Synthesis and performance of guanidinium-based cationic organic polymer for the efficient removal of TcO 4 - /ReO 4

Cationic organic polymers have found relatively extensive utility for TcO /ReO removal, but the harsh preparation conditions constrain their practical application. The bifunctional guanidinium-based cationic organic polymer (GBCOP) was successfully and facilely synthesized in benign conditions within 1 h. Batch experiments showed that GBCOP exhibited rapid removal kinetics (1 min, >98.0%) and a substantial removal capacity of 536.8 mg/g for ReO . Even in 1000-fold co-existing NO anions, the removal efficiency of GBCOP for ReO was 74.0% indicating its good selectivity. Moreover, GBCOP had high removal efficiencies for ReO across a wide pH (3.0-10.0) range and presented remarkable stability under the conditions of strong acid and base. GBCOP could be reused four times while removing 80.8% ReO from simulated Hanford wastewater. SEM and XPS results revealed that the mechanism of ReO removal involved Cl ion exchange within the channels of GBCOP. Theoretical calculation results supported that existing the strong electrostatic interaction between guanidinium and ReO . This dual function GBCOP material is cost-effective and holds significant potential for large-scale preparation, making it a promising solution for TcO removal from nuclear wastewater.