Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
583304 | Journal of Hazardous Materials | 2008 | 7 Pages |
Abstract
The aqueous phase oxidation of gaseous elemental mercury (Hg0) by potassium persulfate (K2S2O8, KPS) catalyzed by Ag+ and Cu2+ was investigated using a glass bubble column reactor. Concentrations of gaseous Hg0 and aqueous Hg2+ were measured by cold vapor generation atomic absorption spectrometry (CVAAS). The effects of several experimental parameters on the oxidation were studied; these include different types of catalysts, pHs and concentrations of potassium persulfate, temperatures, Hg0 inlet concentrations and tertiary butanol (TBA). The results showed that the removal efficiency of Hg0 increased with increasing concentration of potassium persulfate and catalysts Ag+, Cu2+ and Ag+ provided better catalytic effect than Cu2+. For example, in the presence of 5.0 mmol lâ1 KPS, the mercury removal efficiency could reach 75.4 and 97.0% for an Ag+ concentration of 0.1 and 0.3 mmol lâ1, respectively, and 69.8 and 81.9% for 0.1 and 0.3 mmol lâ1 Cu2+. On the other hand, high temperature and the introduction of TBA negatively affect the oxidation. Furthermore, the removal efficiency of Hg0 was much greater in neutral solution than in either acidic or alkaline solution. But the influence of pH was almost eliminated upon the addition of Ag+ and Cu2+, and high Hg0 inlet concentration also has positive impact on the removal efficiency of Hg0. The possible catalytic oxidation mechanism of gaseous mercury by KPS was also proposed.
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Authors
Xinhua Xu, Qunfeng Ye, Tingmei Tang, Dahui Wang,