褐煤吸附汞离子的动力学特征

doi:10.16597/j.cnki.issn.1002-154x.2022.02.001

褐煤吸附汞离子的动力学特征

褚海艳∗ 高叶玲 梁苗

(鄂尔多斯生态环境职业学院,内蒙古 鄂尔多斯 017010)

Adsorption Kinetic Characteristics of Mercury on Lignite

Chu Haiyan∗; Gao Yeling; Liang Miao;

(Ordos Ecological Environment Career Academy, Inner Mongolia Ordos 017010)

摘要:

选用褐煤作为原材料,分析其吸附汞离子的动力学特征,探讨其在不同温度、不同 pH 值、不同离子强度下的 吸咐效果。 结果表明,褐煤对汞离子的吸附在 05 min 内为快速吸附阶段,此后呈现为慢速吸附阶段,直至20 min 基本达到吸附平衡。 随着温度(25~55 ℃ ) 和 pH(3~6) 的升高,褐煤对 Hg²⁺ 的饱和吸附量增加。 而随着离子强度 (CaCl₂ 0.005~0.05 mol/L)的增大,褐煤对 Hg²⁺ 的饱和吸附量降低。准二级动力学方程能更好的拟合褐煤对 Hg²⁺ 的 吸附过程,说明该吸附过程为化学吸附。

关键词：褐煤；汞离子；吸附；吸附动力学；

Abstract：

Lignite was used as raw material. The experiments were performed to explore the adsorption kinetic characteristics of Hg²⁺ on the lignite and investigate the effect of temperature, pH and ionic strength on this adsorption. The results showed that the sorption process of Hg²⁺ on the lignite was rapid in 0 ~ 5 min. After that, it appeared as a slow adsorption step. The reaction approached equilibrium at about 20 min. With the increase of temperature (25 ~ 55 ℃ ) and pH (3 ~ 6), the saturated adsorption capacities of Hg²⁺ on lignit was increased. And with the increase of ionic strength (CaCl₂ 0. 005 ~ 0. 05 mol / L),the saturated adsorption capacity of Hg²⁺ on lignit was decreased. Quasi-second-order kinetics equation was described well for the adsorption of Hg²⁺ onto the lignite. It showed that the adsorption process dominated by chemical adsorption.

Keywords：lignite; Hg²⁺; adsorption; kinetics;