The distribution and conversion of selenite and selenate with the bubbling of simulated flue gas in simulated WFGD slurry

Qiyu Weng; Yingli Gong; Xiongwei Tian; Yuqun Zhuo; Shujuan Wang; Pengbo Hu; Tao Lyu

doi:10.1016/j.jhazmat.2021.125823

The distribution and conversion of selenite and selenate with the bubbling of simulated flue gas in simulated WFGD slurry

J Hazard Mater. 2021 Aug 15:416:125823. doi: 10.1016/j.jhazmat.2021.125823. Epub 2021 Apr 20.

Authors

Qiyu Weng¹, Yingli Gong¹, Xiongwei Tian¹, Yuqun Zhuo², Shujuan Wang², Pengbo Hu¹, Tao Lyu¹

Affiliations

¹ Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China; Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China.
² Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China; Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China; Beijing Engineering Research Center for Ecological Restoration and Carbon Fixation of Saline-Alkaline and Desert Land, Beijing 100084, China.

PMID: 34492785
DOI: 10.1016/j.jhazmat.2021.125823

Abstract

Selenium is one of the hazardous trace elements emitted from coal-fired power plants. The distribution of selenium in Wet Flue Gas Desulfurization (WFGD) process is still unclear and even in controversial, impeding the development of selenium removal technologies. This research has found that the selenite in simulated slurry could be reduced by SO₂ while selenate has not been affected. Characterization methods including X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to provide an evidence that the product of the reduction reaction is amorphous elemental selenium. Meanwhile, the influences of other gaseous components, pH, temperature and S₂O₈^2- in simulated slurry has also been considered in this research. It is found that with the increase of SO₂ concentration in flue gas, the reduction of selenite increased and the reduction reaction is an exothermic reaction. Meanwhile, the oxidation effect of S₂O₈^2- competes with the reduction effect of SO₂. This study introduced the influence of flue gas into the research of the conversion of selenium in FGD slurry and indicate the effect of flue gas on the potential emission treatment techniques of selenium in FGD slurry.

Keywords: Flue gas desulfurization; Selenium; Sulfur dioxide.