| 麦富生,李晓雯,吕睿,沈倩,杨健,赵好轩,VÄHÄTALO Anssi V.,肖宜华.水铁矿对土壤溶解性有机质的吸附固持作用[J].农业环境科学学报,2024,43(3):627-635. |
| 水铁矿对土壤溶解性有机质的吸附固持作用 |
| Adsorption and sequestration of soil-dissolved organic matter by ferrihydrite |
| 投稿时间：2023-07-10 |
| DOI：10.11654/jaes.2023-0545 |
| 中文关键词: 水铁矿 溶解性有机质 土壤 紫外-可见吸收光谱 平行因子分析 |
| 英文关键词: ferrihydrite dissolved organic matter soil UV-Vis absorption spectrum PARAFAC analysis |
| 基金项目:山东省泰山学者青年专家项目（tsqn201909126）；山东省自然科学基金项目（ZR2021MD125） |
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| 中文摘要: |
| 基于水解法将氯化铁和氢氧化钠合成了一种水铁矿，通过不同浓度水铁矿与土壤溶解性有机质（DOM）的混合避光培养实验，研究了水铁矿对土壤DOM的吸附固持作用。结果表明：在水铁矿浓度为10~30 g·L-1范围内，水铁矿对土壤DOM的吸附能力与其浓度呈正相关。随着培养时间的延长，DOM的光谱斜率（S275-295）显著降低，表明水铁矿优先吸附土壤DOM中的大分子芳香族化合物。三维荧光光谱耦合平行因子模型（EEM-PARAFAC）分析表明，土壤DOM包含类腐殖质组分（C1）（Ex/Em=240/410）、类色氨酸组分（C2）[Ex/Em=290（240）/350]及类酪氨酸组分（C3）（Ex/Em=270/300）3种荧光组分。3种组分荧光强度均随着培养时间延长呈现明显降低趋势，且类腐殖质组分的下降最为明显。被水铁矿吸附后，土壤DOM的腐殖化指数（HIX）显著降低且生物源指数（BIX）明显升高，表明随着吸附作用的进行，土壤DOM的腐殖质组分相对占比下降，而自生源组分相对占比上升。研究表明，水铁矿对土壤DOM有显著的吸附固持作用，且对大分子腐殖质物质吸附作用强于对小分子类蛋白组分，水铁矿对土壤DOM分子的固持作用能够提高土壤有机质的生物可利用度，改善土壤环境。 |
| 英文摘要: |
| A ferrihydrite was synthesized from ferric chloride and sodium hydroxide using the hydrolysis method. The absorption behavior of soil-dissolved organic matter(DOM) on ferrihydrite was studied by mixing different concentrations of ferrihydrite with soil-extracted DOM solution. UV-Vis absorption spectra analysis showed that in the range of 10-30 g·L-1 ferrihydrite concentration, the adsorption capacity of ferrihydrite to soil DOM is positively correlated with ferrihydrite concentration. The significant decrease in the absorption slope S275-295 indicates that ferrihydrite preferentially adsorbs macromolecular aromatic compounds in soil DOM. Three-dimensional fluorescence spectra coupled parallel factor model(EEM-PARAFAC) analysis showed that soil DOM comprises three fluorescent components. They were humus-like component C1(Ex/Em=240/410), tryptophan-like component C2[Ex/Em=290(240)/350], and tyrosine-like component C3(Ex/Em=270/300). The fluorescent intensity of the three components showed a significant decreasing trend with incubation time. The decrease in the humic-like C1 component was greater than for the protein-like components of C2 and C3. After adsorption, soil DOM's humification index(HIX) decreased significantly. Meanwhile, the biological index(BIX) increased significantly, indicating that the relative proportion of humus fraction in soil DOM decreased and the relative proportion of autogenetic fraction increased with the process of adsorption. In conclusion, ferrihydrite has a significant adsorption and removal effect on soil DOM, and the adsorption effect on macromolecular humus is more potent than that of small molecular amino acids. The retention of soil DOM molecules by ferrihydrite can increase the bioavailability of soil organic matter and improve the soil environment. |
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