不同粒级煤胶体对汞的吸附热力学

发布时间：2018-01-03 05:00

本文关键词：不同粒级煤胶体对汞的吸附热力学　出处：《煤炭学报》2017年04期 　论文类型：期刊论文

【摘要】：采集煤样并提取煤胶体,通过分批实验研究其对汞的吸附热力学特性。结果表明:温度和粒径都能显著影响煤胶体对汞的吸附作用,随温度的升高、粒径的减小,煤胶体对汞的吸附量均增大。煤胶体对汞的吸附过程可用吸附-分配复合模型较好的描述,这说明汞在煤胶体上的吸附并不是单一的表面吸附或分配作用,而是这两种吸附作用的叠加。其中,0~2,2~5μm的煤胶体对汞的吸附以表面吸附为主,而汞在5~10μm的煤胶体上的吸附则主要是分配作用。另外,温度越高、煤胶体的粒径越小,分配作用在煤胶体对汞的吸附中的贡献越小,表面吸附的贡献越大。吸附反应的ΔG~0为负值,ΔH在24.5~86.1 k J/mol,ΔS为正值,说明煤胶体对汞的吸附可自发进行,为吸热反应,吸附过程中系统的混乱度增加。汞在0~2μm煤胶体上以化学吸附为主,而在2~5和5~10μm的煤胶体上则主要为物理吸附。
[Abstract]:Coal sample collection and extraction of coal colloid, by way of experimental study on the adsorption of mercury on thermodynamic properties. The results show that the temperature and particle size can significantly affect the adsorption of colloidal mercury on coal, with the increase of temperature, the particle size decreases the adsorption capacity of coal colloid on mercury increased. Coal colloid on Mercury the adsorption process can be described better adsorption distribution composite model, which shows that the adsorption of colloidal mercury in coal is not adsorbed on the surface of single or distribution, but these two kinds of superposition adsorption. The adsorption of 0~2,2~5 m colloid on mercury in coal surface adsorption, and the adsorption of mercury in 5~10. M coal colloid is mainly the distribution function. In addition, the higher the temperature is, the smaller the diameter of colloidal coal, coal distribution in colloid adsorption of mercury in the smaller contribution, the greater the contribution of surface adsorption. G~0 adsorption reaction is negative, H at 24.5 ~86.1 K J/mol The value of S is positive, indicating that the adsorption of mercury by coal colloid can be carried out spontaneously. It is endothermic reaction. The degree of chaos increases in the adsorption process. Mercury is mainly chemical adsorption on 0~2 m coal colloid, while 2~5 and 5~10 m m are mainly physical adsorption.

【作者单位】：辽宁工程技术大学环境科学与工程学院;辽宁省煤炭资源安全开采与洁净利用工程研究中心;
【基金】：国家自然科学基金资助项目(41373125) 辽宁工程技术大学生产技术问题创新研究基金资助项目(20160005T) 辽宁省煤炭资源安全开采与洁净利用工程研究中心开放基金资助项目(LNTU15KF13)
【分类号】：X50
【正文快照】： 汞是环境中毒性极强的重金属元素之一。不同于有机污染物,汞无法降解。一旦进入食物链,会在生物体内蓄积[1-2],对中枢神经系统、肾、肺和生殖系统产生急性或慢性毒性作用[3-5]。由于汞具有持久性、生物富集性和强毒性等特性,因此被许多国际机构列为优先污染物[6-7]。聚氯乙烯

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