The scale up of bioelectrochemical systems (BESs) is a challenging problem that limits the advancement and practical implementation of the technology. The goal of this work is to acquire an understanding of the limitations on scaling up anodic biofilms in BESs. We hypothesized that scaling up is dependent on the availability of electron donors. We tested this hypothesis by enriching anodic biofilms on electrodes of multiple sizes (15 cm2 to 466 cm2) and quantified the anodic current densities while varying the electron donor concentrations. The anodic biofilms were enriched on electrodes under two conditions: (1) in raw wastewater and (2) in wastewater supplemented with 20 mM acetate. Following anodic biofilm enrichment, the current density for each electrode was quantified in artificial wastewater medium with variable COD loadings using acetate as an electron donor. Current generated using anodic biofilms scaled up at a high COD loading (1500 mg/L), while current density decreased with increasing electrode size at lower COD loadings. Further, microbial community analysis revealed that the microbial community was independent of the electrode size but dependent on the medium composition during the enrichment phase. These results provide a practical framework for the design of large-scale BESs based on laboratory-scale measurements.

中文翻译：

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电子供体的可用性控制可放大阳极生物膜。

生物电化学系统（BESs）的规模化是一个具有挑战性的问题，限制了该技术的进步和实际应用。这项工作的目的是获得对扩大BES中阳极生物膜的局限性的理解。我们假设扩大规模取决于电子供体的可用性。我们通过在多种尺寸（15平方厘米至466平方厘米）的电极上富集阳极生物膜，并在改变电子供体浓度的同时量化阳极电流密度，从而检验了这一假设。在两个条件下，阳极生物膜富集在电极上：（1）在原废水中和（2）在补充了20 mM乙酸盐的废水中。在阳极生物膜富集之后，使用乙酸盐作为电子供体，在COD负载可变的人造废水介质中，定量每个电极的电流密度。使用阳极生物膜产生的电流在高COD负载（1500 mg / L）时会按比例增加，而电流密度在较低COD负载下会随着电极尺寸的增加而降低。此外，微生物群落分析表明，微生物群落与电极大小无关，但与富集阶段的培养基组成有关。这些结果为基于实验室规模的测量设计大型BES提供了实用的框架。微生物群落分析表明，微生物群落与电极大小无关，但与富集阶段的培养基组成有关。这些结果为基于实验室规模的测量设计大型BES提供了实用的框架。微生物群落分析表明，微生物群落与电极大小无关，但与富集阶段的培养基组成有关。这些结果为基于实验室规模的测量设计大型BES提供了实用的框架。