Assessment of mercury transformations in marine sediment using isotope labeling in situ experiments

摘要

The objective of this work is to develop field experiments to investigate the bio-geochemical control of monomethylmercury (MMHg) production in surface marine sediments. In situ experiments were developed performing sediments core incubations after spiking isotopically enriched labelled mercury species (~(199)Hg~(2+),CH~(201)_3Hg~+). Small cores (10 cm depth) were collected in the Mediterranean Sea and subsequently incubated in the field. The use of double spike of isotopically enriched species was found to be a powerful tool to investigate species behavior during incubation experiments and to calculate potential methylation in marine sediments. Potential demethylation using the ~(201)MMHg could not be detected implying further investigations on this specific pathway. The overall results obtained in this work should provide new insights to assess the potential MMHg production in Mediterranean Sea sediments.