Adsorption Kinetics of Fluroxypyr Herbicide in Aqueous Solution onto Granular Activated Carbon

• Published in: Separation science and technology 2011-06, Vol.46 (10), p.1582-1590
• Main Authors: Pastrana-Martínez, Luisa María, López-Ramón, María Victoria, Moreno-Castilla, Carlos, Joly, Jean-Pierre, Perrard, Alain, Morlay, Catherine
• Format: Article
• Language: English
• Subjects: Activated carbon; Adsorption; adsorption kinetics; Catalysis; Chemical Sciences; Coefficients; Environment and Society; Environmental Sciences; fluroxypyr; herbicide; Herbicides; Mathematical models; Reactors; Surface chemistry; Surface diffusion
• ISSN: 0149-6395; 1520-5754
• DOI: 10.1080/01496395.2011.572573

Fluroxypyr is a widely used herbicide whose presence in natural waters has prompted research into its removal by adsorption. This article reports a kinetics study of fluroxypyr adsorption on a commercial activated carbon. The experimental study used a micro differential column batch reactor operated at three solution flow rates and two initial fluroxypyr concentrations, establishing a differential regime in order to obtain correct experimental data. Initial rates at zero coverage permitted the external transfer coefficient k L to be calculated. Internal surface diffusion coefficients D S were determined by using the Homogeneous Surface Diffusion Model running the FAST software and taking advantage of tabulated user-oriented solutions. This model satisfactorily fits the experimental data. D S values were 2.5 × 10 −14 and 4.2 × 10 −14  m 2  s −1 for initial concentrations of 30 and 50 mg/L, respectively. These values were confirmed by experiments in a widely used shaken batch reactor with a determined k L value.