Ultrafiltration of Oil-in-Water Emulsions with a Dynamic Nylon–Polystyrene Membrane

Resumo

Dynamic nylon–polystyrene membranes with polystyrene contents of 2.6 and 4.1 wt % have been obtained by applying polystyrene with a particle size of 142–452 nm onto the surface of a nylon membrane with a pore size of 0.45 μm. The deposition of polystyrene onto the surface of the nylon membrane was indirectly confirmed by Fourier-transform IR spectroscopy and probe microscopy. The contact angle of distilled water on the membrane has been found to increase from 44.5° to 106.2° as a result of the deposition of polystyrene particles onto the surface of the initial membrane. The specific productivity of the initial and modified membranes with respect to distilled water and a water–oil emulsion was determined. It has been found that the membrane modification leads to an increase in the degree of removal of petroleum products from an oil-in-water emulsion by 62%; the size of particles separated by the membrane after modification decreased from 450 to 151 nm. It has also been revealed that the specific productivity of the nylon–polystyrene membrane and the original nylon membrane is restored to 98 and 90% of the initial values, respectively, by regeneration.