Modification of PVDF Membranes Using Dopamine/Zinc Oxide for Lead Removal from Aqueous Media

Abstract

Ultrafiltration (UF) have long been a leading separation technology with a strong historic track record for a wide range of applications such as the treatment of groundwater and wastewater. The fast development of techniques for producing nanostructured materials and nanoparticles has led to breakthroughs in a membrane preparation. In the present work, polyvinylidene fluoride (PVDF) based nanocomposite membranes modified with zinc oxide (ZnO), polydopamine (PDA), and ZnO/PDA powders were fabricated using phase inversion technique. ZnO/PDA nanoparticles, which were synthesized via sol-gel method, were incorporated into the membrane matrix by blending and PDA powders were incorporated into the PVDF membrane matrix by coating methods. Surface and cross-sectional morphology, thermal behavior, and mechanical strength of the membranes were characterized using both analytical techniques and instruments. Filtration performance of nanocomposite membranes was tested in terms of water flux, sodium alginate (SA) rejection, and antifouling properties in comparison to those of pristine PVDF membrane. Moreover, lead (Pb+2) removal of the prepared membranes from aqueous solutions complexed with chitosan was thoroughly investigated. Although modification of pristine PVDF membrane using different powders could not improve water flux and SA rejections substantially, anti-fouling properties could be enhanced markedly. PVDF/ZnO/PDA membrane was found to exhibit the best performance in filtration experiments with 92% flux recovery ratio and 97% SA rejection and had the highest lead removal (88.5%) from aqueous solutions.