Effects of ozonized rapeseed oil on bioremediation of diesel oil contaminated soil by <i>Bacillus mycoides NS1020</i>

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.