School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, People's Republic of China.
Global Centre for Environmental Remediation, ATC Building, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contaminant Assessment and Remediation of the Environment (CRC CARE), The University of Newcastle, Callaghan, NSW 2308, Australia.
Bioresour Technol. 2017 Dec;246:271-281. doi: 10.1016/j.biortech.2017.06.154. Epub 2017 Jun 30.
Biochar is chemically more reduced and reactive than the original feedstock biomass. Graphite regions, functional groups, and redox-active metals in biochar contribute to its redox characteristics. While the functional groups such as phenolic species in biochar are the main electron donating moieties (i.e., reducers), the quinones and polycondensed aromatic functional groups are the components accepting electrons (oxidants). The redox capacity of biochar depends on feedstock properties and pyrolysis conditions. This paper aims to review and summarize the various synthesis techniques for biochars and the methods for probing their redox characteristics. We review the abiotic and microbial applications of biochars as electron donors, electron acceptors, or electron shuttles for pollutant degradation, metal(loid)s (im)mobilization, nutrient transformation, and discuss the underlying mechanisms. Furthermore, knowledge gaps that exist in the exploration and differentiation of the electron transfer mechanisms involving biochars are also identified.
生物炭比原始原料生物质在化学上更具还原性和反应性。生物炭中的石墨区域、官能团和氧化还原活性金属有助于其氧化还原特性。虽然生物炭中的官能团，如酚类物质，是主要的电子供体部分（即还原剂），但醌和多缩合芳族官能团是接受电子的成分（氧化剂）。生物炭的氧化还原能力取决于原料特性和热解条件。本文旨在综述生物炭的各种合成技术以及探测其氧化还原特性的方法。我们综述了生物炭作为电子供体、电子受体或电子穿梭体在污染物降解、金属（类）的活化和固定、养分转化方面的非生物和微生物应用，并讨论了其潜在机制。此外，还确定了在探索和区分涉及生物炭的电子转移机制方面存在的知识空白。
