Application of a novel Polydopamine@EDTA@Fe3O4 material for efficient simultaneous nitrogen and nickel removal in an immobilized biofilm reactor

Abstract

AbstractHigh NO3− and Ni(II) concentrations in mining wastewater pose a risk to public health. In this study, the NO3− and Ni(II) removal process was performed using a novel PDA@EDTA@Fe3O4 immobilization carrier. The effects of hydraulic retention time (HRT; 6, 8, and 10 h), along with Fe(II) (10, 15, and 20 mg/L) and Ni(II) (10, 20, and 30 mg/L) influent concentrations on the simultaneous removal of NO3− and Ni(II) were investigated in immobilized biofilm reactors. Results showed that the highest NO3− removal efficiency (97.78%) and Ni(II) removal efficiency (91.21%) were obtained in the immobilized biofilm reactor with PDA@EDTA@Fe3O4 under the conditions of 10 h HRT, influent Fe(II) concentrations of 20 mg/L and Ni(II) concentrations of 10 mg/L. High-throughput sequencing results confirmed that Cupriavidus sp.CC1 plays a major role in the functioning of the immobilized reactor. This process provides the potential for effective treatment of NO3− and Ni(II) polluted water.