Simultaneous Complexation of Organic Compounds and Heavy Metals by a Modified Cyclodextrin

The cleanup of contaminated soil and groundwater at hazardous waste sites has become a major focus of research and policy debate. A major factor complicating the cleanup of many sites is the cooccurrence of organic compounds and heavy metals, the so-called mixed wastes. We investigated the ability of a modified cyclodextrin to simultaneously complex low-polarity organic compounds and heavy metals. The results of the experiments showed that carboxymethyl-β-cyclodextrin could simultaneously increase the apparent aqueous solubilities of the selected organic compounds (anthracene, trichlorobenzene, biphenyl, and DDT) and complex with Cd²⁺. This complexation was not significantly affected by changes in pH or by the presence of relatively high concentrations of Ca²⁺. It is possible that this reagent can be used successfully to remediate hazardous waste sites contaminated by mixed wastes.