Formatted Title
Remediation of a Chlorinated Solvents Contaminated Site by a Thermal Remediation System
Background/Objectives
In an old industrial unit with contamination of chlorinated solvents (mainly vinyl chloride [VC]) in the soil and groundwater, the human health risk assessment identified concentrations above the maximum acceptable concentration (MAC). To mitigate the risks, a remediation system was designed to act in the non-saturated zone of the aquifer. After evaluating alternatives, the thermal system was implemented with the aim of removing the mass of volatile organic compound (VOC) and reducing the concentrations of organochlorines in groundwater until the targets established by the MAC.
Approach/Activities
The system was installed with a heating unit formed by 17 lances and 13 temperature monitoring wells, an extract unit formed by 13 extract wells and a vapor treatment unit formed by cooling tower, heat exchanger and activated carbon adsorption column, to promote soil warming and volatilization of volatile compounds.
Results/Lessons Learned
The hydrogeological characteristics of the area allowed the implementation of a thermal remediation system, which was operated for 8 months, removing 25 kg of contaminants, promoting a considerable reduction in the concentrations of organochlorine compounds in the dissolved phase (groundwater) and soil, being below the MAC and reference standards.