Scale-up treatment of petroleum hydrocarbon-contaminated soil using a defined microbial consortium

Bioremediation strategies apply environmental microbes to metabolize organic compounds and can be useful for the treatment of oil-contaminated soils. In this study, different approaches of bioremediation were compared on a scale-up treatment. The defined microbial consortium was formulated with degrading microorganisms previously selected ( Pseudomonas mendoncina BPB 1.8, Bacillus cereus BPB 1.20, Bacillus cereus BPB 1.26, and Bacillus sphaericus BPB 1.35). Bioaugmentation/biostimulation, biostimulation, and natural attenuation strategies were evaluated after 60 days of treatment by gas chromatography. The contaminant level remained elevated after the treatments using natural attenuation and biostimulation. However, the bioaugmentation with biostimulation treatment showed a satisfactory ability to degrade petroleum hydrocarbons (85%). Interestingly, no correlation was observed with the presence of hydrocarbon-degrading microorganisms and CO 2 production, and denaturing gradient gel electrophoresis exhibited no significant difference in the biodiversity of the treatments. Although, the results showed that the microbial consortium was imperative to the successful biodegradation of TPH-contaminated gas station soil.