Porous metal organic framework CuBDC nanosheet incorporated thin-film nanocomposite membrane for high-performance forward osmosis

Surfactant assisted synthesis of hierarchical porous metal-organic frameworks nanosheets

Two-dimensional metal-organic frameworks show increasing research attention due to their unique properties including tunable thickness, simple packing into a film and membrane, and high surface-to-volume atom ratios. A bottom-up synthesis strategy using cetyltrimethylammonium bromide for the synthesis of copper-benzenedicarboxylate (Cu(BDC)) nanosheets is reported. The method offers the synthesis of hierarchical porous Cu(BDC) lamellae with micrometer lateral dimensions, and nanometer thickness (100-150 nm). Electron microscope (scanning and transmission), and N₂ adsorption isotherms confirm the formation of lamellae Cu(BDC) with mesopore size of 5-80 nm. The material has thermal stability up to 400 °C with good chemical stability in several organic solvents. However, the material transforms to another phase (Cu(BDC)(H₂O)₂) when soaked in water and alcohols. The transformation reduces crystal size and offers the formation of hydrogen bond resulting in an increase in the sorption of CO₂ by ∼10% compared to the pristine material Cu(BDC).

Forward osmosis membrane processes for wastewater bioremediation: Research needs

Increasing research and development works have been made to develop forward osmosis (FO) processes as a cost-effective substitute for energy intensive water vacuum suction facility in submerged membrane bioreactor (MBR) applications. Perceived to be a spontaneous water driven process without external applied pressures, the FO has been applied in lab and pilot scales for wastewater bioremediation. This paper reviewed the state-of-the-art developments on the FO unit, the process, and ways of enhancing process performance, particularly on the aspects of flux enhancement, flow resistance reduction, and draw solute with low reverse salt diffusion, which are relevant to enhanced osmotic MBR performance. The perspective to realize the use of FO processes in revision of currently existing energy intensive osmotic MBR processes is discussed with research needs being highlighted.