Biogeochemistry and natural attenuation of nitrate in groundwater at an explosives test facility

Beller, Harry R.; Madrid, V.; Hudson, G. B.; McNab, W. W.; Carlsen, Tina M.

doi:10.1016/j.apgeochem.2003.12.010

Cited by 52 publications

(35 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous reports have suggested that explosives, including RDX, may be a source of NO 3 Ϫ contamination in groundwater and that the isotopic characteristics of explosivesderived NO 3 Ϫ may be distinguishable from other typical sources (23)(24)(25) product of anaerobic RDX degradation (Ϫ42 to Ϫ24‰) (e.g., in soils with heterogeneous redox conditions) could be substantially lower than those of most common NO 3 Ϫ sources. Conclusions.…”

Section: Discussionmentioning

confidence: 99%

“…Some reports have suggested that the degradation of explosives and propellants could be a source of NO 2 Ϫ or NO 3 Ϫ contamination in groundwater, with isotopic characteristics that may be distinguishable from other NO 3 Ϫ sources (23)(24)(25). Preliminary experiments indicate that NO 3 Ϫ produced during photochemical RDX degradation can have relatively low ␦ 15 N values compared to other major NO 3 Ϫ sources, whereas ␦ 18 O results appear to be more variable (23,24).…”

mentioning

confidence: 96%

“…Preliminary experiments indicate that NO 3 Ϫ produced during photochemical RDX degradation can have relatively low ␦ 15 N values compared to other major NO 3 Ϫ sources, whereas ␦ 18 O results appear to be more variable (23,24). Nitrate collected from RDX-contaminated groundwater may or may not exhibit distinctive isotopic characteristics, depending on the mechanisms of RDX degradation and whether other sources of groundwater NO 3 Ϫ are more dominant (23,26). Isotopic data from different processes and field settings are needed to determine whether NO 3 Ϫ from RDX degradation can be identified reliably and used for constraining possible RDX reaction mechanisms occurring in the field.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Relating Carbon and Nitrogen Isotope Effects to Reaction Mechanisms during Aerobic or Anaerobic Degradation of RDX (Hexahydro-1,3,5-Trinitro-1,3,5-Triazine) by Pure Bacterial Cultures

Fuller

Heraty

Condee

et al. 2016

Appl Environ Microbiol

View full text Add to dashboard Cite

Kinetic isotopic fractionation of carbon and nitrogen during RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) biodegradation was investigated with pure bacterial cultures under aerobic and anaerobic conditions. Relatively large bulk enrichments in 15 ؊ production were much larger than, but systematically related to, the bulk RDX N isotope effects with different bacteria. Apparent intrinsic 15 N-NO 2 ؊ values were consistent with an initial denitration pathway in the aerobic experiments and more complex processes of NO 2 ؊ formation associated with anaerobic ring cleavage. These results indicate the potential for isotopic analysis of residual RDX for the differentiation of degradation pathways and indicate that further efforts to examine the isotopic composition of potential RDX degradation products (e.g., NO x ) in the environment are warranted. IMPORTANCEThis work provides the first systematic evaluation of the isotopic fractionation of carbon and nitrogen in the organic explosive RDX during degradation by different pathways. It also provides data on the isotopic effects observed in the nitrite produced during RDX biodegradation. Both of these results could lead to better understanding of the fate of RDX in the environment and help improve monitoring and remediation technologies. Explosives manufacturing, testing, and training range activities have resulted in the release of explosive compounds, including the nitramine explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), in soils at numerous U.S. Department of Defense (DoD) installations. Because RDX is mobile in soils and persistent, it has also been detected in groundwater or drinking water at some of these sites (1, 2).There has been extensive research examining the biological degradation of explosive compounds by pure cultures of bacteria as well as mixed consortia (for a review, see reference 3). RDX biodegradation has been observed under a range of redox conditions (4-9), and at least three predominant degradation pathways have been elucidated (Fig. 1). Typically, RDX is degraded anaerobically as an electron acceptor, requiring a carbon source as an electron donor, and entails either successive reduction of the three nitro groups via successive two-electron (2e Ϫ ) transfers followed by ring cleavage (pathway A) or an earlier opening of the ring structure (pathway B1), with or without initial denitration (pathway B2). The specific mechanism of ring destabilization and the steps that lead to ring cleavage may be variable and remain subject to debate (6,7,10). A denitration reaction that converts hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) (in pathway A) through multiple intermediates to methylenedinitramine (MEDINA) (in pathway B) under anaerobic conditions has also been proposed (7,11,12). Aerobic degradation proceeds via two single-electron transfer steps resulting in sequential denitration (2 NO 2 Ϫ removed) followed by ring cleavage and production of 4-nitro-2,4-diazabutanal (NDAB) (pathway C) (7). Some bacteria are able to utilize R...

