Sorption and Intraparticle Diffusion of Fluorescent Dyes with Consolidated Aquifer Media
Sorption and Intraparticle Diffusion of Fluorescent Dyes with Consolidated Aquifer Media
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固结含水层介质对荧光染料的吸附和颗粒内扩散
DOI：
10.1111/j.1745-6584.2000.tb02700.x
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发表时间：
2000
期刊：
影响因子：
2.6
通讯作者：
D. Sabatini
中科院分区：
文献类型：
--
作者：
D. Sabatini
两种荧光染料（荧光素和磺酰罗丹明B）的吸附进行了评价与两个相反的电荷，巩固含水层材料（砂岩和石灰岩）。具有阴离子羧基的黄绿素在带负电荷的砂岩上的吸附可忽略不计，并且在带正电荷的石灰石上的吸附远小于具有两个磺酸基的磺酰罗丹明B。磺酰罗丹明B上的阳离子电荷使其吸附在带负电荷的砂岩上。这些结果验证和扩展了以前的研究与纯矿物表面（氧化铝和二氧化硅）。吸附动力学速率随着粒径的增加而降低，这与扩散限制的颗粒内吸附一致。通过将扩散限制的颗粒内吸附模型与一种粒度的动力学数据拟合来确定曲折因子（所有其他参数均独立确定）。该弯曲因子与基于阿尔奇定律的估计值和其他独立确定的参数一致，随后用于预测第二种粒度的动力学吸附结果。实验数据和模型预测之间的密切一致性证实了颗粒内扩散限制吸附是一个重要的过程。扩散限制吸附可影响具有内部孔隙的未固结颗粒或具有双重孔隙的固结或破裂介质中的染料传输。因此，这些结果表明，在设计和解释示踪剂研究时，了解染料吸附的平衡和动力学的重要性。
Sorption of two fluorescent dyes (fluorescein and sulforhodamine B) was evaluated with two oppositely charged, consolidated aquifer materials (sandstone and limestone). Fluorescein, which has an anionic carboxylic group, experienced negligible sorption onto negatively charged sandstone and sorbed much less than sulforhodamine B, with its two sulfonic groups, onto positively charged limestone. The cationic charge on sulforhodamine B caused it to adsorb onto negatively charged sandstone. These results validate and extend previous research with pure mineral surfaces (alumina and silica). Sorption kinetic rates decreased with increasing particle size, which is consistent with diffusion‐limited intraparticle sorption. Tortuosity factors were determined by fitting a diffusion ‐limited intraparticle sorption model to kinetic data for one particle size (all other parameters being determined independently). This tortuosity factor, which was consistent with Archie's law‐based estimates and other independently determined parameters, was subsequently used to predict kinetic adsorption results for a second particle size. Close agreement between experimental data and model predictions corroborated intraparticle diffusion‐limited sorption as an important process. Diffusion‐limited sorption can impact dye transport in unconsolidated grains having internal porosity or consolidated or fractured media having dual porosity. These results thus demonstrate the importance of understanding both the equilibrium and kinetics of dye sorption when designing and interpreting tracer studies.