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| 水铁矿对小麦秸秆腐解衍生溶解性有机质的分馏作用 |
| Fractionation of dissolved organic matter derived from wheat straw decomposition by ferrihydrite |
| 投稿时间：2025-01-16 |
| DOI：10.13254/j.jare.2025.0045 |
| 中文关键词: 小麦秸秆，腐解，溶解性有机物，水铁矿，分馏 |
| 英文关键词: wheat straw, decomposition, dissolved organic matter, ferrihydrite, fractionation |
| 基金项目:国家自然科学基金面上项目（42377067）；河南省自然科学基金优秀青年基金（242300421148） |
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| 中文摘要: |
| 小麦秸秆腐解衍生的溶解性有机质（WSDOM）是驱动腐解微生物代谢的关键底物，也是协调农业废弃物资源化、土壤功能提升、环境风险调控与碳中和目标实现的核心纽带。为系统揭示WSDOM的分子组成与结构动态特征，并阐明水铁矿对其组分的分馏效应，本研究通过多种光谱技术，结合分馏实验，解析了腐解过程中WSDOM的吸光特性、分子量分布、荧光组分及官能团演替规律。结果表明：随着周期为7 d的腐解进行，WSDOM的SUVA254、SUVA260和A253/A203分别从1.73、1.68和0.32降至0.91、0.88和0.23，而E2/E3显著增大，从最初的2.74增至3.41，说明芳香性逐渐减小，形成不溶于水的大分子腐殖质；此外，WSDOM中类蛋白物质相对含量由腐解第0天的0.775升高至第3天的0.812再降低至第7天的0.728，类富里酸和类胡敏酸物质相对含量分别由腐解第0天的0.172和0.053降低至第3天的0.144和0.044再升高至第7天的0.202和0.070；水铁矿对不同天数WSDOM的吸附效果存在显著差异，其中第3天的WSDOM吸附效果最为突出，吸附量（以C计）可达52.835 mg·g-1。腐解过程中类蛋白物质和挥发性脂肪族有机酸被分解，同时不稳定的类富里酸类物质也在这一过程中逐渐转化为腐殖质；水铁矿对WSDOM中高芳香性、高分子量和含氧组分具有显著的分馏作用。研究结果为开发高效、快速的秸秆腐解技术，提升秸秆资源化利用效率与农田土壤固碳增汇能力提供一定的理论依据。 |
| 英文摘要: |
| Wheat straw-derived dissolved organic matter（WSDOM） is a key substrate driving the metabolism of decomposing microorganisms and a core link coordinating the resource utilization of agricultural waste, the improvement of soil functions, the regulation of environmental risks, and the achievement of carbon neutrality goals. To systematically reveal the molecular composition and structural dynamic characteristics of WSDOM and clarify the fractionation effect of goethite on its components, this study analyzed the light absorption properties, molecular weight distribution, fluorescence components, and functional group evolution of WSDOM during decomposition through multiple spectroscopic techniques and fractionation experiments. The results showed that as decomposition progressed over 7-day cycles, SUVA254, SUVA260, and A253/A203 of WSDOM decreased from 1.73, 1.68, and 0.32 to 0.91, 0.88, and 0.23, respectively, while E2/E3 significantly increased from the initial 2.74 to 3.41, indicating a gradual decrease in aromaticity and the formation of water-insoluble macromolecular humus. Additionally, the relative content of protein-like substances in WSDOM increased from 0.775 on day 0 of decomposition to 0.812 on day 3 and then decreased to 0.728 on day 7, while the relative contents of fulvic acid-like and humic acid-like substances decreased from 0.172 and 0.053 on day 0 to 0.144 and 0.044 on day 3 and then increased to 0.202 and 0.070 on day 7. The adsorption effect of goethite on WSDOM at different decomposition days was significantly different, with the adsorption effect on WSDOM on day 3 being the most prominent, with an adsorption capacity（calculated in C） of up to 52.835 mg·g-1. During the decomposition process, protein-like substances and volatile fatty acids were decomposed, and unstable fulvic acid-like substances gradually transformed into humus. Goethite had a significant fractionation effect on high-aromaticity, high-molecular-weight, and oxygencontaining components in WSDOM. The research results provide a certain theoretical basis for developing efficient and rapid straw decomposition technologies, improving the efficiency of straw resource utilization and the carbon sequestration and carbon sink enhancement capacity of farmland soil. |
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