NISCAIR Online Periodicals Repository

NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR)  >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Chemical Technology (IJCT) >
IJCT Vol.18 [2011] >
IJCT Vol.18(2) [March 2011] >


Title: Kinetics and thermodynamics study of copper ions removal by natural clinoptilolite
Authors: Ćurković, Lidija
Trgo, Marina
Rožić, Mirela
Medvidović, Nediljka Vukojević
Keywords: Clinoptilolite
Copper
Diffusion
Kinetic models
Thermodynamic parameters
Issue Date: Mar-2011
Publisher: NISCAIR-CSIR, India
Abstract: The process of removal of copper ions by means of clinoptilolite type natural zeolite has been studied as a function of the particle size and temperature. Results indicate that increase in temperature and decrease of particle size improves the removal of copper from aqueous solutions. The parabolic diffusion model is well described process in all examined range of time and it shows that the calculated diffusion coefficient increases with temperature. This increase is more visible at higher particle sizes what assume diffusion through zeolite particle as main mass transfer mechanism. The film diffusion model provides calculation of initial sorption rate (k´) and dimensionless parameter proportional to the diffusion film thickness (xi), in relation of particle size and temperature. Diffusion from the surface of zeolite particles through the micro and macro pores is well described with homogenous diffusion model, where change of the calculated overall rate constant is observed at »60 min of the process. This indicates the change of mass transfer rate through porous zeolite particle. The activation energy (Ea), activation enthalpy (H), activation entropy (S) and free energy of activation (G) have been calculated based on kinetic data. These thermodynamic parameters characterize process as diffusion dependent, weakly endothermic and nonspontaneous, where structural changes in structure of natural zeolite particle are not observed.
Page(s): 137-144
CC License:  CC Attribution-Noncommercial-No Derivative Works 2.5 India
ISSN: 0975-0991 (Online); 0971-457X (Print)
Source:IJCT Vol.18(2) [March 2011]

Files in This Item:

File Description SizeFormat
IJCT 18(2) 137-144.pdf213.46 kBAdobe PDFView/Open
 Current Page Visits: 1329 
Recommend this item

 

National Knowledge Resources Consortium |  NISCAIR Website |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2012 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 606142 since 06-Feb-2009  Last updated on 21-Oct-2014Webmaster: nopr@niscair.res.in