Ageing and Characterization of PES Ultrafiltration Membranes Exposed to Hypochlorite
Polyethersulfone (PES) ultrafiltration (UF) hollow fibers are widely used for drinking water production. During onsite operation, backwashing (brief, high occurrence, low concentration in free chlorine: 10 ppm to 20 ppm) and chemical washing (longer, less frequent, high concentration in free chlorine: 200 ppm to 400 ppm) are applied to PES fibers to ensure their proper functioning.
Impact of industrial washing on membrane properties is still relatively unknown. It has been reported that polysulfone (PSf)  and PES  fibers immersed in chlorinated solutions at different pH undergo more severe degradation at slightly basic pH (pH 8). Authors proposed that PSf and PES fibers degradation rate is directly linked to hypochlorite ion (ClO-) predominance combined to hypochlorous acid (HClO) in solution.
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