Cyclodextrin-enhanced solubilization and removal of residual-phase chlorinated solvents from porous media
- Univ. of Arizona, Tucson, AZ (United States)
The development of improved methods for remediation of contaminated aquifers has emerged as a significant environmental priority. One technology that appears to have considerable promise involves the use of solubilization agents such as surfactants and cosolvents for enhancing the removal of residual phase immiscible liquids. The authors examined the use of cyclodextrin, a glucose-based molecule, for solubilizing and removing residual-phase immiscible liquid from porous media. Batch experiments were conducted to measure the degree of trichloroethene (TCE) and tetrachloroethene (PCE) solubilization induced by hydroxypropyl-{beta}-cyclodextrin (HPCD) and methyl-{beta}-cyclodextrin (MCD). These studies revealed that the solubilities of TCE and PCE were enhanced by up to 9.5 and 36.0 times, respectively. Column experiments were conducted to compare water and cyclodextrin-enhanced flushing of Borden sand containing residual saturations of TCE and PCE. The results indicate that solubilization and mass removal were enhanced substantially with the use of cyclodextrins. The effluent concentrations during the steady-state phase of the HPCD and MCD flushing experiments were close to the apparent solubilities measured with the batch experiments, indicating equilibrium concentrations were maintained during the initial phase of cyclodextrin flushing. Mobilization was observed for only the TCE-MCD and PCE-5%MCD experiments.
- OSTI ID:
- 335327
- Journal Information:
- Environmental Science and Technology, Vol. 33, Issue 5; Other Information: PBD: 1 Mar 1999
- Country of Publication:
- United States
- Language:
- English
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