Thin Film Nanocomposite Forward Osmosis Membrane with Exfoliated Layered Double Hydroxide Nanosheets Embedded Support for Fouling-Resistant Microalgae Dewatering

Microalgae dewatering using membrane technology has become feasible. The features of membrane are essential for achieving efficient dewatering performance. Thin-film nanocomposite membrane with layered double hydroxide (LDH) nanosheet incorporated substrate and its performance in microalgae dewatering were examined in this research. The membrane has been developed to address the drawbacks of FO in regards to concentration polarization, reverse draw solute diffusion, and antifouling. The morphology, wettability, permeability, fouling resistance, and long-term performance of the membranes was improved by incorporating exfoliated LDH within the polyethersulfone (PES) support layer of polyamide TFN membranes. Dewatering of Chlorella vulgaris by FO in active layer facing feed solution (AL-FS) and active layer facing draw solution (AL-DS) was evaluated with 2M NaCl as draw solution. The findings revealed the 0.5% LDH embedded within PES support, the water flux improved by 111.43% contrasted with neat membrane. The 0.5% LDH-TFN showed improved antifouling properties during the 4-cycle microalgae dewatering. In addition, the incorporation of LDH supressed internal concentration polarization of TFC membranes thus exhibiting good flux stability throughout the 72h operation. This research evidenced the intriguing prospect of exfoliated Zn-Al LDH as a promising additive to modify TFC membrane for high performance microalgae dewatering.