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

摘要

Polycyclic aromatic hydrocarbon (PAH) compounds have low solubilities and strongrnsorption properties - making PAH compounds sparingly available for biodegradation. Althoughrnapplication of bioremediation such as land farming has been shown to be an appropriaterntechnology for the treatment of PAH-contaminated soils, land farming treatment is usually slowrnrequiring more than 100 to reach clean up levels. In this study, bioremediation of PAHcontaminatedrnsoils was enhanced by pretreating the soils with ethanol or acetone. Bench-scalernsolid phase experiments (representing the land farming treatment process) were conducted byrnfirst treating the contaminated soils with ethanol or acetone. Water was added and the solventrnand water allowed to evaporate. Nutrients (N and P) were then added along with water tornmaintain the moisture content at 15%. The treated soils were mixed weekly and soil samplesrnwere collected and analyzed for PAHs. Degradation of Total PAH for soils pretreated withrnethanol or acetone was found to be about 1.5 to 2 times faster than soils that were not pretreatedrnwith solvents. The concentrations of carcinogenic PAH in pretreated soils were at least 50% lessrnthan the carcinogenic PAH concentration in nonpretreated soils after 90 days. The results of thernexperiment showed that ethanol or acetone may be used to enhance PAH availability and PAHrndegradation.