Aggregation kinetics of humic acids in the presence of calcium ions

Autores
Kloster, Nanci Soledad; Brigante, Maximiliano Eduardo; Zanini, Graciela Pilar; Avena, Marcelo Javier
Año de publicación
2013
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The aggregation kinetic of a humic acid (HA) sample as a function of Ca2+ concentration at pH 5, 7 and 9 was investigated. UV-VIS spectroscopy was employed to quantify the progress of the aggregation reaction and zeta potential measurements were used to evaluate the charging state of the HA molecules. The aggregation rate increases significantly by increasing Ca2+ concentration at all investigated pH, being higher at pH 9 than at pH 5 and 7. An aggregation mechanism is proposed, which consists of at least two steps: a rapid binding of Ca2+ to humic molecules, followed by a slower process where HA molecules approach each other and become aggregated. This aggregation is possible because Ca2+ binding decreases the zeta potential of HA from -37 mV to -15 mV and because it is able to form calcium bridges between HA molecules. There is no molecular fractionation up to 60% of aggregation. Above this value, HA aggregates become enriched with more aromatic HA molecules. The fast aggregation of HA in the presence of calcium ions implies that aggregates may temporarily trap, protect and transport pollutants in the environment.
Fil: Kloster, Nanci Soledad. Instituto Nacional de Tecnología Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria Anguil; Argentina
Fil: Brigante, Maximiliano Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; Argentina
Fil: Zanini, Graciela Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; Argentina
Fil: Avena, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; Argentina
Materia
Coagulation Kinetics
Humic Substances
Aggregation Mechanism
Flocculation
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/5324
Acceder
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network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Aggregation kinetics of humic acids in the presence of calcium ionsKloster, Nanci SoledadBrigante, Maximiliano EduardoZanini, Graciela PilarAvena, Marcelo JavierCoagulation KineticsHumic SubstancesAggregation MechanismFlocculationhttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1The aggregation kinetic of a humic acid (HA) sample as a function of Ca2+ concentration at pH 5, 7 and 9 was investigated. UV-VIS spectroscopy was employed to quantify the progress of the aggregation reaction and zeta potential measurements were used to evaluate the charging state of the HA molecules. The aggregation rate increases significantly by increasing Ca2+ concentration at all investigated pH, being higher at pH 9 than at pH 5 and 7. An aggregation mechanism is proposed, which consists of at least two steps: a rapid binding of Ca2+ to humic molecules, followed by a slower process where HA molecules approach each other and become aggregated. This aggregation is possible because Ca2+ binding decreases the zeta potential of HA from -37 mV to -15 mV and because it is able to form calcium bridges between HA molecules. There is no molecular fractionation up to 60% of aggregation. Above this value, HA aggregates become enriched with more aromatic HA molecules. The fast aggregation of HA in the presence of calcium ions implies that aggregates may temporarily trap, protect and transport pollutants in the environment.Fil: Kloster, Nanci Soledad. Instituto Nacional de Tecnología Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria Anguil; ArgentinaFil: Brigante, Maximiliano Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Zanini, Graciela Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Avena, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaElsevier2013-06info: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/11336/5324Kloster, Nanci Soledad; Brigante, Maximiliano Eduardo; Zanini, Graciela Pilar; Avena, Marcelo Javier; Aggregation kinetics of humic acids in the presence of calcium ions; Elsevier; Colloids And Surfaces A: Physicochemical And Engineering Aspects; 427; 6-2013; 76-820927-7757enginfo:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0927775713002197info:eu-repo/semantics/altIdentifier/doi/info:eu-repo/semantics/altIdentifier/doi/10.1016/j.colsurfa.2013.03.030info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:55:28Zoai:ri.conicet.gov.ar:11336/5324instacron: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:34982025-09-03 09:55:28.468CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Aggregation kinetics of humic acids in the presence of calcium ions
title Aggregation kinetics of humic acids in the presence of calcium ions
spellingShingle Aggregation kinetics of humic acids in the presence of calcium ions
Kloster, Nanci Soledad
Coagulation Kinetics
Humic Substances
