Laboratoire COVACHIM M2E, EA 3592 Université des Antilles, Campus de Fouillole BP 250, Pointe à Pitre Cedex, Guadeloupe, France.
Environ Sci Pollut Res Int. 2017 Nov;24(33):25488-25499. doi: 10.1007/s11356-017-9542-z. Epub 2017 Jul 11.
Since 1972, the French departments of Guadeloupe and Martinique have intensively used organochlorinated pesticides such as chlordecone (CLD) and hexachlorocyclohexane (HCH) isomers to prevent the proliferation of banana weevil (Cosmopolite sordidus). These molecules are stable in the environment, leading to a continuous contamination of soils, water, and food chain in the banana-producing areas. In these polluted areas, water treatment plants are equipped with activated carbon (AC) filters. In order to improve treatment of CLD-contaminated waters by AC, CLD adsorption and desorption kinetic studies are carried out using different ACs produced from sugar cane bagasse as adsorbents and subsequent CLD degradation is performed using reduced vitamin B12 (VB12). A GC-MS method for CLD quantification is as well optimized. This study shows that bagasse ACs are able to capture the pollutant, leading to a CLD concentration decrease from 1 to 73 μg L, with an adsorption capacity of 162 μg mg. Adsorption capacity increase with the temperature indicates an endothermic process. Polar solvents favor CLD desorption from ACs, suggesting hydrogen bonding between CLD and surface groups of ACs, the best solvent for chemical desorption being ethanol. Subsequent degradation of CLD in ethanol is performed using vitamin B12 reduced by either 1,4-dithiotreitol (DTT) or zerovalent zinc, leading to 90% of CLD removal and to the molecule cage structure opening for formation of a pentachloroindene intermediate product, characterized by GC MS/MS. A pathway for pentachloroindene formation from CLD is proposed.
自 1972 年以来，法属瓜德罗普岛和马提尼克岛的部门就一直在密集使用有机氯杀虫剂，如氯丹（CLD）和六氯环己烷（HCH）异构体，以防止香蕉象鼻虫（ Cosmopolite sordidus）的繁殖。这些分子在环境中稳定，导致香蕉种植区的土壤、水和食物链持续受到污染。在这些污染地区，水处理厂都配备了活性炭（AC）过滤器。为了改善 AC 对受 CLD 污染水的处理效果，本研究使用从甘蔗渣中生产的不同 AC 作为吸附剂进行了 CLD 吸附和解吸动力学研究，随后使用还原态维生素 B12（VB12）对 CLD 进行了降解。还优化了用于 CLD 定量的 GC-MS 方法。该研究表明，甘蔗渣 AC 能够捕获污染物，使 CLD 浓度从 1 至 73μg/L 降低，吸附能力为 162μg/mg。吸附能力随温度升高而增加表明这是一个吸热过程。极性溶剂有利于 CLD 从 AC 上解吸，这表明 CLD 与 AC 表面基团之间存在氢键，最适合化学解吸的溶剂是乙醇。随后使用 1,4-二硫苏糖醇（DTT）或零价锌还原的维生素 B12 在乙醇中对 CLD 进行降解，导致 90%的 CLD 去除，并使分子笼结构打开，形成五氯茚中间产物，通过 GC-MS/MS 对其进行了表征。提出了从 CLD 形成五氯茚的途径。
