High-salt conditions reduce the efficiency of electricity generation and nitrogen removal in microbial fuel cells (MFCs). In this work, we propose a three-phase single-chamber MFC (TP-MFC) by setting up a phase with immobilized cells in a conventional bipolar single-chamber MFC (common MFC). Cells from Halomonas were used as the immobilized phase, because these cells secrete the compatible solute ectoine and exhibit simultaneous nitrification and denitrification (SND). This enhanced the efficiency of SND and subsequent electricity generation under high-salt conditions. The average voltage of TP-MFC generated during the stable period in the presence of 30 g/L NaCl was 439.3 mV, which was 55.2% higher than that generated in common MFC. In addition, the N-removal rate of TP-MFC at 72 h was 63.4%, which was 38.4% higher than that of common MFC. The 16S rRNA diversity analysis showed an improved abundance of Pseudomonas, Acinetobacter, Alcaligenes, and Halomonas in TP-MFC, indicating that the ectoine secreted by immobilized Halomonas conferred substantial salt-tolerance on the electrogenic bacteria growing in a high-salt environment. This paper establishes an efficient and convenient method for improving the salt tolerance of microbial flora in MFCs, which is of great significance for the application of MFCs in high-strength wastewater treatment.

中文翻译：

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高盐条件下三相单室MFC中发电与反硝化的耦合。

高盐条件会降低微生物燃料电池（MFC）中的发电效率和脱氮效率。在这项工作中，我们提出了一种三相单室MFC（TP-MFC），方法是在常规的双极单室MFC（普通MFC）中通过固定化细胞建立一个相。来自Halomonas的细胞被用作固定相，因为这些细胞分泌相容的溶质ectoine，并同时显示硝化和反硝化作用（SND）。这提高了高盐条件下SND和后续发电的效率。在30 g / L NaCl的存在下，稳定期产生的TP-MFC的平均电压为439.3 mV，比普通MFC产生的平均电压高55.2％。此外，TP-MFC在72 h的脱氮率为63.4％，比普通MFC高38.4％。16S rRNA多样性分析显示TP-MFC中假单胞菌，不动杆菌，产碱菌和嗜盐单胞菌的丰度提高，表明固定化的嗜盐单胞菌分泌的植物素赋予了在高盐环境中生长的产电细菌很大的耐盐性。本文建立了一种提高MFCs微生物群耐盐性的有效简便方法，对于MFCs在高强度废水处理中的应用具有重要意义。