抄録
The micro bubbles entraining method using alkaline water has been applied to the remediation of oil-contaminated sand and soil. Although this method can effectively remove not only light but also heavy oils such as asphaltene, the resultant soil sometimes needs further treatment to meet environmental standards. Biodegradation can be used as one means of removing the remaining oils. Therefore, the aim of this research was to collect microorganisms capable of degrading oils remaining in alkaline-washed soil, and to investigate the effects of such microorganisms on oil removal from alkaline-washed soil.
Sixty soil samples were acclimatized in the wastewater from the washing process. We obtained seven microorganisms capable of degrading oils out of the sixty selected. One of them removed 90% of the oil in the alkaline-washed soil in 60 days. A mass balance of about 100% was achieved for the degradation of oil in the alkaline-washed soil. Continuous addition of the collected microorganism and a continuous supply of air accelerated the microbial oil degradation in the alkaline-washed soil.
