TY - JOUR T1 - Adsorption of fluoride ions by Zn-Al layered double hydroxides JF - Applied Clay Science Y1 - 2008 A1 - Mandal, Sujata A1 - Mayadevi, S. KW - Adsorption KW - Anionic clay KW - Fluoride KW - Layered double hydroxide AB -

Zn-Al layered double hydroxides (LDHs) with different molar ratios Zn/Al (0, 0.17, 0.34, 0.97, 3.47, proportional to) were prepared by the co-precipitation of chlorides, characterized and evaluated for their fluoride adsorption at room temperature from aqueous solutions. The fluoride adsorption of the as-synthesized LDHs was influenced by the chemical composition of the LDHs and ZA-11 (Zn/Al = 0.97) had the highest capacity for fluoride adsorption (1.14-4.16 mg/g). The adsorption increased after calcination of the LDH up to 500 degrees C. The equilibrium data were fitted to the Freundlich, Langmuir, and Temkin equations. The kinetics of fluoride adsorption followed the pseudo-second order model. (C) 2007 Elsevier B.V All rights reserved.

PB - ELSEVIER SCIENCE BV CY - PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS VL - 40 IS - 1-4 U3 - Foreign U4 - 2.586 ER -