Desorption of oil in naturally polluted soil promoted by ß-cyclodextrin

In this study, ß-cyclodextrin (ß-CD) was used to promote desorption of total petroleum hydrocarbons (TPH) in severely naturally oil-polluted soil close to oil-producing wells because it has a better solubilization of hydrophobic organics and nearly no toxic effect on soil. The experimental results indicated that different concentrations of ßCD all had a solubilizing effect on contaminants. The desorption process had a good fit with a pseudo-second-order kinetics equation, and the R² values were all above 0.9. Since soil adsorbed ß-CD, the desorption of TPH was not enhanced with an increase in ß-CD concentration. Therefore, the best removal of 79% was obtained when TPH content was 78.61mg/g dry soil (DS), and ß-CD concentration was 1674 mg/L. GC-MS analysis was used to determine the component changes of TPH with the addition of ß-CD, and it was suggested that the removal of shorter chain hydrocarbons (C <20) was more efficient. Results of this study revealed that ß-CD can efficiently promote the desorption of TPH in soil and support field elution tests of oil-contaminated soil.