A membrane-aerated biofilm-coupled Fe/C supported sludge system (MABR-Fe/C) was constructed to achieve electron production for NO-N reduction enhancement in different Fe/C loadings (10 g and 200 g). The anoxic environment formed in the MABR-Fe/C promoted a continual Ferelease of Fe/C in 120 d operation (average Feconcentrations is 1.18 and 2.95 mg/L in MABR-Fe/C10 and MABR-Fe/C200, respectively). Metagenomics results suggested that the electrons generated from ongoing Fe oxidation were transferred via the Quinone pool to rather than to complete the process of NO-N reduction to NO-N in , and . In the absence of organic matter, the NO-N removal in MABR-Fe/C10 and MABR-Fe/C200 increased by 11.99 and 12.52 mg/L, respectively, compared to that in MABR. In the further NO-N reduction, even if the minimum binding free energy (MBFE) was low, NO-N in and preferentially bind the Gln-residues for dissimilatory nitrate reduction (DNR) in the presence of Fe/C. Increasing Fe/C loading (MABR-Fe/C200) caused the formation of different residue binding sites, further enhancing the already dominant DNR. When DNR in MABR-Fe/C200 intensified, the TN in the effluent increased by 3.75 mg/L although the effluent NO-N concentration was lower than that in MABR-Fe/C10. This study demonstrated a new MABR-Fe/C system for electron generation to enhance biological nitrogen removal and analyzed the NO-N reduction pathway and metabolic mechanism, thus providing new ideas for nitrogen removal in electron-deficient wastewater.

中文翻译：

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通过 Fe/C 负载污泥与反扩散生物膜原位产生电子用于缺电子废水处理：硝酸盐还原酶的结合特性和催化竞争机制


构建了膜曝气生物膜耦合 Fe/C 负载污泥系统 (MABR-Fe/C)，以实现不同 Fe/C 负载量（10 g 和 200 g）下增强 NO-N 还原的电子产生。 MABR-Fe/C 中形成的缺氧环境促进了 Fe/C 在 120 d 的运行中持续释放 Fe（MABR-Fe/C10 和 MABR-Fe/C200 中的平均 Fe 浓度分别为 1.18 和 2.95 mg/L）。宏基因组学结果表明，持续进行的 Fe 氧化产生的电子通过醌池转移到，而不是完成 、 和 中 NO-N 还原为 NO-N 的过程。在没有有机物存在的情况下，MABR-Fe/C10和MABR-Fe/C200的NO-N去除率比MABR分别增加了11.99和12.52 mg/L。在进一步的NO-N还原中，即使最小结合自由能（MBFE）较低，NO-N也会优先结合Gln残基，在Fe/C存在下进行异化硝酸盐还原（DNR）。增加 Fe/C 负载量 (MABR-Fe/C200) 导致不同残基结合位点的形成，进一步增强了已经占主导地位的 DNR。当MABR-Fe/C200中DNR增强时，虽然出水NO-N浓度低于MABR-Fe/C10，但出水TN增加了3.75 mg/L。该研究展示了一种新型MABR-Fe/C系统用于产生电子来增强生物脱氮，并分析了NO-N还原途径和代谢机制，从而为缺电子废水脱氮提供新思路。