Kinetics of diuron and amitrole adsorption from aqueous solution on activated carbons
Metadatos
Mostrar el registro completo del ítemAutor
Fontecha-Cámara, María Ángeles; López-Ramón, M.V.; Pastrana Martínez, Luisa María; Moreno Castilla, CarlosEditorial
Elsevier
Fecha
2008-08-15Referencia bibliográfica
Journal of Hazardous Materials, Volume 156, Issues 1–3, Pages 472-477
Resumen
A study was conducted on the adsorption kinetics of diuron and amitrole from aqueous solutions on activated carbons of different particle sizes and on an activated carbon fiber. Different kinetic models were applied to the experimental results obtained. A pseudo-second-order rate equation fitted the adsorption kinetics data better than a pseudo-first-order rate equation. Amitrole showed faster adsorption kinetics compared with diuron because of the smaller size of the former herbicide, despite its lower driving force for adsorption. Both reaction rate constants increased when the particle size decreased. The activated carbon fiber and the activated carbon of smallest particle size (0.03 mm) showed similar adsorption kinetics. The intraparticle diffusion rate constant increased with higher initial concentration of herbicides in solution and with lower particle size of the adsorbent. This is because the rise in initial concentration increased the amount adsorbed at equilibrium, and the reduction in particle size increased the number of collisions between adsorbate and adsorbent particles. Demineralization of the activated carbon with particle size of 0.5 mm had practically no effect on the adsorption kinetics.