Modeling the desorption of organic contaminants from long-term contaminated soil using distributed mass transfer rates
Modeling the desorption of organic contaminants from long-term contaminated soil using distributed mass transfer rates
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DOI：
10.1021/es9600946
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发表时间：
1997-06-01
影响因子：
11.4
通讯作者：
Smith, JA
中科院分区：
文献类型：
--
作者：
Culver, TB;Hallisey, SP;Smith, JA
地下水污染物归宿和迁移的模拟模型是检验我们对长期污染场地迁移现象的理解和设计补救行动计划的重要工具。本文提出了一种考虑污染物质量迁移率分布的污染物迁移有限差分公式。使用对数正态分布和伽马分布的传质速率的最佳模型模拟进行了比较，两个网站的平衡/动力学模型。在所有情况下，最佳的吸附参数确定的最佳拟合实验室数据。对于三氯乙烯从长期污染的土壤解吸，分布传质速率模型提供了显着改善的模拟水的浓度相比，两个网站的模型，批处理和土柱实验。然而，使用一个明显的分配系数表明，两个网站的模型的性能是非常敏感的分配系数的值，而分布式模型的性能是强大的分配系数在很宽的范围内。在连续流搅拌槽反应器与实验室污染土壤的解吸研究表明，作为污染期的长度增加，两个网站模型的模拟能力下降。
Simulation models for the fate and transport of groundwater contaminants are important tools for testing our understanding of transport phenomena at long-term contaminated sites and for designing remedial action plans. A finite difference formulation for contaminant transport including a distribution of contaminant mass-transfer rates between the water and soil is developed. Optimal model simulations using both log-normal and gamma distributions of mass transfer rates are compared to the two-site equilibrium/kinetic model. In all cases, optimal sorption parameters were determined by best fit to laboratory data. For desorption of trichloroethene from long-term contaminated soils, the distributed mass-transfer rate model provided significantly improved simulations of aqueous concentrations, as compared to the two-site model, for both batch and soil column experiments. However, use of an apparent partition coefficient demonstrated that the performance of the two-site model was very sensitive to the value of the partition coefficient, while the performances of the distributed models were robust over a wide range of partition coefficients. Desorption studies in continuous-flow stirred tank reactors with laboratory-contaminated soils demonstrated that as the length of the contamination period increases, the simulation capability of the two-site model decreases.