Oxidative regeneration of toluene-saturated natural zeolite by gaseous ozone: The influence of zeolite chemical surface characteristics

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dc.contributor.authorAlejandro, Serguei
dc.contributor.authorValdes, Hector
dc.contributor.authorManero, Marie Helene
dc.contributor.authorZaror, Claudio A.
dc.date2014
dc.date.accessioned2021-04-30T17:06:06Z
dc.date.available2021-04-30T17:06:06Z
dc.description.abstractIn this study, the effect of zeolite chemical surface characteristics on the oxidative regeneration of toluene saturated-zeolite samples is investigated. A Chilean natural zeolite (53% clinoptilolite, 40% mordenite and 7% quartz) was chemically modified by acid treatment with hydrochloric acid and by ion-exchange with ammonium sulphate. Thermal pre-treatments at 623 and 823 K were applied and six zeolite samples with different chemical surface characteristics were generated. Chemical modification of natural zeolite followed by thermal out-gassing allows distinguishing the role of acidic surface sites on the regeneration of exhausted zeolites. An increase in Bronsted acid sites on zeolite surface is observed as a result of ammonium-exchange treatment followed by thermal treatment at 623 K, thus increasing the adsorption capacity toward toluene. High ozone consumption could be associated to a high content of Lewis acid sites, since these could decompose ozone into atomic active oxygen species. Then, surface oxidation reactions could take part among adsorbed toluene at Bronsted acid sites and surface atomic oxygen species, reducing the amount of adsorbed toluene after the regenerative oxidation with ozone. Experimental results show that the presence of adsorbed oxidation by-products has a negative impact on the recovery of zeolite adsorption capacity. (C) 2014 Elsevier B.V. All rights reserved.
dc.identifier.citationJOURNAL OF HAZARDOUS MATERIALS,Vol.274,212-220,2014
dc.identifier.doi10.1016/j.jhazmat.2014.04.006
dc.identifier.urihttp://repositoriodigital.uct.cl/handle/10925/4024
dc.language.isoen
dc.publisherELSEVIER SCIENCE BV
dc.sourceJOURNAL OF HAZARDOUS MATERIALS
dc.subject.englishBronsted acid sites
dc.subject.englishLewis acid sites
dc.subject.englishOzone
dc.subject.englishToluene
dc.subject.englishZeolite
dc.titleOxidative regeneration of toluene-saturated natural zeolite by gaseous ozone: The influence of zeolite chemical surface characteristics
dc.typeArticle
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