密度效应对修复药剂在含水层迁移的影响——以KMnO4溶液为例的室内实验研究

利用典型的地下水修复药剂KMnO₄，通过一系列二维模拟槽实验，探究了密度效应作用下KMnO₄在模拟含水层的迁移分布规律，并分析了溶液浓度和介质粒径对密度效应的影响.结果表明，KMnO₄溶液在中砂和粗砂的模拟含水层中产生了明显的下沉现象，且迁移锋面的下沉程度会随着迁移进程不断加重，这导致KMnO₄的运移逐渐由推流向分层流转变，致使部分浅层模拟含水层无法接触KMnO₄；介质粒径越大、药剂浓度越高，密度效应造成的初期锋面下沉现象越明显，但后期下沉的变化幅度却和粒径与浓度成反比；对于锋面后的药剂迁移主体区域，KMnO₄会随着迁移时间延长逐渐分布均匀，并达到与原浓度基本一致的水平.

Influences of density effect on the migration of remedial reagent in aquifer-Laboratory study using KMnO4 solution as an example

The solution of KMnO₄ was used in this study to investigate the migration and distribution of KMnO₄ in simulated aquifer.This study focused on the influence of concentration and aquifer material size on density effect through a series of two-dimensional simulation tank experiments.The sinking phenomenon of KMnO₄ solution in the medium and coarse sand simulated aquifers was obvious.The sinking degree of migration front was more and more obvious during the migration process,which changed the migration form from plug flow to stratified flow and resulted in the failure of KMnO₄ distribution at shallow simulated aquifer.The greater the material size and the higher the concentration of remedial reagent,the more obvious the frontal sinking phenomenon at the preliminary stage was,but the extent of solution sinking was inversely proportional to the medium size and the concentration at the later stage.For the main migration region behind the migration front,KMnO₄ gradually distributed more uniformly with the extension of migration time.