title: Adsorption behavior of 2,4-dichlorophenol and pentachlorophenol in an allophanic soil.
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 0.1M KCl (25 degrees 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 K(d) 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.
authors.affiliation: Department of Chemical Engineering, University of La Frontera, PO Box 54-D, Temuco, Chile. mcea@ufro.cl
authors.forename: Mara
authors.initials: M
authors.lastname: Cea
authors.forename: J C
authors.initials: JC
authors.lastname: Seaman
authors.forename: Alejandra A
authors.initials: AA
authors.lastname: Jara
authors.forename: Bárbara
authors.initials: B
authors.lastname: Fuentes
authors.forename: M L
authors.initials: ML
authors.lastname: Mora
authors.forename: M C
authors.initials: MC
authors.lastname: Diez
mesh_terms: D000327:Adsorption; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002677:Chile; D002733:Chlorophenols / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D003627:Data Interpretation, Statistical; D006863:Hydrogen-Ion Concentration; D010416:Pentachlorophenol / Q000737:chemistry*; D012044:Regression Analysis; D012989:Soil Pollutants / Q000032:analysis*; D013816:Thermodynamics
chemical_list: D002733:Chlorophenols; D012989:Soil Pollutants; D010416:Pentachlorophenol; C004762:2,4-dichlorophenol