Adsorption of mercury in coal-fired power plants gypsum slurry on TiO2/chitosan composite material

2016 Global Conference on Polymer and Composite Materials

材料科学;化学

Gao, P.^1 ; Gao, B.B.^1 ; Gao, J.Q.^1 ; Zhang, K.^1 ; Chen, Y.J.^1 ; Yang, Y.P.^1 ; Chen, H.W.^1

School of Energy, Power and Mechanical Engineering, North China Electric Power University, Baoding

071000, China^1

关键词: Adsorption behaviour;    Adsorption effect;    Adsorption process;    Coal-fired power plant;    Intra-particle diffusion effect;    Mercury adsorption;    Multilayer adsorption;    Surface adsorption;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/137/1/012008/pdf
DOI  :  10.1088/1757-899X/137/1/012008

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

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 Hg2+. 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 TiO2uniformly 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 TiO2reacted with CS, it resulted in Ti-C, Ti-O and Ti-N bonds. The Br- can prevent the growth of TiO2crystal 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 Hg2+is an inhomogeneous multilayer adsorption process. The surface adsorption and intraparticle diffusion effects are both important in the Hg2+adsorption process.