On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration

Autores
Brigante, Maximiliano Eduardo; Zanini, Graciela Pilar; Avena, Marcelo Javier
Año de publicación
2007
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The dissolution kinetics of humic acid particles has been studied in batch experiments by UV-vis spectrophotometry, and the effects of pH, temperature, stirring rate and Ca2+ concentrations are reported. The dissolution rate increases by more than two orders of magnitude by increasing the pH from 4 to 11 in 10-3 M KCl solutions. There is also an important increase in the dissolution rate by increasing temperature and stirring rate. The presence of Ca2+ in the electrolyte solution, on the contrary, strongly decreases the dissolution rate at constant pH. The results suggest that the increase in the dissolution rate by increasing pH is strongly related to the breaking of hydrogen bonds that hold HA molecules in the solid phase and to the increased electrostatic repulsion among negatively charged humic acid molecules. This electrostatic repulsion overcomes attractive intermolecular forces among individual molecules constituting HA particles and thus a progressive dissolution takes place. Calcium ions, on the contrary, seem to block negatively charged groups of the surface molecules reducing electrostatic repulsion. These ions may also act as bridges between functional groups of two adjacent molecules, increasing the attractive intermolecular forces.
Fil: Brigante, Maximiliano Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina
Fil: Zanini, Graciela Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina
Fil: Avena, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina
Materia
ACTIVATION ENERGY
DISSOLUTION RATE
HUMIC ACID-WATER INTERFACE
SOLID HUMIC ACID
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/96896
Acceder
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repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentrationBrigante, Maximiliano EduardoZanini, Graciela PilarAvena, Marcelo JavierACTIVATION ENERGYDISSOLUTION RATEHUMIC ACID-WATER INTERFACESOLID HUMIC ACIDhttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1The dissolution kinetics of humic acid particles has been studied in batch experiments by UV-vis spectrophotometry, and the effects of pH, temperature, stirring rate and Ca2+ concentrations are reported. The dissolution rate increases by more than two orders of magnitude by increasing the pH from 4 to 11 in 10-3 M KCl solutions. There is also an important increase in the dissolution rate by increasing temperature and stirring rate. The presence of Ca2+ in the electrolyte solution, on the contrary, strongly decreases the dissolution rate at constant pH. The results suggest that the increase in the dissolution rate by increasing pH is strongly related to the breaking of hydrogen bonds that hold HA molecules in the solid phase and to the increased electrostatic repulsion among negatively charged humic acid molecules. This electrostatic repulsion overcomes attractive intermolecular forces among individual molecules constituting HA particles and thus a progressive dissolution takes place. Calcium ions, on the contrary, seem to block negatively charged groups of the surface molecules reducing electrostatic repulsion. These ions may also act as bridges between functional groups of two adjacent molecules, increasing the attractive intermolecular forces.Fil: Brigante, Maximiliano Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Zanini, Graciela Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Avena, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaElsevier Science2007-02info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/96896Brigante, Maximiliano Eduardo; Zanini, Graciela Pilar; Avena, Marcelo Javier; On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration; Elsevier Science; Colloids and Surfaces A: Physicochemical and Engineering Aspects; 294; 1-3; 2-2007; 64-700927-7757CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/sciencedirect.com/science/article/pii/S0927775706006054info:eu-repo/semantics/altIdentifier/doi/10.1016/j.colsurfa.2006.07.045info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-15T15:43:58Zoai:ri.conicet.gov.ar:11336/96896instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-15 15:43:59.081CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration
title On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration
spellingShingle On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration
Brigante, Maximiliano Eduardo
ACTIVATION ENERGY
DISSOLUTION RATE
HUMIC ACID-WATER INTERFACE
SOLID HUMIC ACID
title_short On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration
title_full On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration
