The role of biomass in polyethylenimine-coated chitosan/bacterial biomass composite biosorbent fiber for removal of Ru from acetic acid waste solution

•Bacterial biomass in fiber provides the driving force for binding of cationic PEI.•GA cross-linking is needed to keep stable PEI coating on the fiber surface.•SEM, FTIR, and XPS results revealed that PEI was well coated on the fiber surface.•The maximum Ru uptake of PBBF was 6.9 times higher than that of raw biomass.•Kinetic studies showed that PBBF was as fast as powder form of raw biomass.

The present study is aimed at understanding the role of bacterial biomass in functionalizing polyethylenimine (PEI)-coated bacterial biosorbent fiber (PBBF). To make PBBF, chitosan/biomass composite fiber was coated with PEI and then cross-linked by glutaraldehyde. The role of biomass in the fiber was investigated through sorption experiments and SEM, FTIR and XPS analyses with differently prepared fiber sorbents. In the case that the chitosan fiber was made without the biomass, it could not be coated with PEI. Meanwhile, the chitosan/biomass composite fiber could successfully coated with PEI and primary amine groups were significantly increased on the surface of the fiber. Therefore, the biomass should be essential to make PEI-reinforced chitosan fiber.