Nonsingularity of Naphthalene Sorption in Soil
Nonsingularity of Naphthalene Sorption in Soil
复制标题
土壤中萘吸附的非奇异性
DOI：
10.2136/sssaj2001.1622
复制
发表时间：
2001
影响因子：
2.9
通讯作者：
D. Rolston
中科院分区：
文献类型：
--
作者：
J. Gamst;T. Olesen;H. Jonge;P. Møldrup;D. Rolston
现实的有机化学品在土壤中的传输模型需要准确的预测吸附-解吸动力学。在这项研究中，一个基于物理的两室一速率（TCOR）吸附模型进行了评估，通过比较模型模拟测得的吸附-解吸等温线萘（C10 H8）为5种不同的土壤在短期（48 h）和长期（504 h）的时间尺度。两种土壤表现出轻微的吸附-解吸非奇异性（标记为I型土壤），两种土壤显着的非奇异性（II型土壤），和第五土壤显着的非奇异性仅在较长的时间尺度（I/II型土壤）。TCOR吸附模型拟合，测量的吸附-解吸等温线以及短期和长期的时间尺度。然而，TCOR吸附模型参数变化的短期和长期数据之间的每种土壤，特别是II型土壤。TCOR模型拟合的唯一性通过改变使用的解吸数据的数量进行了测试，导致参数值显著变化。TCOR吸附模型进行了评估，通过使用从短期数据中获得的模型参数，以预测长期的吸附结果。TCOR对I类土壤吸附-解吸行为的预测效果较好，对I/II类土壤的预测效果较好，对II类土壤的预测效果较差。从短期和长期的实验获得的模型参数被用来预测独立测量的吸附动力学，表现出降低预测精度增加吸附非奇异性。结果表明，TCOR吸附模型描述的扩散过程在晶粒尺度上是过于简化，吸附非奇异性不能很好地解释动力学因素单独。
Realistic models for transport of organic chemicals in soil require accurate predictions of the adsorption-desorption kinetics. In this study, a physically based two-compartment one-rate (TCOR) sorption model was evaluated by comparison of model simulations to measured adsorption-desorption isotherms of naphthalene (C 10 H 8 ) for five different soils on a short-term (48 h) and a longer-term (504 h) time scale. Two soils exhibited minor adsorption-desorption nonsingularity (labeled Type I soils), two soils pronounced nonsingularity (Type II soils), and the fifth soil pronounced nonsingularity only on the longer-term time scale (Type I/II soil). The TCOR sorption model fitted, measured adsorption-desorption isotherms well on both short-term and longer-term time scales. However, the TCOR sorption model parameters varied for each soil between short-term and longer-term data, especially for Type II soils. The uniqueness of the TCOR model fit was tested by varying the number of desorption data used, resulting in markedly changed parameter values. The TCOR sorption model was evaluated by using model parameters obtained from short-term data to predict longer-term sorption results. The TCOR prediction of adsorption-desorption behavior was good for Type I soils, satisfactory for the Type I/II soil, and poor for Type II soils. Model parameters obtained from short-term and longer-term experiments were used to predict independently measured adsorption kinetics, showing decreasing prediction accuracy with increasing sorption nonsingularity. The results imply that the TCOR sorption model description of the diffusion process at the grain scale is oversimplified, and that sorption nonsingularity is not well explained by kinetic factors alone.