Black carbon is ubiquitous in soils and sediments and can participate in a number of important biogeochemical processes. It has been shown recently that black carbon possesses a considerable electron storage capacity (ESC) and can serve as a reactive medium to support abiotic and biotic redox transformation. To understand how black carbon controls contaminant fate in subsurface environments and to evaluate its potential for remediation, it is important that we determine the accessibility of ESC to contaminants, as well as the kinetics and mechanisms through which ESC promotes redox reactions. In this study, we investigated the reductive transformation of 3-nitro-1,2,4-triazole-5-one (NTO) by a wood-derived black carbon (Soil Reef Biochar, or SRB). NTO is an insensitive munitions constituent in IMX-101 and IMX-104 formulations and has been detected in soil and groundwater near military sites across the U.S. due to its high solubility and mobility. NTO was chemically reduced to 3-amino-1,2,4-triazole-5-one (ATO) by reduced SRB. The amount of SRB's ESC that was accessible to and reactive toward NTO was constant over a range of pH and was a fraction of the total ESC measured using dithionite (Eh = –0.43 V vs. SHE at pH 7) and dissolved O2 (+0.80 V vs. SHE at pH 7, PO2 = 0.21 atm). Similar to the reactions between SRB and redox agents in our recent study, the reduction of NTO by SRB appeared to be controlled by pore diffusion within black carbon particles. This study has important implications for the fate of NTO in contaminated groundwater, for the role of black carbon in the natural attenuation of NTO, and for the development of potential biochar-enhanced remediation strategies for military sites. In addition, the study offers insights into how black carbon ESC can influence contaminant fate in reducing environments.

Reductive transformation of 3-nitro-1,2,4-triazole-5-one (NTO) by black carbon

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.