Preliminary study on Polysulphone (PSF) membranes employed in separation processes for wastewaters purification application

In the sustainable global development context, the increasing demand of water for human requirements favoured the research on alternative wastewaters purification processes. In the last 50 years, new technologies for substances separation, so-called membrane processes (Microfiltration, Nanofiltration, Ultrafiltration, Osmosis), have been extensively studied. They use different membranes and operative conditions promoting the separation and removing contaminant particles in a wide molecular cut-off range. Ultrafiltration process, used for water treatment, works in low-pressure conditions. One of the most used polymers is Polysulphone (PSF) due to its high thermal, chemical and hydrolytic stability. In the present work, a preliminary investigation on PSF membranes with hydrophilic and antifouling properties is presented. The phase inversion method was used to obtain asymmetric membranes with different characteristics of porosity, hydrophilic properties, macro-voids size and shape. The membranes were characterised in terms of XRD, TGA-DSC, dimensional analysis, water retention, qualitative contact-angle, DMA. Cross-section SEM was used to evaluate the relationship between membrane formation parameters and obtained morphology. Promising results in terms of compromise morphology/hydrophilic properties/stiffness were obtained and some of these samples permitted having a good approximation about morphology suitable to the final application. Permeability tests, contact angle and zeta potential measurements are actually in progress in order to individuate the most suitable procedure and the most performing sample for application in the industrial wastewaters purification and recovery of contaminating species.