Biological denitrification of hydrolysates from octahydro-1,3,5,7 tetranitro-1,3,5,7-tetrazocine.
Alternatives for the destruction of common military explosives, including trinitrotoluene; hexahydro-1,3,5-trinitro-1,3,5-triazine; and octahydro-1,3,5,7 tetranitro-1,3,5,7-tetrazocine (HMX) are being investigated in the post-cold war period. One alternative combines chemical treatment (i.e., base hydrolysis of the explosives) and biological treatment (i.e., denitrification of the hydrolysate). This paper focuses on results of the biological part of the treatment process, during which Hyphomicrobium sp. bacteria were isolated from a seed obtained from a denitrification facility. The bacteria were enriched and maintained on a surrogate waste with methanol as the carbon source. The resulting culture is capable of anoxic growth in waste solutions containing up to 5000 mg/L of nitrite-nitrogen. The culture efficiently denitrifies both surrogate and actual hydrolysate wastes. A substrate inhibition model was used to accurately predict denitrification rates. Comparisons are made between denitrification rates obtained for surrogate versus actual wastes. Denitrification rates were higher when actual waste streams were used. This work demonstrates the feasibility of using Hyphomicrobiun sp. bacteria to treat HMX hydrolysate and presents a model that can be used to design a large-scale system.
Ogden
Kimberly L
KL
Department of Chemical and Environmental Engineering, University of Arizona, Tucson 85721, USA. ogden@erc.arizona.edu
Gadgill
Jaideep
J
Akin
Tulin
T
D001392:Azocines / Q000737:chemistry / Q000378:metabolism*; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry / Q000378:metabolism*; D006868:Hydrolysis; D020582:Hyphomicrobium / Q000502:physiology*; D008962:Models, Theoretical; D010100:Oxygen; D012037:Refuse Disposal / Q000379:methods*
D001392:Azocines; D006573:Heterocyclic Compounds, 1-Ring; C007950:octogen; D010100:Oxygen