Abstract:
Shewanella oneidensis MR-1 has been proved to be a potential bacterium to decolorize methyl orange (MO). Nevertheless, longer reaction time was needed to achieve higher decolorization efficiency. Thus, it's necessary to further improve the decolorization efficiency of azo dyes using
S. oneidensis MR-1. The embedding of
S. oneidensis MR-1 and nano-Fe
3O
4 with sodium alginate (SA) is an ideal mode for efficient decolorization of MO. Morphology, rheology and mechanical strength were studied to better understand the decolorization capacity and recycle of the beads. The MO decolorization efficiency with SA, SA/Fe
3O
4, SA/
S. oneidensis MR-1 and SA/
S. oneidensis MR-1/Fe
3O
4 beads was studied. Compared with the beads of SA/
S. oneidensis MR-1, the decolorization efficiency with SA/
S. oneidensis MR-1/Fe
3O
4 was improved. After three cycles, 77.83% of decolorization capability could be recovered with beads of SA/
S. oneidensis MR-1/Fe
3O
4 while only 53.19% recovered with SA/
S. oneidensis MR-1 at 1.75 h in cycle 4 under transverse condition, respectively. The addition of Fe
3O
4 not only improved the decolorization capacity of beads of SA/
S. oneidensis MR-1/Fe
3O
4 but also increased the mechanical strength. This research would provide the feasibility for recycling of immobilized microbial with higher efficiency and longer lifetime during wastewater treatment.