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 96%

mentioning

confidence: 99%

See 1 more Smart Citation

Relating Carbon and Nitrogen Isotope Effects to Reaction Mechanisms during Aerobic or Anaerobic Degradation of RDX (Hexahydro-1,3,5-Trinitro-1,3,5-Triazine) by Pure Bacterial Cultures

Fuller

Heraty

Condee

et al. 2016

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Yet, in absence of organic carbon as electron donor, sulfur and reduced iron were reported as electron donor species necessary for denitrification ( Fig. 2) (Bottcher et al 1990;Pauwels et al 2000;Beller et al 2004;Korom et al 2005). Figure 2 illustrates the preferential order of common electron acceptor species based on their Gibbs free energy in a saturated region.…”

Section: Electron Donor Availabilitymentioning

confidence: 96%

“…Inorganic electron donors have also found to be contributing in lithotrophic denitrification (Bottcher et al 1990;Pauwels et al 2000;Beller et al 2004 andKnoller 2005). Chemolithotropic denitrification is gaining attention these days as it lowers cell production, reduces risk of biological contamination, and eliminates external carbon source and problems associated with surplus organics (Alvarez et al 2007).…”

Section: Solid-phase Autotrophic Denitrificationmentioning

confidence: 98%

Remediation of nitrate-contaminated water by solid-phase denitrification process—a review

Ashok

Hait

2015

Environ Sci Pollut Res

129

View full text Add to dashboard Cite

The paper presents a compilation of various autotrophic and heterotrophic ways of solid-phase denitrification. It covers a complete understanding of various pathways followed during denitrification process. The paper gives a brief review on various governing factors on which the process depends. It focuses mainly on the solid-phase denitrification process, its applicability, efficiency, and disadvantages associated. It presents a critical review on various methodologies associated with denitrification process reported in past years. A comparative study has also been carried out to have a better understanding of advantages and disadvantages of a particular method. We summarize the various organic and inorganic substances and various techniques that have been used for enhancing denitrification process and suggest possible gaps in the research areas whi'ch are worthy of future research.

show abstract

Biological Nutrient Removal

Wiesmann

Choi

Dombrowski

2006

Fundamentals of Biological Wastewater Treatment

View full text Add to dashboard Cite

Biogeochemistry and natural attenuation of nitrate in groundwater at an explosives test facility

Cited by 52 publications

References 21 publications

Relating Carbon and Nitrogen Isotope Effects to Reaction Mechanisms during Aerobic or Anaerobic Degradation of RDX (Hexahydro-1,3,5-Trinitro-1,3,5-Triazine) by Pure Bacterial Cultures

Relating Carbon and Nitrogen Isotope Effects to Reaction Mechanisms during Aerobic or Anaerobic Degradation of RDX (Hexahydro-1,3,5-Trinitro-1,3,5-Triazine) by Pure Bacterial Cultures

Remediation of nitrate-contaminated water by solid-phase denitrification process—a review

Biological Nutrient Removal

Contact Info

Product

Resources

About