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Explosive attacks are increasing day by day in the present era, and the design optimization of protective structures without increasing their weight is mainly a critical task for vehicles. Assessment of the dynamic response of the structures under explosive loading through experimentation is costly, with many restrictions, and highly harmful for both people and the environment. Hence, the present study deals with an explicit numerical investigation of the protective sandwich structures' blast performance. The influence of the number of stages of honeycomb on the sandwich structures' blast mitigation capacity was evaluated with the effective utilization of face sheets' material as their intermediate sheets while maintaining the total volumes as well as masses of the structure's constant. The explosive loads of 1 to 3 kg of trinitrotoluene were used for the stand-off distance of 100 mm. The rate-dependent Johnson-Cook plasticity model was implemented on the designed sandwich models to discover their damage behaviors. The sandwiches' face deflection, energy absorption, kinetic energy variation, and crushing behaviors were considered to characterize their blast mitigation capacity. The obtained results showed that increasing the number of stages of core in the sandwich structure by using a fraction of the back face sheet materials for intermediate sheets significantly improved their blast performance without increasing their volume occupancies and masses. For the two-stage and three-stage sandwich designs, 50% and 20%, respectively, utilization of their back face material for their intermediate sheet was found to be optimal. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental study of the dynamic characteristics of the process of laser fragmentation/laser-induced fluorescence (LF/LIF) of trinitrotoluene traces on a paper surface under synchronized double-pulse laser irradiation. An Nd:YAG-laser (266 nm) was used for the fragmentation of TNT molecules, while fluorescence excitation of their NO fragments was performed using a KrF laser with a generation line of 247.867 nm in the region of the location of the bandhead of the P12 branch of the γ(0, 2) absorption band of the NO molecule. It was shown that the dissociation process of TNT traces has an inertial character and continues after the cessation of the fragmenting laser pulse. It was found that with the delay values between the fragmenting and probing laser pulses in the region of 200 ns, the efficiency of the LF/LIF method can be increased by 12 times. This paper presents the results of an experimental evaluation of the efficiency of two-pulse LF/LIF compared to single-pulse laser exposure, where the fragmentation of TNT molecules and excitation of their NO fragments were simultaneously performed by KrF laser pulses. The possibility of multiple increases in the efficiency of two-pulse LF/LIF with an increase in the energy density of the fragmenting laser radiation was shown. The obtained results are important in terms of increasing the sensitivity and/or range of the LF/LIF method for remote detection of traces of nitrocompounds. [ABSTRACT FROM AUTHOR]

Due to the high energy absorption capability and excellent bending strength of the sandwich panels, they are mostly preferred as protective structures against explosive blast attacks. The evaluation of their blast-mitigation characteristics through experiments is highly dangerous, costly, time-consuming, and polluting for the environment. Therefore, in this presented work, a series of numerical analyses were performed to evaluate the blast mitigation of the outstanding sandwich panels with honeycomb, corrugated, auxetic, and foam cores. The masses of sandwich panels were kept constant, and their areal densities were maintained constant throughout the study to effectively compare their performance under identical air blast loading conditions. To apply the air blast loads to the designed sandwiches, 1–3kg of spherical-shaped trinitrotoluene charges were used for a 100mm stand-off distance. The sandwiches are made of high-strength AL-6XN steel and crushable aluminum foam. The rate-dependent Johnson–Cook constitutive model of plasticity and the crushable foam model with volumetric hardening were used for the evaluation of sandwich panels’ plastic deformations. The findings of the work depicted that the honeycomb core is more efficient than the other core structures of the same masses because the sandwich panels with honeycomb core provide smaller back skin deflections, globalized core crushing, and higher core energy absorption than the other sandwich panels for extreme conditions of air blast loading. [ABSTRACT FROM AUTHOR]

Past and recent applications of 2,4,6-trinitrotoluene (TNT) in military and civilian industries have led to contamination of soil and marine ecosystems. Among various TNT remediation techniques, biological remediation is widely accepted for its sustainability, low cost, and scalable applications. This study was designed to isolate a fungus strain from a TNT-contaminated soil to investigate its tolerance to and potential for removal of TNT. Thus, a soil column with a history of periodic TNT amendment was used to isolate dominant strains of fungi Fusarium solani isolate, which is not commonly reported for TNT mineralization and was found predominant in the subsurface layer of the TNT-amended soil. F. solani was investigated for TNT concentration tolerance at 30, 70, and 100 mg/L on agar plates and for TNT removal in liquid cultures at the same given concentrations. F. solani activity was compared with that of a reference soil-born fungus that has been intensively studied for TNT removal (Phanerochaete chrysosporium) obtained from the American Type Culture Collection. On agar media, F. solani showed a larger colony diameter than P. chrysosporium at similar TNT concentrations, indicating its high potential to tolerate toxic levels of TNT as found in contaminated sites. In the liquid culture medium, F. solani was able to significantly produce higher biomass than P. chrysosporium in all TNT concentrations. The TNT removal percentage from the liquid culture at the highest TNT concentration of 100 mg/L reached about 85% with F. solani, while P. chrysosporium was no better than 25% at the end of an 84-h incubation period. Results indicate a significant potential of using F. solani in the bioremediation of polluted TNT soils that overcome the high concentration barrier in the field. However, further investigation is needed to identify enzymatic potential and the most effective applications and possible limitations of this method on a large scale. [ABSTRACT FROM AUTHOR]

