A review on remediation of chlorinated organic contaminants in soils by thermal desorption

Soil contamination with chlorinated organic chemicals is a widespread issue, stemming primarily from industrial chemical waste or the extensive use of pesticides in agriculture. Conventional remediation methods, including ex-situ thermal desorption (ESTD) and in-situ thermal desorption (ISTD), are highly effective in removing chlorinated organic contaminants (COCs) from soils. This paper summarizes the current status of thermal desorption techniques for the removal of COCs, with a focus on their energy efficiency. It also discusses improvements and the judicious selection of thermal desorption technologies, considering the challenges of higher energy consumption and secondary pollution caused by partial degradation and improper disposal. Among various methods, electrical resistance heating (ERH) has emerged as a promising alternative, owing to its cost-effectiveness, energy efficiency, and minimal environmental impact. Notably, the total carbon emission from treating 1 m3 of contaminated soil using ERH was 200.17 kg CO2eq, which is lower than that resulting from ESTD.