Aggregation Mechanism
Flocculation
title_short Aggregation kinetics of humic acids in the presence of calcium ions
title_full Aggregation kinetics of humic acids in the presence of calcium ions
title_fullStr Aggregation kinetics of humic acids in the presence of calcium ions
title_full_unstemmed Aggregation kinetics of humic acids in the presence of calcium ions
title_sort Aggregation kinetics of humic acids in the presence of calcium ions
dc.creator.none.fl_str_mv Kloster, Nanci Soledad
Brigante, Maximiliano Eduardo
Zanini, Graciela Pilar
Avena, Marcelo Javier
author Kloster, Nanci Soledad
author_facet Kloster, Nanci Soledad
Brigante, Maximiliano Eduardo
Zanini, Graciela Pilar
Avena, Marcelo Javier
author_role author
author2 Brigante, Maximiliano Eduardo
Zanini, Graciela Pilar
Avena, Marcelo Javier
author2_role author
author
author
dc.subject.none.fl_str_mv Coagulation Kinetics
Humic Substances
Aggregation Mechanism
Flocculation
topic Coagulation Kinetics
Humic Substances
Aggregation Mechanism
Flocculation
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 aggregation kinetic of a humic acid (HA) sample as a function of Ca2+ concentration at pH 5, 7 and 9 was investigated. UV-VIS spectroscopy was employed to quantify the progress of the aggregation reaction and zeta potential measurements were used to evaluate the charging state of the HA molecules. The aggregation rate increases significantly by increasing Ca2+ concentration at all investigated pH, being higher at pH 9 than at pH 5 and 7. An aggregation mechanism is proposed, which consists of at least two steps: a rapid binding of Ca2+ to humic molecules, followed by a slower process where HA molecules approach each other and become aggregated. This aggregation is possible because Ca2+ binding decreases the zeta potential of HA from -37 mV to -15 mV and because it is able to form calcium bridges between HA molecules. There is no molecular fractionation up to 60% of aggregation. Above this value, HA aggregates become enriched with more aromatic HA molecules. The fast aggregation of HA in the presence of calcium ions implies that aggregates may temporarily trap, protect and transport pollutants in the environment.
Fil: Kloster, Nanci Soledad. Instituto Nacional de Tecnología Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria Anguil; Argentina
Fil: Brigante, Maximiliano Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; Argentina
Fil: Zanini, Graciela Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; Argentina
Fil: Avena, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; Argentina
description The aggregation kinetic of a humic acid (HA) sample as a function of Ca2+ concentration at pH 5, 7 and 9 was investigated. UV-VIS spectroscopy was employed to quantify the progress of the aggregation reaction and zeta potential measurements were used to evaluate the charging state of the HA molecules. The aggregation rate increases significantly by increasing Ca2+ concentration at all investigated pH, being higher at pH 9 than at pH 5 and 7. An aggregation mechanism is proposed, which consists of at least two steps: a rapid binding of Ca2+ to humic molecules, followed by a slower process where HA molecules approach each other and become aggregated. This aggregation is possible because Ca2+ binding decreases the zeta potential of HA from -37 mV to -15 mV and because it is able to form calcium bridges between HA molecules. There is no molecular fractionation up to 60% of aggregation. Above this value, HA aggregates become enriched with more aromatic HA molecules. The fast aggregation of HA in the presence of calcium ions implies that aggregates may temporarily trap, protect and transport pollutants in the environment.
publishDate 2013
dc.date.none.fl_str_mv 2013-06
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/11336/5324
Kloster, Nanci Soledad; Brigante, Maximiliano Eduardo; Zanini, Graciela Pilar; Avena, Marcelo Javier; Aggregation kinetics of humic acids in the presence of calcium ions; Elsevier; Colloids And Surfaces A: Physicochemical And Engineering Aspects; 427; 6-2013; 76-82
0927-7757
url http://hdl.handle.net/11336/5324
identifier_str_mv Kloster, Nanci Soledad; Brigante, Maximiliano Eduardo; Zanini, Graciela Pilar; Avena, Marcelo Javier; Aggregation kinetics of humic acids in the presence of calcium ions; Elsevier; Colloids And Surfaces A: Physicochemical And Engineering Aspects; 427; 6-2013; 76-82
0927-7757
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0927775713002197
info:eu-repo/semantics/altIdentifier/doi/
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.colsurfa.2013.03.030
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
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
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score 13.13397

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