徐州东部废弃矿井地下水化学及其时空演化特征分析

Characteristics of Groundwater Chemistry and Its Spatio-Temporal Variation in Abandoned Mine in Eastern Xuzhou

矿区闭坑后,区域地下水动力条件的改变以及引起的地下水污染可能对环境影响较大。本文以徐州东部废弃矿井为研究对象,在进行水文地质调查分析的基础上,采集地下水样,进行水化学分析,结果表明研究区内太原组灰岩含水层的水化学类型具有明显分带性,从西北向东南由HCO_3·SO_4-Ca型、SO_4-Ca·Mg型向HCO_3·SO_4-Ca·Mg型、HCO_3-Ca·Mg型依次过渡。矿井关闭后,地下水位抬升,水文地质条件发生改变,地下水水化学组分相应有所变化。对研究区水化学特征的演化特点进行分析,发现地下水受阳离子交替吸附作用影响,呈现出Ca^(2+)、Mg^(2+)、SO4^(2-)增大,Na^+、K^+减小的趋势。

When the mine is closed,the changes of groundwater hydrodynamic conditions may cause groundwater pollution and greatly threaten the environment.The abandoned mine in eastern Xuzhou was chosen in this study,and groundwater samples were collected for chemical analysis on the basis of hydrogeological survey.The results showed that the hydrochemical types in Taiyuan Formation Aquifer exhibited obvious zonation,the types of which changed gradually from HCO3·SO4-Ca and SO4-Ca·Mg in north-west to HCO3·SO4-Ca·Mg and HCO3-Ca·Mg in south-east.With the mine being closed,the groundwater level rose and the hydrogeological conditions changed,leading to the variations of groundwater chemical components.According to the analysis of the evolution of groundwater hydrochemical characteristics,groundwater in the study area was affected by cation exchange and adsorption,and the concentrations of calcium ions,magnesium ions and sulfate ions increased,while those of sodium ions and potassium ions decreased.