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-, SO42-, NO3-, and CO32-, 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 S2-. Meanwhile, the corresponding S2- becomes SO42- and remains in the liquid after the reaction. This work provides a breakthrough solution for effectively removing IO3-.