摘要
针对地下水中微量致癌物——Ni(Ⅱ)的超标问题,开发了一种超声氧化多壁碳纳米管(MWCNTs-Mn)吸附剂,并将其用于去除水中Ni(Ⅱ)。通过单因素变量法优化了MWCNTs-Mn的制备条件,基于动力学和等温吸附实验考察了MWCNTs-Mn对水中Ni(Ⅱ)的吸附效能,最后基于表面物化特性分析了MWCNTs-Mn对水中Ni(Ⅱ)的吸附机理。结果表明:在KMnO_(4)投量为2.1 g、超声氧化时间为2.5 h、温度为35℃时,MWCNTs-Mn对Ni(Ⅱ)吸附效能最佳,MWCNTs-Mn对水中Ni(Ⅱ)的最大吸附量可达22.37 mg·g^(−1),比氧化前提高了16.61倍;MWCNTs-Mn对水中Ni(Ⅱ)的吸附可用Langmuir等温吸附模型(R^(2)=0.9962)和准二阶动力学吸附模型(R^(2)=0.9971)拟合,说明该吸附为单分子层吸附和化学吸附;与超声氧化前相比,MWCNTs-Mn的中孔孔容降低了72.25%,O含量增加了12.68%,这说明超声氧化增加了MWCNTs-Mn表面的亲水性含氧官能基团(羟基和羧基)含量,并通过与水中Ni(Ⅱ)的表面络合进而提高其吸附效能。此吸附材料的优化合成可为地下水中Ni(Ⅱ)的有效去除提供技术支持。
In order to solve the problem of excessive Ni(Ⅱ),a kind of trace carcinogen in ground water,we herein developed an efficient adsorbent for Ni(Ⅱ)in this study,which was called ultrasonically oxidized multiwalled carbon nanotubes(MWCNTs-Mn).Firstly,the preparation conditions of MWCNTs-Mn was optimized by single factor variable method,and the adsorption efficiency of MWCNTs-Mn toward Ni(Ⅱ)in water was investigated through kinetics and isothermal adsorption,and then the adsorption mechanism was explored based on the surface physicochemical characterization.The results showed that the highest adsorption efficiency of MWCNTs-Mn toward Ni(Ⅱ)occurred at the KMnO4 dosage of 2.1 g,ultrasonic oxidation time of 2.5 h and temperature of 35℃,and the maximum adsorption capacity of MWCNTs-Mn toward Ni(Ⅱ)in water was 22.37 mg·g^(−1),which was 16.61 times higher than that before oxidation;the adsorption of Ni(Ⅱ)in water by MWCNTs-Mn could be fitted with Langmuir(R^(2)=0.9962)and quasi-second-order kinetic adsorption model(R^(2)=0.9971),indicating that the adsorption was a monolayer and chemical adsorption;compared with that before ultrasonic oxidation,the mesopore volume of MWCNTs-Mn decreased by 72.25%,the oxygen amount increased by 12.68%,which suggested that the ultrasonic oxidation improved the amount of hydrophilic oxygen-containing functional group(hydroxyl and carboxyl)on the surface of MWCNTs-Mn.The improved adsorption performance was accomplished by the surface complexation with Ni(Ⅱ)in water.The optimized synthesis of the adsorbent material can provide a good theoretical basis and technical support for the effective removal of Ni(Ⅱ)from groundwater.
作者
侯嫔
杨晓瑜
霍燕龙
张南南
刘昊
郭建辉
董慧峪
强志民
HOU Pin;YANG Xiaoyu;HUO Yanlong;ZHANG Nannan;LIU Hao;GUO Jianhui;DONG Huiyu;QIANG Zhimin(School of Chemical&Environmental Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;State Key Joint Laboratory of Environment Simulation and Pollution Control,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Key Laboratory of Drinking Water Science and Technology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2021年第7期2256-2264,共9页
Chinese Journal of Environmental Engineering
基金
国家重点研发计划资助项目(2018YFC0406404-5)
中央高校越崎青年学者资助项目(2020QN09)
中央高校基本科研业务费专项资金资助(2020YQHH03)。
关键词
超声氧化
多壁碳纳米管
吸附
Ni(Ⅱ)
ultrasonic oxidation
multi-walled carbon nanotubes
adsorption
Ni(Ⅱ)
作者简介
第一作者/通信作者:侯嫔(1985—),女,博士,副教授。研究方向:功能化活性炭材料的制备等。E-mail:phou.beijing@cumtb.edu.cn。
