Abstract Tracer tests use conservative dyes to estimate hydraulic parameters of aquifers such as permeability and velocity. However, deionized water is rarely used in tracer tests. A novel permeable reactive barrier (PRB) designed and installed to collect and treat acidic water seeps from spoil heaps was investigated. In the present work, deionized water as a tracer was used to estimate the residence time and velocity distribution in reactive media placed in the PRB. Drift pump back tracer tests were carried out in multilevel boreholes in the reactive media using deionized water. Breakthrough curves of relative electrical conductivity were analyzed. The velocity and residence time differed horizontally and vertically at less than the optimum values predetermined in the design phase for effective treatment. The treatment efficiency is higher in the lower level than that at upper level inside the PRB. The quantity of deionized water used as a tracer should be big enough to force the tracer to move out of the well bore zone and travel significant distances into the reactive media. Consequently, representative breakthrough curves are obtained and better estimate the residence time and velocity. Using deionized water as a tracer has advantages over other tracer dyes such as fluorescein as it is inexpensive and requires no lab analysis for water samples and has less ionic strength and sorption. The disadvantage of using deionized water in reactive media is that it is recharged with high saline acidic water drainage from spoil. In drift tests the velocity is in direct proportion to permeability, drift time and time to recover half tracer mass. To overcome porosity reduction due to mineral fouling in the reactive media, the contaminated water should be forced to flow into several avenues in the reactive media in a direction parallel to PRB length instead of crossing the reactive media to increase the residence time inside the reactive media.

中文翻译：

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工程处理系统中停留时间分布的漂移泵回试验

摘要 示踪剂测试使用保守染料来估计含水层的水力参数，例如渗透率和速度。然而，去离子水很少用于示踪剂测试。研究了一种设计和安装的新型可渗透反应屏障 (PRB)，用于收集和处理来自弃渣堆的酸性水渗出液。在目前的工作中，去离子水作为示踪剂用于估计放置在 PRB 中的反应介质中的停留时间和速度分布。使用去离子水在反应介质中的多层钻孔中进行了漂移泵回示踪剂测试。分析了相对电导率的突破曲线。速度和停留时间在水平和垂直方向上的差异小于在设计阶段为有效处理预先确定的最佳值。PRB内下层处理效率高于上层处理效率。用作示踪剂的去离子水的量应足够大，以迫使示踪剂移出井眼区并移动到反应介质中相当长的距离。因此，获得了代表性的突破曲线，并更好地估计了停留时间和速度。使用去离子水作为示踪剂比其他示踪染料（如荧光素）具有优势，因为它价格低廉，不需要对水样进行实验室分析，并且离子强度和吸附性较低。在反应介质中使用去离子水的缺点是它被从弃土中排出的高盐酸性水补给。在漂移测试中，速度与渗透率、漂移时间和恢复半示踪剂质量的时间成正比。