Artículos de revistas
Characterization of the Atrazine Sorption Process on Andisol and Ultisol Volcanic Ash-Derived Soils: Kinetic Parameters and the Contribution of Humic Fractions
Fecha
2013Registro en:
J. Agric. Food Chem. 2013, 61, 6150−6160
DOI: 10.1021/jf400950d
Autor
Báez Contreras, María Estrella
Fuentes Pérez, Edwar
Espinoza González, Jeannette
Institución
Resumen
Atrazine sorption was studied in six Andisol and Ultisol soils. Humic and fulvic acids and humin contributions
were established. Sorption on soils was well described by the Freundlich model. Kf values ranged from 2.2−15.6 μg1−1/nmL1/ng−1.
The relevance of humic acid and humin was deduced from isotherm and kinetics experiments. KOC values varied between 221
and 679 mLg−1 for these fractions. Fulvic acid presented low binding capacity. Sorption was controlled by instantaneous
equilibrium followed by a time-dependent phase. The Elovich equation, intraparticle diffusion model, and a two-site
nonequilibrium model allowed us to conclude that (i) there are two rate-limited phases in Andisols related to intrasorbent
diffusion in organic matter and retarded intraparticle diffusion in the organo−mineral complex and that (ii) there is one ratelimited
phase in Ultisols attributed to the mineral composition. The lower organic matter content of Ultisols and the slower
sorption rate and mechanisms involved must be considered to assess the leaching behavior of atrazine.