A new energetic co-crystal of trinitrotoluene (TNT) and pyrene (PYRN) with a 1:1 molar ratio was prepared by a slow solvent evaporation technique. Co-crystal physicochemical properties have also been examined using optical microscopy, powder X-ray diffraction, single crystal X-ray diffraction, and differential scanning calorimetry. The results of single-crystal X-ray diffraction and non-covalent interaction calculations showed that non-covalent interactions (donor–acceptor π-π interaction) govern the structures of the TNT:PYRN co-crystal. The experimental and theoretical outcomes supported each other in the study. Thermal stability, impact sensitivity, and detonation performance of the co-crystal were investigated. DSC measurement indicates that the co-crystal has a melting point of 167 °C and a decomposition temperature of 293 °C, indicating outstanding thermal stability. The co-crystal was found to be less impact-sensitive than TNT using the BAM fall hammer instrument. Furthermore, the calculated detonation velocity and detonation pressure of the co-crystal are 5.29 km·s−1 and 8.48 G Pa, respectively. As an outcome, the TNT:PYRN co-crystal may be a promising intermediate energy explosive with low sensitivity and, as such, may be a desirable explosive alternative in the future instead of TNT for low-vulnerability formulations. [ABSTRACT FROM AUTHOR]

In today's world, concrete structures are exposed to various influences, including explosive actions. With the increasing use of fiber-reinforced concrete (FRC), it is essential to investigate its response to blast effects. As there are few studies on this topic worldwide, this research is dedicated to the question of how blast effects affect the damage and properties of six different types of reinforced concrete (RC) slabs. These samples differ in concrete classes (C30/37 and C50/60) and in the type of fibers added (steel and polypropylene). Visual inspections and non-destructive measurements are carried out before and after blasting. The damaged area of the concrete surface is determined by visual inspection, while non-destructive measurements evaluate parameters such as the rebound value of the Schmidt hammer, the electrical resistivity of the concrete, the velocity of the ultrasonic wave, and the dynamic modulus of elasticity. Equal amounts of explosives are applied to five of the RC slabs to enable a comparative analysis of the resulting damage. Based on the comparison of the measured data from these five RC slabs, conclusions are drawn regarding the effects of the explosive impacts on conventionally reinforced concrete slabs compared to those with added fibers. In addition, one of the RC slabs with steel fibers is exposed to approximately three times the amount of explosives to assess the extent of increased damage and to evaluate the suitability of military standards in the calculation of explosive charges for blasting RC elements with fibers. [ABSTRACT FROM AUTHOR]

Wastewater originating from the production of TNT explosives (red water) contains special hazardous substances that must be treated before discharging into the water environment. In this study, we applied both conventional Fenton and photo-Fenton (UV-Fenton) processes to treat COD and color in red water. In the Fenton process, the COD and color removal efficiencies were 75.5 and 92.4%, respectively, under optimal operating conditions of pH = 3, [Fe2+] = 0.3 g L-1, H2O2/Fe(Ⅱ) ratio = 10:1, reaction time = 120 min. In the UV-Fenton process, the efficiencies were 76.1 and 94.2%, respectively, under optimal operating conditions of pH = 3, [Fe2+] = 0.21 g L-1, H2O2/Fe(Ⅱ) ratio = 7:1, reaction time = 90 min. These results indicate that the use of ultraviolet could reduce not only the reaction time but also the chemical use (i.e. H2O2 and Fe2+), thus reducing the sludge production. Importantly, the UV-Fenton process significantly increased the BOD5/COD ratio from 0.13 to 0.58, which greatly enhanced the biodegradability of the wastewater for biological treatment. Therefore, UV-Fenton can be applied as an effective pretreatment in the treatment of red water with high color and organic pollutants.

