地下水矿物饱和度的水文地球化学模拟分析--以娘子关泉域岩溶水为例

通过分析娘子关泉域岩溶水的水文地质条件、岩溶发育规律以及水文地球化学特征，发现在该泉域内不应出现方解石、白云石、石膏等矿物溶解饱和状态。运用地球化学模拟软件PHREEQC模拟该区可能的化学条件（地下水中二氧化碳分压）及相应条件下的矿物溶解状态，同时结合野外溶解实验推断所处条件范围。这一研究推测出地下水与其溶解矿物所处极限状态应为饱和状态，而实际常常应处于非饱和状态，若计算为过饱和状态，则应可能是分析数据错误所致。

HYDROGEOCHEMICAL MODELING ON SATURATION OF MINERALS IN GROUNDWATER∶A CASESTUDY AT NIANGZIGUAN,NORTHERN CHINA

Saturation indexes of minerals in groundwater are the major factors to control dissolving or precipitating of minerals.Unfortunately, the data from inaccurate analyses due to the CO 2 outgas result in the misunderstanding of the hydrogeochemical process during the groundwater movement.An example by hydrogeochemical modeling and in situ experiment in Nianziguan spring area, Northern China shows that calcite, dolomite and gypsum are more likely to be undersaturated.The results from hydrogeochemical modeling also agree with groundwater situations in the area. This paper suggests that the oversaturation of the minerals obtained by calculating in other areas are also more likely to come from the inaccurate data of groundwater. Probably, the hydrogeochemical process is so slow that it is difficult for minerals to be oversaturated in the groundwater.