Control of Hg0 Re-emission from Simulated Wet Flue Gas Desulfurization Liquors by Sodium Dithiocarbamate

Secondary atmospheric pollutions may result from wet flue gas desulfurization (WFGD) systems caused by the reduction of Hg2+ to Hg-0 and lead to a damping of the co-benefit mercury removal efficiency by WFGD systems. The effects of the operating conditions,which included the pH, temperature, and oxygen concentrations, on Hg-0 re-emission inhibition efficiency by DTCR from WFGD liquors was carried out. The established data reflected an outstanding performance on the Hg-0 re-emission inhibition from the simulated WFGD liquors by adding DTCR. Our data suggested that a concentration of 0.0005% (v/v) was enough for Hg-0 re-emission inhibition in the simulated WFGD liquors. The results also indicated that the Hg-0 re-emission inhibition efficiency by adding DTCR decreased as the operational temperatures increased and the Hg-0 re-emission inhibition efficiency increased as pH values and the oxygen concentration in the flue gas increased. The present findings could be valuable for industrial application of DTCR as a precipitant for stabilizing dissolved Hg2+ to prevent re-emission of Hg-0 in WFGD solutions.