Preparation and characterization of novel polysulfone nanofiltration membranes for removal of cadmium from contaminated water

In this research, novel asymmetric polysulfone (PSF) membranes with high hydrophilicity, contact angel 53°, and noticeable rejection of cadmium, up to 98%, were prepared from PSF/IGEPAL/NMP system via immersion precipitation. The effect of adding IGEPAL as an amphiphilic additive as well as coagulation bath temperature (CBT) on morphology, wettability and permeability of the prepared membranes were studied by scanning electron microscopy (SEM), contact angle measurement and permeation experiments. The results demonstrated that both hydrophilicity and cadmium removal of the prepared membranes were significantly enhanced by small addition of IGEPAL surfactant in the casting solution along with using the lowest level of CBT. Also it was found out that initial addition of IGEPAL in the casting solution along with increasing the CBT resulted in formation of membranes with high permeability and sub-layer porosity and thin top layer.

► Novel asymmetric PSF membranes with high hydrophilic property were prepared.
► Hydrophilic membranes achieved using cold coagulation bath and IGEPAL addition.
► High removal of toxicant material, Cd, was obtained using the modified membranes.
► High porosity and water permeation achieved using normal coagulation bath.