Introducing Micro Flowerlike Bismuth Sulfide for Iodate Anion Removal

There are strong radiological hazards and the risk of direct cell damage in living organisms for radioactive iodate (¹³¹IO₃^-/¹²⁹IO₃^-). Thus, it is essential to capture and remove them. In the contribution, the micro flower-like Bi₂S₃ (MF-Bi₂S₃) was prepared via a hydrothermal method to investigate its adsorption behavior toward IO₃^-. MF-Bi₂S₃ exhibits the maximum adsorption capacity of 875.6 mg/g for IO₃^- at pH ≈ 3, and the adsorbent achieves a removal efficiency of 98.98% within 2 h. Furthermore, the removal efficiency of MF-Bi₂S₃ can still reach 96.37% at high concentrations of coexisting anions such as Cl^-, SO₄^2-, NO₃^-, and CO₃^2-, demonstrating excellent anti-interference performance. In simulated artificial groundwater, the adsorbent achieves a removal rate of 88.8% for IO₃^-, suggesting its potential to solve the problem of IO₃^- in actual wastewater. Notably, the adsorbed products change depending on iodine content, with BiI₃O₉ and BiOI as the intermediate products, and the final product is BiOIO₃. X-ray photoelectron spectroscopy detects the presence of I₂ and I₃^- in the product, which is attributed to the reduction and fixed to iodine by S^2-. Meanwhile, the corresponding S^2- becomes SO₄^2- and remains in the liquid after the reaction. This work provides a breakthrough solution for effectively removing IO₃^-.