Simultaneous removal of nitrate, manganese, zinc, and bisphenol a by a biofilm reactor with β-CD modified corn stover biochar and PU sponges: Performance and microbial community response

In the present study, a biofilm reactor with manganese (Mn) redox cycling was established to remove nitrate (NO3 --N), bisphenol A (BPA), zinc (Zn(II)), and Mn(II) using beta-cyclodextrin (beta-CD) modified corn stover biochar (BC) and polyurethane sponges loaded with Cupriavidus sp. HY129 and Pantoea sp. MFG10. At C/N = 2.0, HRT = 6 h, Mn(II) = 10.0 mg L- 1, and BPA and Zn(II) concentrations = 1.0 mg L- 1, the removal efficiencies of NO3 --N, Zn(II), BPA, and Mn(II) were 81.5%, 86.5%, 87.9%, and 75.5%, respectively. The outcomes demonstrated the success that the addition of beta-CD could accelerate electron transfer activity and the denitrification process. The remediation of BPA and Zn(II) was mainly through the adsorption of bioprecipitation generated by reactor operation. The bioreactor could preserve the stability of the biological community and the expression of pertinent functional genes under the coercion of BPA and Zn(II).