融雪对土壤溶解性有机质溶析作用的影响

发布时间：2018-03-17 04:18

本文选题：溶解性有机物　切入点：融雪　出处：《环境科学学报》2016年12期 　论文类型：期刊论文

【摘要】：利用土壤浸提实验和土柱淋洗实验,考察了化学离子的种类与浓度对进入融雪径流的土壤溶解性有机物(DOM)的含量和光谱学特性的影响,以及不同化学特征的积雪融化过程中土壤DOM的释放规律.土壤浸提实验结果表明,随着Na~+、Mg~(2+)和Ca~(2+)浓度的升高,土壤浸提液中的溶解性有机碳(DOC)浓度显著降低;随着Cl~-、SO_4~(2-)、Mg~(2+)和Ca~(2+)浓度的升高,土壤浸提液中波长254 nm处的紫外吸光度(UV-254)逐渐降低;随着Na~+和Mg~(2+)浓度的升高,土壤浸提液中单位浓度DOC的紫外吸收值(SUVA)值逐渐升高.NO_3~-、SO_4~(2-)和Na~+的浓度过高或过低时,土壤浸提液中DOM的类腐殖酸和类富里酸荧光峰强度较低;随着Cl~-、Mg~(2+)和Ca~(2+)浓度的升高,土壤浸提液中DOM的类腐殖酸荧光峰强度逐渐降低.土柱淋溶实验结果表明,类腐殖酸和类富里酸荧光物质是土壤淋滤液中的主要荧光物质.与纯水相比,融雪水作为淋洗液导致土壤淋滤液中DOC浓度的降低,以及类微生物代谢产物荧光峰强度的增高.冻融交替抑制DOM自土壤解吸进入淋滤液,并且导致土壤淋滤液中芳香族化合物相对含量的降低.
[Abstract]:The effects of kinds and concentrations of chemical ions on the content and spectroscopic properties of dissolved organic matter (DOM) in soil into snowmelt runoff were investigated by soil extraction and column leaching experiments. The results of soil extraction experiments showed that the concentration of dissolved organic carbon (DOM) decreased significantly with the increase of Na ~ (2) and Ca~(2) concentrations. The UV absorbance at 254nm in the soil extract gradually decreased with the increase of the concentration of Cl-so _ 4 and Ca~(2), and with the increase of the concentration of Na ~ and Mg~(2, the UV absorbance at 254nm in the soil leachate decreased gradually, and the concentration of Na ~ and Mg~(2 increased with the increase of the concentration of Ch _ (2) -so _ (4) and Mg~(2). The UV absorption value of unit concentration of DOC in soil extract increased gradually. When the concentration of no _ 3 and Na ~ was too high or too low, the fluorescence peak intensity of humic acid and fulvic acid-like acid in soil extract solution was lower than that in soil extract solution, and with the increase of Cl-Mg2) and Ca~(2) concentration, the fluorescence peak intensity of DOM in soil extract solution was lower than that in soil extract solution, and with the increase of Cl-Mg2) and Ca~(2 concentration, the fluorescence peak intensity of humic acid and fulvic acid-like acid in soil extract solution was lower than that in soil extract solution. The intensity of humic acid-like fluorescence peak of DOM in soil extract gradually decreased. The results of column leaching experiment showed that humic acid-like and fulvic acid-like fluorescent substances were the main fluorescent substances in soil leachate. The concentration of DOC in the leachate and the intensity of fluorescence peak of the metabolites of microbes were decreased by snow melt water as the eluent. Freeze-thaw alternately inhibited DOM desorption from the soil into the leachate. And the relative content of aromatic compounds in soil leachate was decreased.
【作者单位】：辽宁大学环境学院;
【基金】：国家自然科学基金(No.21107039) 辽宁省教育厅科学技术研究项目(No.L2011002) 辽宁省科学技术计划项目(No.2011230009)~~
【分类号】：X144;X52

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