Evaluating decolorization capacity about alginate encapsulation system of Shewanella oneidensis MR-1 mingled with conductive materials

Abstract

Sodium alginate (SA) encapsulation system of Shewanella oneidensis MR-1 mingled with different conductive materials (single-walled carbon nanotube (SWCNT), graphene oxide (GO) or Fe3O4) were employed to decolorize of methyl orange (MO). The result of batch experiment showed that beads of SA/SWCNT/S. oneidensis MR-1 and SA/GO/S. oneidensis MR-1 revealed better decolorization capability compared with SA/Fe3O4/S. oneidensis MR-1 and SA/S. oneidensis MR-1. Recycle batch experiment revealed that the addition of SWCNT had superiority ability to improve decolorization capability. From cycle 1 to 6, the decolorization capability decreased from 100% to 58.90% with beads of SA/S. oneidensis MR-1, while from 100% to 94.44% with beads of SA/SWCNT/S. oneidensis MR-1 at 2.25 h, respectively. The results of morphology, rheology, and mechanical strength demonstrated that the addition of SWCNT also increased the mechanical strength. Thus, this research would provide the feasibility for recycling of immobilized microbial with higher efficiency and longer lifetime during wastewater treatment.