Preparation of High-efficiency Powdered Activated Carbon Derived from Waste Tires for Removing Gas-phase Mercury (II) Emitted from Municipal Solid Waste Incinerator
The objectives of this study were to investigate the adsorption equilibrium of gas-phase HgCl2 by powdered activated carbon derived from waste tires (WTPAC) and to establish a kinetic model to simulate the uptake rate of HgCl2. A bench-scale column adsorption system was designed and applied to conduct the adsorption isotherms. The HgCl2 concentration considered in this study ranged from 50 to 250 μg/m3, while the adsorption temperatures were at 30 and 150 °C. Four isothermal models, including Langmuir, Freundlich, Redlich-Peterson, and Toth equations, were used in the modeling of adsorption isotherms of HgCl2. Furthermore, the adsorption kinetic data was fitted with both a pseudo-first-order and a pseudo-second-order reaction models. Experimental results indicated that HgCl2 adsorption at 30 °C can be simulated by the Freundlich model, while it can be simulated by the Langmuir model at 150 °C. The simulation of Langmuir and Freundlich models depicted the favorable adsorption of HgCl2 onto WTPAC. The pseudo-first-order reaction model appeared the best correlation with the HgCl2 adsorption at 30 and 150 °C. In addition, a commercial powdered activated carbon (CPAC) commonly used in municipal solid waste incinerators was applied to compare the influence of PAC’s properties on the adsorptive capacity of gas-phase HgCl2.
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机译：本研究的目的是通过粉末活性炭（WTPAC）来研究气相HgCl2的吸附平衡，并建立动力学模型以模拟HGCl2的摄取率。设计并施加了台阶柱吸附系统以进行吸附等温线。本研究中考虑的HgCl2浓度范围为50至250μg/ m 3，而吸附温度为30℃和150℃。在HGCl2的吸附等温线的建模中使用了四种等温模型，包括Langmuir，Freundlich，Redlich-Peterson和Toth方程。此外，吸附动力学数据配有伪第一阶和伪二阶反应模型。实验结果表明，30℃的HgCl2吸附可以通过Freundlich模型模拟，而可以通过150℃的Langmuir模型进行模拟。 Langmuir和Freundlich模型的仿真描绘了HgCl2在WTPAC上的良好吸附。伪一阶反应模型出现了与30和150℃的HGCL2吸附的最佳相关性。此外，应用了城市固体废物焚烧炉中常用的商业粉末活性炭（CPAC），以比较PAC性能对气相HgCl2的吸附容量的影响。
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