Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration

Detalhes bibliográficos
Autor(a) principal: Marchi,Giuliano
Data de Publicação: 2015
Outros Autores: Vilar,Cesar Crispim, O’Connor,George, Silva,Marx Leandro Naves
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Revista Brasileira de Ciência do Solo (Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000501387
Resumo: ABSTRACT Intrinsic equilibrium constants of 17 representative Brazilian Oxisols were estimated from potentiometric titration measuring the adsorption of H+ and OH− on amphoteric surfaces in suspensions of varying ionic strength. Equilibrium constants were fitted to two surface complexation models: diffuse layer and constant capacitance. The former was fitted by calculating total site concentration from curve fitting estimates and pH-extrapolation of the intrinsic equilibrium constants to the PZNPC (hand calculation), considering one and two reactive sites, and by the FITEQL software. The latter was fitted only by FITEQL, with one reactive site. Soil chemical and physical properties were correlated to the intrinsic equilibrium constants. Both surface complexation models satisfactorily fit our experimental data, but for results at low ionic strength, optimization did not converge in FITEQL. Data were incorporated in Visual MINTEQ and they provide a modeling system that can predict protonation-dissociation reactions in the soil surface under changing environmental conditions.
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spelling Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titrationintrinsic equilibrium constantsOxisolsFITEQLVisual MINTEQchemical equilibrium softwareABSTRACT Intrinsic equilibrium constants of 17 representative Brazilian Oxisols were estimated from potentiometric titration measuring the adsorption of H+ and OH− on amphoteric surfaces in suspensions of varying ionic strength. Equilibrium constants were fitted to two surface complexation models: diffuse layer and constant capacitance. The former was fitted by calculating total site concentration from curve fitting estimates and pH-extrapolation of the intrinsic equilibrium constants to the PZNPC (hand calculation), considering one and two reactive sites, and by the FITEQL software. The latter was fitted only by FITEQL, with one reactive site. Soil chemical and physical properties were correlated to the intrinsic equilibrium constants. Both surface complexation models satisfactorily fit our experimental data, but for results at low ionic strength, optimization did not converge in FITEQL. Data were incorporated in Visual MINTEQ and they provide a modeling system that can predict protonation-dissociation reactions in the soil surface under changing environmental conditions.Sociedade Brasileira de Ciência do Solo2015-10-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000501387Revista Brasileira de Ciência do Solo v.39 n.5 2015reponame:Revista Brasileira de Ciência do Solo (Online)instname:Sociedade Brasileira de Ciência do Solo (SBCS)instacron:SBCS10.1590/01000683rbcs20140528info:eu-repo/semantics/openAccessMarchi,GiulianoVilar,Cesar CrispimO’Connor,GeorgeSilva,Marx Leandro Naveseng2015-12-04T00:00:00Zoai:scielo:S0100-06832015000501387Revistahttp://www.scielo.br/scielo.php?script=sci_serial&pid=0100-0683&lng=es&nrm=isohttps://old.scielo.br/oai/scielo-oai.php||sbcs@ufv.br1806-96570100-0683opendoar:2015-12-04T00:00Revista Brasileira de Ciência do Solo (Online) - Sociedade Brasileira de Ciência do Solo (SBCS)false
dc.title.none.fl_str_mv Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration
title Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration
spellingShingle Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration
Marchi,Giuliano
intrinsic equilibrium constants
Oxisols
FITEQL
Visual MINTEQ
chemical equilibrium software
title_short Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration
title_full Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration
title_fullStr Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration
title_full_unstemmed Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration
title_sort Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration
author Marchi,Giuliano
author_facet Marchi,Giuliano
Vilar,Cesar Crispim
O’Connor,George
Silva,Marx Leandro Naves
author_role author
author2 Vilar,Cesar Crispim
O’Connor,George
Silva,Marx Leandro Naves
author2_role author
author
author
dc.contributor.author.fl_str_mv Marchi,Giuliano
Vilar,Cesar Crispim
O’Connor,George
Silva,Marx Leandro Naves
dc.subject.por.fl_str_mv intrinsic equilibrium constants
Oxisols
FITEQL
Visual MINTEQ
chemical equilibrium software
topic intrinsic equilibrium constants
Oxisols
FITEQL
Visual MINTEQ
chemical equilibrium software
description ABSTRACT Intrinsic equilibrium constants of 17 representative Brazilian Oxisols were estimated from potentiometric titration measuring the adsorption of H+ and OH− on amphoteric surfaces in suspensions of varying ionic strength. Equilibrium constants were fitted to two surface complexation models: diffuse layer and constant capacitance. The former was fitted by calculating total site concentration from curve fitting estimates and pH-extrapolation of the intrinsic equilibrium constants to the PZNPC (hand calculation), considering one and two reactive sites, and by the FITEQL software. The latter was fitted only by FITEQL, with one reactive site. Soil chemical and physical properties were correlated to the intrinsic equilibrium constants. Both surface complexation models satisfactorily fit our experimental data, but for results at low ionic strength, optimization did not converge in FITEQL. Data were incorporated in Visual MINTEQ and they provide a modeling system that can predict protonation-dissociation reactions in the soil surface under changing environmental conditions.
publishDate 2015
dc.date.none.fl_str_mv 2015-10-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000501387
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000501387
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/01000683rbcs20140528
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Sociedade Brasileira de Ciência do Solo
publisher.none.fl_str_mv Sociedade Brasileira de Ciência do Solo
dc.source.none.fl_str_mv Revista Brasileira de Ciência do Solo v.39 n.5 2015
reponame:Revista Brasileira de Ciência do Solo (Online)
instname:Sociedade Brasileira de Ciência do Solo (SBCS)
instacron:SBCS
instname_str Sociedade Brasileira de Ciência do Solo (SBCS)
instacron_str SBCS
institution SBCS
reponame_str Revista Brasileira de Ciência do Solo (Online)
collection Revista Brasileira de Ciência do Solo (Online)
repository.name.fl_str_mv Revista Brasileira de Ciência do Solo (Online) - Sociedade Brasileira de Ciência do Solo (SBCS)
repository.mail.fl_str_mv ||sbcs@ufv.br
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