This paper presents the results of an experimental study of the dynamic characteristics of the process of laser fragmentation/laser-induced fluorescence (LF/LIF) of trinitrotoluene traces on a paper surface under synchronized double-pulse laser irradiation. An Nd:YAG-laser (266 nm) was used for the fragmentation of TNT molecules, while fluorescence excitation of their NO fragments was performed using a KrF laser with a generation line of 247.867 nm in the region of the location of the bandhead of the P12 branch of the γ(0, 2) absorption band of the NO molecule. It was shown that the dissociation process of TNT traces has an inertial character and continues after the cessation of the fragmenting laser pulse. It was found that with the delay values between the fragmenting and probing laser pulses in the region of 200 ns, the efficiency of the LF/LIF method can be increased by 12 times. This paper presents the results of an experimental evaluation of the efficiency of two-pulse LF/LIF compared to single-pulse laser exposure, where the fragmentation of TNT molecules and excitation of their NO fragments were simultaneously performed by KrF laser pulses. The possibility of multiple increases in the efficiency of two-pulse LF/LIF with an increase in the energy density of the fragmenting laser radiation was shown. The obtained results are important in terms of increasing the sensitivity and/or range of the LF/LIF method for remote detection of traces of nitrocompounds.

Global pollution of soil and water supplies due to the leftover dumping of nitroexplosives is a critical issue. Increasing mining and construction activity leads to a significant growth in the trinitrotoluene (TNT) market, making it a lethal contaminant that should be detected early to prevent consumption. Here, in this work, a highly sensitive voltammetric trinitrotoluene (TNT) sensor has been fabricated by modifying a gold electrode (AuE) with a ZnO2/carbon nanotube (CNT) nanocomposite (ZnO2/CNT@AuE). The ZnO2/CNT nanocomposite was synthesized by the coprecipitation method. Morphological and chemical analyses of the synthesized nanostructure was done through different high-end characterization techniques [Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM)]. The electrocatalytic reduction behavior of the electrochemical probe, ZnO2/CNT@AuE, toward TNT was studied in phosphate buffer solution (PBS, pH 7.0) using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. The ZnO2/CNT nanocomposite deposited on the electrode surface improves the conductivity and active sites for electrocatalytic reduction, significantly enhancing the designed sensor's performance. The fabricated sensor exhibited an outstanding sensing performance and a rapid response when exposed to TNT with a higher sensitivity (80.53 μA cm–2 μM–1) and a lower detection limit (3.4 nM). In addition to the excellent efficacy, the newly developed sensor showed high reproducibility and long-term stability on repeated use. The sensor detects TNT over a wide linear range (4–500 nm) and has good anti-interference capabilities. The ZnO2/CNT@AuE probe has been applied successfully to detect TNT in real water samples. Moreover, electrochemical applications can be expanded by implementing the present electrochemical strategy. [ABSTRACT FROM AUTHOR]

Advanced energetic metal–organic frameworks (MOFs) can expose novel characteristics. Highly crystalline nickel hydrazine nitrate (NHN) MOF of 50 nm size was developed via wet coordination. NHN experienced superior decomposition enthalpy of 3100 J g−1 at 222 °C using differential scanning calorimetry. NHN could act as a sensitizer for trinitrotoluene (TNT) and could boost its decomposition enthalpy, detonation velocity, and decomposition kinetics. NHN nanoparticles were effectively integrated into TNT energetic matrix; proper particle dispersion was verified via energy-dispersive X-ray analysis, whereas TNT experienced decomposition enthalpy of 340 J g−1; NHN boosted TNT decomposition enthalpy by 282%, with decrease in main decomposition temperature by 31 °C. NHN/TNT nanocomposite revealed a decrease in TNT activation energy by − 23.5% and − 22% via Kissinger and KAS models, respectively. The synergistic effect of NHN on TNT was ascribed its high decomposition enthalpy, gaseous products. NHN could secure novel catalytic effect on TNT decomposition with increase in detonation velocity by 11%; this was ascribed to the release of active hydrogen that could support CH-α attack with the exclusive formation of nickel nanocatalyst. [ABSTRACT FROM AUTHOR]

Submerged munitions are present in marine waters across the globe. They contain energetic compounds (ECs), such as TNT and metabolites thereof, which are considered carcinogenic, exhibit toxic effects in marine organisms, and may affect human health. The aim of this study was to investigate the occurrence of ECs and their trends in blue mussels from the annual collections of the German Environmental Specimen Bank sampled over the last 30 years at three different locations along the coastline of the Baltic and North Sea. Samples were analyzed by GC-MS/MS for 1,3-dinitrobenzene (1,3-DNB), 2,4-dinitrotoluene (2,4-DNT), 2,4,6-trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (2-ADNT), and 4-amino-2,6-dinitrotoluene (4-ADNT). The first signals indicating trace levels of 1,3-DNB were observed in samples from 1999 and 2000. ECs were also found below the limit of detection (LoD) in subsequent years. From 2012 onwards, signals just above the LoD were detected. The highest signal intensities of 2-ADNT and 4-ADNT, just below the LoQ (0.14 ng/g d.w. and 0.17 ng/g d.w., respectively), were measured in 2019 and 2020. This study clearly shows that corroding submerged munitions are gradually releasing ECs into the waters that can be detected in randomly sampled blue mussels, even though the concentrations measured are still in the non-quantifiable trace range. [ABSTRACT FROM AUTHOR]

