Volume 19, Issue 73 (fall 2015)                   jwss 2015, 19(73): 35-44 | Back to browse issues page


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1. Dept. of Soil Sci., College of Agric., Isf. (Khorasgan) Branch, Islamic Azad Univ., Isfahan, Iran. , chavoshie@yahoo.com
Abstract:   (9363 Views)

The sorption and desorption of fluoride by soil can play an important role in the transport of fluoride in soil. The study was conducted on the soil from Isfahan University of Technology research station site (two depths of 0-30 and 30- 60 cm). Fluoride sorption reactions were examined by equilibrating 0, 2.5, 5, 10, 25, 50 and 100 mg L-1 NaF solution with soils for 23 hr. The desorption experiments were performed using 0.03 mol L-1 NaCL solutions immediately following the completion of sorption experiments. The sorption isotherms of F were well described by the Langmuir and Freundlich models. The n values for Freundlich isotherm were 0.57 and 0.55 for two depths of the studied soil, respectively. The kF values for Freundlich isotherm were 0.026 and 0.025 mg (1-n) Ln g-1 for two depths, respectively. Maximum monolayer sorption capacities (q max) were obtained to be 0.4 and 0.35 mg g-1 for 1 and 2 layers of the studied soil, respectively. The desorption isotherms of F were well described by the Freundlich model. The fitted model parameters’ (kF and n) values for desorption branches were larger than these values for sorption branches. Also, the results showed a positive hysteresis (ndesrb sorb and kdesorb >Ksorb). It seems fluoride sorption to be reversible.

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Type of Study: Research | Subject: Ggeneral
Received: 2015/11/14 | Accepted: 2015/11/14 | Published: 2015/11/14

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