Evaluation of an Imidazolium-Based Porous Organic Polymer as Radioactive Waste Scavenger

⁹⁹TcO₄^- is highly radioactive and hazardous to both the environment and public health, meanwhile, it is quite challenging to have it efficiently removed. Herein an imidazolium-based cationic porous polymer (ImPOP-1) is evaluated for removal of TcO₄^-, with nonradioactive ReO₄^- as the surrogate for experimental operation. It is demonstrated that ImPOP-1 is a rare example that can integrate high adsorption capacity (610 mg g^-1), fast kinetics (93.3% in 30 s), and high selectivity (72.9% in 1000 times excess of SO₄^2- ions) in one material. The distribution coefficient K_d is among the top up to 3.2 × 10⁵ mL g^-1. ImPOP-1 also displays high adsorption performance over a wide range of pH values, and removal efficiency up to 64.3% in a highly alkaline solution (3 M NaOH). Recyclability experiments demonstrate that ImPOP-1 can be reused at least four times. The ImPOP-1 also retains a consistent adsorption capacity up to 609 ± 6.1 mg g^-1 between three different batches of samples. In addition, a real-scenario experiment shows that ImPOP-1 can remove 97.4% of ReO₄^- in a simulated Hanford LAW stream.