Diffusive Mobility of Fluoride in Soil: Some Mechanistic Aspects
2007
Rai, K. | Agarwal, M. | Dass, S. | Shrivastav, R.
The diffusive mobility of fluoride (F) in soil (Entisol heplaquent) has been investigated as a function of soil water content and F-concentration gradient. The data on F-diffusion coefficients were recorded by determining the F-concentration profile in horizontally incubated and homogenized soil columns, under varied experimental conditions (volumetric soil water content (theta) = 0.12 - 0.25 cm3 cm(-3), initial concentration of F at source (Ft=0) = 8-32 micromolar/g, pH = 7.6 +/- 0.5, incubation time (t) = 96 and 384 h, temperature = 303 +/- 1.2 K). The effects of aluminum (Al) and calcium (Ca) ions, which are known to be strong binders for F in soil, on the F mobility have also been investigated by observing F diffusion in soils amended with externally added Al and Ca. The study suggests that F diffusion in soil increases with increase in theta and Ft=0. Further, when the soil was amended with Ca, F diffusion was observed to decrease regularly with the increase in Ca amount. In Al-amended soil, when Al concentration is raised, F diffusion increases, at 96 h incubation time but decreases at 384 h incubation.
显示更多 [+] 显示较少 [-]