Ultrafast and Highly Selective Sequestration of Radioactive Barium Ions by a Layered Thiostannate
Yaning Wang, Jinting Wu, Bao-Han Li, Yan Yang, Jun Li, Bo Zhang
Abstract
As a simulant of hazardous 226 Ra 2+, the simultaneously selective and rapid elimination of radioactive 133 Ba 2+ ions from geothermal water is necessary but still challenging. In this paper, we demonstrated the usability of a layered thiostannate with facile synthesis and inexpensive cost, namely, K 2 x Sn 4– x S 8– x (KTS-3, x = 0.65–1), for the remediation of radioactive 133 Ba 2+ in multiple conditions, including sorption isotherm, kinetics, and the influences of competitive inorganic/organic ions, pH values, and dosages. KTS-3 has a strong barium uptake ability (171.3 mg/g) and an ultrafast adsorption kinetics (about 2 min). Impressively, it can achieve a high preference for barium regardless of the excessive interference ions (Na +, K +, Mg 2+, Ca 2+, and humic acid) and acidic/alkaline environments, with the largest distribution coefficient K d value reaching 6.89 × 10 5 mL/g. Also, the Ba 2+ -laden products can be easily eluted by a concentrated KCl solution, and its adsorption performances for barium resist well even after five consecutive cycles. In addition, owing to the regular appearance and excellent mechanical strength, the prepared KTS-3/PAN (PAN = polyacrylonitrile) granule displays a good removal efficiency in the flowing ion-exchange column. These advantages mentioned above render it very promising for the effective and efficient cleanup of radioactive 133 Ba 2+ -contaminated wastewater.