Trinitrotoluene Concentration Research Articles

Palladium 촉매와 포름산을 활용한 액상 trinitrotoluene 분해 특성 연구

Various methods to degrade explosives efficiently in natural soil and water that include trinitrotoluene (TNT) have been studied. In this study, TNT in water was degraded by reduction with palladium (Pd) catalyst impregnated onto alumina (henceforth Pd-Al catalyst) and formic acid. The degradation of TNT was faster when the temperature of water was high, and the initial TNT concentration, pH, and ion concentration in water were low. The amounts of Pd-Al catalyst and formic acid were also important for TNT degradation in water. According to the experimental results, the degradation constant of TNT with unit mass of Pd-Al catalyst was . The degradation constant of TNT was higher than the results of previous studies which used zero valent iron. 2,6-diamino-4-nitrotoluene and 2-amino-4,6-dinitrotoluene were detected as by-products of TNT degradation showing that TNT was reduced. The by-products of TNT were also completely degraded after reaction when both Pd-Al catalyst and formic acid existed. Even though there are several challenges of Pd-Al catalyst (e.g., deactivation, poisoning, leaching, etc.), the results of this study show that TNT degradation by Pd-Al catalyst and formic acid is a promising technique to remediate explosive contaminated water and soil.

Poly vinyl alcohol cryogel as a selective test kit for pre and post blast trinitrotoluene

A cryogel test kit was successfully developed for the detection of trinitrotoluene (TNT). Tetramethylammonium hydroxide (TMAH) entrapped within a polyvinyl alcohol (PVA) cryogel matrix acted as the colourimetric reagent. The PVA cryogel TNT test kit was fabricated within a micro-PCR tube to which the sample solution could be directly added for in-tube detection. This made the developed test kit small and easily portable. The test kit was used to demonstrate the rapid quantitative analysis of TNT in soil sample in conjunction with digital image colourimetry. The digital image of the colourimetric product from the test kit was captured using the built-in digital camera of a mobile phone. Red-Green-Blue (RGB) colour data from the digital image was used as the analytical data to establish a calibration graph for the target analyte using a series of TNT standard solutions. The concentrations of TNT detected in post-blast soil samples by the test kit were in good agreement to values obtained using spectrophotometric detection and method validation indicated good precision both for intra- and inter-day (2.77–4.21%RSD and 3.34–7.82%RSD, respectively). The TNT test kit could be stored for almost 3 months in a freezer exhibiting only a −0.73% change in intensity of green channel. The test kit was also reusable and after nine uses only a 0.8% change in intensity of green channel was evident. These results demonstrate that the PVA cryogel TNT test kit has the potential to be used for TNT detection in a complex sample matrix. When the test kit was used in combination with digital image colourimetry, it provided an ideal novel platform for the rapid quantitative analysis of TNT in post blast samples.

Application of Bacillus sp. strain VT-8 for decontamination of TNT-polluted sites

Bacterial strain Bacillus sp. VT-8 was shown to use trinitrotoluene (TNT) as the sole source of carbon, nitrogen, and energy, as well as to carry out its co-oxidation. Resistance of Bacillus sp. VT-8 to high TNT concentrations was shown. Efficient detoxification of TNT-contaminated soil and water samples was demonstrated. This strain may be recommended for TNT biodegradation at concentrations of up to 140 mg/L due to its high degradation activity and the absence of toxic effect of TNT on Bacillus sp. VT-8.

The Good, the Bad, and the Toxic: Approaching Hormesis in Daphnia magna Exposed to an Energetic Compound

A hormetic response is characterized by an opposite effect in small and large doses of chemical exposure, often resulting in seemingly beneficial effects at low doses. Here, we examined the potential mechanisms underlying the hormetic response of Daphnia magna to the energetic trinitrotoluene (TNT). Daphnia magna were exposed to TNT for 21 days, and a significant increase in adult length and number of neonates was identified at low concentrations (0.002-0.22 mg/L TNT), while toxic effects were identified at high concentrations (0.97 mg/L TNT and above). Microarray analysis of D. magna exposed to 0.004, 0.12, and 1.85 mg/L TNT identified effects on lipid metabolism as a potential mechanism underlying hormetic effects. Lipidomic analysis of exposed D. magna supported the hypothesis that TNT exposure affected lipid and fatty acid metabolism, showing that hormetic effects could be related to changes in polyunsaturated fatty acids known to be involved in Daphnia growth and reproduction. Our results show that Daphnia exposed to low levels of TNT presented hormetic growth and reproduction enhancement, while higher TNT concentrations had an opposite effect. Our results also show how a systems approach can help elucidate potential mechanisms of action and adverse outcomes.

