Optimizing Anode Construction for Improved Performance in Ecological Floating Bed Microbial Electrochemical System (ECOFB-MES): Engineering Application and Construction Strategy

As an emerging technology, ecological floating beds coupled with microbial electrochemical systems (ECOFB-MESs) offer the road for synchronous remediation of actual polluted surface water and sediment along with the recovery of bioenergy from pollutants. However, the selection and arrangement of large-scale anodes to achieve optimal pollutant removal efficiency and system output performance remain unexplored. In this study, various types of anode units (2D anodes: carbon cloth and 3D anodes: carbon felt) with different configurations (integral and independent connection) were employed in the remediation of actual polluted surface water to investigate their impact on system performance. The results indicate that 2D integral anodes exhibited superior sediment organic pollutant removal rates (integral: 73.6 +/- 1.1%, independent connection: 71.2 +/- 0.8%) and bioelectrochemical performance (integral: 2.881 +/- 0.016 mW/m(2), independent connection: 2.387 +/- 0.008 mW/m(2)) compared to independently connected anodes of the same projected areas. Model simulations using COMSOL software revealed that the connection of multiple independent anodes led to system performance degradation due to increased potential drop during electron transport in the anode. Furthermore, the introduction of pores in 3D anodes did not contribute to an increased potential drop. However, it resulted in improved pollutant removal rates and system output performance by 3.1 and 11.2%, respectively. Model simulations suggested that integral anodes should be employed in practical applications to mitigate potential drops caused by connections and ensure optimal system performance. This research provides valuable insights and strategies for the large-scale construction of anodes in ECOFB-MES.