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论文类型：期刊论文

发表时间：2011-02-01

发表刊物：Transactions of Tianjin University

收录刊物：EI

卷号：17

期号：1

页面范围：51-56

ISSN号：10064982

摘要：Some laboratory diffusion tests were conducted with diffusion device to determine the diffusion coefficient of Cr(VI) ion passing through Dalian red clay samples. The concentrations of Cr(VI) at different places of the samples were then measured spectrophotometrically after a standing time of 1 000 d. A one-dimensional solute transport equation was used to simulate the transport of Cr(VI) through clay samples. Back-calculation of diffusion coefficient of Cr(VI) was made with finite difference method. Parametric analysis was conducted to simulate variations in soil dry density, temperature, pH and standing time. The results show that the method used in this paper is simple and effective. The diffusion coefficient of Cr(VI) in Dalian red clay varies from 1.50×10-7 cm2/s to 2.08×10-7 cm2/s. After 1 000 d diffusion, the concentration of the source solution drops down to 1.27 mg/L from 62.5 mg/L, and the diffusion distance is only 3.5 cm. Under the assumption that diffusion coefficient is constant, the diffusion effect becomes more obvious with lower density, lower temperature, higher pH value, and much more time. © 2011 Tianjin University and Springer-Verlag Berlin Heidelberg.