Preparation of fly ash based titanium dioxide composite photocatalysts using spent SCR catalyst carriers. Issue 3 (June 2022)

• Record Type: Journal Article
• Authors: Qian, Xi; Ao, Weihua; Wang, Xuan; Sun, Sijia; Zhang, Jianmeng; Ding, Hao
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 3(2022)
• Publication Date: 2022-06
• Subjects: Spent SCR catalyst -- Fly ash -- Photocatalysis -- Hydrolytic precipitation method -- Degradation of dyes; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.107980
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Selective catalytic reduction of NOx with NH3 (NH3 -SCR) is a commonly used method to remove NOx from flue gas. However, spent SCR catalysts that have been landfilled bring potential environmental hazards and an enormous waste of resources. To resolve the problem, this paper explores a method for recycling spent SCR catalysts by compositing it with fly ash to prepare a high value-added photocatalyst. Ti in the spent catalysts was extracted into TiOSO4 via the acid leaching method. Then the surface of FA was loaded via hydrolysis precipitation to form nano-TiO2 -coated composite particles (Ti-FA). Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) spectra confirmed the formation of heterogeneous structures including Si-O-Ti, Fe-O-Ti. The UV degradation of 10 ppm rhodamine B was found to be consistent with that of P25 at 60 min (97.12%), confirming the reliable activity of the prepared photocatalyst. A heterostructures photocatalyst with excellent catalytic performance was successfully constructed by using spent SCR catalysts and loaded on the surface of another solid waste FA via its dispersion and the abundance of active components. The catalytic ability for rhodamine B exceeds that of P25, and the technology has broad application prospects in light of its cost advantage. Graphical Abstract: The surface of fly ash was loaded via hydrolysis precipitation to form nano-TiO2 -coated composite particles. Degradation experiments revealed that Ti-FA degraded approximately 97.13% rhodamine B at 60 min UV irradiation. ga1 Highlights: A method for co-recycling of spent SCR catalyst and fly ash is proposed. Recycling of hazardous solid waste as a photocatalyst for organic pollutants. The Fe in fly ash is important for the enhancement of photocatalytic activity. The Si in fly ash plays a key role in obtaining nano-anatase TiO2.