Enhanced oil–water separation using polysulfone membranes modified with polymeric additives

For separation of oil and water mixture using ultrafiltration (UF), polysulfone (Psf) membranes were synthesized by phase inversion method using N-methyl-2-pyrrolidone (NMP). In order to achieve both higher permeation flux and fouling resistance, modification of Psf has been done by adding polymeric additives such as polyvinylpyrrolidone (PVP), polyetherimide (PEI), polyethylene glycol (PEG) and polyethersulfone (PES). Pure Psf membrane showed a lower flux of about 0.26 L m− 2 h− 1 which on PVP addition helped to enhance flux to the highest value of 33.66 L m− 2 h− 1. The performance in oil and water separation in terms of rejection efficiency with respect to the concentration polarisation phenomenon was measured for each modified Psf membrane. The morphology and hydrophilicity of the modified membranes were investigated by a scanning electron microscopy (SEM) and contact angle analysis respectively. The UF experimental results using synthetic vegetable oil–water mixture showed that retention of oil over the membrane was nearly 99.8% for Psf/PVP membrane and also have excellent oil-fouling resistance ability even during dead-end batch UF under higher operation pressure.