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Carbon nanotubes as catalysts for catalytic wet peroxide oxidation of highly concentrated phenol solutions: towards process intensification

dc.contributor.authorPinho, Maria
dc.contributor.authorGomes, Helder
dc.contributor.authorRibeiro, Rui
dc.contributor.authorFaria, Joaquim
dc.contributor.authorSilva, Adrián
dc.date.accessioned2015-02-03T12:47:27Z
dc.date.available2015-02-03T12:47:27Z
dc.date.issued2015
dc.description.abstractCommercial multi-walled carbon nanotubes with different properties (two samples from Sigma-Aldrich,SA1 and SA2; one sample from Nanocyl, NC; and two samples from Shenzhen Nanotech, SZ and LSZ),and SA2 modified by hydrothermal treatment with concentrated sulfuric acid (SA2-H), were tested ascatalysts in wet peroxide oxidation. Phenol was selected as model compound since it represents a classof noxious compounds for human health and for the environment and, due to this, phenol is typically considered in wastewater treatment studies. The experiments were carried out under the following inten-sified conditions: phenol concentration = 4.5 g L−1, hydrogen peroxide concentration = 25 g L−1, catalystload = 2.5 g L−1, pH 3.5, T = 353 K and 24 h.The results demonstrated that phenol is poorly adsorbed in this type of carbon materials (11% as max-imum when using the NC sample). However, in the catalytic experiments, complete removal of phenol isachieved when using some of the carbon nanotubes (SA1, NC and SA2), together with a remarkable total organic carbon removal (77, 69 and 67%, respectively). These materials have the less pronounced acidiccharacter, which is often considered favorable for oxidation reactions in advanced oxidation processesand may explain the higher performance of SA1, NC and SA2 regarding the other materials. Leaching of Fespecies into the solution was also observed in all cases (that can also have some influence on the degra-dation of phenol), SA1 leading to the highest concentration of Fe species leached (26 mg L−1), followedby SA2 (2 mg L−1) and NC (1 mg L−1).Considering the lower Fe leaching levels observed for SA2 and NC, these catalysts were then testedin consecutive reusability cycles. SA2 showed a superior performance than NC, but temperature-programmed desorption as well as thermogravimetric analysis suggested that the carbon material isoxidized by hydrogen peroxide at the employed conditions and/or that carboxylic acids are adsorbed onthe catalyst surface after consecutive runs (mainly after the first use). However, only a slight decrease inthe catalyst activity was observed.por
dc.identifier.citationPinho, Maria; Gomes, Helder; Ribeiro, Rui; Faria, Joaquim; Silva, Adrián (2015). Carbon nanotubes as catalysts for catalytic wet peroxide oxidation of highly concentrated phenol solutions: towards process intensification, Applied Catalysis B: Environmental. ISSN 0926-3373. 165, p. 706-714por
dc.identifier.doi10.1016/j.apcatb.2014.10.057
dc.identifier.urihttp://hdl.handle.net/10198/11635
dc.language.isoengpor
dc.peerreviewedyespor
dc.subjectCatalytic wet peroxide oxidationpor
dc.subjectCarbon nanotubespor
dc.subjectPhenolpor
dc.subjectHighly polluted effluentspor
dc.subjectIntensified process conditionspor
dc.titleCarbon nanotubes as catalysts for catalytic wet peroxide oxidation of highly concentrated phenol solutions: towards process intensificationpor
dc.typejournal article
dspace.entity.typePublication
oaire.citation.endPage714por
oaire.citation.startPage706por
oaire.citation.titleApplied Catalysis B: Environmentalpor
oaire.citation.volume165por
person.familyNameGomes
person.givenNameHelder
person.identifier.ciencia-id6218-1E19-13EE
person.identifier.orcid0000-0001-6898-2408
rcaap.rightsrestrictedAccesspor
rcaap.typearticlepor
relation.isAuthorOfPublication0eb96337-224a-4339-9918-334436fbbb99
relation.isAuthorOfPublication.latestForDiscovery0eb96337-224a-4339-9918-334436fbbb99

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