(702c) Functionalized Magnetic Metal Organic Framework Thin-Film Nanocomposite Membranes with Real-Time Induced Vibrations for Enhanced Antifouling

Membrane fouling is still one of the main limiting factors of membrane separation, even though membrane technologies have been established across the world as one of the most efficient water and wastewater treatment. Fouling reduces membrane separation efficiency by reducing membrane permeability and rejection, shortening membrane lifespan, and increasing process costs due to higher washing requirements. In this work, we report, the electromagnetic-antifouling mechanism based on the surface functionalization of membranes using the metal organic framework (MOF). The generated electromagnetically-induced vibration on the interference of membranes and foulant will hinder and prevent different fouling mechanisms such as cake layer formation, concentration polarization, and pore blocking. The resonance frequency creates the largest vibrations in the membrane; therefore, the foulants absorb the highest energy of vibration, which move them from the membrane surface. We synthesized Fe₃O₄ magnetic nanoparticles (mnp) and then synthesized Fe/Fe₃O₄ MOF using hydrothermal synthesis method. Scanning Electron Microscopy (SEM), X-ray powder diffraction (XRD), size, and zeta potential Brunauer–Emmett–Teller (BET) (for surface area, pore size, pore volume) were used for characterization of fabricated MOFs. The synthesized Fe/Fe₃O₄ MOFs are added to the (i) polyamide (PA) selective layer of thin-film nanocomposite membranes (TFC) and (ii) the support layer of TFC membrane to make mixed matrix membranes. The electromagnetically-induced vibration effect on repellent and movement of foulants (humic acid) are compared for these two conditions. Each foulant has a certain resonance frequency in which it shows the highest vibration. Therefore, it is possible to target specific foulants to be removed from the membrane by producing vibrations with frequencies corresponding to the resonance of foulants. These vibrations do not need high amplitude; even a minimal amplitude (in the range of a millimeter or less) can excite them. We also report the correct frequency of vibration for different foulants.