(507g) Bioinspired Polydopamine Based Nanocomposite Coatings for Industrial Oily Water Treatment Membranes

Large quantities of oily wastewater are produced daily from industrial processes, including petrochemical, textile, leather, and steel processing. Various approaches including oil-absorbing materials, gravity separation, flocculation, and coagulation have been applied for oil/water separations. However, these concepts are ineffective in separating oil/water emulsions with oil droplet size smaller than 20 µm and do not perform well upon incorporating chemicals or using an electric field. Membrane filtration is one of the best strategies for large-scale oil/water emulsions, especially surfactant-stabilized emulsions, due to their highly pure permeate, simplicity, and recyclability properties. However, the hydrophobic nature of polymeric membranes make them vulnerable for pore plugging by oil droplets and/or surfactant adsorption, and thus, a dramatic decrease in the water flux. To overcome this challenge, this work presents a strategy that utilizes hydrophilic polydopamine (PDA) coatings that mimic foot protein 5 (Mefp-5) of Mytilus edulis. Different fillers were used in combination with the PDA including MXene, chitosan, and CuO nanoparticles. The modified membranes displayed significant enhancement in separating oil from water in tight emulsions while demonstrating remarkably high resistance to fouling over five runs in comparison to the unmodified and PDA treated membranes that instantly fouled within only two emulsion runs. The modified membranes were tested for coating’ chemical stability against cleaning protocols, mechanical integrity, water flux and oil rejection, SEM, surface charge, and water contact angle.

This presentation will outline the membranes’ oil rejection efficiency, chemical, morphological, and mechanical stability of the coatings after cycles of cleaning and reuse. Finally, the membranes were tested using synthetic oily water and real-field samples and testing protocols from the oil & gas companies in Qatar.