Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE), Aix Marseille Université, CNRS, IRD, Avignon Université, 13397, Marseille Cedex 20, France.
IRD, UMR IMBE, Campus Agro Environnemental Caraibes B. P. 214 Petit Morne, 97235, Le Lamentin, Martinique.
Environ Sci Pollut Res Int. 2018 Aug;25(22):21350-21361. doi: 10.1007/s11356-017-9370-1. Epub 2017 Jun 3.
Some volcanic soils like andosols contain short-range order nanoclays (allophane) which build aggregates with a tortuous and fractal microstructure. The aim of the work was to study the influence of the microstructure and mesoporosity of the allophane aggregates on the pesticide chlordecone retention in soils. Our study shows that the allophane microstructure favors pollutants accumulation and sequestration in soils. We put forth the importance of the mesoporous microstructure of the allophane aggregates for pollutant trapping in andosols. We show that the soil contamination increases with the allophane content but also with the mesopore volume, the tortuosity, and the size of the fractal aggregate. Moreover, the pore structure of the allophane aggregates at nanoscale favors the pesticide retention. The fractal and tortuous aggregates of nanoparticles play the role of nanolabyrinths. It is suggested that chlordecone storage in allophanic soils could be the result of the low transport properties (permeability and diffusion) in the allophane aggregates. The poor accessibility to the pesticide trapped in the mesopore of allophane aggregates could explain the lower pollutant release in the environment.
一些火山土壤，如红壤，含有短程有序纳米粘土（埃洛石），这些粘土可与具有曲折和分形微观结构的团聚体结合。这项工作的目的是研究埃洛石团聚体的微观结构和中孔性对土壤中氯丹农药保留的影响。我们的研究表明，埃洛石的微观结构有利于污染物在土壤中的积累和固定。我们提出了埃洛石团聚体的中孔微观结构对红壤中污染物截留的重要性。我们表明，土壤污染随着埃洛石含量的增加而增加，但也随着中孔体积、曲折度和分形团聚体的大小而增加。此外，埃洛石纳米颗粒团聚体的纳米级孔结构有利于农药的保留。纳米颗粒的分形和曲折团聚体充当纳米级的迷宫。因此，氯丹在埃洛石土壤中的储存可能是由于埃洛石团聚体中低传输性能（渗透性和扩散性）所致。被捕获在埃洛石团聚体中中孔内的农药难以接近，这可以解释污染物在环境中释放的减少。
