Please use this identifier to cite or link to this item:
|Title:||Adsorption Equilibria of Hg(II) on Clays in Presence of Organic Materials|
|Authors:||Abraham, Beena T|
Anirudhan, T S
|Abstract:||Adsorption of Hg(II), organic ligands (HA, NTA, EDTA and CDTA) and Hg(II) in the presence of organic ligands on montmorillonite, illite and kaolin from water environment is reported. The maximum adsorption of Hg(II) onto montmorillonite and kaolin lakes place in the pH range 5-10. The maximum removal of Hg(II) by illite is observed at pH 8. The efficiency for the removal of Hg(II) by adsorption is in the order: montmorillonite > illite > kaolin. The adsorption isotherm data follows both the Langmuir and Freundlich isotherm equations. The maximum removal of organic ligands by adsorption is observed at low pH and is in the order: HA >NTA > EDTA > CDTA. The monovalent species of EDT A and CDTA have lower adsorption capacity than divalent species of NTA on the clay surface at pH 3.0. In ligand titration experiments, if the Hg and clay concentrations are kept constant and the ligand concentration is allowed to vary, conditions under which ligand enhances and inhibits Hg adsorption with the solid phase are noted. The experimental equilibrium data for the adsorption of Hg(II) in the presence of ligand at constant L/M ratio are analysed using Langmuir isotherm model. The enhanced uptake of metal in the presence of organic ligands, at least at certain circumstances, may be due to the formation of an adsorbed organic layer on the clay providing new adsorption sites for metal at the surface.|
|ISSN:||0975-1084 (Online); 0022-4456 (Print)|
|Appears in Collections:||JSIR Vol.58(11) [November 1999]|
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.