Formatted Title
Heat-Enhanced Plume Attenuation with ERH Treatment of a Highly Contaminated Source Area
Background/Objectives
In situ thermal remediation (ISTR) using electrical resistance heating (ERH) was selected as the remedy for a vacant industrial site in Brazil that was highly contaminated with chlorinated volatile organic carbons (CVOCs). This industrial site revealed maximum concentrations of PCE and its degradation products on the order of 790,000 µg/L in groundwater and therefore a site mass estimate of 25,000 kgs. Heat-enhanced plume attenuation is being implemented in a nearby area with less significant starting concentrations. This area will be heated to 35°C and that temperature will be maintained for the duration of the ERH project.
Approach/Activities
There are three distinct areas for this R&D study. The first area is designated as, “unheated.” The unheated area will be used as a control of the site for bacterial populations and has low starting CVOC concentrations. The second area is designated as, “bioremediation.” This area also has low starting CVOC concentrations and will be heated to approximately 35°C, the temperature in which Dehalococcoides has the highest level of activity. The final area to be studied is designated as, “Thermal,” in which an ERH system will be operated, and boiling temperatures will be achieved within the treatment volume. This area has significant starting CVOC contamination.
Results/Lessons Learned
The project is ongoing with only starting concentrations known at this time. Groundwater bacterial populations will be measured along with CVOC concentrations at scheduled intervals during operation of the system. The thermal system is scheduled to complete operations in March 2024. The intent is to demonstrate the effectiveness of combined remedies for cost efficient project completion. By minimizing the ERH system to the souce area, a less costly heating infrastructure and vapor treatment system can be used in the larger plume if it is not brought to boiling temperatures.