磷石膏渗滤液对碳酸盐岩的溶蚀试验

Dissolution Experiment of Phosphogypsum Leachate on Carbonatite

磷石膏渗滤液对碳酸盐岩及岩溶地下水产生重要影响,但其影响机制尚不清楚。本文开展了磷石膏渗滤液对碳酸盐岩的溶蚀试验,对比分析了不同p H值、水动力条件及溶蚀时间对研究区不同碳酸盐岩样品的溶蚀效果,探讨各试验条件对溶蚀作用的影响机制。结果表明:岩样失重率呈现对数型增长趋势;渗滤液pH值为1.86的试验组中岩样失重率大小依次为娄山关组、法郎组、青岩组,pH值为2.71的试验组中岩样失重率大小依次为:法郎组、青岩组、娄山关组;动态试验失重率明显高于静态试验。渗滤液pH值和水动力条件与其他变量的交互作用均表现强烈,渗滤液pH值、水动力条件及二者间交互作用对岩样溶蚀的影响在试验前期作用较大而在后期减弱,岩石层组类别在试验后期作用凸显。整体上看,试验变量对岩样失重率的影响作用大小依次为渗滤液p H值、溶蚀时间、水动力条件、岩石层组类别。

Phosphogypsum leachate has caused dissolution on carbonatite and led to karst groundwater pollution,however,its effect mechanism is not clear.In this study,the dissolution experiments of phosphogypsum leachate on Carbonatite were carried,dissolution effects of different carbonate rock samples under different pH values,hydrodynamic conditions and dissolution time were compared,and the influence mechanisms of these factors were discussed.The results indicate that the weight loss ratios of rock samples showed a logarithmic growth trend.The weight loss ratios from high to low was Loushanguan Formation,Falang Formation and Qingyan Formation at pH 1.86,and the sequence was Falang Formation,Qingyan Formation and Loushanguan Formation at pH 2.71.Otherwise dynamic weight-loss-ratio was higher than static obviously.Interactions between pH values of leachate,hydrodynamic conditions and other variables were strong.In the early stages of the dissolution,pH values of leachate,hydrodynamic conditions and their interactions played a major role on the impact of dissolution,but weakened in the later stages,while the effects of rock formation began to burgeon.As a whole,the effect of experimental variables on the weight loss rate of rock samples is as follows:pH value of leachate,dissolution time,hydrodynamic conditions,and rock group category.