基于电导率实测方法的开放体系中灰岩溶解动力学试验研究

在碳酸盐岩地区,水电站的兴建会改变库坝区地下水流场,由此引起溶蚀及渗漏问题。为研究灰岩在实际条件下的平均反应速率,在常温常压条件下、相对开放的体系中进行了5组灰岩试样的室内溶解试验,对溶液的电导率、pH值和温度等进行定时检测。根据化学动力学的基本理论,建立了两组不同模型以反映溶解速率与电导率之间的函数关系,依据实测的三组溶液电导率值,求得平均反应速率参数,并将其代入另两组试验进行验证,结果较为一致。由此表明,基于电导率所建的模型可以有效地反映灰岩在实际条件下的溶解过程,可为建立灰岩介质中的反应—运移模型提供化学动力学参数。

Experiment Research on Limestone Dissolution Kinetics in Open System by Measuring Conductivity

Construction of hydropower station in carbonate area causes the change of groundwater flow field and it leads to the erosion and leakage within the domain. To obtain the average reaction rate of limestone in actual situation, five sets of experiments in lab were designed and carried out under the normal temperature and pressure in the open system. During the experiment, the conductivity, pH value and temperature of solution were measured in definite time. According to the chemical kinetic theory, two models were established to show the relationship between dissolution rate and conductivity. The parameters, such as average reaction rate and others, were calculated by three of five sets and checked by the other two, which have a good agreement. It shows that the models based the conductivity measurement could display the dissolution process in actual situation, which is the base of the reactive transport model in limestone.