Luo, Jiewen, Lin, Litao, Liu, Cun et al. (13 more authors) (2020) Reveal a hidden highly toxic substance in biochar to support its effective elimination strategy. Journal of hazardous materials. 123055. ISSN 0304-3894
Abstract
With the aim to develop optimized biochar with minimal contaminants, it is important significance to broaden the understanding of biochar. Here, we disclose for the first time, a highly toxic substance (metal cyanide, MCN, such as KCN or NaCN) in biochar. The cyanide ion (CN−) content in biochar can be up to 85,870 mg/kg, which is determined by the inherent metal content and type in the biomass with K and Na increasing and Ca, Mg and Fe decreasing its formation. Density functional theory (DFT) analysis shows that unstable alkali oxygen-containing metal salts such as K2CO3 can induce an N rearrangement reaction to produce for example, KOCN. The strong reducing character of the carbon matrix further converts KOCN to KCN, thus resulting biochar with high risk. However, the stable Mg, Ca and Fe salts in biomass cannot induce an N rearrangement reaction due to their high binding energies. We therefore propose that high valent metal chloride salts such as FeCl3 and MgCl2 could be used to inhibit the production of cyanide via metal interactive reaction. These findings open a new point of view on the potential risk of biochar and provide a mitigation solution for biochar's sustainable application.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 Published by Elsevier B.V. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. |
Keywords: | Biochar,Metal cyanide,Theoretical calculation,Toxic substance |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Electronic Engineering (York) The University of York > Faculty of Sciences (York) > Chemistry (York) |
Depositing User: | Pure (York) |
Date Deposited: | 09 Jul 2020 16:30 |
Last Modified: | 08 Feb 2025 00:38 |
Published Version: | https://doi.org/10.1016/j.jhazmat.2020.123055 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1016/j.jhazmat.2020.123055 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:163091 |
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Filename: Reveal_a_hidden_highly_toxic_substance_in_biochar_Accepted_Manuscript.docx
Description: Reveal a hidden highly toxic substance in biochar - Accepted Manuscript
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