Metal organic framework in membrane separation for wastewater treatment: potential and way forward

Abstract

Metal organic framework (MOF) is a class of porous material that has been acknowledged for its high porosity, tunable pores and distinctive chemical functionalities. This paper reviewed some of the selected MOF applied in adsorption and membrane separation for wastewater treatment. As adsorbent, certain MOF demonstrated high solute rejection and adsorption capacity, much contributed by high surface area and more active sites to bind with solutes. In another way, MOF can be incorporated as nanofiller in thin-film nanocomposite or mixed-matrix membrane. This water stable MOF inclusion has tuned the membrane chemistry and morphology to be more selective toward solute while enhancing water permeability. The stability of MOF was governed by high number of positive charge per atom, high coordination number, presence of hydrophobic functional groups and also their ability to resist coordination with water molecules. Important issues regarding with MOF in membrane had been addressed, particularly MOF agglomeration that further deteriorated membrane performance. At the end of the review, a conclusion and future perspective is suggested as remarks.