MICROBIAL COMMUNITY CHANGES IN TNT SPIKED SOIL BIOREMEDIATION TRIAL USING BIOSTIMULATION, PHYTOREMEDIATION AND BIOAUGMENTATION

Trinitrotoluene (TNT), a commonly used explosive for military and industrial applications, can cause serious environmental pollution. 28-day laboratory pot experiment was carried out applying bioaugmentation using laboratory selected bacterial strains as inoculum, biostimulation with molasses and cabbage leaf extract, and phytoremediation using rye and blue fenugreek to study the effect of these treatments on TNT removal and changes in soil microbial community responsible for contaminant degradation. Chemical analyses revealed significant decreases in TNT concentrations, including reduction of some of the TNT to its amino derivates during the 28-day tests. The combination of bioaugmentation-biostimulation approach coupled with rye cultivation had the most profound effect on TNT degradation. Although plants enhanced the total microbial community abundance, blue fenugreek cultivation did not significantly affect the TNT degradation rate. The results from molecular analyses suggested the survival and elevation of the introduced bacterial strains throughout the experiment.

Low-Cost Electronic Tongue System and Its Application to Explosive Detection

The use of biomimetic measurement systems as electronic tongues and noses has considerably increased in the last years. This paper presents the design of a low-cost electronic tongue system that includes a software application that runs on a personal computer and electronic equipment based on a 16-b microcontroller. The designed system is able to implement voltammetry and impedance spectroscopy measurements with different-electrode configurations. The data obtained from the electrochemical measurements can be used to build statistical models able to assess physicochemical properties of the samples. The designed system has been applied to the detection and quantification of trinitrotoluene (TNT), which is one of the most common explosive materials. Pulse voltammetry measurements were carried out on TNT samples with different concentration levels. The principal component analysis of the obtained results shows that the electronic tongue is able to detect TNT in acetonitrile samples. Prediction models were built with partial least squares regression, and a good correlation was observed between the pulse voltammetry measurements and the TNT concentration levels. In this experience, a new voltammetric data compression algorithm based on polynomial approximations has been tested with good results. The electronic tongue has also been applied to the prediction of water quality parameters in wastewater and to the evaluation of different-pulse array designs for pulse voltammetry experiences.

Trinitrotoluene and Its Metabolites in Shoots and Roots of Panicum maximum in Nano-Phytoremediation

Phytoremediation is one of chemical removal methods but this is a long term process. Nanotechnology is a novelty method that can be used for toxic remediation. The objective of this study aimed to determine Trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) translocation in shoots and roots based on the nano-phytoremediation experiments. For methodology, the transplantation method of Panicum maximum (Purple guinea grass) were selected for this study. The plants were transferred and grown in the soil that was spiked with TNT with concentrations of 100 and 500 mg/kg and also added with nanoscale zero valent iron (nZVI) with concentrations of 100, 500, and 1000 mg/kg. The determination of TNT accumulation in Panicum maximum was carried out after harvesting at the end of 1 st , 2 nd , 3 rd , and 4 th months. The plants were divided into shoots and roots for the measurements of TNT and its metabolite residue concentrations. The present study can be concluded that the TNT uptake by roots in nZVI added soil was more effective than that without nZVI, particularly, the experiments with TNT concentration of 500 mg/kg. The results also showed that TNT was found in roots higher than that in shoots in all experimental groups. The 2-ADNT and 4-ADNT were only found in roots in all sets of the experiments. Both metabolites were undetectable in shoots. Index Terms—Translocation, Panicum maximum, Trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (2-ADNT), 4-amino-2,6-dinitrotoluene (4-ADNT), Nanoscale zero valent iron particles (nZVI), phytoremediation. I. I NTRODUCTION Nano-phytoremediation involves nanotechnology and phytotechnology in remediation of the contaminated environment. Panicum maximum (Purple guinea grass) has been widely used as one of hyperaccumulators. The phytotechnology concerns four main processes. There are phytostabilization (the contaminants in soil are immobilized by means of plant roots), phytofiltration (plants take up contaminants by binding within their roots and shoots), phytodegredation or rhizodegradation (the contaminants are degraded and transformed to its metabolites within plants or

