Surface patterning has captured the interest of the membrane community, particularly after the success of the Sharklet® pattern, which mimics the structure and function of shark skin in the biomedical field. These surface designs alter fluid dynamics at the membrane interface, encouraging localized mixing that can reduce fouling and simplify membrane cleaning. Fouling leads to decreased rejection and water transport through the membrane, as well as a reduced membrane lifespan. Previous research has demonstrated that patterns either larger or smaller than the foulant size can lower the fouling rate. Water produced during oil extraction, characterized by high salinity levels (around 35,000 ppm) and elevated selenium (Se) concentrations (ranging from 500 ppm to 300 ppt), presents significant challenges for reuse. Selenium is known for its bioaccumulative nature, posing risks to aquatic organisms, wildlife, and humans if consumed in amounts exceeding 50 ppb. Nanofiltration membranes are over 93% effective in removing Se oxyanions, but they also filter out other impurities, necessitating additional treatment. Se-selective adsorptive membranes allow for adsorption during the filtration process. This project investigates the impact of patterned membranes with metal-organic frameworks (MOFs) attached to their surfaces on fouling in nanofiltration with foulants approximately 10 microns in size and on Se adsorption/removal. MOF-808, which has an adequate selenite removal capacity of approximately 75 mg/g, was chosen for chemical grafting onto TFC membranes to create MOF-membranes. Both pristine and 50-micron patterned membranes will be evaluated, along with MOF-808 attached to the surface, in a cross-flow filtration system at 150 psi to assess the effectiveness of MOF addition in reducing fouling in the presence of high salinity. The project's hypothesis is that attaching MOFs to the membrane surface will enhance localized turbulence, thereby increasing flux recovery and efficiently removing Se.
