In situ treatment usually requires contact between an injected reagent and target contaminant to realize mass removal from source zones and plumes. Despite significant site characterization efforts, unknown heterogeneities that exist at all spatial scales often hinder prediction of the distribution of injected reagents. To provide remediation practitioners with additional information on the distribution of injected reagents, a prototype real‐time monitoring probe was designed and tested. This new probe comprises a two‐wire resistivity circuit, hence the designation dipole resistivity probe (DRP). The low‐cost DRPs were built to be attached as arrays to a central stalk, and installed by direct‐push techniques. An installed network of multilevel DRPs can be used to detect the arrival, persistence, and relative concentration of a high‐conductivity reagent solution in real‐time across a zone of interest. Static cell and sandbox experiments were conducted to test and refine the DRP design before field testing. Static cell experimental results indicated that the DRP was sensitive to solution electrical conductivity (EC), and that the probe response and EC relationship is nonlinear and dependent on the fixed resistor used. The choice of fixed resistor can be adjusted to optimize the DRP response over a critical EC range of interest. Under dynamic conditions in the sandbox, the DRP was able to reproduce breakthrough profiles collected by a commercial EC sensor. The results from two field studies demonstrated the utility of the DRPs to generate information regarding the arrival and persistence of reagents in an efficient and cost‐effective manner. The first field study used a network of DRPs to monitor the land application of a sodium sulfate solution, and the second field study employed DRPs to monitor the distribution and longevity of a persulfate solution. While additional field testing is warranted, the results presented are encouraging and suggest that this low‐cost system can be used to improve our understanding of the detailed migration of injected reagents in treatment zones.

中文翻译：

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简单的电阻率探针系统，用于实时监测注入的试剂

原位处理通常需要在注入的试剂和目标污染物之间进行接触，以实现从源区和羽流中去除质量。尽管进行了大量的位点表征工作，但在所有空间尺度上均存在的未知异质性通常会阻碍对所注入试剂分布的预测。为了给补救从业人员提供有关注射试剂分布的更多信息，设计并测试了原型实时监控探针。这种新型探头包括两线电阻率电路，因此称为偶极电阻率探头（DRP）。低成本DRP可以作为阵列连接到中央秸秆，并通过直接推动技术进行安装。已安装的多级DRP网络可用于检测到达，持久性，高电导率试剂溶液在感兴趣区域中的实时相对浓度。在进行现场测试之前，进行了静态单元和沙箱实验以测试和完善DRP设计。静态电池实验结果表明，DRP对溶液的电导率（EC）敏感，并且探针响应和EC关系是非线性的，并且取决于所使用的固定电阻器。可以调整固定电阻的选择，以在关键的EC感兴趣范围内优化DRP响应。在沙箱中的动态条件下，DRP能够再现由商业EC传感器收集的突破性轮廓。两项现场研究的结果表明，DRP的作用是以有效且具有成本效益的方式生成有关试剂到达和持久性的信息。第一个现场研究使用DRPs网络监视硫酸钠溶液的土地应用，第二个现场研究使用DRPs监视过硫酸盐溶液的分布和寿命。尽管有必要进行额外的现场测试，但给出的结果令人鼓舞，这表明该低成本系统可用于增进我们对注射试剂在处理区域中详细迁移的理解。