The image analysis technique approach links the dye concentration and color intensity, enabling quantification of spatial and temporal dye dynamics in clay media. In this study, batch adsorption tests and two-dimensional diffusion experiments with three types of clays (kaolinite, montmorillonite, and bentonite) were conducted for quantifying the vertical distribution of fluorescein dye tracer to evaluate the feasibility of the image analysis technique. In clay domains, color intensities were measured using images obtained during diffusion experiments, and these intensities were converted to aqueous fluorescein concentrations. Concentration profiles simulated from a one-dimensional analytical solution agreed well with those measured by the LRV technique with a single-channel application for kaolinite (blue channel, E = 0.94 and 0.96) and montmorillonite (green channel, E = 0.99 and 0.91 in the early (31.1, 54.6 PVs) and later (75.7, 93.9 PVs) diffusion times, respectively. The single-channel application for the bentonite was appropriate for concentration ranges of 0 − 400 mg/L for the blue channel and 400 − 1800 mg/L for the green channel. For quantifying the bentonite concentration profile with a wide range of dye concentrations (0 − 1800 mg/L), multi-channel application (blue + green channels) was required. Measured LRV concentration profiles with the multi-channel application showed better agreement (E = 0.94) with simulated concentration profiles from the analytical solution than those with the single-channel application (E = 0.56). The results of this study offer guidance on the application of the LRV approach as a non-destructive optical dye measurement method to diffusion problems between high and low permeability zones.

中文翻译：

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用于量化粘土中荧光素浓度分布的图像分析技术

图像分析技术方法将染料浓度和颜色强度联系起来，从而能够量化粘土介质中的空间和时间染料动态。在本研究中，对三种粘土（高岭石、蒙脱石和膨润土）进行了批量吸附试验和二维扩散实验，以量化荧光素染料示踪剂的垂直分布，以评估图像分析技术的可行性。在粘土域中，使用扩散实验期间获得的图像测量颜色强度，并将这些强度转换为水性荧光素浓度。对于高岭石（蓝色通道，E = 0.94 和 0.96）和蒙脱土（绿色通道，E = 0.99 和 0.91），一维分析溶液模拟的浓度分布与单通道应用 LRV 技术测量的浓度分布非常吻合。早期（31.1、54.6 PV）和晚期（75.7、93.9 PV）扩散时间分别 膨润土的单通道应用适合蓝色通道的浓度范围为 0 – 400 mg/L 和 400 – 1800 mg/L。 L 代表绿色通道。为了量化各种染料浓度 (0 – 1800 mg/L) 的膨润土浓度曲线，需要使用多通道测量 LRV 浓度曲线。与单通道应用 (E = 0.56) 相比，该应用与分析溶液的模拟浓度分布表现出更好的一致性 (E = 0.94)。本研究的结果为 LRV 方法作为非破坏性应用提供了指导。光学染料测量方法解决高渗透率区域和低渗透率区域之间的扩散问题。