Degradation of chlordecone and beta-hexachlorocyclohexane by photolysis, (photo-)fenton oxidation and ozonation

• Published in: Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes Vol. 53; no. 2; pp. 121 - 125
• Main Authors: Cruz-González, Germán, Julcour, Carine, Chaumat, Hélène, Bourdon, Valérie, Ramon-Portugal, Felipe, Gaspard, Sarra, Jáuregui-Haza, Ulises J., Delmas, Henri
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01.02.2018; Taylor & Francis Ltd
• Subjects: advanced oxidation process; Agrochemicals; Biodegradation, Environmental; Chemical and Process Engineering; Chemical engineering; Chemical Sciences; Chlordecone; Chlordecone - chemistry; Contamination; Degradation; Degradation products; Engineering Sciences; Fenton reaction; HCH; Hexachlorocyclohexane; Hydrogen peroxide; Hydrogen Peroxide - chemistry; Insecticides - chemistry; Iron; Iron - chemistry; Irradiation; Lindane - chemistry; micropollutant; Oxidation; Oxidation-Reduction; Ozonation; Ozone - chemistry; pesticide; Pesticides; Photolysis; Pollutants; Sediment pollution; Soil contamination; Solutions; Surface water; Ultraviolet radiation; Ultraviolet Rays; UV treatment; Water Pollutants, Chemical - chemistry; Water treatment; micropollutant; Water treatment; advanced oxidation process; pesticide; Fenton reaction; ozonation; HCH; UV treatment; chlordecone; Pesticide; Chlordecone; Ozonation; Micropollutant; Advanced oxidation process
• ISSN: 0360-1234; 1532-4109
• DOI: 10.1080/03601234.2017.1388682

Intensive use of chlorinated pesticides from the 1960s to the 1990s has resulted in a diffuse contamination of soils and surface waters in the banana-producing areas of the French West Indies. The purpose of this research was, for the first time, to examine the degradation of two of these persistent pollutants - chlordecone (CLD) and beta-hexachlorocyclohexane (β-HCH) in 1 mg L −1 synthetic aqueous solutions by means of photolysis, (photo-) Fenton oxidation and ozonation processes. Fenton oxidation is not efficient for CLD and yields less than 15% reduction of β-HCH concentration in 5 h. Conversely, both molecules can be quantitatively converted under UV-Vis irradiation reaching 100% of degradation in 5 h, while combination with hydrogen peroxide and ferrous iron does not show any significant improvement except in high wavelength range (>280 nm). Ozonation exhibits comparable but lower degradation rates than UV processes. Preliminary identification of degradation products indicated that hydrochlordecone was formed during photo-Fenton oxidation of CLD, while for β-HCH the major product peak exhibited C 3 H 3 Cl 2 as most abundant fragment.