Project: Thermally Enhanced Bioremediation for Xylene Using Thermal Conduction Heating to 35°C
Xylenes, Ethylbenzene, Toluene and Naphthalene
Reduce soil concentrations of all COCs to below 1000 mg/kg
Number of Heaters
Important Project Details
• Approach: To stimulate biological degradation, oxygen needed to be delivered to the target volume, and gentle heating to temperatures between 30 and 40°C was shown to greatly enhance rates. The subsurface was heated while air was pulled into the xylene-rich zones, facilitating bioremediation. Interim soil sampling was used to track the progress
• Challenges: The first interim soil sampling round revealed that the goals had
been met in more than 75% of the volume, with two hotspots remaining – xylene concentrations remained above 1,000 mg/kg. System enhancements were made to improve the distribution of heat – and more time allowed for the remediation.
• Results: Subsequent soil sampling events in the two smaller areas showed significant progress towards the goals, and eventually the completion of the remedy.
What Makes this Project Unique
This project demonstrated the efficacy and sustainability of low temperature thermal remediation using thermal conduction heating to remediate petroleum LNAPL and associated contaminants by thermally enhancing natural aerobic biodegradation mechanisms.