Effects of ozonized rapeseed oil on bioremediation of diesel oil contaminated soil by Bacillus mycoides NS1020

Abstract

This research investigated the effect of ozonized rapeseed oil on the bioremediation of soil contaminated with diesel oil hydrocarbons performed by Bacillus mycoides NS1020. It is a new approach to cleaning up soil contaminated with petroleum compounds combining chemical and biological remediation. Two different doses of ozone (0.5 mg O3g−1 hydrocarbons, 2 mgO3g−1 hydrocarbons) and three different doses of rapeseed oil (10 g kg−1 soil, 50 g kg−1 soil, 100 g kg1 soil) were used. During the process, the contamination reduction, changes in soil dehydrogenase activity and pH were monitored. After 8 weeks of bioremediation, the loss of hydrocarbons in samples enhanced with rapeseed oil and ozonized rapeseed oil ranged between 97 and 99.7%. An inhibition in the metabolic activity of microorganisms (from 6 to 95%) in the first stage in trials enhanced with ozonized rapeseed oil was observed while non-ozonized vegetable oil increased the values of soil dehydrogenase activity. All the results indicated that a mixed treatment including ozonized vegetable oil and microbial degradation is a promising bioremediation technology for cleaning up soil contaminated with diesel fuel.