Polysulfone/Brij-58 blend nanofiltration membranes: preparation, morphology and performance

Abstract

In present research, novel asymmetric polysulfone (PSF)membraneswith high hydrophilicity and noticeable rejection of arsenic, as one of the major environmental problems, were prepared from PSF/Brij-58/NMP (1-methyl-2-pyrrolidone) system via immersion precipitation. Pure water was used as gelation media. The variation effect of coagulation bath temperature (CBT) and addition of Brij-58 on morphology, wettabiliy, pure water permeation flux and rejection of As (III) and As (V), as two dominant states of arsenic in the nature, were studied by scanning electron microscopy, contact<br><br>angle measuring instrument and experimental setup. The results demonstrated that both hydrophilicity and rejection properties of the preparedmembranes were significantly enhanced by small addition of Brij-58 surfactant in the casting solution along with using the lowest level of CBT. Addition of 4 wt.%of Brij-58 and using cold coagulation bath resulted in the highest rejection of As (V). Initial increase in Brij-58 concentration, from 0 wt. % to 2 wt. %, resulted in higher rejection of As (III). However, higher Brij-58 concentrations than 2 wt. % (increase from 2 wt. % to 6 wt. %) led to lower rejection of As (III). Also, it was found out that addition of Brij-58 in the casting solution along with increasing the CBT<br><br>resulted in formation ofmembraneswith high permeability and sub-layer porosity and thin top layer.