University of Antwerp, Ecosystem Management Research Group, Universiteitsplein 1, 2610 Wilrijk, Belgium.
Sci Total Environ. 2012 Mar 1;419:187-95. doi: 10.1016/j.scitotenv.2012.01.016. Epub 2012 Jan 31.
The combination of flood prevention and tidal marsh restoration will be implemented on a large scale in the Schelde estuary (Belgium). Densely populated and industrialized, this estuary was found to be severely contaminated with trace metals. In this study we evaluated the effect of tidal restoration on sediment trace metal concentrations. To asses historical contamination of embanked-, a restored- and natural tidal areas, deep sediment cores were sampled while the evolution of metal concentrations was determined by means of superficial samples taken during 10 sampling campaigns spread over the first 3 years of the restoration project. Metal concentrations in the natural tidal marsh reflected the estuaries' contamination history. Fertilization by irrigation caused high metal concentrations in superficial soil layers of some embanked areas. However, reintroduction of the tide resulted in deposition of a new sediment layer with lower metal concentrations, comparable to the natural tidal marsh. Despite diagenetic mobility of manganese no diagenetic movements of the trace metals were observed during these first three years. Removal of metals from the estuary and burial of contaminated sediments in the restored site emphasize the potential of these restoration projects to decrease metal contamination risks. However, more research under field conditions on the effects of changes in land use and inundation related changes in metal bioavailability is needed to draw clear conclusions on the environmental consequences.
在斯海尔德河口（比利时）将大规模实施防洪与潮滩恢复相结合的措施。该河口人口密集且工业化程度高，被发现受到痕量金属的严重污染。在这项研究中，我们评估了潮汐恢复对沉积物痕量金属浓度的影响。为了评估堤坝内、恢复区和自然潮汐区的历史污染情况，采集了深部沉积物岩芯，同时通过在恢复项目的头 3 年期间进行的 10 次采样活动中采集的表层样本，确定了金属浓度的演变情况。自然潮汐沼泽的金属浓度反映了河口的污染历史。灌溉施肥导致一些堤坝区的表层土壤中金属浓度很高。然而，重新引入潮汐导致沉积了一层新的金属浓度较低的沉积物，与自然潮汐沼泽相当。尽管锰的成岩迁移性很高，但在最初的三年中没有观察到痕量金属的成岩运动。从河口中去除金属并将受污染的沉积物埋在恢复区，强调了这些恢复项目减少金属污染风险的潜力。然而，需要在现场条件下进行更多关于土地利用变化和与淹没相关的金属生物利用度变化影响的研究，以便对环境后果得出明确的结论。
