Environmental Engineering Soil Laboratory

Soil vapor extraction is a useful remediation technique for soil that has been contaminated with dangerous, volatile organics. The process applies a vacuum to the soil that creates an airflow to remove the unwanted elements. The team designed a lab to demonstrate this transport phenomenon on a smaller, controlled scale to students.

In the lab, soil is purposefully contaminated with small amounts of toluene. The soil is then deposited into several extraction vessels. These vessels are attached to a vacuum system that creates airflow through them, removing the contamination. The toluene is then delivered to an activated carbon filter for disposal. Individual extraction vessels are taken out of the system on set time intervals for analysis. The remediated soil then goes through a liquid extraction process where a small amount of hexane is added to extract the remaining toluene. Finally, the concentration of toluene is measured via gas chromatography/flame ionization detector analysis. This gives the students data to model the extraction process.