Which PCB remediation method involves ex situ desorption by heating soil?

Which PCB remediation method involves ex situ desorption by heating soil?

• A. Incineration
• B. Bioremediation
• C. ex situ thermal desorption
• D. Phytoremediation

Answer: (C)

Ex situ thermal desorption uses heat to detach PCBs from soil. In this approach, contaminated soil is excavated and moved to a treatment unit, where it’s heated to temperatures that cause PCBs to desorb from the soil particles into a vapor. The vapors are then captured and treated, while the soil is cooled and returned to the site or disposed of. This method focuses on removing the contaminants from the soil matrix through heating, rather than destroying them in place or relying on biological processes. Incineration, by contrast, actually burns PCBs to destroy them, while bioremediation and phytoremediation rely on microorganisms or plants to degrade or accumulate contaminants rather than desorb them with heat.

Ex situ thermal desorption uses heat to detach PCBs from soil. In this approach, contaminated soil is excavated and moved to a treatment unit, where it’s heated to temperatures that cause PCBs to desorb from the soil particles into a vapor. The vapors are then captured and treated, while the soil is cooled and returned to the site or disposed of. This method focuses on removing the contaminants from the soil matrix through heating, rather than destroying them in place or relying on biological processes. Incineration, by contrast, actually burns PCBs to destroy them, while bioremediation and phytoremediation rely on microorganisms or plants to degrade or accumulate contaminants rather than desorb them with heat.