Application of a constrained regularization method to extraction of affinity distributions: Proton and metal binding to humic substances

The binding of proton and metal cations to humic substances has been analyzed with a regularized fitting procedure (using the CONTIN software package) to extract conditional affinity distributions, valid at a given ionic strength, from binding (titration) curves. The procedure was previously tested...

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Autores principales:	Orsetti, S., Andrade, E.M., Molina, F.V.
Formato:	JOUR
Materias:	Binding equilibrium CONTIN Humic substances Pollutant retention Soil organic matter Binding energy Biogeochemistry Biological materials Curve fitting Ionic strength Metal recovery Organic acids Organic pollutants Phenols Protons Soils Spectroscopic analysis Titration Waste incineration Binding sites carboxylic acid fulvic acid lead phenol proton article binding affinity computer program computer simulation constrained regularization method humic substance ionic strength metal binding methodology normal distribution priority journal reliability spectroscopy statistical model validation process
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_00219797_v336_n2_p377_Orsetti
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	todo:paper_00219797_v336_n2_p377_Orsetti
record_format	dspace
spelling	todo:paper_00219797_v336_n2_p377_Orsetti2023-10-03T14:25:12Z Application of a constrained regularization method to extraction of affinity distributions: Proton and metal binding to humic substances Orsetti, S. Andrade, E.M. Molina, F.V. Binding equilibrium CONTIN Humic substances Pollutant retention Soil organic matter Binding equilibrium CONTIN Humic substances Pollutant retention Soil organic matter Binding energy Biogeochemistry Biological materials Curve fitting Ionic strength Metal recovery Organic acids Organic pollutants Phenols Protons Soils Spectroscopic analysis Titration Waste incineration Binding sites carboxylic acid fulvic acid lead phenol proton article binding affinity computer program computer simulation constrained regularization method humic substance ionic strength metal binding methodology normal distribution priority journal reliability spectroscopy statistical model validation process The binding of proton and metal cations to humic substances has been analyzed with a regularized fitting procedure (using the CONTIN software package) to extract conditional affinity distributions, valid at a given ionic strength, from binding (titration) curves. The procedure was previously tested with simulated titration curves using a simple bi-Gaussian model, the NICA-Donnan model, and the Stockholm humic model. Application to literature data for proton binding shows that in several cases the affinity distribution found is bimodal (carboxylic and phenolic sites) as usually assumed; however in other cases, specially for fulvic acids, a trimodal distribution is clearly discerned, with a smaller peak between the two noted above attributed to the presence of vicinal carboxylic groups. The analysis of metal binding curves has been performed in a few cases where the available data could be reliably processed, separating the proton affinity distribution and obtaining the conditional affinity spectra. For Cd(II) and Pb(II) a bimodal distribution is found, attributed in principle to mono- and bidentate binding, based on spectroscopic data. In the case of Cu(II), a more complex affinity distribution is found showing 3-4 peaks; this is consistent with spectroscopic studies, where different binding modes, up to tetradentate, have been observed. © 2009 Elsevier Inc. All rights reserved. Fil:Orsetti, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Andrade, E.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Molina, F.V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00219797_v336_n2_p377_Orsetti
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Binding equilibrium CONTIN Humic substances Pollutant retention Soil organic matter Binding equilibrium CONTIN Humic substances Pollutant retention Soil organic matter Binding energy Biogeochemistry Biological materials Curve fitting Ionic strength Metal recovery Organic acids Organic pollutants Phenols Protons Soils Spectroscopic analysis Titration Waste incineration Binding sites carboxylic acid fulvic acid lead phenol proton article binding affinity computer program computer simulation constrained regularization method humic substance ionic strength metal binding methodology normal distribution priority journal reliability spectroscopy statistical model validation process
spellingShingle	Binding equilibrium CONTIN Humic substances Pollutant retention Soil organic matter Binding equilibrium CONTIN Humic substances Pollutant retention Soil organic matter Binding energy Biogeochemistry Biological materials Curve fitting Ionic strength Metal recovery Organic acids Organic pollutants Phenols Protons Soils Spectroscopic analysis Titration Waste incineration Binding sites carboxylic acid fulvic acid lead phenol proton article binding affinity computer program computer simulation constrained regularization method humic substance ionic strength metal binding methodology normal distribution priority journal reliability spectroscopy statistical model validation process Orsetti, S. Andrade, E.M. Molina, F.V. Application of a constrained regularization method to extraction of affinity distributions: Proton and metal binding to humic substances
topic_facet	Binding equilibrium CONTIN Humic substances Pollutant retention Soil organic matter Binding equilibrium CONTIN Humic substances Pollutant retention Soil organic matter Binding energy Biogeochemistry Biological materials Curve fitting Ionic strength Metal recovery Organic acids Organic pollutants Phenols Protons Soils Spectroscopic analysis Titration Waste incineration Binding sites carboxylic acid fulvic acid lead phenol proton article binding affinity computer program computer simulation constrained regularization method humic substance ionic strength metal binding methodology normal distribution priority journal reliability spectroscopy statistical model validation process
description	The binding of proton and metal cations to humic substances has been analyzed with a regularized fitting procedure (using the CONTIN software package) to extract conditional affinity distributions, valid at a given ionic strength, from binding (titration) curves. The procedure was previously tested with simulated titration curves using a simple bi-Gaussian model, the NICA-Donnan model, and the Stockholm humic model. Application to literature data for proton binding shows that in several cases the affinity distribution found is bimodal (carboxylic and phenolic sites) as usually assumed; however in other cases, specially for fulvic acids, a trimodal distribution is clearly discerned, with a smaller peak between the two noted above attributed to the presence of vicinal carboxylic groups. The analysis of metal binding curves has been performed in a few cases where the available data could be reliably processed, separating the proton affinity distribution and obtaining the conditional affinity spectra. For Cd(II) and Pb(II) a bimodal distribution is found, attributed in principle to mono- and bidentate binding, based on spectroscopic data. In the case of Cu(II), a more complex affinity distribution is found showing 3-4 peaks; this is consistent with spectroscopic studies, where different binding modes, up to tetradentate, have been observed. © 2009 Elsevier Inc. All rights reserved.
format	JOUR
author	Orsetti, S. Andrade, E.M. Molina, F.V.
author_facet	Orsetti, S. Andrade, E.M. Molina, F.V.
author_sort	Orsetti, S.
title	Application of a constrained regularization method to extraction of affinity distributions: Proton and metal binding to humic substances
title_short	Application of a constrained regularization method to extraction of affinity distributions: Proton and metal binding to humic substances
title_full	Application of a constrained regularization method to extraction of affinity distributions: Proton and metal binding to humic substances
title_fullStr	Application of a constrained regularization method to extraction of affinity distributions: Proton and metal binding to humic substances
title_full_unstemmed	Application of a constrained regularization method to extraction of affinity distributions: Proton and metal binding to humic substances
title_sort	application of a constrained regularization method to extraction of affinity distributions: proton and metal binding to humic substances
url	http://hdl.handle.net/20.500.12110/paper_00219797_v336_n2_p377_Orsetti
work_keys_str_mv	AT orsettis applicationofaconstrainedregularizationmethodtoextractionofaffinitydistributionsprotonandmetalbindingtohumicsubstances AT andradeem applicationofaconstrainedregularizationmethodtoextractionofaffinitydistributionsprotonandmetalbindingtohumicsubstances AT molinafv applicationofaconstrainedregularizationmethodtoextractionofaffinitydistributionsprotonandmetalbindingtohumicsubstances
_version_	1807316406146957312

Application of a constrained regularization method to extraction of affinity distributions: Proton and metal binding to humic substances

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