Formation mechanisms and environmental applications of persistent free radicals in biochar: a review

doi:10.16085/j.issn.1000-6613.2019-1284

Abstract

Abstract:

Persistent free radicals (PFRs) have attracted increasing attention due to their persistent reactivity and potential toxicity. PFRs can be produced from biochar preparation by high-temperature pyrolysis and hydrothermal carbonization, which can be transformed to form reactive oxygen species and promote the transformation and degradation of environmental pollutants, but it creates potential environmental health risks as well. This review summarized the recent research progress of PFRs in biochar, formation mechanisms of PFRs during biochar preparation. The application studies of organic pollutants degradation by reactive oxygen species(ROS), the light induced oxidation of organic pollutants, and oxidation-reduction of heavy metals mediated by PFRs in biochar were also reviewed. And the toxicity of PFRs in biochar was preliminarily discussed. Finally, the future research directions with respect to PFRs in biochar were suggested. The aim of this work were to provide direction and evidence for the environmental applications of PFRs in biochar.

Key words: biochar, persistent free radicals, high-temperature pyrolysis, hydrothermal carbonization, reactive oxygen species

摘要：

持久性自由基（PFRs）因其持续反应活性和潜在毒性而日益受到广泛关注。生物炭在高温热解和水热碳化制备过程中会产生PFRs，并可转化形成活性氧物质，从而促进环境污染物的氧化还原转化和降解，同时也产生潜在的环境健康风险。本文综述了生物炭PFRs的国内外研究进展，归纳了PFRs在生物炭制备过程中的形成和转化机制，总结了生物炭PFRs生成ROS降解有机污染物、光诱导氧化降解有机污染物、重金属氧化还原转化等方面的环境应用研究现状，初步探讨了生物炭PFRs的毒性效应，并对今后的研究发展方向提出了展望，以期为生物炭PFRs的进一步环境应用提供方向和依据。

关键词: 生物炭, 持久性自由基, 高温热解, 水热碳化, 活性氧物质

CLC Number:

Zheng TANG,Song ZHAO,Yajie QIAN,Gang XUE,Hanzhong JIA,Pin GAO. Formation mechanisms and environmental applications of persistent free radicals in biochar: a review[J]. Chemical Industry and Engineering Progress, 2020, 39(4): 1521-1527.

唐正,赵松,钱雅洁,薛罡,贾汉忠,高品. 生物炭持久性自由基形成机制及环境应用研究进展[J]. 化工进展, 2020, 39(4): 1521-1527.

Figures/Tables 3

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