CONVERSION OF MERCURY(II) INTO MERCURY(O), MONOMETHYLMERCURY CATION, AND DIMETHYLMERCURY IN SALT-MARSH SEDIMENT SLURRIES

This paper describes conversion of mercury(II) to elemental mercury (H g-0), monomethylmercury cation (MeHg+), and dimethylmercury (Me2Hg) in slurries of saltmarsh sediments collected from April to October in 19 96. Variables in these mercury conversion studies included nature of n utrient media, reaction time, and anaerobic vs. aerobic conditions. Hg -0 forms in all spiked experiments and most unspiked controls. MeHg+ o ccurs in most slurries made from sediments sampled in all months excep t May and June, while Me2Hg occurred regularly only in slurries of Apr il sediments. The discussion describes how interactions between mercur y and sulfur chemistry affect mercury speciation in the slurries, and how seasonal processes in the saltmarsh affect the net production of M eHg+. (C) 1998 Elsevier Science Ltd.