Adsorption of Mercury in Aqueous Solution by Zeolite Prepared from Coal Fly Ash Using Alkali Fusion-Hydrothermal Method

Abstract

Abstract: Mercury is regarded as one of the most hazardous heavy metals. A variety of water treatment technologies are used to remove mercury in water. However, they may not be achieved large-scale industrial application, largely due to their high implementation costs. In this paper, zeolite was synthesized from industrial solid waste coal fly ash by alkali fusion-hydrothermal method and it was applied to the adsorption of mercury in aqueous solution. The results show that the stable mullite, quartz and amorphous minerals in coal fly ash are transformed into sodium aluminosilicate, sodium silicate and nepheline, which are dissolved in sodium hydroxide solution to form alkaline solution with plenty of sodium, aluminum and silicon. NaA zeolite with high purity is synthesized by adjusting the ratio of aluminum to silicon under a suitable hydrothermal conditions. The zeolite synthesized by this method adsorbs Hg (II) in aqueous solution effectively, and the adsorption removal rate reaches about 95%. The kinetic studies show that the pseudo second-order rate equation fits the experimental data well, and the reaction rate is affected by internal and external diffusion at the same time.

Key words: coal fly ash, alkali fusion-hydrothermal method, zeolite, adsorption, mercury

CLC Number:

YAN Kechong, LI Zipeng, LI Yangmin, WANG Pingzhi. Adsorption of Mercury in Aqueous Solution by Zeolite Prepared from Coal Fly Ash Using Alkali Fusion-Hydrothermal Method[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2020, 39(12): 3939-3944.

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