Trinitrotoluene removal in a soil slurry and soil box systems by an oil-degrading mixed bacterial culture

Abstract

Bioremediation of trinitrotoluene (TNT)-contaminated soil has proven difficult due to the low bioavailability of the contaminant and its resistance to biocatalytic attack, causing slow rates of biodegradation. We have previously described a mixed bacterial culture acclimated and maintained on crude oil-containing medium that is capable of high rates of TNT biotransformation activity with low production of metabolites. We investigated the ability of this culture to bioremediate TNT-spiked soil and artificially weathered soil slurry systems, as well as a soil box system. The culture was able to remove up to 302 ppm (mg/l) of TNT within 24 h in a spiked-soil slurry system, which is among the highest rates of TNT removal reported to date. The toxicity of artificially weathered TNT-spiked soil to Vibrio fischeri decreased over a period of 39 h from a 15-min EC 50 of 15.7 to 32.5 ppm. Preliminary results of a soil box system, in which no agitation was used, showed similar TNT removal to the soil slurry system, with 100 ppm TNT being removed within 24 h.

Statistical factor-screening and optimization in slurry phase bioremediation of 2,4,6-trinitrotoluene contaminated soil

“…Therefore, slurry phase bioremediation, where a mixture of contaminated soil, water and co-substrates is treated under controlled mixing and aeration conditions, has been used as an alternative to solve this problem [25]. This technique has been applied to TNT-contaminated soils by several researchers [24,[26][27][28][29][30][31] and higher removal efficiencies have been observed in slurry phase bioremediation as compared to solid phase [27,29,31].…”

“…This includes supplemental carbon and nitrogen sources [31][32][33][34][35], microorganism [36], pH and temperature [32,36] in aqueous phase as well as slurry concentration, agitation speed [28] and surfactant [29,37] in slurry phase. Nevertheless, a one at a time approach was used to look at the effect of each factor in slurry phase and therefore the possible interactions among the effective factors have not yet been assessed.…”

Union Support Recovery in High-Dimensional Multivariate Regression

“…The reported products for systems that were not N limited were very similar to those for abiotic processes (e.g. aminotoluene) (Cruz-Uribe and Rorrer 2005, Gonzalez-Perez et al 2007, Newcombe and Crawford 2005, Nyanhongo et al 2006, Popesku et al 2006, Smets et al 2007. The amount of mineralization (usually reported as a percentage of the starting material rather than a rate) is usually low (less than 2%).…”

Reduction and conversion of 2,4,6-trinitrotoluene (TNT) by sulfide under simulated anaerobic conditions

“…As TNT is toxic, carcinogenic, and mutagenic [2,[8][9][10][11], the extensive use of TNT poses environmental risks. Hence, removal of TNT from soil, surface water and ground water has attracted much attention.…”