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 kinetics 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 electrophoresis was used to evaluate the zeta potential 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 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 (INTA). 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
Fil: Zanini, Graciela Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química 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
Fuente
Colloids and surfaces. A: Physicochemical and engineering aspects 427 : 76-82. (2015).
Materia
Suelo
Soil
Calcium
Ions
Humic Acids
Flocculation
Calcio
Iones
Acido Húmico
Floculación
Cinética
Agregación
Iones de Calcio
Coagulation Kinetics
Aggregation Mechanism
Calcium Ions
Nivel de accesibilidad
acceso restringido
Condiciones de uso
Repositorio
INTA Digital (INTA)
Institución
Instituto Nacional de Tecnología Agropecuaria
OAI Identificador
oai:localhost:20.500.12123/1281
Acceder
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oai_identifier_str oai:localhost:20.500.12123/1281
network_acronym_str INTADig
repository_id_str l
network_name_str INTA Digital (INTA)
spelling Aggregation kinetics of humic acids in the presence of calcium ionsKloster, Nanci SoledadBrigante, Maximiliano EduardoZanini, Graciela PilarAvena, Marcelo JavierSueloSoilCalciumIonsHumic AcidsFlocculationCalcioIonesAcido HúmicoFloculaciónCinéticaAgregaciónIones de CalcioCoagulation KineticsAggregation MechanismCalcium IonsThe aggregation kinetics 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 electrophoresis was used to evaluate the zeta potential 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 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 (INTA). 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; ArgentinaFil: Zanini, Graciela Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; ArgentinaFil: Avena, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina2017-09-21T13:18:30Z2017-09-21T13:18:30Z2013info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttp://hdl.handle.net/20.500.12123/1281http://www.sciencedirect.com/science/article/pii/S09277757130021970927-7757https://doi.org/10.1016/j.colsurfa.2013.03.030Colloids and surfaces. A: Physicochemical and engineering aspects 427 : 76-82. (2015).reponame:INTA Digital (INTA)instname:Instituto Nacional de Tecnología Agropecuariaenginfo:eu-repo/semantics/restrictedAccess2025-09-04T09:47:01Zoai:localhost:20.500.12123/1281instacron:INTAInstitucionalhttp://repositorio.inta.gob.ar/Organismo científico-tecnológicoNo correspondehttp://repositorio.inta.gob.ar/oai/requesttripaldi.nicolas@inta.gob.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:l2025-09-04 09:47:03.861INTA Digital (INTA) - Instituto Nacional de Tecnología Agropecuariafalse
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
Suelo
Soil
Calcium
Ions
Humic Acids
Flocculation
Calcio
Iones
Acido Húmico
Floculación
Cinética
Agregación
Iones de Calcio
Coagulation Kinetics
Aggregation Mechanism
Calcium Ions
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 Suelo
Soil
Calcium
Ions
Humic Acids
Flocculation
Calcio
Iones
Acido Húmico
Floculación
Cinética
Agregación
Iones de Calcio
Coagulation Kinetics
Aggregation Mechanism
Calcium Ions
topic Suelo
Soil
Calcium
Ions
Humic Acids
Flocculation
Calcio
Iones
Acido Húmico
Floculación
Cinética
Agregación
Iones de Calcio
Coagulation Kinetics
Aggregation Mechanism
Calcium Ions
dc.description.none.fl_txt_mv The aggregation kinetics 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 electrophoresis was used to evaluate the zeta potential 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 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 (INTA). 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
Fil: Zanini, Graciela Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química 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
description The aggregation kinetics 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 electrophoresis was used to evaluate the zeta potential 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 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
2017-09-21T13:18:30Z
2017-09-21T13:18:30Z
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/20.500.12123/1281
http://www.sciencedirect.com/science/article/pii/S0927775713002197
0927-7757
https://doi.org/10.1016/j.colsurfa.2013.03.030
url http://hdl.handle.net/20.500.12123/1281
http://www.sciencedirect.com/science/article/pii/S0927775713002197
https://doi.org/10.1016/j.colsurfa.2013.03.030
identifier_str_mv 0927-7757
dc.language.none.fl_str_mv eng
language eng
dc.rights.none.fl_str_mv info:eu-repo/semantics/restrictedAccess
eu_rights_str_mv restrictedAccess
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv Colloids and surfaces. A: Physicochemical and engineering aspects 427 : 76-82. (2015).
reponame:INTA Digital (INTA)
instname:Instituto Nacional de Tecnología Agropecuaria
reponame_str INTA Digital (INTA)
collection INTA Digital (INTA)
instname_str Instituto Nacional de Tecnología Agropecuaria
repository.name.fl_str_mv INTA Digital (INTA) - Instituto Nacional de Tecnología Agropecuaria
repository.mail.fl_str_mv tripaldi.nicolas@inta.gob.ar
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score 12.623145

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