LAUSR

Abstract Exceptionally successful conventional bilayer system of thin film composite (TFC) polyamide nanofiltration and reverse osmosis (NF/RO) membranes are gradually facing several challenges, including trade-off relationship between flux and rejection due to high tendency to fouling. Herein, we demonstrate preparation of nanocomposite membranes comprising functionalized natural clay Bentonite in polyamide selective layer as flux promoting and antifouling agent for NF applications. Herein, the sulfonated clay was induced in polyamide selective layer via modified interfacial polymerization method. Polyamide (PA) thin selective layer on polysulfone (PSf) ultrafiltration membrane was used as support for both facial coating on fabric support as well as free standing membranes. Morphology of modified PA layer was considerably altered by introduction of functionalized nanoclay. Further, membranes were characterized for their functionality, and morphologies using ATR-IR and field emission scanning electron microscopy (FESEM), respectively. Membrane performance in NF processes was evaluated in terms of pure water flux, commercial standard MgSO4 salt (>20%) and malachite green oxalate dye (>98%) rejections. The anti-fouling studies were performed using humic acid feed. At low operating pressure modified membrane showed exceptional flux reclamation potential (3–4 fold) making it economical for NF process operations. Hydrophilicity characteristics of pristine and modified membranes were recorded using contact angle measurements.