Black carbon-mediated degradation of organic pollutants: A critical review

Black carbon (BC) has a large specific surface area and abundant surface functional groups, so it is traditionally regarded as an adsorbent and a metal catalyst carrier. In addition to this, it has recently been found that a variety of BCs can also be used as a metal-free catalyst to mediate the transformation and degradation of specific organic pollutants at room temperature. This paper reviews the recent findings and current developments of the mediating roles of BC in both chemical and microbial degradation of organic pollutants, including azo dyes, nitroaromatic compounds and halogenated hydrocarbons. It starts with a brief overview of the source, properties and sorption characteristics of BC and focuses on the mediating effects and mechanisms of various BCs (such as activated carbon, chars, graphite), as well as types of surface modified carbon materials, on the transformation and degradation of organic pollutants. Moreover, it also introduces the research on engineered carbon-based nanomaterials (i.e., carbon nanotubes and graphene), which have similar physical and chemical characteristics, for reference. Finally, the application prospects of using BC as a metal-free catalyst to mediate the transformation and degradation of organic pollutants are discussed to provide a reference and expand new ideas for further research in this field.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.