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研究报告

Adsorption characteristics of mercury from flue gas by denitrifying bacteria

摘要：采用反硝化菌对烟气中Hg⁰、Hg²⁺的吸附特性进行研究，反硝化菌对Hg⁰和Hg²⁺吸附性能良好，在pH为8、初始Hg⁰（Hg²⁺）浓度为95.7 μg·m^-3（0.4 μg·L^-1）和吸附剂用量为0.35 g·L^-1时，Hg⁰和Hg²⁺的吸附效率分别达到43.01%和98.12%.反硝化菌吸附Hg⁰的过程遵循拟一级动力学，符合Langmuir等温吸附模型，最大吸附容量为126.1 μg·g^-1.反硝化菌吸附Hg²⁺遵循拟二级动力学模型，符合Langmuir等温吸附模型，最大吸附容量为36.23 μg·g^-1.采用傅里叶红外光谱（FTIR）和热场发射环境扫描电镜-能谱电子背散射衍射系统（EDS）表征吸附前后的反硝化菌，结果表明吸附过程中细菌表面的糖环、磷酸及脂肪化合物基团发挥了吸附汞作用.

Abstract：The biosorption of Hg⁰ and Hg²⁺ from flue gas by denitrifying bacteria was investigated in this study. The results show that the denitrifying bacteria had good adsorption performance for Hg⁰ and Hg²⁺. The biosorption efficiencies of Hg⁰ and Hg²⁺ reached 43.01% and 98.12%, respectively, under pH 8, initial Hg⁰ (Hg²⁺) concentration of 95.7 μg·m^-3 (0.4 μg·L^-1) and the adsorbent dosage of 0.35 g·L^-1. The adsorption process of Hg⁰ and Hg²⁺ by denitrifying bacteria follows the Pseudo-first-order and pseudo-second-order kinetics model, respectively, and also Langmuir isotherm adsorption model. The maximal adsorption capacity was 126.1 and 36.23 μg·g^-1 for Hg⁰ and Hg²⁺, respectively. The denitrifying bacteria was characterized with infrared spectrum (IR) and energy dispersive spectrometer (EDS) before and after adsorption. The results show that the sugar ring, phosphoric acid and fatty compound groups on the cell surface of denitrifying bacteria may have great effect on the adsorption of mercury.