Chlordecone (kepone or CLD) was formerly used in French West Indies as an insecticide. Despite its formal ban in 1993, high levels of this pesticide are still found in soils. As such, sequestering matrices like biochars or activated carbons (ACs) may successfully decrease the bioavailability of halogenated compounds like CLD when added to contaminated soils. The present study intends (i) to produce contrasted sequestering matrices in order to (ii) assess their respective efficiency to reduce CLD environmental availability. Hence, the work was designed following two experimental steps. The first one consisted at producing different sequestering media (biochars and ACs) via pyrolysis and distinct activation processes, using two lignocellulosic precursors (raw biomass): oak wood (Quercus ilex) and coconut shell (Cocos nucifera). The chemical activation was carried out with phosphoric acid while physical activation was done with carbon dioxide and steam. In the second step, the CLD environmental availability was assessed either in an OECD artificial soil or in an Antillean contaminated nitisol (i.e., 2.1-1μg CLD per g of soil dry matter, DM), both amended with 5 wt% of biochar or 5 wt% of AC. These both steps aim to determine CLD environmental availability reduction efficiency of these media when added (i) to a standard soil material or (ii) to a soil representative of the Antillean CLD contamination context. Textural characteristics of the derived coconut and oak biochars and ACs were determined by nitrogen adsorption at 77 K. Mixed microporous and mesoporous textures consisting of high pore volume (ranging from 0.38 cm3.g-1 to 2.00 cm3.g-1) and specific (BET) surface areas from 299.9 m2.g-1 to 1285.1 m2.g-1 were obtained. Overall, soil amendment with biochars did not limit CLD environmental availability (environmental availability assay ISO/DIS 16751 Part B). When soil was amended with ACs, a significant reduction of the environmental availability in both artificial and natural soils was observed. AC soil amendment resulted in a reduced CLD transfer by at least 65% (P < 0.001) for all lignocellulosic matrices (excepted for coconut sample activated with steam, which displayed a 47% reduction). These features confirm that both pore structure and extent of porosity are of particular importance in the retention process of CLD in aged soil. Owing to its adsorptive properties, AC amendment of CLD-contaminated soils appears as a promising approach to reduce the pollutant transfer to fauna and biota.

中文翻译：

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通过土壤改良木质纤维素生物质中的生物炭和活性炭来降低十氯酮的环境利用率。

十氯酮（酮或CLD）以前在法属西印度群岛用作杀虫剂。尽管在1993年正式禁止使用该农药，但仍在土壤中发现了高含量的这种农药。因此，螯合基质（如生物炭或活性炭（AC））当添加到受污染的土壤中时，可能会成功降低卤化化合物（如CLD）的生物利用度。本研究旨在（i）产生对比的螯合基质，以便（ii）评估其各自的效率，以降低CLD的环境利用率。因此，这项工作是按照两个实验步骤设计的。第一种方法包括使用两种木质纤维素前体（原始生物质）通过热解和独特的活化过程生产不同的螯合介质（生物炭和AC）：橡木（Quercus ilex）和椰子壳（Cocos nucifera）。化学活化用磷酸进行，而物理活化用二氧化碳和蒸汽进行。第二步，在OECD人工土壤中或在Antillean污染的尼古丁溶液（即每克土壤干物质DM中有2.1-1μgCLD）中评估了CLD的环境可用性，均用5 wt％的生物炭或5 AC的重量％。这两个步骤旨在确定将（i）添加到标准土壤材料或（ii）添加到代表Antillean CLD污染背景的土壤中时，降低这些介质的CLD环境可用性的效率。衍生的椰子，橡树生物炭和活性炭的质地特征是通过在77 K下吸附氮来确定的。混合的微孔和中孔结构由高孔隙体积（范围为0.38 cm3.g-1至2.00 cm3）组成。g-1）和比（BET）表面积为299.9 m2.g-1至1285.1 m2.g-1。总体而言，用生物炭进行土壤改良不会限制CLD的环境可用性（环境可用性测定ISO / DIS 16751 B部分）。当用AC改良土壤时，在人工土壤和天然土壤中都观察到环境利用率的显着降低。交流土壤改良剂可使所有木质纤维素基质的CLD转移降低至少65％（P <0.001）（用蒸汽活化的椰子样品除外，其降低了47％）。这些特征证实孔结构和孔隙度在老化土壤中CLD的保留过程中特别重要。由于其吸附特性，