The effect of chloride on the adsorption of Hg onto three bacterial species

Bulk adsorption and X-ray absorption spectroscopy experiments were conducted in order to investigate the ability of three bacterial species to adsorb Hg in the absence and presence of chloride from pH2 to 10. Adsorption experiments were performed using non-metabolizing cells of Bacillus subtilis, Shewanella oneidensis MR-1, and Geobacter sulfurreducens suspended in a 0.1M NaClO4 electrolyte to buffer ionic strength. After equilibration, the aqueous phases were sampled and analyzed using inductively coupled plasma-optical emission spectroscopy (ICP-OES) for remaining Hg concentrations. The biomass from some experiments was analyzed using Hg X-ray absorption spectroscopy (XAS) to determine the binding environment of the Hg.