Department of Chemical and Environmental Engineering, University of the Basque Country, Alameda Urquijo z/g, Bilbao 48013, Basque Country, Spain.
Université de Toulouse, INP, UPS, EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement), ENSAT, Avenue de l'Agrobiopole, 31326 Castanet Tolosan, France; CNRS, EcoLab, 31326 Castanet Tolosan, France.
Sci Total Environ. 2015 May 1;514:10-25. doi: 10.1016/j.scitotenv.2015.01.078. Epub 2015 Feb 1.
The purpose of this study was to assess the influence of anthropogenic factors (infrastructure construction and industrial and wastewater inputs) and hydrological factors (high-magnitude flood events) on metal and organic contamination and on the source variability of sediments taken from the Deba River and its tributaries. The pollution status was evaluated using a sequential extraction procedure (BCR 701), enrichment factor, individual and global contamination factors and a number of statistical analysis methods. Zn, Cu and Cr were found to have significant input from anthropogenic sources, with moderately severe enrichment, together with an extremely high potential risk of contamination. The principal scavenger of Cu and Cr was organic matter, whereas Zn was uniformly distributed among all non-residual fractions. For Fe, the anthropogenic contribution was more obviously detected in bulk sediments (<2 mm) than in fine fractions (<63 μm). Finally, the recent construction of a rail tunnel traversing Wealden Facies evaporites, together with intense rainfalls, was the main reason for the change in the source variability of bottom sediments and metal distribution in headwaters. The occurrence of a high-magnitude flood event resulted in a washout of the river bed and led to a general decrease in fine-grained sediment and metal concentrations in labile fractions of channel-bottom sediments, and a consequent downstream transfer of the pollution.
本研究旨在评估人为因素（基础设施建设、工业和废水输入）和水文因素（大洪水事件）对金属和有机污染以及德巴河及其支流沉积物源变异性的影响。采用顺序提取程序（BCR701）、富集因子、个体和整体污染因子以及多种统计分析方法评价污染状况。Zn、Cu 和 Cr 被发现具有显著的人为来源，中度严重富集，同时具有极高的污染潜在风险。Cu 和 Cr 的主要俘获剂是有机物，而 Zn 则均匀分布在所有非残留物中。对于 Fe，在粗沉积物（<2mm）中比在细颗粒（<63μm）中更明显地检测到人为贡献。最后，最近修建的一条穿过 Wealden 相蒸发岩的铁路隧道以及强降雨是底质和源头金属分布源变异性变化的主要原因。大洪水事件的发生导致河床被冲走，导致可移动河道底部沉积物和细颗粒金属浓度普遍下降，随后污染物向下游转移。
