Fabrication and characterization of anti-fouling and non-toxic polyvinylidene fluoride-sulphonated carbon nanotube ultrafiltration membranes for membrane bioreactors applications. (original) (raw)

The ultrafiltration (UF) membrane in membrane bioreactor (MBR) technology is the mostsuitable in a wastewater treatment plant (WWTP). In MBR systems, bacteria consumeorganic waste for energy to survive. Hence, the membranes should be non-toxic to thebacteria but still possess antifouling capability. In this study, carbon nanotube (CNT)-and sulphonated CNT (SCNT)-blended ultrafiltration polyvinylidene fluoride (PVDF) mem-branes were fabricated with the aim of conserving the bacterial population. The successfulsulphonation of CNTs was observed by X-ray photoelectron spectroscopy, X-ray diffractionand transmission electron microscopy. The porosity of PVDF-CNT and -SCNT membraneswas 81 and 84%, respectively. The mean pore size was 50 and 60 nm, respectively, and thecorresponding water flux experiment was 360.43 and 680 L m−2h−1. The fouling recoveryratio (FRR) of the CNTs and SCNTs were 72.74 and 83.52%, respectively. In addition, theBSA (bovine serum albumin) rejection was 90% in the PVDF-SCNT. The CNTs and SCNTs(150 g/mL) had a significant antibacterial effect against Escherichia coli, Pantoea agglomerans,and Pseudomonas graminis isolated from full scale MBR with 60% cell viability. On the otherhand, PVDF-CNT and -SCNT membranes were nontoxic (90%, p < 0.0001) to the bacterial pop-ulation. Therefore, the fabricated UF membranes have sustainable antifouling propertiesand are non-toxic to bacteria. This study suggests that PVDF-CNT and -SCNT are promisingmaterials for MBR systems in WWTPs.