Coinstantaneous removal of nitrate and phenol by modified corncob and manganese dioxide based immobilized bioreactor: Enhancement and microbial synergistic mechanisms

In this study, polyvinyl alcohol (PVA), modified corncob powder and manganese dioxide (PCCM) cubes were prepared for entrapping Cupriavidus sp. ZY7 and Pantoea sp. MFG10 in the bioreactor. The denitrification and phenol removal efficiencies reached 89.38% and 89.17% at carbon to nitrogen (C/N) ratio of 1.0, hydraulic retention time (HRT) of 6 h, and the nitrate and phenol concentration of inflow was 15 and 1 mg L-1, respectively. Strain ZY7 could degrade cellulose in corncob to provide available carbon source in the bioreactor, and the enhancement effect was more obvious as C/N ratio increased. High-throughput data confirmed that Cupriavidus and Pantoea were the prevalent strains in the PCCM cubes bioreactor. The synergistic relationship between strains ZY7 and MFG10 was the key to the excellent pollutants removal ability of the bioreactor at low C/N ratio, which was important for the treatment of wastewater with complex contaminants.

Automated summary

In this study, polyvinyl alcohol (PVA), modified corncob powder, and manganese dioxide (PCCM) cubes were used to immobilize Cupriavidus sp. ZY7 and Pantoea sp. MFG10 in a bioreactor. The denitrification and phenol removal efficiencies reached 89.38% and 89.17% at specific conditions. Strain ZY7 was able to degrade cellulose in corncob and provide a carbon source. Cupriavidus and Pantoea were identified as the prevalent strains in the PCCM cubes bioreactor. The synergistic relationship between strains ZY7 and MFG10 played a key role in the excellent pollutants removal ability of the bioreactor at low C/N ratio, which is important for treating wastewater with complex contaminants.