Performance and antifouling behaviour of nanoclay incorporated polysulfone ultrafiltration membrane for wastewater treatment

Montmorillonite clay (MMT) modified with dimethyl dialkyl amine (mMMT) are introduced to transform the hydrophobic polysulfone (psf) ultrafiltration membranes into hydrophilic membranes. In the present work, ultrafiltration membranes are prepared using the solvent N-methyl pyrrolidone (NMP) and polyvinylpyrrolidone (PVP) as porogen by phase inversion technique and the amount of mMMT is varied from 1 to 5 wt.%. The prepared membranes are characterized by scanning electron microscopy and X-ray diffractometer. Water uptake, contact angle, and porosity of the membranes are evaluated to analyze the hydrophilicity of the membrane. Performance studies are conducted in a cross-flow filtration unit using a synthetic solution containing 5 ppm chromi- um(VI) ions and membranes with varying percentages of mMMT. A chromium ion rejection of 93% and a flux rate of 200 L/m2h were obtained for membrane incorporated with 3% mMMT compared to a rejection of 64% and flux rate of 44 L/m2h for neat psf membrane. The antifouling behavior was studied using organic foulant, bovine serum albumin (BSA) solution (100 mg/L). Antifouling studies show that for 3 wt.% mMMT, flux recovery ratio increases from 58% to 77% with the reduction of irreversible resistance from 41% to 22% and the total resistance 67% to 45% as compared to neat psf membranes. The addition of mMMT improved the chromium ion removal efficiency and antifouling property of the membrane.