Water and Environment Laboratory, Department of Geotechnics, Environment, Risks and Soil Sciences, French Institute of Science and Technology for Transport, Development and Networks (IFSTTAR), Centre de Nantes, Route de Bouaye CS4, 44344, Bouguenais, France,
Environ Sci Pollut Res Int. 2014;21(16):9764-76. doi: 10.1007/s11356-014-2850-7. Epub 2014 Apr 25.
Sediment management from stormwater infiltration basins represents a real environmental and economic issue for stakeholders due to the pollution load and important tonnages of these by-products. To reduce the sediment volumes to treat, organic and metal micropollutant-bearing phases should be identified. A combination of density fractionation procedure and microanalysis techniques was used to evaluate the distribution of polycyclic aromatic hydrocarbons (PAHs) and trace metals (Cd, Cr, Cu, Ni, Pb, and Zn) within variable density fractions for three urban stormwater basin sediments. The results confirm that PAHs are found in the lightest fractions (d < 1.9, 1.9 < d < 2.3 g cm(-3)) whereas trace metals are equally distributed within the light, intermediary, and highest fractions (d < 1.9, 1.9 < d < 2.3, 2.3 < d < 2.6, and d > 2.8 g cm(-3)) and are mostly in the 2.3 < d < 2.6 g cm(-3) fraction. The characterization of the five fractions by global analyses and microanalysis techniques (XRD and MEB-EDX) allowed us to identify pollutant-bearing phases. PAHs are bound to the organic matter (OM) and trace metals to OM, clays, carbonates and dense particles. Moreover, the microanalysis study underlines that OM is the main constituent responsible for the aggregation, particularly for microaggregation. In terms of sediment management, it was shown that density fractionation is not suitable for trace metals but could be adapted to separate PAH-enriched phases.
由于污染负荷和这些副产品的重要吨位，雨水渗透盆地的泥沙管理对利益相关者来说是一个真正的环境和经济问题。为了减少要处理的泥沙量，应确定含有有机和金属微量污染物的相。采用密度分级程序和微分析技术的组合，评估了三种城市雨水盆地沉积物中不同密度级分中多环芳烃（PAHs）和痕量金属（Cd、Cr、Cu、Ni、Pb 和 Zn）的分布。结果证实，PAHs 存在于最轻的级分（d < 1.9、1.9 < d < 2.3 g cm(-3)) 中，而痕量金属则均匀分布于轻、中、高级分（d < 1.9、1.9 < d < 2.3、2.3 < d < 2.6 和 d > 2.8 g cm(-3)) 中，主要存在于 2.3 < d < 2.6 g cm(-3) 级分中。通过全局分析和微分析技术（XRD 和 MEB-EDX）对这五个级分进行的特征描述，使我们能够确定含有污染物的相。PAHs 与有机物（OM）结合，痕量金属与 OM、粘土、碳酸盐和致密颗粒结合。此外，微分析研究强调，OM 是导致团聚的主要成分，特别是对微团聚体的团聚。在泥沙管理方面，已经表明密度分级不适合痕量金属，但可以适应分离富含 PAH 的相。
