Adsorption of mercury in coal-fired power plants gypsum slurry on TiO2/chitosan composite material. Issue 1 (July 2016)

• Record Type: Journal Article
• Authors: Gao, P; Gao, B B; Gao, J Q; Zhang, K; Chen, Y J; Yang, Y P; Chen, H W
• Is Part Of: IOP conference series. Volume 137:Issue 1(2016)
• Publication Date: 2016-07
• Subjects: Materials science -- Periodicals; 620.1105
• DOI: 10.1088/1757-899X/137/1/012008
• Languages: English
• ISSNs: 1757-8981

Abstract

Abstract: In this study, a simple method was used to prepare a chitosan adsorbent to mix with KI and TiO2 . Gravimetric analysis (TG), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the samples before and after adsorption of Hg 2+ . A mercury adsorption experiment was also conducted in the gypsum slurry. The results show that using hydrobromic acid as a solvent of adsorbent resulted in a better adsorption effect than using acetic acid alone. Also, the sample (CS-KI/TiO2 -HBr) had a maximum mercury adsorption capacity when the pH=5 and the t=50°C. The characterization experiments showed that the thermal stability of composite materials declined and the TiO2 uniformly dispersed in the surface of the samples with a lamellar structure, generating a lot of cracks and recesses that increased the reactive sites. Furthermore, when the TiO2 reacted with CS, it resulted in Ti-C, Ti-O and Ti-N bonds. The Br- can prevent the growth of TiO2 crystal grains and strengthen the ability of I - to remove mercury. The adsorption isotherm and kinetic results indicated that the adsorption behaviour of CS-KI/TiO2 -HBr as it removes Hg 2+ is an inhomogeneous multilayer adsorption process. The surface adsorption and intraparticle diffusion effects are both important in the Hg 2+ adsorption process.