Solubility enhancement of seven metal contaminants using carboxymethyl-beta-cyclodextrin (CMCD)

  • J Contam Hydrol. 2009 Jul 21;107(3-4):108-13. doi: 10.1016/j.jconhyd.2009.04.006.
Magnus E Skold  1 ,  Geoffrey D Thyne ,  John W Drexler ,  John E McCray
Affiliations
  • 1. Department of Geology and Geological Engineering, Colorado School of Mines, Golden, CO 80401, USA. [email protected]
PMID: 19487046 DOI: 10.1016/j.jconhyd.2009.04.006
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.

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