REMEDIATION OF PETROLEUM CONTAMINATED LOESS SOIL BY SURFACTANT-ENHANCED FLUSHING ALTERNATIVE

摘要

A laboratory study was carried out to evaluate the feasibility of in situ remediation at a diesel contaminated site where an underground storage tank resulted in leakage. The favorable topographic and hydrogeological conditions had surfactant-enhanced flushing alternative available. The average oil residual concentration was 5,000mg/kg at the contaminated site. Through the comparison, aliphatic polyethenoxy ether (AEO_9) and aliphatic polyethenoxy ether sodium sulfate (AES) were optioned for application in the flushing operation. The results proved that AEO_9 was more adapted than AES. Furthermore, the mixing surfactant solution made by 0.8% (v/v) AEO_9 and 0.1% (v/v) AES could significantly enhance the removal rate by 10% as compared with the standard AEO_9 solution. It is estimated that the mixing surfactant solution of 60 pore volumes was able to remove 60% of petroleum remaining in the contaminated unsaturated zone for 9 days.