Electrochemical properties and pollution remediation mechanism of P-MFC anode under cadmium stress

Abstract

To explore the remediation feasibility of heavy metal pollution in wetland soil using a plant-microbial fuel cell (P-MFC) and the corresponding mechanism, a P-MFC system was constructed with in situ simulations of real wetland environment. By using Typhalatifolia L. as the trial plant, the electrochemical properties of the anode under different cadmium (Cd) concentrations are analyzed by cyclic voltammetry and electrochemical impedance, and the microbial community structure is determined by high-throughput sequencing. The maximum P-MFC output voltage of 546.65 mV and Cd accumulation of 36.461 mg/kg at the Typhalatifolia L. roots are revealed. Cd stress could not only decrease the output voltage and anodic electrochemical activity of the P-MFC system but also affect the accumulation ability of Typhalatifolia L. and the internal resistance and microbial community structure of P-MFC. We find it feasible to apply P-MFC to large-scale heavy metal remediation in wetland soil, but it is critical to consider the tolerance range of pollution stress to achieve the best balance between energy output and environmental restoration.