【摘要】 为探讨玉米秸秆作为固相碳源去除地下水中硝酸盐的可持续性能及组织差异影响机制，研究通过循环异养反硝化实验，系统评估了叶片、茎髓、茎皮、茎节、苞叶及混合组织为碳源体系的脱氮效能、脱氮可持续性、DOC释放特性、碳源利用率、中间产物积累及环境因子变化，并结合动力学拟合、相关性分析与结构方程模型揭示其脱氮调控机制。结果表明：以混合组织与苞叶为碳源的体系表现出最高的反硝化效率，展现出良好缓释特性与持续供碳能力，4次重复脱氮实验中，硝酸盐去除率均稳定维持在98%以上，NO^-₂-N和NH⁺₄-N等副产物浓度处于较低水平。相关性分析与结构方程模型表明，碳源类型主要通过调控DOC释放进而影响体系pH、电导率及三氮（NO^-₃-N、NO^-₂-N和NH⁺₄-N）转化路径，间接决定总氮去除效率。以玉米秸秆不同组织作为碳源的体系在反硝化效率、碳源利用率、氮素转化路径及微环境调控方面存在差异，其中混合组织和苞叶作为碳源兼具效率与稳定性，是较优碳源选择，但需注意苞叶在反应过程中易释放异味，可能对实际应用环境造成影响，需进一步处理。更多还原

【Abstract】 This study investigated the performance and tissue-specific mechanisms of corn straw as a solid-phase carbon source for nitrate removal from groundwater. Through cyclic heterotrophic denitrification experiments, the denitrification efficiency, sustainability, DOC release characteristics, carbon utilization efficiency, intermediate accumulation, and environmental parameter variations were systematically evaluated across different tissues(leaf, stem pith, stem bark, stem node, husk, and mixed tissue). Kinetic modeling, correlation analysis, and structural equation modeling were employed to elucidate the regulatory mechanisms of denitrification. The systems utilizing mixed tissues and bracts as carbon sources demonstrated the highest denitrification efficiency, exhibiting favorable slow-release characteristics and sustained carbon supply capacity. Across four repeated denitrification experiments, the nitrate removal rates were consistently maintained above 98%, while the concentrations of byproducts such as N and N remained at low levels. Correlation analysis and structural equation modeling revealed that carbon source type primarily influenced total nitrogen removal efficiency indirectly by regulating dissolved organic carbon(DOC) release, which subsequently affected system pH, electrical conductivity, and the transformation pathways of three nitrogen species(, and N. Significant differences were observed among corn stover tissue-based carbon sources in terms of denitrification efficiency, carbon utilization rate, nitrogen transformation pathways, and micro-environmental regulation. Among them, mixed tissues and bracts emerged as superior carbon sources due to their combined efficiency and stability. However, it is noteworthy that bracts tend to release odorous compounds during the reaction process, which may pose challenges in practical applications and necessitate further treatment.更多还原