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Humic acid was immobilized on a polypropylene supported sodium alginate/hydroxyethyl cellulose blend membrane in the current work. The adsorption property of this membrane for the removal of cationic dyes, namely, methylene blue (MB) and rhodamine B (RhB) was extensively studied. Batch-adsorption experiments were conducted to investigate the adsorption behavior of dyes on the membrane with variation in adsorbent mass, initial dye concentration, pH, time and temperature. The membranes were characterized by Scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR) and Atomic force microscopy (AFM). Prepared membranes showed more than 98% removal capacity for both dyes under optimal conditions. Kinetic experiments revealed that, the pseudo second order model exhibited best correlation with the adsorption data. Dubinin-Radushkevich model indicated that, the adsorption of dyes onto the membrane surface was by simple physisorption. The membrane was easily regenerated by simple acid treatment and its efficiency remained significant even after four adsorption cycles.

A cellulose acetate (CA)-based ultrafiltration membrane was prepared by incorporation of mechanically strong, sulfonated poly­(1,4-phenylene ether ether sulfone) (SPEES) to which hydrolyzed poly­(styrene-co-maleic anhydride) (PSMA) was added as a novel additive. The preparation of SPEES was investigated in detail. SPEES having a degree of sulfonation of 21%, was more suitable for the blend. The chemical constitutions of SPEES, PSMA, and the blend membranes were confirmed by attenuated total reflectance fourier transform infrared spectroscopy. The scanning electron microscopy images revealed finger-like projections in the membrane structure. The performance of the membranes was analyzed on the basis of water content, porosity, flux, and antifouling studies. A membrane comprising 30% SPEES and 2% additive showed superior performance with flux and flux recovery ratio of 228 L/(m2 h) and 91%, respectively. It was concluded that the prepared membranes showed better performance in comparison with neat CA membranes.

Composite membrane having chitosan (CH) as the active layer supported on Poly(1,4phenylene ether ether sulfone) (PPEES) membrane was synthesized in the current study. The chitosan layer was crosslinked by glutaraldehyde in two different concentrations. The scanning electron microscopic images and hydraulic permeability coefficient revealed the ultrafiltration (UF) nature of the neat PPEES membrane. This was used as a new support material for the casting of chitosan layer in order to get composite membranes. The composite nature of the PPEES/CH membranes was confirmed by FESEM and DSC analysis. The Infrared spectroscopy results confirmed the crosslinking of the chitosan surface by glutaraldehyde (GA). The changes in the hydrophobic nature of the PPEES membrane surface due to deposition of chitosan active layer followed by crosslinking were studied by their contact angle measurement and water flux study. From our studies, PPEES has proved to be a good support membrane for preparation of composite membranes. Increase in GA concentration increased the salt rejection of the membrane up to 34% for NaCl and 53% for MgSO4 on one hand with a simultaneous decrease in the flux values. The hydraulic permeability coefficient values confirmed that the prepared membranes are in nanofiltration range.

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