| 苏州景观河道表层沉积物间隙水-上覆水中DOM特性分析 |
| 摘要点击 2021 全文点击 684 投稿时间：2021-05-19 修订日期：2021-06-24 |
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| 中文关键词 溶解性有机物(D0M) 相对分子质量 荧光光谱 紫外-可见吸收光谱 荧光区域积分 |
| 英文关键词 dissolved organic matter(DOM) relative molecular weight fluorescence spectrum UV-Vis absorption spectrum fluorescence region integral |
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| 中文摘要 |
| 为了解苏州景观河道间隙水和上覆水中溶解性有机物（DOM）的特性和相互关系，利用紫外-可见吸收光谱、高效液相色谱和荧光光谱结合荧光区域积分法，分析了苏州城区自2020年汛期过后，7~9月景观河道沉积物间隙水和上覆水中的DOM的特性.结果表明，间隙水和上覆水中DOM的相对分子质量均为1000左右，且随着时间的推移，相对分子质量均以相同的趋势变大.间隙水和上覆水中DOM均是类蛋白质类含量最高，质量分数达到68%~79%，类腐殖质含量较低，质量分数在21%~32%左右，而且均以低激发色氨酸占主导.7~9月，间隙水中DOM含量大量提升后，上覆水中DOM含量逐渐提升，可能是源于夏季藻类暴发后沉积到河底，而后再裂解释放到间隙水和上覆水之中，间隙水和上覆水的荧光指标FI在7月时差异较大，而后以相同的变化趋势先增大后减小，但都大于1.2.自生源指标BIX值都大于0.8，且偏向于1.腐殖化指标HIX值均小于4，而且间隙水和上覆水都以相同的趋势变小.上覆水和间隙水中DOM的6个荧光组分之间均呈现相同的正相关（P<0.05），低激发酪氨酸、a254和HIX均存在显著相关性.苏州景观河道中间隙水和上覆水中DOM关系紧密，间隙水可能是上覆水中DOM潜在来源. |
| 英文摘要 |
| In order to understand the characteristics and interrelationship of dissolved organic matter (DOM) in interstitial water and overlying water of a landscape river in Suzhou, the characteristics of DOM in interstitial water and overlying water of landscape river sediments in the urban area of Suzhou from July to September after the 2020 flood season were analyzed using the UV-Vis absorption spectrum, high-performance liquid chromatography(HPLC), and fluorescence spectrum combined with the fluorescence region integration method. The results showed that the relative molecular weight of DOM in both the interstitial water and the overlying water was about 1000, and the relative molecular weight tended to increase in the same way over time. Both interstitial water and overlying water had the highest DOM of protein-like content, with a mass fraction that reached 68%-79%. By contrast, the content of humus-like substances was lower, with a mass fraction accounting for approximately 21%-32%, and both were dominated by low-excitation tryptophan. From July to September, a large increase in DOM levels appeared in the interstitial water, followed by a gradual increase in DOM levels in overlying water. These increases might have come from the deposition of algae on the river bottom after summer outbreaks, likely followed by cleavage and release into the interstitial and overlying water. The fluorescence indices (FI) of the interstitial water and overlying water differed more in July and then increased and decreased following the same trend; however, both were greater than 1.2. The authigenic indicator BIX indicator values were all greater than 0.8 and tended toward 1. The humification index (HIX) values were all less than 4; moreover, the interstitial water and overlying water became smaller in the same trend. The same positive correlation was present between the six fluorescent components of DOM (P<0.05), with a significant correlation between low-excitation tyrosine, α254, and HIX. The relationship between interstitial water and DOM in the overlying water in the Suzhou landscape river was closely related, and the interstitial water may be a potential source of DOM in overlying water. |
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