纳米零价铁改性生物炭对水中氨氮的吸附特性及机制  

Adsorption Characteristics and Mechanism of Ammonia Nitrogen in Water by Nano Zero-valent Iron-modified Biochar

作　　者：陈文静 石峻岭 李雪婷 张李金 刘富强 陈正祝 庞维海[3] 杨殿海[3,4] CHEN Wen-jing;SHI Jun-ling;LI Xue-ting;ZHANG Li-jin;LIU Fu-qiang;CHEN Zheng-zhu;PANG Wei-hai;YANG Dian-hai(School of Environmental Science and Engineering,Yangzhou University,Yangzhou 225000,China;Jiangsu Dayang Environmental Protection Engineering Co.,Ltd.,Yangzhou 225000,China;School of Environmental Science and Engineering,Tongji University,Shanghai 200092,China;State Key Laboratory of Pollution Control and ResourceRecovery,Tongji University,Shanghai 200092,China)

机构地区：[1]扬州大学环境科学与工程学院,扬州225000 [2]江苏大洋环保工程有限公司,扬州225000 [3]同济大学环境科学与工程学院,上海200092 [4]同济大学污染控制与资源化国家重点实验室,上海200092

出　　处：《环境科学》2023年第6期3270-3277,共8页Environmental Science

基　　金：国家自然科学基金项目(52070160);中国博士后科学基金项目(2020M671624);江苏省产学研合作项目(BY2021504);污染控制与资源化研究国家重点实验室开放课题项目(PCRRF20011)。

摘　　要：传统生物炭材料对水中氨氮(NH_(4)^(+)-N)的吸附效果不佳.以生物炭为载体负载纳米零价铁制得生物炭基纳米零价铁复合吸附剂nZVI@BC,通过吸附实验,考察nZVI@BC对NH_(4)^(+)-N的吸附特性,并采用SEM-EDS、BET、XRD和FTIR分析nZVI@BC的组成和结构特性,探讨nZVI@BC吸附NH_(4)^(+)-N的主要机制.结果表明,在298K下铁/生物炭质量比为1∶30时制备的复合吸附剂(nZVI@BC1/30)对NH_(4)^(+)-N的吸附性能最佳,比负载前生物炭的吸附量提高了45.96%,饱和吸附量可达16.60 mg·g^(-1).伪二级动力学模型和Langmuir模型更符合nZVI@BC1/30对NH_(4)^(+)-N的吸附过程.共存阳离子与NH_(4)^(+)-N之间存在竞争吸附,其对nZVI@BC1/30吸附NH_(4)^(+)-N的影响顺序为:Ca^(2+)>Mg^(2+)>K^(+)>Na^(+).nZVI@BC1/30吸附NH_(4)^(+)-N的主要机制为氢键结合和离子交换.综上所述,采用纳米零价铁对生物炭进行改性能够提高NH_(4)^(+)-N的吸附效果,提升生物炭在水体脱氮领域的应用潜力.The adsorption performances of ammonia nitrogen(NH_(4)^(+)-N)in water by unmodified biochar are ineffective.In this study,nano zero-valent iron-modified biochar(nZVI@BC)was prepared to remove NH_(4)^(+)-N from water.The NH_(4)^(+)-N adsorption characteristics of nZVI@BC were investigated through adsorption batch experiments.The composition and structure characteristics of nZVI@BC were analyzed using scanning electron microscopy,energy spectrum analysis,BET-N_(2) surface area(SSA),X-ray diffraction,and FTIR spectra to explore the main adsorption mechanism of NH_(4)^(+)-N by [e-mail] results showed that the composite synthesized at the iron to biochar mass ratio of 1:30(nZVI@BC1/30)performed well in NH_(4)^(+)-N adsorption at 298 K.The maximum adsorption amount of nZVI@BC1/30 at 298 K was remarkably increased by 45.96% and reached 16.60 mg·g^(-1).The pseudo-second-order model and Langmuir model fitted well with the adsorption process of NH_(4)^(+)-N by nZVI@BC1/30.There was competitive adsorption between coexisting cations and NH_(4)^(+)-N,and the sequence of coexisting cations to the adsorption of NH_(4)^(+)-N by nZVI@BC1/30 was Ca^(2+)>Mg^(2+)>K^(+)>Na^(+).The adsorption mechanism of NH_(4)^(+)-N by nZVI@BC1/30 could be mainly attributed to ion exchange and hydrogen bonding.In conclusion,nano zero-valent iron-modified biochar can improve the adsorption performance of NH_(4)^(+)-N and enhance the application potential of biochar in the field of nitrogen removal from water.

关 键 词：生物炭 零价铁 改性 吸附 氨氮(NH_(4)^(+)-N) 

分 类 号：X131.2[环境科学与工程—环境科学] X703.1