title_fullStr On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration
title_full_unstemmed On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration
title_sort On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration
dc.creator.none.fl_str_mv Brigante, Maximiliano Eduardo
Zanini, Graciela Pilar
Avena, Marcelo Javier
author Brigante, Maximiliano Eduardo
author_facet Brigante, Maximiliano Eduardo
Zanini, Graciela Pilar
Avena, Marcelo Javier
author_role author
author2 Zanini, Graciela Pilar
Avena, Marcelo Javier
author2_role author
author
dc.subject.none.fl_str_mv ACTIVATION ENERGY
DISSOLUTION RATE
HUMIC ACID-WATER INTERFACE
SOLID HUMIC ACID
topic ACTIVATION ENERGY
DISSOLUTION RATE
HUMIC ACID-WATER INTERFACE
SOLID HUMIC ACID
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The dissolution kinetics of humic acid particles has been studied in batch experiments by UV-vis spectrophotometry, and the effects of pH, temperature, stirring rate and Ca2+ concentrations are reported. The dissolution rate increases by more than two orders of magnitude by increasing the pH from 4 to 11 in 10-3 M KCl solutions. There is also an important increase in the dissolution rate by increasing temperature and stirring rate. The presence of Ca2+ in the electrolyte solution, on the contrary, strongly decreases the dissolution rate at constant pH. The results suggest that the increase in the dissolution rate by increasing pH is strongly related to the breaking of hydrogen bonds that hold HA molecules in the solid phase and to the increased electrostatic repulsion among negatively charged humic acid molecules. This electrostatic repulsion overcomes attractive intermolecular forces among individual molecules constituting HA particles and thus a progressive dissolution takes place. Calcium ions, on the contrary, seem to block negatively charged groups of the surface molecules reducing electrostatic repulsion. These ions may also act as bridges between functional groups of two adjacent molecules, increasing the attractive intermolecular forces.
Fil: Brigante, Maximiliano Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina
Fil: Zanini, Graciela Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina
Fil: Avena, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina
description The dissolution kinetics of humic acid particles has been studied in batch experiments by UV-vis spectrophotometry, and the effects of pH, temperature, stirring rate and Ca2+ concentrations are reported. The dissolution rate increases by more than two orders of magnitude by increasing the pH from 4 to 11 in 10-3 M KCl solutions. There is also an important increase in the dissolution rate by increasing temperature and stirring rate. The presence of Ca2+ in the electrolyte solution, on the contrary, strongly decreases the dissolution rate at constant pH. The results suggest that the increase in the dissolution rate by increasing pH is strongly related to the breaking of hydrogen bonds that hold HA molecules in the solid phase and to the increased electrostatic repulsion among negatively charged humic acid molecules. This electrostatic repulsion overcomes attractive intermolecular forces among individual molecules constituting HA particles and thus a progressive dissolution takes place. Calcium ions, on the contrary, seem to block negatively charged groups of the surface molecules reducing electrostatic repulsion. These ions may also act as bridges between functional groups of two adjacent molecules, increasing the attractive intermolecular forces.
publishDate 2007
dc.date.none.fl_str_mv 2007-02
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/96896
Brigante, Maximiliano Eduardo; Zanini, Graciela Pilar; Avena, Marcelo Javier; On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration; Elsevier Science; Colloids and Surfaces A: Physicochemical and Engineering Aspects; 294; 1-3; 2-2007; 64-70
0927-7757
CONICET Digital
CONICET
url http://hdl.handle.net/11336/96896
identifier_str_mv Brigante, Maximiliano Eduardo; Zanini, Graciela Pilar; Avena, Marcelo Javier; On the dissolution kinetics of humic acid particles: Effects of pH, temperature and Ca2+ concentration; Elsevier Science; Colloids and Surfaces A: Physicochemical and Engineering Aspects; 294; 1-3; 2-2007; 64-70
0927-7757
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/sciencedirect.com/science/article/pii/S0927775706006054
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.colsurfa.2006.07.045
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier Science
publisher.none.fl_str_mv Elsevier Science
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
_version_ 1846083543514480640
score 13.22299

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