Show simple item record

dc.contributor.authorFábrega, José
dc.contributor.authorLi, Hui
dc.contributor.authorJafvert, Chad
dc.contributor.authorLee, Linda
dc.date.accessioned2018-03-22T13:35:42Z
dc.date.accessioned2018-03-22T13:35:42Z
dc.date.available2018-03-22T13:35:42Z
dc.date.available2018-03-22T13:35:42Z
dc.date.issued1998-12-08
dc.date.issued1998-12-08
dc.identifierhttps://pubs.acs.org/doi/abs/10.1021/es9802394
dc.identifier.issn1520-5851
dc.identifier.urihttp://ridda2.utp.ac.pa/handle/123456789/4441
dc.identifier.urihttp://ridda2.utp.ac.pa/handle/123456789/4441
dc.descriptionThe applicability of a distributed parameter model for describing the distribution of aniline and α-naphthylamine between soil and aqueous phases at short contact times was assessed. Mass action equations considered in the distributed parameter model were (a) acid dissociation of the protonated organic amine (BH+); (b) sorption of the neutral species (B) to soil organic carbon through the partition coefficient Koc; and (c) ion exchange of the protonated organic amine and inorganic divalent cations (Ca2+ + Mg2+ = D2+). The last reaction was expressed mathematically as separated association reactions for each cation to unoccupied cation exchange sites, with constants KBH and KD. A Gaussian distribution on log KBH values with mode μ and standard deviation σ was employed. The overall model was expressed as a system of two nonlinear equations with two unknown values (BH+ and D2+). The model was evaluated with aniline and α-naphthylamine isotherms measured on three Indiana soils ranging in pH (4.5−7.0) and added calcium concentration (0.5−50 mM) after a 24 h contact period. The parameters Koc, μ, and σ for each amine were obtained by minimizing the sum of squared residuals between predicted and measured aqueous-phase organic amine concentrations (i.e., [B]aq + [BH+]aq) for all soil, pH, and CaCl2 conditions, simultaneously. Calculated isotherms were compared against those calculated with the general form of the speciation model in which a singular value of KBH was employed. The distributed parameter form of the model resulted in nonlinear calculated isotherms in general agreement with the curvature of α-naphthylamine measured isotherms. Skewed distributions on log KBH were evaluated also.
dc.description.abstractThe applicability of a distributed parameter model for describing the distribution of aniline and α-naphthylamine between soil and aqueous phases at short contact times was assessed. Mass action equations considered in the distributed parameter model were (a) acid dissociation of the protonated organic amine (BH+); (b) sorption of the neutral species (B) to soil organic carbon through the partition coefficient Koc; and (c) ion exchange of the protonated organic amine and inorganic divalent cations (Ca2+ + Mg2+ = D2+). The last reaction was expressed mathematically as separated association reactions for each cation to unoccupied cation exchange sites, with constants KBH and KD. A Gaussian distribution on log KBH values with mode μ and standard deviation σ was employed. The overall model was expressed as a system of two nonlinear equations with two unknown values (BH+ and D2+). The model was evaluated with aniline and α-naphthylamine isotherms measured on three Indiana soils ranging in pH (4.5−7.0) and added calcium concentration (0.5−50 mM) after a 24 h contact period. The parameters Koc, μ, and σ for each amine were obtained by minimizing the sum of squared residuals between predicted and measured aqueous-phase organic amine concentrations (i.e., [B]aq + [BH+]aq) for all soil, pH, and CaCl2 conditions, simultaneously. Calculated isotherms were compared against those calculated with the general form of the speciation model in which a singular value of KBH was employed. The distributed parameter form of the model resulted in nonlinear calculated isotherms in general agreement with the curvature of α-naphthylamine measured isotherms. Skewed distributions on log KBH were evaluated also.en_US
dc.formatapplication/pdf
dc.languageeng
dc.language.isoengen_US
dc.rightsinfo:eu-repo/semantics/embargoedAccess
dc.subjectModeling Short-Termen_US
dc.subjectWater Distributionen_US
dc.subjectAromatic Aminesen_US
dc.subjectModeling Short-Term
dc.subjectWater Distribution
dc.subjectAromatic Amines
dc.titleModeling Short-Term Soil−Water Distribution of Aromatic Aminesen_US
dc.typeinfo:eu-repo/semantics/article
dc.typeinfo:eu-repo/semantics/publishedVersion


Files in this item

FilesSizeFormatView

There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record