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以豫中平原地热水补给区裸露地表处广泛种植的毛白杨(Populus tomentosa)落叶提取的DOM为研究对象,首先确定了对DOM提取的的最佳时间,然后通过对DOM的紫外-可见光谱和三维荧光光谱的测定及对SUVA_(254)、A_(253)/A_(203)、A_(250)/A_(365)、r_(A/C)等参数的计算,对DOM中的有机物结构和类型进行了研究。研究结果表明:毛白杨落叶DOM浸提的最佳振荡时间为24 h,DOC和UV_(254)具有较高的线性相关关系,说明毛白杨落叶DOM中有较多的含苯环的简单芳香族化合物,并且芳香环取代基中含有较多的羰基、羧基、羟基、脂类。DOM中存在有4类荧光峰,荧光强度由大到小的顺序依次为类腐殖质峰(包括紫外区类富里酸峰(A峰)和腐殖酸类物质峰(C峰))、酪氨酸类芳香族蛋白峰T、溶解性微生物代谢产物峰B。在DOM样品不同的稀释倍数条件下,所反映的有荧光特性的溶解性有机物的结构和相对含量有所变化,这与DOM样品的pH变化、复杂的成分种类、混合荧光信号的存在等因素有关。
Taking the dominated Populus tomentosa deciduous DOM, which is widely planted in the exposed surface of the geothermal water recharge area, as the research object, the optimal extraction time for DOM was determined. Then, the UV-Vis spectrum And three-dimensional fluorescence spectroscopy and the calculation of parameters such as SUVA 254, A 253 / A 203, A 250 / A 365 and r A / C, And type of research. The results showed that the optimal shaking time of DOM in deciduous Populus tomentosa leaves was 24 h, and there was a high linear correlation between DOC and UV_ (254), indicating that there were more simple aromatics containing benzene rings in DOM of Populus tomentosa Compounds, and aromatic ring substituents contain more carbonyl, carboxyl, hydroxyl, lipid. There are four kinds of fluorescence peaks in DOM, and the order of fluorescence intensity from descending order is humic type peak (including UV-like peak (A peak) and humic acid peak (C peak)), tyrosine Aromatic protein peak T, peak of soluble microbial metabolite B. The structure and relative content of the dissolved organic matter with the fluorescence characteristics changed under different dilution conditions of the DOM sample, which is related to the pH of the DOM sample, the composition of the complex components, the presence of the mixed fluorescence signal and the like .