Conversion of mercury(II) into mercury(O), monomethylmercury cation, and dimethylmercury in saltmarsh sediment slurries

This paper describes conversion of mercury(II) to elemental mercury (Hg-0), monomethylmercury cation (MeHg+), and dimethylmercury (Me2Hg) in slurries of saltmarsh sediments collected from April to October in 1996. Variables in these mercury conversion studies included nature of nutrient media, reaction time, and anaerobic vs. aerobic conditions. Hg-0 forms in all spiked experiments and most unspiked controls. MeHg+ occurs in most slurries made from sediments sampled in all months except May and June, while Me2Hg occurred regularly only in slurries of April sediments. The discussion describes how interactions between mercury and sulfur chemistry affect mercury speciation in the slurries, and how seasonal processes in the saltmarsh affect the net production of MeHg+. (C) 1998 Elsevier Science Ltd.