Mekhloufi, Malika, Zehhaf, Abdelhafid, Benyoucef, Abdelghani, Quijada Tomás, César, Morallon, Emilia
Removal of 8-quinolinecarboxylic acid pesticide from aqueous solution by adsorption on activated montmorillonites
Environmental Monitoring and Assessment. 2013, 185(12): 10365-10375. doi:10.1007/s10661-013-3338-5
URI: http://hdl.handle.net/10045/46334
DOI: 10.1007/s10661-013-3338-5
ISSN: 0167-6369 (Print)
Abstract: 
Sodium montmorillonite (Na-M), acidic montmorillonite (H-M), and organo-acidic montmorillonite (Org-H-M) were applied to remove the herbicide 8-quinolinecarboxylic acid (8-QCA). The montmorillonites containing adsorbed 8-QCA were investigated by transmission electron microscopy, FT-IR spectroscopy, X-ray diffraction analysis, X-ray fluorescence thermogravimetric analysis, and physical adsorption of gases. Experiments showed that the amount of adsorbed 8-QCA increased at lower pH, reaching a maximum at pH 2. The adsorption kinetics was found to follow the pseudo-second-order kinetic model. The Langmuir model provided the best correlation of experimental data for adsorption equilibria. The adsorption of 8-QCA decreased in the order Org-H-M > H-M > Na-M. Isotherms were also used to obtain the thermodynamic parameters. The negative values of ΔG indicated the spontaneous nature of the adsorption process.
Keywords:Adsorption isotherms, 8-Quinolinecarboxylic acid, Activated montmorillonite, Kinetics, Thermodynamic data
Springer Science+Business Media Dordrecht
info:eu-repo/semantics/article