Mercury distribution in water, sediment and soil in the Idrijca and Soca river systems

摘要

The results presented in this study clearly show that the area around the mine continues to supply relatively high quantities of Hg to the Idrijca and Soca river system, which empties into the Gulf of Trieste some hundred km downstream. Beside soils that are naturally elevated in Hg due to the high levels of Hg in geological materials in the Idrija district, there are also Hg-laden material and tailings that are continuously eroded and serve as an important additional source for the river, flood plains and the Gulf of Trieste. During such a transport important transformation mechanisms take place, which is evidenced from the presence of MMHg in the various samples analysed. The percentage of Hg as MeHg is highest in water samples, followed by sediments and soil (Figure 5).