Ag/AgCl可见光催化剂湿法脱除烟气中单质汞研究

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Abstract

A series of studies on the performance of Hg⁰ removal from simulated flue gas were carried out in a wet Hg⁰ bubbling reactor using a visible-light-responsive Ag/AgCl photocatalyst prepared by a precipitation-photoreduction method. The effects of SO₂, NO, and reaction temperature were also investigated in detail. The properties of fresh and used photocatalysts were characterized by N₂ adsorption/desorption, scanning electron microscope and energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) techniques. The results showed that compared with the Hg⁰ removal efficiencies of only visible light irradiation and only Ag/AgCl, Hg⁰ removal efficiency was greatly enhanced when visible light and Ag/AgCl were employed simultaneously. Due to large amounts of reactive species consumption, the presences of SO₂ and NO would inhibit the performance of Hg⁰ removal. The activity of Hg⁰ removal could be restored to their initial values when SO₂ and NO were turned off. The reactive species, such as hydroxyl radicals (·OH), superoxide radicals (·O₂^-), were produced in the Ag/AgCl solution under visible light. The ·OH, holes (h⁺), and Cl₂, were reactive species responsible for removing Hg⁰, and in particular the ·O₂^- played a key role in Hg⁰ removal.

Key words： wet process visible light photocatalyst Ag/AgCl Hg⁰ removal

Received: 06 June 2016

PACS:

X511

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	Articles by authors
	XING Wei-bo
	LU Hao
	ZHANG An-chao
	LIU Mu
	LIU Zhi-chao
	HU Song
	XIANG Jun

Cite this article:

XING Wei-bo,LU Hao,ZHANG An-chao等. Wet process of elemental mercury removal from flue gas using Ag/AgCl photocatalyst under visible light[J]. CHINA ENVIRONMENTAL SCIENCECE, 2017, 37(2): 503-510.

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http://manu36.magtech.com.cn/Jweb_zghjkx/EN/ OR http://manu36.magtech.com.cn/Jweb_zghjkx/EN/Y2017/V37/I2/503

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