Adsorption mechanism of Cd(Ⅱ)by calcium‑modifed lignite‑derived humin in aqueous solutions  

作　　者：Ping Wang Zhanbin Huang Zhanyong Fu Peng Zhao Zeshen Feng Yao Wang Fangze Li 

机构地区：[1]School of Chemical and Environmental Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China

出　　处：《International Journal of Coal Science & Technology》2022年第3期221-231,共11页国际煤炭科学技术学报（英文）

基　　金：supported by the National Key R&D Program of China(No.2020YFC1806504);Science and Technology Innovation and venture Fund of China Coal Technology and Engineering Group(No.2020-2-CXY001);We thank the editor and anonymous reviewers for their valuable comments.

摘　　要：Lignite-derived humin(CHM)was extracted from raw coal in Heihe City,China,producing calcium-modifed lignite-derived humin(Ca-CHM)by Ca(OH)_(2).The physical and chemical performances of CHM and Ca-CHM were analyzed with SEM,^(13)C spectra and XPS techniques.The results show that Ca-CHM exhibited weaker aliphatic,more aromatic polar compared with CHM,which improves the adsorption capacity for Cd(Ⅱ).XPS analysis indicates that Ca(Ⅱ)has been loaded onto Ca-CHM successfully after modifcation.This batch adsorption experiments report the adsorption performance of CHM and Ca-CHM for Cd(Ⅱ).The adsorption process of CHM and Ca-CHM for Cd(Ⅱ)conform to pseudo-second-order model,which is chemical adsorption,and the adsorption data presented good fts to the Langmuir model.The maximum adsorption amount(Q_(m))of Cd(Ⅱ)onto CHM and Ca-CHM by the Langmuir model is 15.29 mg/g and 41.84 mg/g,respectively.Based on the results of SEM,^(13)C spectra,and XPS analysis,we concluded that the main adsorption mechanism of Ca-CHM on Cd(Ⅱ)was ion exchange of Cd(Ⅱ)for Ca(Ⅱ),static-adsorbed and surface complexation.Therefore,Ca(Ⅱ)can be loaded on the surface of Ca-CHM by chemical modifcation,improving the adsorption capacity of materials in aqueous solutions.

关 键 词：Lignite-derived humin Modifcation CD(II) Adsorption Mechanism 

分 类 号：O64[理学—物理化学]