Removal and degradation of phenanthrene and pyrene from soil by coupling surfactant washing with photocatalysis

In this study, two environmental remediation technologies, surfactant washing and photocatalytic oxidation, have been investigated to remove and decompose phenanthrene (Phe) and pyrene (Pry). Aqueous solutions containing the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) and the nonionic surfactant Tween-80 (TW-80) were used to extract the contaminants from the soil samples. The effects of concentration of surfactant, washing time and temperature on the desorption efficiency of the contaminants from soil samples were studied. The photocatalytic oxidation treatment of the obtained washing wastes, performed in the presence of Fenton-TiO2 suspensions irradiated with a 250W high pressure mercury lamp, showed an effective abatement of the two kinds of polycyclic aromatic hydrocarbons (PAHs) due to the relevant concentrations of organics in the waste. This study demonstrates the two-stage progress process can be an effective treatment method for PAHs not only desorption by soil washing but also degradation by photocatalytic oxidation.