title: Wide-range and accurate modeling of linear alkylbenzene sulfonate (LAS) adsorption/desorption on agricultural soil.
abstract: In this paper, rigorous data and adequate models about linear alkylbenzene sulfonate (LAS) adsorption/desorption on agricultural soil are presented, contributing with a substantial improvement over available adsorption works. The kinetics of the adsorption/desorption phenomenon and the adsorption/desorption equilibrium isotherms were determined through batch studies for total LAS amount and also for each homologue series: C10, C11, C12 and C13. The proposed multiple pseudo-first order kinetic model provides the best fit to the kinetic data, indicating the presence of two adsorption/desorption processes in the general phenomenon. Equilibrium adsorption and desorption data have been properly fitted by a model consisting of a Langmuir plus quadratic term, which provides a good integrated description of the experimental data over a wide range of concentrations. At low concentrations, the Langmuir term explains the adsorption of LAS on soil sites which are highly selective of the n-alkyl groups and cover a very small fraction of the soil surface area, whereas the quadratic term describes adsorption on the much larger part of the soil surface and on LAS retained at moderate to high concentrations. Since adsorption/desorption phenomenon plays a major role in the LAS behavior in soils, relevant conclusions can be drawn from the obtained results.
authors.affiliation: Research Group of Analytical Chemistry and Life Sciences, Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Campus of Fuentenueva, E-18071 Granada, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Oliver-Rodríguez
authors.affiliation: Research Group of Analytical Chemistry and Life Sciences, Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Campus of Fuentenueva, E-18071 Granada, Spain. Electronic address: azafra@ugr.es.
authors.forename: A
authors.initials: A
authors.lastname: Zafra-Gómez
authors.affiliation: CIEPQPF - Department of Chemical Engineering, University of Coimbra, Coimbra, Portugal.
authors.forename: M S
authors.initials: MS
authors.lastname: Reis
authors.affiliation: CIEPQPF - Department of Chemical Engineering, University of Coimbra, Coimbra, Portugal.
authors.forename: B P M
authors.initials: BP
authors.lastname: Duarte
authors.affiliation: Cepsa Química, Avenida del Partenón 12, E-28042 Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Verge
authors.affiliation: Cepsa Química, Avenida del Partenón 12, E-28042 Madrid, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: de Ferrer
authors.affiliation: Cepsa Química, Avenida del Partenón 12, E-28042 Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Pérez-Pascual
authors.affiliation: Research Group of Analytical Chemistry and Life Sciences, Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Campus of Fuentenueva, E-18071 Granada, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Vílchez
mesh_terms: D000327:Adsorption; D000383:Agriculture; D017738:Alkanesulfonic Acids / Q000032:analysis*; D007700:Kinetics; D008962:Models, Theoretical; D044367:Phase Transition; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D017738:Alkanesulfonic Acids; D012987:Soil; D012989:Soil Pollutants; C030641:alkylbenzyl sulfonic acid
keywords: Adsorption/desorption kinetic; Agricultural soil; Environmental behavior; Equilibrium isotherm; Linear alkylbenzene sulfonate; Modeling