兖州煤田奥陶系灰岩地下水水化学特征及其形成机理

发布时间：2018-02-03 07:26

本文关键词： 水化学特征饱和指数水岩相互作用灰岩含水层兖州煤田　出处：《地球学报》2017年02期 　论文类型：期刊论文

【摘要】：鲁西南兖州煤田的奥陶系灰岩地下水对煤田深部煤炭开采具有潜在的水害威胁,且为研究区的主要供水水源之一,其水化学特征及形成机理分析,可为该区深部煤炭开采水害防治和地下水资源利用提供依据。经过目的层水样的采集与测试可知,地下水水化学类型以SO_4-Ca-Mg型为主,SO_4~(2-)含量为537~2 296 mg/L,Ca~(2+)和Mg~(2+)的平均含量分别为455.7 mg/L和116.6 mg/L,TDS的范围为961~3 555 mg/L,pH值为6.9~8.0。Ca~(2+)和SO_4~(2-)随TDS的增加而增加,呈良好线性关系,推断TDS的增加主要来自Ca~(2+)和SO_4~(2-)的贡献。由饱和指数(SI)可知,地下水中的白云石和方解石均处于过饱和状态,而绝大部分的水样的石膏饱和指数均小于0,处于不饱和状态。石膏的饱和指数与地下水中TDS呈正相关关系。这些结果表明,在该含水层中地下水运移过程中不断发生水岩相互作用,主要包括石膏溶解、白云石和方解石沉淀或溶解、离子交换等反应。
[Abstract]:Ordovician limestone groundwater in Yanzhou coalfield in southwest Shandong has potential water hazard threat to deep coal mining in coal field and is one of the main water supply sources in the study area. Its hydrochemical characteristics and formation mechanism are analyzed. It can provide the basis for the prevention and control of water hazards in deep coal mining and the utilization of groundwater resources. Through the collection and test of water samples from the target layer, it can be concluded that the main type of groundwater hydrochemistry is SO_4-Ca-Mg type. The content of so _ 4 ~ (2 ~ (2)) was 537 ~ (2 296 mg/L). The average contents of Ca~(2 and Mg~(2 were 455.7 mg/L and 116.6 mg / L TDs, respectively. The range of TDs was 961g / L 3 555 mg/L. The pH value of TDS increased with the increase of TDS, showing a good linear relationship. It is inferred that the increase of TDS mainly comes from the contribution of Ca~(2) and so _ 4 ~ (2). The saturation index (SI) shows that both dolomite and calcite in groundwater are supersaturated. In most of the water samples, the gypsum saturation index is less than 0, which is in an unsaturated state. There is a positive correlation between the gypsum saturation index and the TDS in groundwater. The water-rock interaction occurs continuously in the process of groundwater migration in the aquifer, including gypsum dissolution, precipitation or dissolution of dolomite and calcite, ion exchange and so on.
【作者单位】：中国地质博物馆;中国地质大学(北京);华北科技学院;
【基金】：国家自然科学基金(编号:41272269) 国土资源部部门预算项目(编号:121113000000160034)联合资助~~
【分类号】：P641.461
【正文快照】： 兖州煤田作为华北地区最大的煤炭产业基地,历经多年的采掘生产,浅部煤层开采已经进入尾期,探索研究并着手准备深部煤层开采成为当前课题。由于矿区石炭—二叠系煤系地层直接上覆于奥陶系灰岩之上,在自然或采动条件下可能与奥陶系灰岩具有一定的水力联系,从而奥陶系灰岩地下水

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