Progress of gaseous arsenic removal from flue gas by adsorption: Experimental and theoretical calculations

Abstract

Because of its high mobility and difficult capture, gaseous arsenic pollution control has become the focus of arsenic pollution control. It mainly exists in the form of highly toxic As₂O₃ in the flue gas. Therefore, removing gaseous As₂O₃ from flue gas is of great practical significance for arsenic pollution control. Stabilizing gaseous As₂O₃ on the surface of adsorbents by physical or chemical adsorption is an effective way to reduce the content of arsenic in the flue gas and alleviate arsenic pollution. Over the past few decades, various adsorbents have been developed to capture gaseous As₂O₃ in the flue gas, and their adsorption mechanisms have been studied in detail. Thus, it is necessary to review the strategies of arsenic removal from flue gas by adsorption, which can inspire further research. Based on summarizing the morphological distribution of gaseous As₂O₃ in the flue gas, this review further summarizes the removal of gaseous As₂O₃ by several adsorbents and the effect of temperature and the main components of the flue gas on arsenic adsorption. In addition, the mechanism of arsenic removal based on adsorption in the flue gas is discussed in depth through theoretical calculations, which is the particular focus of this review. Finally, prospects based on the present research state of arsenic removal by adsorption are proposed to provide ideas for developing effective and stable adsorbents for arsenic removal from flue gas.

Keywords: Adsorption; Flue gas; Gaseous arsenic; Mechanism; Theoretical calculation.