IMT Lille Douai, University Lille, EA 4515 - LGCgE - Laboratoire de Génie Civil et Géoenvironnement, Département Génie Civil & Environnemental, 941 rue Charles-Bourseul, 59508, Douai, France.
Muséum National d'Histoire Naturelle, CNRS UMR 7179, 4 Avenue du Petit Château, 91800, Brunoy, France.
Environ Sci Pollut Res Int. 2018 Jan;25(3):2594-2602. doi: 10.1007/s11356-017-0693-8. Epub 2017 Nov 12.
Chemical analysis of soils contaminated with coal tar indicated that most organic compounds, and particularly PAHs, were contained in coarser particles (> 200 μm). Microscopic observations of this fraction, carried out on polished sections, reported the presence of organic particles in addition to mineral particles. Some organic particles had a very low porosity, and their microstructure did not evolve during biotreatment. Alternatively, other organic particles had a large porosity composed of an interconnected pore network that was open to coal tar surface and thus in contact with soil water. Interconnected porosity seemed to increase during biotreatment in relation to a decrease in the amount of organic compounds. The amount of open porosity in contact with soil water was expected to increase the desorption rate of PAHs. Consequently, the environmental hazard could depend on the amount of open porosity in addition to chemical properties of organic particles, such as their concentration in PAHs. Thus, microscopy can be complementary to chemical analysis and ecotoxicological assays to assess the best strategy for remediation but also to follow the advancement of a biotreatment.
土壤中煤焦油污染的化学分析表明，大多数有机化合物，特别是多环芳烃，都存在于较粗的颗粒中（>200μm）。对这部分物质进行的抛光切片微观观察报告称，除了矿物质颗粒外，还存在有机颗粒。一些有机颗粒的孔隙率非常低，其微观结构在生物处理过程中没有发生变化。另一方面，其他有机颗粒具有由相互连接的孔隙网络组成的大孔隙，这些孔隙网络与煤焦油表面相通，因此与土壤水接触。与有机化合物的量减少相关，连通孔隙似乎在生物处理过程中增加。与土壤水接触的开放孔隙量预计会增加 PAHs 的解吸速率。因此，环境危害可能不仅取决于有机颗粒的化学性质（如多环芳烃的浓度），还取决于开放孔隙的量。因此，显微镜可以作为化学分析和生态毒理学分析的补充，以评估修复的最佳策略，还可以跟踪生物处理的进展。
