Antibacterial and Adsorption Properties of Sulfonated GO-PVDF Nanocomposite Ultrafiltration Membranes for Environmental Applications

Abstract

The application of nanocomposite materials in membrane bioreactors (MBRs) is attractive because of their great potential to enhance the filtration performance and antifouling. This study modified polyvinylidene fluoride (PVDF) ultrafiltration membranes using graphene oxide (GO) and sulfonation GO (SGO). The antibacterial properties of nanocomposite membranes were tested using three Gram-negative bacterial species (Pantoea agglomerans, Escherichia coli, and Pseudomonas graminis). The results showed that PVDF-GO and PVDF-SGO ultrafiltration (UF) membranes had significantly nontoxic properties (>95%, significance at p<0.0001), indicating that it was innocuous to bacterial growth. On the other hand, the nanoparticles (NPs) (GO and SGO) had approximately 50% antibacterial activity based on the viability tests, disc diffusion, and TEM analysis. The performance of membranes was examined using a pure water prermeabilty flux test. The water flux of the PVDF-SGO membrane (720 Lm−2 h−1) significantly increased compared with that of the GO membrane (428 Lm−2 h−1). Furthermore, the PVDF-SGO membrane had a 65.2% removal of methylene blue (MB), indicating that the SGO incorporated in the membrane enhanced the absorption capacity of heterocyclic aromatic compounds such as MB. The nanocomposite membranes (PVDF-GO and PVDF-SGO) are more sustainable than the PVDF membrane and are promising materials for MBRs because they have higher permeability and absorption capacity, and re harmless to bacterial activity.