Microwave-enhanced thermal removal of organochlorine pesticide (chlordecone) from contaminated soils

• Published in: Chemosphere (Oxford) Vol. 352; p. 141486
• Main Authors: Cochennec, Maxime, Devriendt-Renault, Yoann, Massat, Félix, Guérin, Thierry, Ollivier, Patrick, Colombano, Stéfan, Parinet, Julien
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2024; Elsevier
• Subjects: Chlordecone; Earth Sciences; French west indies; Microwaves; Remediation; Sciences of the Universe; Soil; Thermal treatment; Soil; French west indies; Remediation; Chlordecone; Microwaves; Thermal treatment
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2024.141486

Soil contamination with chlordecone, an organochlorine pesticide, is causing serious health problems, affecting crop production and local livestock valorization in the French West Indies. In-situ chemical reduction (ISCR) processes for soil remediation have shown promise but need improvement in terms of time, cost and effective treatment, particularly for andosol soil types. Our study shows that a 10-min microwave treatment significantly reduces chlordecone concentrations (50–90%) in contaminated andosol and nitisol soils. Dry andosol soils show the highest removal yields and reach a higher final temperature (350 °C). Microwave treatment is in all cases more effective or at least as effective as 60 min of conventional heating at a target temperature of 200 °C. The thermal response of andosol and nitisol to microwave exposure is different, as the former is likely to undergo thermal runaway, reaching high temperatures in a short time, resulting in highly efficient thermal removal of chlordecone. These results encourage further scale-up, particularly for the treatment of andosol soils due to their strong microwave response. [Display omitted] •Soils naturally contaminated with chlordecone (CLD) treated with microwaves.•CLD concentration reduced by 50%–90% after 10 min microwave heating.•Microwave heating works best for dry andosol (vs. wet and wet/dry nitisol).•High efficiency for dry andosol explained by thermal runaway.•10 min microwave better or equal than 1h conventional heating at 250 °C.