Feasibility Study of Bioremediation of a Drilling-Waste-Polluted Soil: Stimulation of Microbial Activities and Hydrocarbon Removal

The objective of this study was to determine the feasibility of bioremediation as a treatment option for an aged and chronically polluted drilling waste soil located at the Southeast of Mexico. The polluted drilling-waste site with a mean total petroleum hydrocarbon concentration (TPHs) of 39,397 ± 858 mg/kg was treated with one dose of a nutrient-surfactant commercial product at 40 mg/kg soil and two doses of H₂O₂ (50 and 100 mg H₂O₂/kg soil). In this study, the parameters that were monitored include soil respiration, heterotrophic and hydrocarbon-degrading bacteria as biological indicators, catalase and dehydrogenase activities, and TPHs degradation as decontamination parameters. The results demonstrated that the microbial activities can be stimulated in a polluted drilling-waste site by the addition of H₂O₂ and commercial product, thereby resulting in increasing TPHs degradation. These aspects must be taken into account when biodegradation studies involve the application of a commercial product.

Key Words:

• Catalase
• Dehydrogenase activity
• Drilling wastes
• Hydrogen peroxide
• Total petroleum hydrocarbons.

ACKNOWLEDGMENTS

This study was supported by Grant D.00023 from Instituto Mexicano del Petróleo “Atenuación Natural de Sitios Contaminados.”