Synthesis of a bifunctional metal-organic framework membrane for the removal of anionic and cationic heavy metals from wastewater

Abstract

Abstract A novel adsorption composite composed of metal-organic frameworks with bifunctional groups of -NH2 and -COOH [UIO-66-NH2(-COOH)] loaded onto the fiberglass membrane labelled as F-MOFs-M was fabricated by a two-step method. This surface-modified composite could simultaneously capture both anionic and cationic heavy metal ions from wastewater, and the adsorption priority followed an order of SbO3−, CrO42−, AsO43−, Pb2+, and Ni2+. The adsorption capacity for AsO43−, CrO42−, SbO3−, Ni2+, and Pb2+ was 55 mg·g− 1, 189 mg·g− 1, 342 mg·g− 1, 16 mg·g− 1, and 133 mg·g− 1, respectively. It could be used for the quick removal of these toxic ions by withdrawing the membrane after adsorption. Additionally, the prepared F-MOFs-M provided an excellent stability in 7 days of continuous work, and could be easily regenerated and reused without significant decrease in removal performance even after 5 filtration cycles. The adsorption performances and their corresponding mechanisms were exploited by a series of advanced techniques. The MOF-derived materials loaded on membrane provide a new application scenario in the remediation of polluted water bodies.