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Hg2+ reduction and re-emission from simulated wet flue gas desulfurization liquors
- Source :
- Journal of hazardous materials. 172(2-3)
- Publication Year :
- 2009
-
Abstract
- In this study, considering that Hg(2+) in wet flue gas desulfurization (FGD) systems can easily be reduced and then released into atmosphere, causing secondary pollution, the researches about Hg(2+) reduction and Hg(0) re-emission mechanism were carried out. The effects of several experimental parameters on the reduction were studied, including initial pH, temperature, and concentrations of Cl(-) and S(IV). Our experimental results indicated that Cl(-) had a restraining effect on the Hg(2+) reduction and Hg(0) re-emission, after 24h reaction, only 20.5% of Hg(2+) was reduced with 100mM Cl(-) in simulated desulfurization solution. Cl(-) can slow Hg(2+) reduction and Hg(0) re-emissions dramatically through changing reaction mechanism, with formation of new intermediate: ClHgSO(3)(-), which can decompose to Hg(0), but much more slowly than Hg(SO(3))(2)(2-) or HgSO(3). Simulating the conditions of the practical application (initial pH 5, T=50 degrees C, S(IV)=5 mM, Cl(-)=100 mM), we also found that Ca(2+), NO(3)(-), F(-), etc. all had obvious effects on reduction rates. Based on the material balance and characteristic of the reactants, the reduction emission mechanism of Hg(2+) has been established, providing theoretical basis for industrial application of mercury control in wet FGD systems.
- Subjects :
- MERCURE
Reaction mechanism
Environmental Engineering
Reducing agent
Health, Toxicology and Mutagenesis
Analytical chemistry
chemistry.chemical_element
Industrial Waste
Industrial waste
chemistry.chemical_compound
Nitrate
Chlorides
Air Pollution
Environmental Chemistry
Waste Management and Disposal
Air Pollutants
Environmental engineering
Temperature
Mercury
Hydrogen-Ion Concentration
Pollution
Sulfur
Mercury (element)
Flue-gas desulfurization
chemistry
Reducing Agents
Gases
Oxidation-Reduction
Subjects
Details
- ISSN :
- 18733336
- Volume :
- 172
- Issue :
- 2-3
- Database :
- OpenAIRE
- Journal :
- Journal of hazardous materials
- Accession number :
- edsair.doi.dedup.....6eb99ccf3f3bf7cdef5ba7171c9bf4d1