Effective diesel removal by a novel electrospun composite nanofibrous membrane with immobilized Bacillus cereus LY-1

Abstract

Nanofiber membranes have recently been considered as promising supports for the immobilization of microorganisms due to the simplicity and cost-effectiveness of electrostatic spinning technology and the ability to control fiber morphology, such as obtaining higher surface area and porosity. In this study, electrospun polyvinyl alcohol/sodium alginate/attapulgite (PVA/SA/ATP) nanofiber membrane was prepared as support for immobilized Bacillus cereus LY-1 for diesel degradation in an aqueous medium and a significant improvement in diesel removal efficiency was realized. The effect of modified ATP concentration on diesel removal was investigated. The results showed that the nanofiber membranes complexed with cetyl trimethyl ammonium bromide (CTAB) and 1% ATP (w/w) had the best capacity for diesel removing. When the initial diesel concentration was 2 g L⁻¹, about 87.8% of diesel was removed by the immobilized LY-1 cells after 72 h. Immobilization of bacteria improves the ability of bacteria to survive in adverse environments. Immobilized LY-1 cells maintain the nature to remove diesel at high salinity or pH range of 6–9. Furthermore, the reusability of the LY-1 cells-immobilized PVA/SA/CTAB–ATP nanofiber membrane was tested. A diesel removal rate of 64.9% could be achieved after 4 times of use. PVA/SA/CTAB–ATP nanofibrous membranes with immobilized LY-1 cells are feasible, economical and environmentally friendly for remediation of diesel contamination in the aqueous medium, and have potential applications in the future.