Bioslurry phase remediation of petroleum-contaminated soil using potato peels powder through biosurfactant producing Bacillus licheniformis J1

Soil contamination due to petroleum oil has become significant ecological issue due to their toxicity. Thus, detoxification of petroleum-contaminated soil is of pressing concern. In this study, bench-scale bioslurry experiment was carried for remediation and detoxification of petroleum-contaminated soil. Potato peels powder was used as organic nutrient source in the slurry for biostimulation purpose, while biosurfactant producing Bacillus licheniformis strain J1 identified through molecular approach is used as inocula in the slurry treatment. The strain J1 has the capability to utilized petroleum as carbon source, but its efficiency increase in the presence of potato peels powder. Bioslurry phase experiment was categorized into four groups based on the treatment, such as B0 (soil + H2O), B1 (soil + petroleum oil + H2O), B2 (soil + petroleum oil + strain J1 + H2O), B3 (soil + petroleum oil + potato peels powder + strain J1 + H2O). After 90 days of treatment, the soils from each treatment were subjected to toxicity analysis using earth worm acute toxicity test and seed germination inhibition assay. The results suggest that in B1 treatment the toxicity effect on germination and seedling growth is highest, while decrease in effect was observed in case of B2 and B3 treatment. Results of earthworm acute toxicity test revealed that 30 +/- 5% earthworm survival rates was reported in B1 treatment, whereas 71.6 +/- 2.8 and 78.3 +/- 2.8% was observed in B2 and B3 treatment, respectively. Hence, the result of the present study signifies that bioslurry phase treatment can be effectively and commercially used for detoxification petroleum-contaminated wastelands.