Sr2+ ions conveniently, quickly, and efficiently from complex aqueous solutions. Herein, a composite material, KInSnS4@CFs aerogel (CFs = collagen fibers), was prepared by loading the metal sulfide ion exchanger KInSnS4 on collagen fibers through electrostatic self-assembly. The KInSnS4@CFs aerogel is well shaped and maneuverable. It can efficiently capture Sr2+ with the satisfactory adsorption capacity (qmaxSr = 41.8 mg/g), fast kinetics (adsorption equilibrium within 2 min), broad pH activity (pH = 2–12), and facile elution. The aerogel shows good selectivity for the capture of Sr2+ under the coexistence of Na+, Cs+, Ca2+, and Mg2+, as well as in actual water samples. In addition, it can serve as the stationary phase being used in the ion exchange column for the efficient treatment of Sr2+ solutions by a dynamic manner. The efficient Sr2+ removal of KInSnS4@CFs aerogel mainly originates from ion exchange between Sr2+ and K+ in the interlayer spaces of KInSnS4, while the CFs mainly serve as support materials. This work not only provides a new easy-to-operate and environmentally friendly metal sulfide composite aerogel, but also paves the avenue for the application of CFs from leather industry waste.