Enhancement of Detoxification of Petroleum Hydrocarbons and Heavy Metals in Oil-Contaminated Soil by Using Glycine-β-Cyclodextrin.

Soil contamination with petroleum hydrocarbons and heavy metals is a widespread environmental problem. In recent years, cyclodextrin has attracted research interest because of its special hole structure that can form inclusion complexes with certain small molecules. However, the solubility of β-cyclodextrin (β-CD) in water is low and it crystallizes easily, leading to its low utilization in practice. In this experiment, we connected β-CD with glycine under alkaline conditions to prepare glycine-β-cyclodextrin (G-β-CD), which is water soluble, has stronger coordinating ability with heavy metals, and is more suitable for treating oil-contaminated soil. The results show that G-β-CD provides better desorption of petroleum hydrocarbons and heavy metals in soils with low organic matter content (1%) and NaNO₃ of 0.25 mol/L at 70 g/L G-β-CD under mildly acidic (pH 5⁻6) conditions. The results indicate that petroleum hydrocarbons and heavy metals were removed simultaneously by means of pretreatment with G-β-CD, and the results can provide a theoretical basis for remediation of petroleum-contaminated soil.