Filtration performance improvement of plateled shaped zinc oxide doped polyvinyl chloride ultrafiltration membranes and modelling of flux

In this thesis, filtration performance, morphological and bulk properties of membranes fabricated using designed Zinc oxide powders (MicNo®) with controllable agglomeration, which is considered to be a potential solution to agglomeration issue encountered in nanocomposite membrane applications. To this end, the most suitable casting solution composition of the pristine PVC membrane fabricated via phase inversion technique was determined according to water flux and sodium alginate (SA) rejection values and nanocomposite membranes were prepared based on that recipe. Nanocomposite membranes were fabricated using varying loadings of commercial ZnO nanoparticles (0.25-2%, wt.) and MicNo® powders (0.01-0.1%, wt.) and while filtration performance was investigated in terms of water flux, different foulant rejections, and antifouling properties, morphological properties, thermal and mechanical stabilities were determined using various analytical equipments and techniques. The highest water flux (420 L/m2h) and flux recovery ratio (90.2%) for the commercial ZnO doped membranes were obtained with 0.5% ZnO addition into the membrane matrix. Water flux (456 L/m2h) of PVC based membrane containing 0.05% MicNo® platelets were increased by 30.6% and 9%, respectively compared to those of pristine PVC and 0.5% ZnO membrane. Although the amount of MicNo® platelets (0.05%) added to the membrane matrix were ten times less than that added to commercial ZnO membrane, rejection and antifouling properties were enhanced significantly due to large active hydrophilic surface area of MicNo® powders. Moreover, the flow through membrane pores was numerically modelled based on symmetrical and asymmetrical morphologies and comparison of numerical and experimental results showed that the present numerical model can accurately predict flux values at low transmembrane pressures.