ARS | Publication request: Enhanced Rhizodegradation of Munitions Explosives Tnt and Rdx by Selected Plant Species

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract
Publication Acceptance Date: November 20, 2007
Publication Date: November 20, 2007
Citation: Lin, C.H., Yang, J., Lerch, R.N., Garrett, H.E. 2007. Enhanced rhizodegradation of munitions explosives tnt and rdx by selected plant species [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts. ASA-CSSA-SSSA Annual Meeting. November 4-8, 2007, New orleans, LA. 231-30.

Technical Abstract: Soil and water contamination by the military munitions explosives TNT (2,4.6-trinitrotoluene)and RDX (1,3,5-hexahydro-1,3,5-trinitrotriazine)and their degradation products have raised many public health and environmental concerns. Phytoremediation techniques could provide a potential cost-effective alternative to mitigate the health and ecological risks of these contaminants. A growth chamber study was conducted to investigate the effects of eight plant species on rhizodegradation of 14C-TNT and 14C-RDX and their relationship with soil enzyme activities. The plant species included: 1) switchgrass, 2) eastern gammagrass, 3) tall fescue, 4) orchardgrass, 5) smooth bromegrass, 6) perennial ryegrass, 7) Illinois bundle flower and 8) hoary tick-trefoil. All plant treatments were grown in pots containing Mexico silt loam, while soil without plants served as controls. Plants were grown to maturity (~3 months), and the rhizosphere soils were collected for enzyme analyses. The 14C-labeled TNT or RDX was then applied to the rhizosphere soil and incubated in the dark at 20 degrees celsius for 8 weeks. The preliminary results suggested that rhizodegradation of TNT and RDX was significantly stimulated by selected grasses, particularly by switchgrass and eastern gammagrass. The grass species showing high potential for TNT and RDX rhizodegradation could be incorporated into a phytoremediation approach to reduce contamination of soil and water at military facilities.