College of Natural Resources and Environmental Protection, Wuhan University of Science and Technology, Wuhan 430081, China.
College of Natural Resources and Environmental Protection, Wuhan University of Science and Technology, Wuhan 430081, China.
Bioelectrochemistry. 2022 Feb;143:107984. doi: 10.1016/j.bioelechem.2021.107984. Epub 2021 Oct 16.
Microbial electrochemical system (MES) is a favorable tool for CO emission reduction. Microbial cathode is one of the core components of the system, and its surface energy transfer characteristics can greatly affect the yield of organic matter from MES. In order to solve the problem that the energy transfer characteristics of microbial cathode are not clear, the mathematical model of MES was constructed on the basis of the preliminary experiment with an electrode made of copper foam modified with the reduced graphene oxide, analyzing the current and substrate concentration in the biofilm with conductivity, cathode potential and porosity of the biofilm. The results show that when the cathode potential is higher than -0.8 V (VS SHE), the substrate concentration and current density in the biofilm are related to the cathode potential. However, when the cathode potential decreased to -0.8 V (vs SHE), the ability of biofilm to reduce CO basically reached saturation. Low conductivity (<10S/m) will lead to the formation of significant potential difference in the biofilm, which will reduce the substrate utilization rate and seriously affect the performance of microbial cathode. The current density is highest, when the porosity of the biofilm is about 0.35.
微生物电化学系统（MES）是减少 CO 排放的有利工具。微生物阴极是该系统的核心组件之一，其表面能量传递特性会极大地影响 MES 中有机物的产量。为了解决微生物阴极能量传递特性不明确的问题，在使用还原氧化石墨烯修饰的泡沫铜制成的电极进行初步实验的基础上，构建了 MES 的数学模型，分析了生物膜中的电流和电导率、阴极电势和生物膜的孔隙率与底物浓度之间的关系。结果表明，当阴极电势高于-0.8 V（VS SHE）时，生物膜中的底物浓度和电流密度与阴极电势有关。然而，当阴极电势降低到-0.8 V（VS SHE）时，生物膜还原 CO 的能力基本达到饱和。低电导率（<10 S/m）会导致生物膜中形成显著的电位差，从而降低底物利用率，并严重影响微生物阴极的性能。当生物膜的孔隙率约为 0.35 时，电流密度最高。
