title: Solubility enhancement of seven metal contaminants using carboxymethyl-beta-cyclodextrin (CMCD).
abstract: Carboxymethyl-beta-cyclodextrin (CMCD) has been suggested as a complexing agent for remediation of sites co-contaminated with metals and organic pollutants. As part of an attempt to construct a geochemical complexation model for metal-CMCD interactions, conditional formation constants for the complexes between CMCD and 7 metal ions (Ba, Ca, Cd, Ni, Pb, Sr, and Zn) are estimated from experimental data. Stable metal concentrations were reached after approximately 1 day and estimated logarithmic conditional formation constants range from -3.2 to -5.1 with confidence intervals within +/-0.08 log units. Experiments performed at 10 degrees C and 25 degrees C show that temperature affects the solubility of the metal salts but the strength of CMCD-metal complexes are not affected by this temperature variation. The conditional stability constants and complexation model presented in this work can be used to screen CMCD as a potential remediation agent for clean-up of contaminated soil and groundwater.
authors.affiliation: Department of Geology and Geological Engineering, Colorado School of Mines, Golden, CO 80401, USA. Magnus.Skold@Arcadis-us.com
authors.forename: Magnus E
authors.initials: ME
authors.lastname: Skold
authors.forename: Geoffrey D
authors.initials: GD
authors.lastname: Thyne
authors.forename: John W
authors.initials: JW
authors.lastname: Drexler
authors.forename: John E
authors.initials: JE
authors.lastname: McCray
mesh_terms: D004787:Environmental Pollution / Q000517:prevention & control*; D008670:Metals / Q000737:chemistry*; D012995:Solubility; D013501:Surface-Active Agents; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D008670:Metals; D013501:Surface-Active Agents; D047392:beta-Cyclodextrins; C441457:carboxymethyl-beta-cyclodextrin