Effect of additives on Hg2+ reduction and precipitation inhibited by sodium dithiocarbamate in simulated flue gas desulfurization solutions

Temperature programmed desorption as a tool for the identification of mercury fate in wet-desulphurization systems

“…During the precipitation of the gypsum a part of the mercury contributes to the formation of the HgF 2 and the HgCl 2 species that are adsorbed onto the gypsum particles. It might be expected that at the pH of the scrubber liquor [4][5][6][7], the HgCl 2 would solubilise. However, as already demonstrated [11], in this particular plant the aqueous phase of the gypsum B slurry shows a higher concentration of Cl (3420 lg g À1 ) and there is a high concentration of HgCl 2 in the aqueous phase of this slurry which favours adsorption onto the solid.…”

“…This variation in efficiency is a consequence of to the wide-ranging modifications in the operational parameters and the different pollution control devices (ESP and De-NOX), employed in each plant. The main problem associated with the behaviour of mercury in WFGD systems is that once Hg 2+ is dissolved in the scrubber slurry, it may react with other species to form Hg 0 which is then re-emitted with the gases [7][8][9][10]. The problem is that Hg chemistry in WFGD systems involves several variables, some of which are difficult to control.…”

Process migration and transformation of mercury in simulated wet flue gas desulfurization slurry system

“…While the retention efficiency of Hg 2+ (S) increased from 21.9% to 32.8% with the increasing of NO 3 À concentration from 0 to 15 mM. The strong oxidation potential of NO 3 À in acidic condition could react with S (IV) to inhibit Hg 2+ (L) reduction [28]. Hence, the additive of NO 3 À can inhibit the formation of HgSO 3 complexes in Hg 2+ emission.…”

Absorption characteristics of elemental mercury in mercury chloride solutions

“…When the mole ratio of Na 2 SO 3 to HgCl 2 is higher than 1:1, the excess SO 3 2− ions react with the intermediate HgSO 3 and form [Hg(SO 3 ) 2 ] 2− complex anions, which are more stable in solution (Lu et al, 2011;Wo et al, 2009).…”