Particulate metal speciation in surficial sediments from Loch Dee, southwest Scotland, U.K.

摘要: The geochemical partitioning of ten elements in stratified Holocene sediments from Loch Dee, southwest Scotland, has been established by use a five-stage sequential extraction procedure. Samples below 15 cm sediment depth show minimal evidence modification anthropogenic contamination or active diagenesis and hold Fe, Mg, Cu, Cd, Co, Pb, Ni primarily detrital silicates organic complexes, while Mn, Ca, Zn reside largely adsorbed reducible oxide phases. In the uppermost ca sediment, enhanced total concentrations Zn, Pb reflect increased atmospheric deposition during postindustrial period. Of these metals, only displays any notable adjustment enriched zone, showing disproportionate accumulation labile oxides organic-Pb lack carbonates “contaminated” horizon may inherent thermodynamic instability under acid surface pore-water conditions Dee. Increments to Mn Co surficial 5 are attributable secondary species, consistent with precipitation interstitial pore-waters across sedimentary redox front. presence metals such as Cd soluble acid-volatile phases interfacial implications for future management Dee basin, leaching into overlying waters likely, given continuation current trends lake acidification.