平顶山十矿地下水中天然有机质垂向分布特征

Vertical distribution characteristics of natural organic substances in the groundwater of Pingdingshan No. 10 Coal Mine

为了研究平顶山十矿各含水层的水化学特征差异,检测分析了地下水中天然有机质含量和荧光特性的垂向分布规律。结果表明:天然有机质含量在垂向上先急剧减少后逐渐稳定,且浅部含水体与深部含水层存在显著的有机质含量差异,深部含水层之间则难以区分;浅部含水体中有机质含量高,各荧光指纹区的荧光峰均有显现,且荧光峰强度较高,第四系水中各荧光峰强度略小于地表水;深部含水层中,荧光峰数量与含水层深度成负相关,Ⅱ区和Ⅳ区的荧光峰强度先增加后减小,其他荧光峰的强度则逐渐减小。研究表明,利用天然有机质含量和荧光特性,能够建立各含水层在垂向上的水化学特征。

The paper is inclined to provide our analysis of the vertical distribution features of the contents of the natural organic substances in the groundwater of Pingdingshan No. 10 Coal Mine. In proceeding with our analysis, we have investigated and analyzed the hydrogeological conditions of the coal mine so as to make clear the particular chemical features of the groundwater in the mine. At the same time, we have also done an investigation of DOC, UV254 and 3DEEM （three-dimensional excitation emission matrix fluorescence spec-troscopy） so as to detect the vertical distribution characteristics of fluorescence. The results of our investigation and analysis show that the contents of the natural organic substances, including DOC and UV254, tend to decrease significantly from the surface water to the quaternary water in a stable rate in deep aquifers. Moreover, obvious difference has been found of the organic substance contents between the shallow water （i. e., surface water and quaternary water） and the deep water （i. e., Permian water, Carboniferous water and Cambrian water） , which makes it difficult to distinguish between the content characteristics of the organic substances for the respective deep water layers. For instance, in shallow water, there exist all the five fluorescent peaks, the intensities of which tend to be higher than those in the deep water. In contrast, the fluorescence intensities of the organic substances in the surface water were found slightly higher than those in Quaternary water. Nevertheless, it was found that in the deep water there exists a negative correlation between the degree of the fluorescence peak and the depth of the water. To be accurate, the fluorescence intensities of region Ⅱ and region Ⅳ tend to increase from the Permian water to the Carboniferous water while decreasing from the Carboniferous water to the Cambrian water, with the peak intensities of other fluorescence concentrations decreasing steadily. Thus, it would be possible for us to establish the vertical groundwater chemical characteristics by analyzing the concentrations and fluorescent properties of the natural organic substances of the area under discussion. For instance, it would be possible to use the different contents of the natural organic substances （ e. g. , DOC and UV254 ） to identify the water sources between the shallow water and the deep water. The method can also be used to identify the organic chemical features between the surface water and the Quaternary water. Therefore, what we have achieved in this research can be applied as a method for identifying and classifying the groundwater chemical features, which proves to be effective to identity the water inrush source by using their chemical features in the said coal mine.