Enhanced Biodegradation of PAH-Contaminated Soils with Ethanol or Acetone Pretreatment

摘要

Polycyclic aromatic hydrocarbon (PAH) compounds have low solubilities and strong sorption properties - making PAH compounds sparingly available for biodegradation. Although application of bioremediation such as land farming has been shown to be an appropriate technology for the treatment of PAH-contaminated soils, land farming treatment is usually slow requiring more than 100 to reach clean up levels. In this study, bioremediation of PAHcontaminated soils was enhanced by pretreating the soils with ethanol or acetone. Bench-scale solid phase experiments (representing the land farming treatment process) were conducted by first treating the contaminated soils with ethanol or acetone. Water was added and the solvent and water allowed to evaporate. Nutrients (N and P) were then added along with water to maintain the moisture content at 15%. The treated soils were mixed weekly and soil samples were collected and analyzed for PAHs. Degradation of Total PAH for soils pretreated with ethanol or acetone was found to be about 1.5 to 2 times faster than soils that were not pretreated with solvents. The concentrations of carcinogenic PAH in pretreated soils were at least 50% less than the carcinogenic PAH concentration in nonpretreated soils after 90 days. The results of the experiment showed that ethanol or acetone may be used to enhance PAH availability and PAH degradation.