Polyethersulfone/gelatin nano-membranes for the Rhodamine B dye removal and textile industry effluents treatment under cost effective condition

Abstract

Nanofiltration modified Polyethersulfone (PES) membranes using gelatin biopolymer were prepared via a phase inversion method for textile wastewater treatment. Polyethersulfone (PES) good mechanical, chemical and thermal stability have made it a good candidate in fabricating membranes for the application in medical and industrial wastewater treatment. However, the high hydrophobicity of polyethersulfone has limited its wide application. In this study, blending with a low cost and sustainable biopolymer, gelatin, has been employed. Gelatin dissolved in acetic acid was blended with PES in different ratios1%, 3%, 5% and 7% to elevate PES performance to the nanofilteration level using low pressure for separation (2 and 3 bar). Spectral and thermal analysis were employed to study chemical structure and surface morphology of the prepared membranes. The increase in hydrophilicity was detected by contact angle measurement along with increasing gelatin content. As a result, 427.5% improvement in water flux was recognized by adding 3% of gelatin to PES (3G). 3G membrane showed the highest rejection ratio (98%) of cationic dye, Rodamine B dye (RB). Compared to the pure PES membrane, 3G showed a remarkable antifouling performance. By implementing 3G for the treatment of textile waste, chemical oxygen demand (COD) % removal was 67.7. These results show the good candidacy of the prepared membrane for the treatment of textile industrial fluids and reuse of treated wastewater in the dying process.