Iron oxide decorated graphene oxide embedded polysulfone mixed-matrix membrane: Comparison of different types mixed-matrix membranes on antifouling and performance

Abstract

Polymeric membrane is widely adopted for water treatment due to its stability in thermal and chemical resistance, smaller footprints and relatively low cost. However, polymer membrane always suffers the poor performance due to its hydrophobic nature. In the recent years, nanomaterials were introduced into membrane matrices to increase the hydrophilicity. In this study, three different types of nanomaterial, iron oxide (Fe3O4), graphene oxide (GO), and iron oxide-decorated graphene oxide (Fe3O4/GO) were embedded in the polysulfone (PSf) mixed-matrix membranes (MMM). This study investigated the effect of three different nanomaterials on the membrane characteristics, performance, and antifouling properties. Membrane characterization, performance, and antifouling was carried out by pore size, porosity, contact angle analysis, zeta potential analysis, flux measurements and flux recovery ratio respectively. First, GO, Fe3O4 and Fe3O4/GO nanomaterials were synthesized using Hummers method, co-precipitation method, and co-precipitation method in the presence of GO. After that, membranes were fabricated using phase inversion method. In this study, Fe3O4/GO-PSf MMM (76.35%) and GO-PSf MMM (64.39%) showed enhanced porosity as compared to the pure PSf membrane (56.89%) due to the presence of abundance hydrophilic group in GO nanoplates. However, the Fe3O4-PSf MMM show slightly lower porosity (53.82%). Contact angle analysis also revealed that Fe3O4-PSf MMM (71.47°), GO-PSf MMM (69.17°), Fe3O4/GO-PSf MMM (69.97°) showed improved hydrophilicity as compared to the pure PSf membrane (78.80°). Experiment also demonstrated that all the MMMs exhibit higher negatively surface zeta potential as compared to pure PSf membrane. The membrane performances were investigated using pure water flux and congo red (CR) dye removal. Study showed that Fe3O4/GO-PSf MMM give the best membrane performance with the flux of 112.47 L/m2. h and CR dye removal of 97%±2. Fouling analysis reveal that all MMMs exhibit high flux recovery ratio (>80%) as compare to pure PSf membrane.