Advances in Environmental Research Volume 1, Number 1, March 2012 , pages 1-14 DOI: https://doi.org/10.12989/aer.2012.1.1.001 |
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Enhanced degradation of TNT and RDX by bio-reduced iron bearing soil minerals |
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Changhyun Cho, Sungjun Bae and Woojin Lee
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Abstract | ||
We demonstrated that reductive degradation of 2,4,6-Trinitrotoluene (TNT) and hexahydro- 1,3,5-trinitro-1,3,5-triazine (Royal Demolition Explosive, RDX) can be enhanced by bio-reduced ironbearing soil minerals (IBSMs) using Shewanella putrefaciens CN32 (CN32). The degradation kinetic rate constant of TNT by bio-reduced magnetite was the highest (0.0039 h-1), followed by green rust (0.0022 h-1), goethite (0.0017 h-1), lepidocrocite (0.0016 h-1), and hematite (0.0006 h-1). The highest rate constant was obtained by bio-reduced lepidocrocite (0.1811 h-1) during RDX degradation, followed by magnetite (0.1700 h-1), green rust (0.0757 h-1), hematite (0.0495 h-1), and goethite (0.0394 h-1). Significant increase of Fe(II) was observed during the reductive degradation of TNT and RDX by bio-reduced IBSMs. X-ray diffraction and electron microscope analyses were conducted for identification of degradation mechanism of TNT and RDX in this study. 4-amino-dinitrotoluene were detected as products during TNT degradation, while Hexahydro-1- nitroso-3,5-dinitro-1,3,5-triazine, Hexahydro-1,3-dinitroso-5-nitro-1,3,5triazine, and Hexahydro-1,3,5- trinitroso-1,3,5-triazine were observed during RDX degradation. | ||
Key Words | ||
2,4,6-Trinitrotoluene (TNT); hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX); iron-bearing soil minerals; Shewanella putrefaciens CN32 | ||
Address | ||
Changhyun Cho, Sungjun Bae and Woojin Lee: Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea | ||