过硫酸钾脱除气态元素汞的试验研究

Removal of gaseous elemental mercury in potassium persulfate solution

在鼓泡塔反应器中，用过硫酸钾（K2S2O8）脱除气态元素汞。试验考察了K2S2O8浓度、吸收温度及催化剂等因素对脱汞效率的影响。结果表明：当K2S2O8在1．0～10．0mmol／L时，随着浓度的增加，脱汞效率显著升高；AgNO3对K2S2O8脱汞具有显著的催化作用，且0．3mmol／L AgNO3的催化效果优于0．1mmol／L AgNO3；CuSO4对K2S2O8除汞也具有催化作用，但催化效果不如AgNO3；AgNO3存在下，低温更有利于汞的脱除。

Elemental Hg in a gaseous feed was first absorbed and then oxidized in K2S2O8 solution（to HgSO4 ）. The effects of K2S2O8 concentration, temperature and catalyst on the Hg removal in a small bubble column reactor （working volume=300 mL） were determined. The Hg removal rate increased with concentration of K2S2O8 from 1.0 to 10.0 mmol/L. Presence of AgNO3 enabled achievement of the same removal rate at a lower K2S2O8 concentration; the Hg removal increased with AgNO3 concentration （from 0.1 mmol/L to 0.3 mmol/L）. Relative to AgNO3, CuSO4 was slightly less effective while exhibiting the same catalytic effects. The Hg removal was higher at a lower temperature （25 vs. 55 ℃ ）, suggesting that absorption of Hg vapor was the rate-limiting step of the overall removal process.