Detoxification of high concentrations of trinitrotoluene by bacteria

The ability of the strains-destructors of various aromatic compounds to utilize trinitrotoluene (TNT) up to concentration of 70 mg/1 was shown. An increase in the TNT concentration from 100 to 150 mg/1 did not inhibit its conversion rate by the Kocuria palustris RS32 strain. The Acinetobacter sp. VT 11 strain utilized TNT as a sole substrate for growth; 3,5-dinitro-4-methyl anilide acetate and 2,6-dinitro-4-aminotoluene were identified as intermediates of TNT degradation by active strains of Pseudomonas sp. VT-7W and Kocuria rosea RS51. At the same time, 4-methyl-3,5-dinitroformamide was discovered for the first time upon the TNT destruction by the bacteria strains of Rhodococcus opacus 1G and Rhodococcus sp. VT-7. The active bacterial strains achieved an 82-90% destruction of TNT when they were introduced into the soil.

Vetiver grass is capable of removing TNT from soil in the presence of urea

The high affinity of vetiver grass for 2,4,6 trinitrotoluene (TNT) and the catalytic effectiveness of urea in enhancing plant uptake of TNT in hydroponic media we earlier demonstrated were further illustrated in this soil-pot-experiment. Complete removal of TNT in urea-treated soil was accomplished by vetiver at the low initial soil-TNT concentration (40 mg kg −1), masking the effect of urea. Doubling the initial TNT concentration (80 mg kg −1) significantly ( p < 0.002) increased TNT removal by vetiver, in the presence of urea. Without vetiver grass, no significant ( p = 0.475) change in the soil-TNT concentrations was observed over a period of 48 days, suggesting that natural attenuation of soil TNT could not explain the documented TNT disappearance from soil.

Conjugated polymer-grafted silica nanoparticles for the sensitive detection of TNT

Conjugated polymer-grafted silica nanoparticles were prepared by Sonogashira coupling reaction involving a two-step procedure. The resulting conjugated polymer-grafted silica nanoparticles were characterized by infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, and absorption and fluorescence spectroscopy. The conjugated polymer-grafted silica nanoparticles are highly fluorescent, and the fluorescent response of the nanoparticles of different size towards electron-deficient trinitrotoluene (TNT) was studied by examining how the steady state fluorescence intensity changes with the concentration of TNT. The conjugated polymer-grafted silica nanoparticles show high sensitivity toward TNT, with a detection limit down to 1 μM.

Detection of Explosives Using Field‐Effect Transistors

AbstractThe gate surfaces of ion‐sensitive field‐effect transistor (ISFET) devices were functionalized with the π‐donor units, 6‐hydroxydopamine (1) or 4‐aminothiophenol (2). Concentration of trinitrotoluene, TNT, on the gate via π‐donor‐acceptor interactions yields charge‐transfer complexes that alter the gate potential. This enables the label‐free analysis of TNT with a detection limit corresponding to 1×10−7 M.

Preparation of Anti-dinitrotoluene Polyclonal Antibody and Effect of the Hapten Spacer Length in Coating Antigen on Immunoassay Sensitivity

