Ion exchange studies on natural and modified zeolites and the concept of exchange site accessibility

Inglezakis, VJ; Loizidou, MM; Grigoropoulou, HP

dc.contributor.author	Inglezakis, VJ	en
dc.contributor.author	Loizidou, MM	en
dc.contributor.author	Grigoropoulou, HP	en
dc.date.accessioned	2014-03-01T01:20:41Z
dc.date.available	2014-03-01T01:20:41Z
dc.date.issued	2004	en
dc.identifier.issn	0021-9797	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16011
dc.subject	Activation energy	en
dc.subject	Clinoptilolite	en
dc.subject	Diffusion coefficients	en
dc.subject	Distribution coefficients	en
dc.subject	Heavy metals	en
dc.subject	Ion exchange	en
dc.subject.classification	Chemistry, Physical	en
dc.subject.other	Activation energy	en
dc.subject.other	Colloid chemistry	en
dc.subject.other	Diffusion	en
dc.subject.other	Reaction kinetics	en
dc.subject.other	Zeolites	en
dc.subject.other	Arrhenius activation energy	en
dc.subject.other	Equilibrium behavior	en
dc.subject.other	Ion exchange	en
dc.subject.other	chromium	en
dc.subject.other	clinoptilolite	en
dc.subject.other	copper ion	en
dc.subject.other	ferric ion	en
dc.subject.other	lead	en
dc.subject.other	metal	en
dc.subject.other	sodium ion	en
dc.subject.other	unclassified drug	en
dc.subject.other	zeolite	en
dc.subject.other	article	en
dc.subject.other	diffusion	en
dc.subject.other	energy	en
dc.subject.other	ion exchange	en
dc.subject.other	kinetics	en
dc.subject.other	materials	en
dc.subject.other	priority journal	en
dc.subject.other	sample	en
dc.subject.other	temperature	en
dc.title	Ion exchange studies on natural and modified zeolites and the concept of exchange site accessibility	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.jcis.2004.02.070	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.jcis.2004.02.070	en
heal.language	English	en
heal.publicationDate	2004	en
heal.abstract	In the present study natural and Na-rich form of clinoptilolite are examined, in respect to ion exchange of Pb2+, Cu2+, Cr3+, and Fe3+. Equilibrium and kinetic studies performed, under the same normality (0.01 N). Equilibrium studies demonstrate that Na+ enrichment of clinoptilolite is beneficial in respect to metal uptake for all metals, except Cr3+, which is shown to have the same equilibrium behavior in both materials. Kinetic study shows that diffusion coefficients are in the range of 0.16 to 9 x 10(-9) cm(2)/s, and are not always improved in Na-rich form of clinoptilolite. The effect of temperature on diffusion coefficients is also examined, and Arrhenius activation energy is determined to be in the range of 3.02 to 13.9 kcal/mol, for all metals and materials, except Cu2+, which have extremely low activation energy in the natural sample, equal to 0.04 kcal/mol. (C) 2004 Elsevier Inc. All rights reserved.	en
heal.publisher	ACADEMIC PRESS INC ELSEVIER SCIENCE	en
heal.journalName	Journal of Colloid and Interface Science	en
dc.identifier.doi	10.1016/j.jcis.2004.02.070	en
dc.identifier.isi	ISI:000222064800030	en
dc.identifier.volume	275	en
dc.identifier.issue	2	en
dc.identifier.spage	570	en
dc.identifier.epage	576	en