Adsorption behavior of 2,4-dichlorophenol and pentachlorophenol in an allophanic soil
Mara Ceaa,*, J.C. Seamanb, Alejandra A. Jarac, Bárbara Fuentesd, M.L. Morac and M.C. Dieza
aDepartment
of Chemical Engineering, University of La Frontera, P.O. Box 54-D, Temuco,
Chile
bThe University of Georgia, Savannah River Ecology Laboratory,
Drawer E, Aiken, SC 29802, United States
cDepartment of Chemical Science, University of La Frontera,
P.O. Box 54-D, Temuco, Chile
dDoctorado en Ciencias de Recursos Naturales, University of
La Frontera, P.O. Box 54-D, Temuco, Chile
Abstract
The adsorption of 2,4-dichlorophenol (2,4-DCP) and pentachlorophenol (PCP)
by a variable-charge soil from southern Chile was studied in a series
of batch equilibration experiments. 2,4-DCP and PCP adsorption behavior
was evaluated as a function of pH (pH values of 4.5, 6.0 and 7.5) in a
0.1 M KCl (25 °C) background solution for soil material collected
at three different depths (0-20 cm, 20-40 cm, and 40-60 cm). 2,4-DCP and
PCP adsorption decreased with increasing soil pH, suggesting that the
undissociated species were adsorbed more readily and that electrostatic
repulsion may inhibit partitioning as pH increases. The PCP adsorption
was greater than observed for 2,4-DCP and decreased with soil depth. Multiple
regression analysis between Kd and various soil properties
indicated that the soil organic carbon content is a strong indicator of
chlorophenol adsorption, and in addition to organic carbon, the soil pH
is an important property controlling adsorption behavior.
Keywords
Variable-charge soil; Allophane; Andisol; Adsorption; Hydrophobic partitioning;
2,4-Dichlorophenol; Pentachlorophenol
*Corresponding
author
Tel: +56 45 325490
Fax: +56 45 325053
Email address: mcea@ufro.cl (M. Cea).
SREL Reprint #3017
Cea, M., J. C. Seaman, A. A. Jara, B. Fuentes, M. L. Mora and M. C. Diez. 2007. Adsorption behavior of 2,4-dichlorophenol and pentachlorophenol in an allophanic soil. Chemosphere 67(7): 1354-1360.
