【摘要】 在工业水处理领域，以亚铁[Fe（Ⅱ）]为催化剂，利用硝酸盐依赖亚铁氧化（nitrate-dependent ferrous oxidation, NDFO）和铁氨氧化（anaerobic ammonium oxidation coupled to ferric iron reduction, Feammox）的耦合可实现不同形态氮的去除，但Fe（Ⅱ）是否可以促进湖泊沉积物中NDFO和Feammox的循环或交替发生，目前尚不明确。为此，以太湖梅梁湾沉积物为研究对象，通过厌氧培养实验对该耦合过程进行研究。结果显示，Fe（Ⅱ）添加后体系内硝酸盐氮（NO^-₃-N）和Fe（Ⅱ）质量浓度呈同步快速下降趋势（p<0.01）,且表层沉积物出现棕褐色絮状物，X射线光电子能谱分析也证实沉积物中的三价铁[Fe（Ⅲ）]占比显著提升，表明硝酸盐（NO^-₃）还原与Fe（Ⅱ）氧化发生了耦合。通过高分辨率透射电镜、X射线吸收近边结构谱与X射线衍射联合表征，明确γ-FeOOH为Fe（Ⅱ）氧化的主要产物。进一步添加氨氮（NH⁺₄-N）后，沉积物表层的棕褐色絮状物逐渐消失，同时氨氮浓度降低，表明NDFO产物可有效驱动Feammox进程。宏基因组测序进一步表明，Rhodanobacter和Geothrix等可介导NDFO或Feammox反应的菌属的相对丰度显著提升，揭示了铁、氮循环功能菌群的协同代谢关系。研究所揭示的外源Fe（Ⅱ）介导的NDFO-Feammox耦合机制，深化了沉积物中铁、氮理论，也为富营养化湖泊的氮污染治理提供了基于铁循环调控的生物强化新途径。更多还原

【Abstract】 In the field of industrial water treatment, the coupling of nitrate-dependent ferrous oxidation（NDFO） and anaerobic ammonium oxidation coupled to ferric iron reduction（Feammox） enables the effective removal of nitrogen species using ferrous iron [Fe（Ⅱ）] as catalysts. However, it remains unclear whether Fe（Ⅱ） supplementation can promote the cycling or alternation of NDFO and Feammox in lake sediments. To address this knowledge gap, simulated experiments are conducted using anaerobic incubation systems with sediments from Meiliang Bay in Lake Taihu. The results demonstrate that after the addition of Fe（Ⅱ）, nitrate nitrogen（NO^-₃-N） and Fe（Ⅱ） mass concentrations exhibite synchronous rapid declines（p<0.01）, accompanied by the formation of brown flocs on sediment surfaces. X-ray photoelectron spectroscopy analysis confirms a significant increase in Fe（Ⅲ） proportion, revealing the coupling mechanism between nitrate reduction and ferrous iron oxidation. Combined characterization through high-resolution transmission electron microscopy（HRTEM）, X-ray absorption near-edge structure（XANES） spectroscopy, and X-ray diffraction（XRD）, γ-FeOOH is identified as the primary product of Fe（Ⅱ） oxidation. Subsequent ammonium supplementation experiments shows gradual dissolution of the brown flocs alongside decreasing ammonium concentrations, confirming that NDFO products effectively drive Feammox processes. High-throughput sequencing further reveals substantial enrichment of genera such as Rhodanobacter and Geothrix, which can mediate NDFO or Feammox reactions, elucidating the synergistic metabolic relationships within iron-nitrogen cycling microbial communities. The novel Fe（Ⅱ）-mediated NDFO-Feammox coupling mechanism revealed in this study not only advances the theoretical understanding of iron-nitrogen coupled cycling in sediments, but also provides a bioaugmentation strategy based on iron cycle regulation for nitrogen pollution control in eutrophic lakes.更多还原