Environmental pollution of soil, river water, and underground water by explosive–related compounds is a serious problem in the areas of buried landmines and/or landmine factories (Hilmi et al., 1999). These compounds are suspected to have human toxicity, mutagenicity, and carcinogenicity (Kennel et al., 2000; Sayama et al., 1998; Tchounwou et al., 2001; Banerjee et al., 1999). Therefore, there is a pressing need to determine the concentrations and distributions of these compounds in the environment. The main component of landmines is 2,4,6–trinitrotoluene (TNT). TNT released into the environment is decomposed and converted to dinitrotoluenes (DNTs) and aminodinitrotoluenes (ADNTs), among other products, by microorganisms, light, and heat. These compounds have been measured by using HPLC or other instrumental analytical devices (Borch and Gerlach, 2004; Ahmad and Roberts; 1995). These instrumental analyses, however, require tedious pre–treatments such as extraction from samples (Halasz et al., 2002). On the other hand, detection methods using an antigen–antibody reaction, such as enzyme–linked immunosorbent assay (ELISA) and fluorescent and chemiluminescent immunosensors, are more useful and are able to detect ppb levels of explosive compounds (Goldman et al., 2003; Green et al., 2002; Wilson et al., 2003). We have been engaged in development of an antibody with high avidity to explosive–related compounds. In recent years, we have focused on the development of highly sensitive surface plasmon resonance (SPR) sensing methods for the detection of TNT using an antigen– antibody reaction (Sakai et al., 2003; Shankaran et al., 2004; Shankaran et al., 2005a; Shankaran et al., 2005b; Matsumoto et al., 2005; Shankaran et al., 2006). According to the reports of Jenkins et al. (2000, 2001), the concentrations of 2,4–DNT and other decomposed nitroaromatic compounds around and over buried landmines are higher than the concentration of TNT. In the present study, a polyclonal antibody against 2,4–DNT was raised in a rabbit, and the antibody was applied to the detection of 2,4–DNT using ELISA. The aim was to prepare anti–DNPh–KLH antibody from a rabbit and to clarify the characteristics for the detection of 2,4–DNT based on the principle of indirect competitive ELISA. In the course of the detection of free 2,4–DNT, we recognized that the combination of the structure of the coating antigen–protein, free 2,4–DNT, and the anti– DNPh–KLH antibody are an important factor in sensitivity using an indirect competitive immunoassay. Therefore, the effect of the structures of the coating antigen–protein conjugates on the sensitivity of the detection of free 2,4–DNT was investigated in detail. Preparation of Anti–dinitrotoluene Polyclonal Antibody and Effect of the Hapten Spacer Length in Coating Antigen on Immunoassay Sensitivity

Degradation of trinitrotoluene in contaminated soils as affected by its initial concentrations and its binding to soil organic matter fractions

Trinitrotoluene (TNT), a nitroaromatics, is a major pollutant in explosive contaminated soils. Present study reports the effect of initial concentration of TNT on its degradation kinetics in soils. Soils from two contaminated sites viz. Clausthal and Elsnig, Germany, were mixed with an uncontaminated reference soil to get different initial concentrations (mg/kg) viz Clausthal-1 (54.29), Clausthal-2 (30.86), Clausthal-3 (7.05) Elsnig-1 (879.67), Elsnig-2 (86.43); Elsnig-3 (8.16) and Elsnig-4 (0.99) and were spiked with ring UL-14C-TNT (100KBq/50g soil). Except Elsnig-1 and Elsnig-2 soils, TNT degraded at same rate in all the soils. Higher persistence of TNT in Elsnig-1 and Elsnig-2 soils appears to be due to higher initial concentrations of nitroaromatics which may be toxic to soil microorganisms. 2-Amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) were recovered as major metabolites of TNT. Distribution of bound 14C-activity in different soil organic matter (SOM) fractions (humic acid, fulvic acid and humin) was assayed by alkali extraction of solvent extracted Clausthal-1 and Elsnig-1 soils. Results indicate that humic acid accounted for maximum bound activity followed by fulvic acid and humin fractions. Expressing 14C-activity bound/unit weight of organic carbon content of SOM fractions showed that 3 times more 14C-activity was bound to Elsnig humic acid than Clausthal humic acid. Similarly, activity associated with Elsnig fulvic acid was 7 times higher than that of Clausthal fulvic acid suggesting that chemical nature of SOM fractions plays a significant role in binding of contaminants.

TOXICOLOGICAL RESPONSES OF RED-BACKED SALAMANDERS (PLETHODON CINEREUS) TO SUBCHRONIC SOIL EXPOSURES OF 2,4,6-TRINITROTOLUENE

Since World War I, trinitrotoluene (TNT) has been the most commonly used explosive. Environmental contamination associated with synthesis, manufacture of weapons, and use during training exercises has been extensive, with soil concentrations reaching 145,000 mg/kg. Some of these areas include habitats for amphibian species. Earlier studies have shown that salamanders dermally absorb TNT from soil. To ascertain what soil concentrations of TNT are toxic to amphibians, red-backed salamanders (Plethodon cinereus) were exposed to one of five concentrations of TNT in soil for 28 d and evaluated for indicators of toxicity. A total of 100 salamanders were randomly sorted by weight and assigned to target TNT concentrations in soil of either 3,000, 1,500, 750, 325, or 0 mg/kg dry weight. Food consisted of uncontaminated flightless Drosophila melanogaster. Survival was reduced in salamanders exposed to 1,500 and 3,000 mg/kg by 10 and 55%, respectively. Most mortality/morbidity occurred within the first week of exposure. Salamanders had a reduction in hemoglobin at 750 mg/kg or greater and a reduction in red blood cell concentration at 1,500 mg/kg or greater. Food consumption was affected in salamanders at 750 mg/kg or greater; a reduction in body mass and liver glycogen content also occurred at and above this concentration. Splenic congestion also was observed in salamanders from these groups. These data suggest that soil TNT concentrations of 373 +/- 41.0 mg/kg or greater result in reduced body mass, reduced feed intake, and hematological effects.

