Efficient capture of ReO on magnetic amine-functionalized MIL-101(Cr): Revealing from selectivity to mechanism.

The efficient decontamination of pertechnetate (TcO) is an essential task for managing radioactive Tc in nuclear wastes. Perrhenate, (ReO), as a nonradioactive analog, exhibits almost identical physicochemical properties as TcO. Herein, a novel magnetic amine-functionalized MIL-101(Cr) (NH-MIL-101(Cr)@FeO) was prepared and used to efficiently remove ReO from solution for the facile magnetic separation. A series of environmental parameters were considered to investigate the adsorption performance of NH-MIL-101(Cr)@FeO. Experimental results suggested that NH-MIL-101(Cr)@FeO has reached a satisfied adsorption capacity (~401 mg/g) and a very fast adsorption kinetics at pH 7.0. The selectivity for ReO was maintained even in the presence of interfering anions with relatively high concentrations. ReO were mainly captured by N-donor sites of the surface-decorated amine via complexation and were trapped in the cavities of modified MIL-101(Cr). NH-MIL-101(Cr)@FeO exhibits satisfactory adsorption performance for ReO and can be conveniently separated from wastewaters after adsorption.