School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, United Kingdom; Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600, UKM, Bangi, Malaysia.
School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, United Kingdom; Univ Rennes, CNRS, ISCR-UMR 6226, F-35000, Rennes, France.
Chemosphere. 2022 Feb;288(Pt 2):132548. doi: 10.1016/j.chemosphere.2021.132548. Epub 2021 Oct 22.
A microbial electrolysis cell (MEC) fully catalysed by microorganisms is an attractive technology because it incorporates the state-of-the-art concept of converting organic waste to hydrogen with less external energy input than conventional electrolysers. In this work, the impact of the anode feed mode on the production of hydrogen by the biocathode was studied. In the first part, three feed modes and MEC performance in terms of hydrogen production were evaluated. The results showed the highest hydrogen production under the continuous mode (14.6 ± 0.4), followed by the fed-batch (12.7 ± 0.4) and batch (0 L m cathode day) modes. On one hand, the continuous mode only increased by 15% even though the hydraulic retention time (HRT) (2.78 h) was lower than the fed-batch mode (HRT 5 h). A total replacement (fed-batch) rather than a constant mix of existing anolyte and fresh medium (continuous) was preferable. On the other hand, no hydrogen was produced in batch mode due to the extensive HRT (24 h) and bioanode starvation. In the second part, the fed-batch mode was further evaluated using a chronoamperometry method under a range of applied cell voltages of 0.3-1.6 V. Based on the potential evolution at the electrodes, three main regions were identified depending on the applied cell voltages: the cathode activation (<0.8 V), transition (0.8-1.1 V), and anode limitation (>1.1 V) regions. The maximum hydrogen production recorded was 12.1 ± 2.1 L m cathode day at 1.0 V applied voltage when the oxidation and reduction reactions at the anode and cathode were optimal (2.38 ± 0.61 A m). Microbial community analysis of the biocathode revealed that Alpha-, and Deltaproteobacteria were dominant in the samples with >70% abundance. At the genus level, Desulfovibrio sp. was the most abundant in the samples, showing that these microbes may be responsible for hydrogen evolution.
微生物电解池（MEC）完全由微生物催化是一项很有吸引力的技术，因为它结合了将有机废物转化为氢气的最先进概念，与传统电解槽相比，输入的外部能量更少。在这项工作中，研究了阳极进料方式对生物阴极产氢的影响。在第一部分中，评估了三种进料方式和 MEC 产氢性能。结果表明，连续模式下的产氢量最高（14.6±0.4），其次是分批进料（12.7±0.4）和分批进料（0 L m 阴极天）模式。一方面，尽管水力停留时间（HRT）（2.78 h）低于分批进料模式（HRT 5 h），但连续模式仅增加了 15%。完全替换（分批进料）而不是恒定混合现有阳极液和新鲜介质（连续）更为可取。另一方面，由于 HRT 过长（24 h）和生物阳极饥饿，分批进料模式下没有产生氢气。在第二部分中，在 0.3-1.6 V 的一系列施加电池电压下，使用计时安培法进一步评估了分批进料模式。根据电极上的电位演变，根据施加的电池电压，确定了三个主要区域：阴极激活（<0.8 V）、过渡（0.8-1.1 V）和阳极限制（>1.1 V）区域。当阳极和阴极的氧化还原反应最佳（2.38±0.61 A m）时，记录到的最大产氢量为 12.1±2.1 L m 阴极天在 1.0 V 施加电压下。生物阴极的微生物群落分析表明，α-和δ-变形菌在丰度大于 70%的样品中占主导地位。在属水平上，脱硫弧菌属是样品中最丰富的，表明这些微生物可能负责氢气的产生。