Short term exposure to elevated trinitrotoluene concentrations induced structural and functional changes in the soil bacterial community

We investigated the acute impact of trinitrotoluene (TNT) contamination of soil on the aerobic bacterial community composition and function. The contamination of the environment with explosive residues presents a serious problem at sites across the world, with the highly toxic compound TNT being the most widespread explosive contaminant. We investigated the acute impact of trinitrotoluene (TNT) contamination of soil on the aerobic bacterial community composition and function. Soil microcosms were amended with a range of concentrations of TNT for 30 days. A polyphasic approach encompassing culture-independent molecular analysis by DGGE, community-level physiological profiling (CLPP) and cell enumeration revealed that the amendment of soils with TNT resulted in a shift from slower growing k-strategists towards faster growing r-strategists. Pseudomonads became prevalent at high concentrations of TNT. Pollution induced community tolerance (PICT) was observed as TNT concentrations increased. Chemical analyses revealed that TNT was reduced to its amino derivatives, products of reductive microbial transformation. The transformation to amino derivatives decreased at high concentrations of TNT, indicative of inhibition of microbial TNT transformation.

Microbial and plant ecology of a long-term TNT-contaminated site

The contamination of the environment with explosive residues presents a serious ecological problem at sites across the world, with the highly toxic compound trinitrotoluene (TNT) the most widespread contaminant. This study examines the soil microbial community composition across a long-term TNT-contaminated site. It also investigates the extent of nitroaromatic contamination and its effect on vegetation. Concentrations of TNT and its metabolites varied across the site and this was observed to dramatically impact on the extent and diversity of the vegetation, with the most heavily contaminated area completely devoid of vegetation. Bryophytes were seen to be particularly sensitive to TNT contamination. The microbial population experienced both a reduction in culturable bacterial numbers and a shift in composition at the high concentrations of TNT. DGGE and community-level physiological profiling (CLPP) revealed a clear change in both the genetic and functional diversity of the soil when soil was contaminated with TNT.

Comparative and Mixture Sediment Toxicity of Trinitrotoluene and Its Major Transformation Products to a Freshwater Midge

The explosive trinitrotoluene (TNT) is a prevalent contaminant in many military installations worldwide. Limited knowledge of the comparative toxicity of sediment-associated TNT and related compounds contributes to uncertainty when assessing ecological risks in contaminated sites. Trinitrotoluene undergoes transformation when associated with soils and sediments and typically occurs as a mixture dominated by its reduction products. The objective of this study was to comparatively evaluate the single-compound toxicity of TNT and its major transformation products to the freshwater midge Chironomus tentans in 10-day exposures to sediment spiked with TNT, 2-aminodinitrotoluene (2-ADNT), 2,4-diaminonitrotoluene (2,4-DANT), or trinitrobenzene (TNB). In addition, the nature of the toxicological interactions of the latter compounds in a mixture was evaluated. Upon spiking to sediment, TNT and TNB rapidly degraded to reduced products, and disappearance of extractable compounds suggested irreversible binding to sediment particles. The high degree of transformation and reactivity occurring during 10 days at spiking concentrations as high as 4000 micromol/kg dry weight suggests that TNT and related compounds are unlikely to be encountered in fine-grained sediments at contaminated sites. Similar to previous investigations, the high reactivity of the spiked compound hampered determination of accurate toxic concentrations of TNT and related compounds, and of the nature of toxicological interaction of compounds in a mixture in this study. Sediment concentrations associated with decreased survival were similar for all four compounds, with the 10-d median lethal concentrations (LC50s) determined using initial concentrations ranging from 175 (2-ADNT) to 605 (2,4-DANT) micromol/kg dry weight. Sublethal decrease in growth was not observed for any compound. Results from the mixture experiment suggest additive interaction among TNT and related compounds in sediment exposures.

