Management of metal-contaminated sediments requires an accurate knowledge of metal distribution and metal exchanges between the solid and solution phase. The DGT technique (diffusive gradients in thin films) provides information about the characteristics of metal release from the particles to the porewaters. However, the species of metals that participate in the exchange are not well documented...

Juvenile rainbow trout (Salmo gairdneri) were exposed to 100 ppb mercury (as HgCl2) in the water for 14 days. Concentrations of mercury in water and fish organs were monitored using radiolabeled mercury. Tissues from kidney and liver were fixed, and sections were developed by autometallography, a method whereby accumulations of mercury sulfides and/or mercury selenides are silver amplified. In ...

The Deûle canal is one of the most polluted canals in northern France. It contains large volumes of polluted sediments. These have to be dredged and characterized before deciding about the technology suitable for their treatment. The sediments are thus subjected to a physico-chemical characterization comprising particle size classification and heavy metals sequential extraction studies. The tot...

One important assumption in applying 210Pb-dating is that atmospherically deposited 210Pb is immobilized in the peat or sediment column. This assumption has been challenged widely, but has never been evaluated experimentally. We evaluated Pb mobility and the chemical forms in which Pb is stabilized in peat profiles by adding either soluble or particulate Pb to intact peat cores that were mainta...

Mining activity produces metal sulfide wastes particularly pyrite which remain in the mine long after operations cease. When water percolates through a mine where oxygen is present, a series of chemical reactions occur which produce extremely low pH and high concentrations of toxic sulfate and metal ions. This toxic leachate can cause severe aquatic habitat degradation downstream of the mine. T...

In this work, the highly active polyoxometalate (PW2Mo2) with Venturello structure and its corresponding catalyst were applied in catalytic desulfurization for first time. PW2Mo2 as an component was effectively encapsulated hollow periodic mesoporous organosilica (HPMOS) to form nanoreactor PW2Mo2@HPMOS, where central cavity shell facilitate mass transfer both provide a stable place react organ...

The syntrophic community between anaerobic methanotrophic archaea and sulfate reducing bacteria forms thick, black layers within multi-layered microbial mats in chimney-like carbonate concretions of methane seeps located in the Black Sea Crimean shelf. The microbial consortium conducts anaerobic oxidation of methane, which leads to the formation of mainly two biomineral by-products, calcium car...

In the absence of iron, dissolution of zinc sulfide was enhanced by the action of Acidithiobacillus caldus at 40 o C. The bioleaching mechanism was similar to that observed for mesophilic species of Acidithiobacillus at 30 o C, although the final metal recovery was lower. When iron was added to the cultures, the solubilization of zinc and copper from the sulfides was higher than that in sterile...