Abstract
We examined the potential of photosynthetic microalgae to perform anaerobic transformation of an energetic explosive compound, hexahydro-1,3,5-trinito-1,3,5-triazine (RDX). All species tested, including Microcystis sp., Pediastrum biwae, Nostoc commune, and Scenedesmus obliquus, exhibited the potential for RDX transformation under light and initially anaerobic conditions; 40 µM (∼ 8.9 mg L−1) of RDX decreased to 0∼7 µM within 7 d. The formation and subsequent removal of nitrite and ammonium occurred after RDX transformation in the presence of S. obliquus under light and anaerobic conditions. Significantly more RDX was transformed when incubated with S. obliquus than without microalgae, likely because the cells used RDX and its metabolites as carbon and nitrogen sources. In the absence of microalgae, RDX concentrations decreased by <5%, 40%, and 75% at light intensities of 0, 25, and 50 µmol s−1 m−2, respectively, within 15 d, and nitrite as a byproduct of RDX transformation was detected only under light conditions. This suggested that RDX transformation occurred not only by enzymatic transformation but also through an initial denitration pathway via photodegradation. This study demonstrates that photosynthetic microalgae can transform RDX and its intermediates effectively under light and anaerobic conditions, and suggests that photosynthetic microalgae are a viable option for treating RDX-contaminated wastewater.
Original language | English |
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Pages (from-to) | 1677-1683 |
Number of pages | 7 |
Journal | Environmental Progress and Sustainable Energy |
Volume | 37 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2018 Sept 1 |
Bibliographical note
Funding Information:This work was supported by a National Research Council of Science and Technology (NST) grant from the Ministry of Science, ICT, and Future Planning (No. CRC-15-01-KIST) and the Geo-Advanced Innovative Action Project (no. 2013000540002) of the Ministry of Environment, Korea. YHK was partially supported by National Research Foundation of Korea Grant funded by the Ministry of Science and Technology of Korea (2013, University-Institute cooperation program).
Publisher Copyright:
© 2017 American Institute of Chemical Engineers
Keywords
- RDX
- Scenedesmus
- alkaline hydrolysis
- denitration
- nitramines
- photodegradation
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- General Chemical Engineering
- Renewable Energy, Sustainability and the Environment
- Water Science and Technology
- Waste Management and Disposal
- General Environmental Science