Rapid and effective removal of strontium ions from aqueous solutions by a novel layered metal sulfide NaTS-2

A novel metal sulfide NaTS-2 was prepared using a simple one-step hydrothermal method to remove strontium ions from the simulated radioactive wastewater, in which metal tin was replaced by tin salts to reduce the cost of the raw materials. NaTS-2 has a layered structure with an approximate molar ratio of Na:Sn:S of 1.94:2.87:7. NaTS-2 could rapidly remove Sr²⁺ with a removal efficiency of 99.3% ± 0.23% within 1 min and at an equilibrium of 60 min, followed by the pseudo-second-order model and Langmuir model with a maximum adsorption capacity of 88.9 ± 0.81 mg/g at 298 K. NaTS-2 exhibited an outstanding affinity for Sr²⁺ (K_d ≥ (3.0 ± 0.10) × 10⁵ mL/g) over a broad pH range of 3-11, also displayed significant affinity (K_d ≥ (1.0 ± 0.15) × 10⁵ mL/g) and excellent removal efficiency (≥ 98.5% ± 0.48%) for typical activated corrosion products (Co²⁺, Mn²⁺ and Ni²⁺). NaTS-2 is a promising adsorbent in the field of radioactive wastewater treatment. (author)