| The steady-state version of mathematically linked multispecies fugacity/aquivalence based fate-TRANsport, equilibrium SPECiation-complexation, kinetics, and simple BIOtic uptake (BIOTRANSPEC) model has been developed to estimate fate and biotic uptake of inorganic (HgII and Hg 0) and organic mercury (MeHg) species in dissolved, colloidal and particulate phases in surface aquatic systems. The model considered pseudo-steady-state conditions to describe mercury dynamics in the Lahontan Reservoir, Nevada, wherein the historically deposited mercury is remobilized, and maintains elevated sediment concentrations. The model results for four seasonal snapshots indicate that over 90% of mercury input is retained in sediments as most mercury is in particulate form but movement within the sediments and between sediments and water prolongs its residence time. Aqueous species are dominated by Hg(OH) 2, HgOHCl and MeHgOH in dissolved and Hg(OH)L− in colloidal forms. Reservoir sediments support mercury methylation, whereas MeHg is lost via water-column demethylation and subject to fish uptake. |