Accumulation of trinitrotoluene (TNT) in aquatic organisms: Part 1—Bioconcentration and distribution in channel catfish ( Ictalurus punctatus)

Little is currently known regarding the toxicokinetics of TNT in fish. In the present study, the bioconcentration and distribution of trinitrotoluene (TNT) and TNT biotransformation products was investigated in juvenile channel catfish by exposing catfish to 14C-labeled TNT in water. Uptake experiments showed relatively fast rates ( k u = 10.1 ml g −1 h −1) for TNT from the water; however, bioconcentration factors for TNT were low (0.79 ml g −1) due to rapid biotransformation and potential elimination of TNT. Accumulation of extractable radioactivity (TNT and all extractable biotransformation products) was much greater (BCF = 10.5 ml g −1) than that for parent compound. TNT (parent compound) bioconcentrated to the greatest extent in the gills of the fish, while total radioactivity bioconcentrated to the greatest extent in the viscera. Residual portions of the fish that contained muscle and skin had lower concentrations of TNT than the whole fish, indicating that ingestion of fish filets would result in decreased exposure to human consumers. Although the bioconcentration potential of TNT is very low, future research needs to be conducted to identify the biotransformation products that make up most of the radioactivity in exposed fish and evaluate their potential to promote toxicity.

Accumulation of trinitrotoluene (TNT) in aquatic organisms: Part 2—Bioconcentration in aquatic invertebrates and potential for trophic transfer to channel catfish ( Ictalurus punctatus)

The potential of TNT to accumulate in aquatic organisms was assessed by determining bioconcentration factors for TNT and TNT biotransformation products using two benthic invertebrates ( Chironomus tentans and Lumbriculus variegatus), and by determining the bioaccumulation factor of TNT and TNT biotransformation products due to TNT exposure via feeding for channel catfish ( Ictalurus punctatus). In all three species, TNT was rapidly biotransformed resulting in minimal accumulation. The bioconcentration factors for parent TNT ranged from 3 to 4 ml g −1 for the invertebrates studied, while the TNT bioaccumulation factor for catfish via oral exposure of food pellets was 2.4 × 10 −5 g g −1 based on the concentration of TNT in the food pellet. As indicated by this small bioaccumulation factor, TNT accumulation in channel catfish through trophic transfer would be negligible compared to aqueous exposure (previously reported BCF of 0.79 ml g −1). TNT extractable biotransformation products accumulated to a greater degree than parent TNT for all three species. In addition, a large fraction of the radioactivity within all three species resisted solvent extraction. The highest bioconcentration factors occurred in L. variegatus with extractable radioactivity measuring 76 ml g −1 and total radioactivity measuring 216 ml g −1. Because the bioaccumulation of TNT is very low compared to the bioaccumulation of its biotransformation products, further research including identifying and determining the relative toxicities of these biotransformation products is necessary to fully evaluate the environmental risk posed by exposure to TNT.

Enhanced bioavailability of sorbed 2,4,6-trinitrotoluene (TNT) by a bacterial consortium

Large quantities of trinitrotoluene (TNT) have been associated with past and present military activities worldwide. Because this contaminant is highly toxic and strongly sorbs to soil particles, bacteria that are able to transform it have had very little success, if any. This study was conducted to evaluate the bioavailability of 14C-labeled TNT in soil for microbial mineralization. Sorption–desorption experiments indicated that a Kendaia loam soil effectively adsorbs this explosive compound, with approximately 30–45% of the added TNT remaining sorbed to the soil after a total of 10 washings. A bacterial consortium isolated from explosive-contaminated sites was prepared in liquid medium and then tested in a TNT-spiked Kendaia loam soil. The concentration of TNT in the soil that was inoculated with the bacterial consortium was reduced by more than 30% of the initial concentration compared to the soil that did not contain the bacterial consortium within a period of 20 weeks. Nearly half of the TNT was mineralized as determined by the percentage of 14CO 2 produced. Only one member of the consortium (i.e., Enterobacter sp.) significantly mineralized 25% of TNT although the extent of mineralization was significantly enhanced to 35% in the presence of the other two members of the consortium. The data suggest that some of the strongly adsorbed TNT may be accessible for metabolism if conditions for the right combination of microorganisms with specialized capabilities are optimized. The remaining sorbed fraction of substrate is presumably sequestered and thus unavailable to the microorganisms.