Modeling of arsenic adsorption kinetics of synthetic and contaminated groundwater on natural laterite.
J Hazard Mater
; 172(2-3): 928-34, 2009 Dec 30.
Article
em En
| MEDLINE
| ID: mdl-19717233
ABSTRACT
A simple shrinking core model is applied to predict the adsorption kinetics of arsenite and arsenate species onto natural laterite (NL) in a stirred tank adsorber. The proposed model is a two-resistance model, in which two unknown parameters, external mass transfer coefficient (K(f)) and pore diffusion coefficient (D(e)) are estimated by comparing the simulation concentration profile with the experimental data using a nonlinear optimization technique. The model is applied under various operating conditions, e.g., initial arsenic concentration, NL dose, NL particle size, temperature, stirring speed, etc. Estimated values of D(e) and K(f) are found to be in the range of 2.2-2.6 x 10(-11)m(2)/s and 1.0-1.4 x 10(-6)m/s at 305K for different operating conditions, respectively. D(e) and K(f) values are found to be increasing with temperature and stirrer speed, respectively. Calculated values of Biot numbers indicate that both external mass transfer and pore diffusion are important during the adsorption. The model is also applied satisfactorily to predict the arsenic adsorption kinetics of arsenic contaminated groundwater-NL system and can be used to scale up.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Arsênio
/
Poluentes Químicos da Água
/
Modelos Químicos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article