Abstract:
Because of its high specific surface area and high stability in water, Zr-MOFs has attracted great attention in the field of hydrometallurgy. In this paper, Zr-MOFs was selected as modified matrix materials. The quaternary ammonium active groups were introduced into Zr-MOFs matrix through quaternary-ammonium-functionalized reaction. A quaternary ammonium ionic liquid adsorbent ZJU-101 was constructed for adsorption of Pd(CN)
42−, Co(CN)
63−, and Fe(CN)
63− from wastewater. ZJU-101 has high stability in neutral and weakly alkaline solutions. The adsorption performance test showed that the maximum adsorption capacity of ZJU-101 for Pd(CN)
42− was 126.0 mg·g
−1 at pH=7.0. Introduced quaternary ammonium groups plays a key role in improving the adsorption capacity. The two-step elution method can efficiently separate Pd(CN)
42− in the mixture solution containing Pd(CN)
42−, Co(CN)
63−, and Fe(CN)
63−. Repeated experiments showed that after five cycles, ZJU-101 separated Pd(Ⅱ) from metal cyanide mixture solution with a recovery rate over 93.0%. The mechanism of ZJU-101 adsorption Pd(CN)
42− was confirmed to be an anionexchange process by the analysis of FT-IR, XPS, zeta potentials and the electrostatic potential map.