SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2023, Vol. 56 ›› Issue (4): 97-103.DOI: 10.1016/j.cjche.2022.06.015

• Full Length Article • 上一篇    下一篇

Decontamination of Cr(VI) from water using sewage sludge-derived biochar: Role of environmentally persistent free radicals

Yuhan Zhu, Jia Wei, Jun Li   

  1. Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, China
  • 收稿日期:2022-02-14 修回日期:2022-06-14 出版日期:2023-04-28 发布日期:2023-06-13
  • 通讯作者: Jia Wei,E-mail:weij@bjut.edu.cn
  • 基金资助:
    This work was supported by the Beijing Municipal Natural Science Foundation (8202007) and the National Natural Science Foundation of China (52170148). We also thank anonymous reviewers for their useful suggestions and guidance.

Decontamination of Cr(VI) from water using sewage sludge-derived biochar: Role of environmentally persistent free radicals

Yuhan Zhu, Jia Wei, Jun Li   

  1. Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, China
  • Received:2022-02-14 Revised:2022-06-14 Online:2023-04-28 Published:2023-06-13
  • Contact: Jia Wei,E-mail:weij@bjut.edu.cn
  • Supported by:
    This work was supported by the Beijing Municipal Natural Science Foundation (8202007) and the National Natural Science Foundation of China (52170148). We also thank anonymous reviewers for their useful suggestions and guidance.

摘要: Biochar is a well-known material for pollutant removal owing to its low cost and rich surface functionality. A kind of highly active substance, called environmentally persistent free radicals (EPFRs), can be produced in the preparation process of biochar, playing an important role in the removal of pollutants. In this study, sludge-derived biochars (SBC120 and SBC270) were prepared by the hydrothermal carbonization under two temperatures (120 ℃ and 270 ℃) to investigate their removal abilities of Cr(VI). The maximum removal amounts of Cr(VI) by SBC120 and SBC270 were 16.58 and 22.93 mg·g-1, respectively. It was further revealed that the appearance of Cr(III), as a result of EPFRs on sludge-derived biochar (SBC) transferred electrons to Cr(VI) in neutral solutions. That is to say, oxygen-centered (O-centered) EPFRs on SBC120 and carbon-centered (C-centered) EPFRs on SBC270 all could be used as electron donors to Cr(VI) to make it become Cr(III). This study not only provides a theoretical basis for the mechanism of pollutants removal by sludge-derived biochar but also offers a new perspective on the direct effect of EPFRs on pollutants.

关键词: Sludge-derived biochar, Environmentally persistent free radicals, Chromium, Removal, Reduction

Abstract: Biochar is a well-known material for pollutant removal owing to its low cost and rich surface functionality. A kind of highly active substance, called environmentally persistent free radicals (EPFRs), can be produced in the preparation process of biochar, playing an important role in the removal of pollutants. In this study, sludge-derived biochars (SBC120 and SBC270) were prepared by the hydrothermal carbonization under two temperatures (120 ℃ and 270 ℃) to investigate their removal abilities of Cr(VI). The maximum removal amounts of Cr(VI) by SBC120 and SBC270 were 16.58 and 22.93 mg·g-1, respectively. It was further revealed that the appearance of Cr(III), as a result of EPFRs on sludge-derived biochar (SBC) transferred electrons to Cr(VI) in neutral solutions. That is to say, oxygen-centered (O-centered) EPFRs on SBC120 and carbon-centered (C-centered) EPFRs on SBC270 all could be used as electron donors to Cr(VI) to make it become Cr(III). This study not only provides a theoretical basis for the mechanism of pollutants removal by sludge-derived biochar but also offers a new perspective on the direct effect of EPFRs on pollutants.

Key words: Sludge-derived biochar, Environmentally persistent free radicals, Chromium, Removal, Reduction