Effective removal of humic acid using xanthan gum incorporated polyethersulfone membranes

• Incorporated of XA in neat PES, shows enhanced water flux.
• Modified membranes exhibited better rejection % comparer than neat PES membrane.
• The modified membranes showed similar rejection properties to commercially available PES 30 K Da membrane
• Humic acid rejected up to 97%.

In this study, xanthan gum (XA) was used as a hydrophilic biopolymer additive for the modification of polyethersulfone (PES) membrane to removal of humic acid (HA). The membranes are prepared using phase inversion technique and the concentration of XA was varied from 0.5 to 1.5 wt%. The prepared membranes are characterized as a function of hydrophilicity, equilibrium water content (EWC), porosity studies and functional group analysis. Membrane surface and cross-sectional morphology was studied using scanning electron microscope. The lower contact angle value 64.2° was exhibited, when 1.5 wt% of XA incorporated in PES membrane and this ensures that increase of hydrophilicity in pristine PES membrane. Further, higher water permeability (PWP) of 68.9−9 m/s kPa was observed for 1.5 wt% of XA/PES membrane. The effect of pH on HA removal was studied for neat PES and XA/PES membranes. The rejection performance of XA incorporated in PES membranes were compared with commercial available PES membrane.