Surface modification of Fe3O4 nanoparticles was performed by immobilizing silica, metformine, and amine. Mixed matrix PES nanofiltration membrane was prepared by embedding various concentrations of the modified Fe3O4 based nanoparticles. The membranes were characterized in terms of morphology and performance including investigation of SEM and AFM microphotographs, water contact angle, mean pore size and porosity measurements and determination of pure water flux as well as copper ion removal. Embedding iron oxide nanoparticles resulted in a significant rise in the pure water flux as a result of changes in the mean pore radius, porosity and hydrophilicity of the membranes. Moreover, the copper removal capability of prepared membranes remarkably increased because of improved hydrophilicity and also presence of nucleophilic functional groups on nanoparticles. The membrane fabricated with 0.1 wt.% metformine-modified silica coated Fe3O4 nanoparticles showed the highest copper removal (about 92%) due to high affinity in copper adsorption. Moreover, acceptable reusability was found for the membrane with the best performance after several times of usage/regeneration cycles using EDTA as eluting agent.
