Efficient capture of ReO4− on magnetic amine-functionalized MIL-101(Cr): Revealing from selectivity to mechanism

The efficient decontamination of pertechnetate ( 99 TcO 4 − ) is an essential task for managing radioactive 99 Tc in nuclear wastes . Perrhenate, (ReO 4 − ), as a nonradioactive analog, exhibits almost identical physicochemical properties as 99 TcO 4 − . Herein, a novel magnetic amine-functionalized MIL-101(Cr) (NH 2 -MIL-101(Cr)@Fe 3 O 4 ) was prepared and used to efficiently remove ReO 4 − from solution for the facile magnetic separation. A series of environmental parameters were considered to investigate the adsorption performance of NH 2 -MIL-101(Cr)@Fe 3 O 4 . Experimental results suggested that NH 2 -MIL-101(Cr)@Fe 3 O 4 has reached a satisfied adsorption capacity (~401 mg/g) and a very fast adsorption kinetics at pH 7.0. The selectivity for ReO 4 − was maintained even in the presence of interfering anions with relatively high concentrations. ReO 4 − 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 2 -MIL-101(Cr)@Fe 3 O 4 exhibits satisfactory adsorption performance for ReO 4 − and can be conveniently separated from wastewaters after adsorption.