改性硅藻土对水溶液中Cd的吸附性能及机理研究  

Adsorption performance and mechanisms of modified diatomite for Cd in aqueous solution

作　　者：朱吉颖 刘军武 方迎春 吴振斌[1] 张义[1,2] Zhu Jiying;Liu Junwu;Fang Yingchun;Wu Zhenbin;Zhang Yi(State Key Laboratory of Freshwater Ecology and Biotechnology,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072;University of Chinese Academy of Sciences,Beijing 100049;Hunan Kaidi Engineering Technology Co.,Ltd,Yueyang 414000;Hunan Engineering Research Center of Mine Site Pollution Remediation,Changsha 410004)

机构地区：[1]中国科学院水生生物研究所淡水生态和生物技术国家重点实验室,武汉430072 [2]中国科学院大学,北京100049 [3]湖南凯迪工程科技有限公司,岳阳414000 [4]矿山场地污染修复湖南省工程研究中心,长沙410004

出　　处：《化工新型材料》2025年第3期203-209,共7页New Chemical Materials

基　　金：矿山场地污染修复湖南省工程研究中心开放基金重点项目(KS-2021KDJJA01);中国科学院青年创新促进会项目(2020335)。

摘　　要：颗粒状硅藻土具有良好的重金属吸附性,能够应用于Cd废水处理。为有效去除水中的重金属镉(Cd),以颗粒硅藻土(DE)为吸附剂,通过碱改性法制成Mg(OH)_(2)-DE。采用扫描电镜(SEM)、红外光谱(FT-IR)和BET比表面积分析了DE和Mg(OH)_(2)-DE的组成和结构特性,系统考察了不同因素对DE和Mg(OH)_(2)-DE的Cd^(2+)吸附效果影响,并且对DE和Mg(OH)_(2)-DE吸附Cd^(2+)的主要机制进行了讨论。结果表明:同等条件下相较于DE,Mg(OH)_(2)-DE表现出更优的吸附性能,去除率更加稳定,并且具有更广泛的适用范围。DE和Mg(OH)_(2)-DE对Cd^(2+)的吸附均符合准二级动力学方程和Freundlich等温方程,对Cd^(2+)的吸附过程是以非均质多层吸附为主,物理化学作用共同主导的,吸附机理主要是吸附-络合相互作用。With excellent heavy metal adsorption performance,granular diatomite can be applied to cadmium wastewater treatment.To effectively remove Cd in aqueous phase,granular diatomite(DE) was used as adsorbent and Mg(OH)_(2)-DE was prepared via alkali modification method.Multiple technologies,including scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR) and BET surface area analysis were used to characterize the composition and structure of DE and Mg(OH)_(2)-DE.The effects of various factors on the adsorption performance of Cd^(2+) by DE and Mg(OH)_(2)-DE were investigated.Moreover,the adsorption mechanism of DE and Mg(OH)_(2)-DE towards Cd^(2+) was discussed.The results showed that the adsorption rate constant and adsorption capacity of Mg(OH)_(2)-DE were higher and more stable than those of DE under the same conditions.Mg(OH)_(2)-DE had a wider scope of application than DE.The adsorption kinetics and isotherms of Cd^(2+) by both DE and Mg(OH)_(2)-DE were in line with the pseudo-second-order model and Freundlich model,respectively.The adsorption process was dominated by the heterogeneous multilayer adsorption,and was jointly governed by physicochemical action.The adsorption mechanism was mainly adsorption-complexation interaction.

关 键 词：硅藻土 颗粒 镉 表征 影响因素 吸附机理 

分 类 号：X52[环境科学与工程—环境工程]