Microbial electrolysis cells (MECs) have garnered significant attention as a promising solution for industrial wastewater treatment, enabling the simultaneous degradation of organic compounds and biohydrogen production. Developing efficient and cost-effective cathodes to drive the hydrogen evolution reaction is central to the success of MECs as a sustainable technology. While numerous lab-scale experiments have been conducted to investigate different cathode materials, the transition to pilot-scale applications remains limited, leaving the actual performance of these scaled-up cathodes largely unknown. In this study, nickel-foam and stainless-steel wool cathodes were employed as catalysts to critically assess hydrogen production in a 150 L MEC pilot plant treating sugar-based industrial wastewater. Continuous hydrogen production was achieved in the reactor for more than 80 days, with a maximum COD removal efficiency of 40 %. Nickel-foam cathodes significantly enhanced hydrogen production and energy efficiency at non-limiting substrate concentration, yielding the maximum hydrogen production ever reported at pilot-scale (19.07 ± 0.46 L H m d and 0.21 ± 0.01 m m d). This is a 3.0-fold improve in hydrogen production compared to the previous stainless-steel wool cathode. On the other hand, the higher price of Ni-foam compared to stainless-steel should also be considered, which may constrain its use in real applications. By carefully analysing the energy balance of the system, this study demonstrates that MECs have the potential to be net energy producers, in addition to effectively oxidize organic matter in wastewater. While higher applied potentials led to increased energy requirements, they also resulted in enhanced hydrogen production. For our system, a conservative applied potential range from 0.9 to 1.0 V was found to be optimal. Finally, the microbial community established on the anode was found to be a syntrophic consortium of exoelectrogenic and fermentative bacteria, predominantly and , which appeared to be well-suited to transform complex organic matter into hydrogen.

中文翻译：

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在微生物电解池中试工厂中使用泡沫镍阴极提高工业废水生物电化学产氢能力

微生物电解池（MEC）作为工业废水处理的一种有前途的解决方案而受到了广泛关注，它能够同时降解有机化合物和生产生物氢。开发高效且经济高效的阴极来驱动析氢反应是 MEC 作为可持续技术取得成功的核心。尽管已经进行了大量实验室规模的实验来研究不同的阴极材料，但向中试规模应用的过渡仍然有限，使得这些放大的阴极的实际性能在很大程度上未知。在这项研究中，采用泡沫镍和不锈钢棉阴极作为催化剂，严格评估处理糖基工业废水的 150 L MEC 中试工厂中的氢气产量。反应器实现连续产氢80多天，COD去除率最高达到40%。泡沫镍阴极在非限制底物浓度下显着提高了氢气产量和能源效率，产生了中试规模有史以来报道的最大氢气产量（19.07±0.46 LH md和0.21±0.01 mmd）。与之前的不锈钢棉阴极相比，氢气产量提高了 3.0 倍。另一方面，还应该考虑泡沫镍比不锈钢更高的价格，这可能会限制其在实际应用中的使用。通过仔细分析系统的能量平衡，这项研究表明，MEC 除了有效氧化废水中的有机物之外，还有潜力成为净能量生产者。虽然更高的应用电势导致能量需求增加，但也导致氢气产量增加。对于我们的系统，我们发现 0.9 至 1.0 V 的保守施加电位范围是最佳的。最后，发现阳极上建立的微生物群落是一个由产电细菌和发酵细菌组成的互养群落，主要是 和 ，它似乎非常适合将复杂的有机物转化为氢气。