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Integrated green complexing agent and biochar modified nano zero-valent iron for hexavalent chromium removal: A characterisation and performance study.
Zhou, Hongyi; Ma, Mengyan; Zhao, Yongkang; Baig, Shams Ali; Hu, Shufen; Ye, Mengyao; Wang, Junliang.
Afiliação
  • Zhou H; College of Environment, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China. Electronic address: zhouhy@zjut.edu.cn.
  • Ma M; College of Environment, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China.
  • Zhao Y; College of Environment, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China.
  • Baig SA; Department of Environmental Sciences, Abdul Wali Khan University, Garden Campus, Mardan 23200, Pakistan.
  • Hu S; College of Environment, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China.
  • Ye M; College of Environment, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China.
  • Wang J; College of Environment, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China. Electronic address: upupwang@zjut.edu.cn.
Sci Total Environ ; 834: 155080, 2022 Aug 15.
Article em En | MEDLINE | ID: mdl-35398438
In this study, nano zero-valent iron (nZVI) was loaded on biochar (BC) prepared from recycled waste peanut shells. The loaded BC in the nZVI@BC composite was assumed to weaken the agglomeration of nZVI and the environmentally-friendly complexing agents sodium citrate (Cit) and sodium carboxymethyl cellulose (CMC) were used to establish Cit-nZVI@BC and CMC-nZVI@BC for the effective removal of Cr(VI) from aqueous environments. The characterisation results suggested that Cit and CMC not only inhibited the oxidation of nZVI, but also effectively improved its reactivity. The experimental results demonstrated that the Cr(VI) removal efficiency by nZVI was less than 20%, while CMC-nZVI@BC enhanced the Cr(VI) removal efficiency to 80.73%, because CMC was coated on the nZVI surface for anti-passivation and improved the surface activity of nanoparticles. In addition, the Cr(VI) removal efficiency reached almost 100% with Cit-nZVI@BC, and the citrate dissociated the passivation layer on the surface of the zero-valent iron particles to ensure the reactivity of the zero-valent iron. The reaction mechanism of Cit-nZVI@BC includes adsorption, reduction, and co-precipitation, whereas CMC-nZVI@BC also involves surface complexation reactions. The kinetic studies revealed that the removal of Cr(VI) by Cit-nZVI@BC and CMC-nZVI@BC followed the second-order reaction kinetic model, and the reaction rates of Cit-nZVI@BC and CMC-nZVI@BC were both higher than that of nZVI. The results indicate that the prepared systems are promising for Cr(VI) remediation in contaminated environments.
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Texto completo: 1 Base de dados: MEDLINE Assunto principal: Poluentes Químicos da Água / Ferro Idioma: En Revista: Sci Total Environ Ano de publicação: 2022 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Poluentes Químicos da Água / Ferro Idioma: En Revista: Sci Total Environ Ano de publicação: 2022 Tipo de documento: Article