Efficient and rapid elimination of 99TcO4-/ReO4- from medium-low level acid - Wastewater using anion exchange adsorbent

Efficient removal of (TcO4-)-Tc-99 from nuclear wastewater is of great urgency for both nuclear-related environmental remediation and the safe development of nuclear. In this work, an anion exchange adsorbent PP-g-GMA@EDA/SA(Cl) (PGES(Cl)) based on polypropylene (PP) nonwovens is facilely prepared by radiation-induced grafting and chemical modification for (TcO4-)-Tc-99 elimination. By the analogy of the ReO4-, the batch adsorption experiments at medium-low acidity show that PGES(Cl) possessed fast adsorption kinetics (within 10 min), higher uptake capacity (251.13 mg/g for Re(VII)), and excellent selectivity in the presence of excessive competing anions such as NO3-, Cl- and SO42-. In the actual adsorption exploration of (TcO4-)-Tc-99, PGES(Cl) still possesses a rapid adsorption process and excellent selectivity. X-ray photoelectron spectroscopy (XPS) and energy disperse spectroscopy (EDS) analyses reveal that anion exchange between the (TcO4-)-Tc-99 /ReO4- in solution and the chloride ion in PGES(Cl) plays a dominant role in the adsorption of (TcO4-)-Tc-99 /ReO4-. The adsorbed (TcO4-)-Tc-99 /ReO4- can be completely eluted by 1 mol/L HCl even after five adsorption-desorption cycles, indicating the excellent recyclability to capture (TcO4-)-Tc-99/ReO4-. The performance of PGESCl shows potential for effective (TcO4-)-Tc-99 removal from radioactive nuclear wastewater.