• The research paper conducts an in-depth comparison of graphene's conventional and GA-based optimised designs for THz antennas. • The proposed research examines four graphene and copper combinations, identifying the extremely explosive compound trinitrotoluene (TNT) at a resonance frequency of 5.6 THz. • Among the four designs, the entire graphene design demonstrates higher performance than the other three combinations, with a smaller size. • The optimised graphene antenna is altered to operate as a tri-band antenna with frequencies of 3.37 THz, 4 THz, and 5.2 THz. • The proposed tri-band antenna can detect drugs like l-histidine and explosives like ammonium nitrate (NH4NO3) and PETN in PE with lower, middle and higher resonant frequencies, respectively. The proposed research paper introduces a novel design of THz graphene-based antennas capable of countering terrorism by detecting explosive materials and drugs. The research work is subdivided into three distinct sections; the initial research entails conducting a comparative analysis of conventional and genetic algorithm-based optimised designs of terahertz antennas utilising graphene material. Subsequently, three supplementary designs are evaluated in comparison to the optimum design: one integrating a copper ground with a graphene patch, another integrating a copper patch with a graphene ground, and a third incorporating both a copper patch and ground. All four optimised designs, each resonating at a frequency of 5.6 THz, are used to detect explosive compounds like Trinitrotoluene (TNT). The optimised graphene-based antenna outshines the rest of the designs in terms of radiation efficiency, with a value of 90.03 %. It also exhibits superior performance regarding S 11 parameters, with a value of −53.38 dB, and VSWR, with a value of 1.004, at the resonant frequency. The optimised antenna demonstrates superior performance concerning gain (dB) and directivity (dBi), measuring 6.56 dB and 7.02 dBi, respectively. During the final phase of the proposed research, a graphene antenna was modified to function as a tri-band antenna by incorporating a 180° mirrored f-shaped slot within the antenna's patch. The tri-band antenna functions at resonant frequencies of 3.37 THz, 4 THz, and 5.2 THz. These frequencies detect explosives and narcotics, notably l-histidine, ammonium nitrate (NH 4 NO 3), and PETN in PE. These resonant frequencies hold the potential to be utilised in future applications of 6G technology worldwide. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel strain of Pantoea sp. showed efficient degradation of TNT. • Genomic studies reveal the TNT metabolism-related genes of Pantoea sp. BJ2. • Proteomics identifies differential proteins in TNT degradation by Pantoea sp. BJ2. • Metabolite analysis reveals metabolites of TNT degradation by Pantoea sp. BJ2. • Multiomics analysis reveals the degradation mechanism of TNT by Pantoea sp. BJ2. Trinitrotoluene (TNT) is a highly toxic organic pollutant, and its biodegradation process and mechanism remain unclear. In this study, five TNT-degrading bacteria were isolated and identified, among which Pantoea sp. BJ2 showed the best TNT degradation potential; it could degrade 97.85 % of 100 mg L−1 TNT within 24 h. Further, five genes (three nemA , one nfsA and one nfnB) directly related to TNT metabolism were identified in Pantoea sp. BJ2. During the degradation of TNT by Pantoea sp. BJ2, N-ethylmaleimide reductase, nitrate reductase and ATP-binding protein of the nitrate/nitrite transport system were found to be significantly upregulated, and five metabolites, including 2-amino-4,6-dinitrotoluene, were also identified. Based on the multiomics analysis, the mechanism of TNT degradation by Pantoea sp. BJ2 was proposed, indicating that the degradation of TNT by Pantoea sp. BJ2 was achieved under the joint action of various functional genes and proteins, including material transport, energy supply and exogenous material metabolism. The findings offer reliable theoretical underpinnings and technical support for a safe remediation of TNT-contaminated sites, providing new insights into the microbial degradation mechanisms of TNT from a multiomics perspective. [ABSTRACT FROM AUTHOR]

• Charcoal-based AC was modified with Fe NPs via a carbothermal process. • TNT q max of AC, AC-800, and Fe-AC-800 were 265.52, 339.64, and 387.74 mg/g. • The Fe NPs and carbothermal treatment favored TNT adsorption on Fe-AC-800. • The optimal adsorption capacity of Fe-AC-800 was 464.13 mg/g. • The mechanism of TNT adsorption involved π-π EDA interaction and hydrogen bonding. Activated carbon (AC) is commonly used to remove many pollutants from water due to its appealing adsorption properties. However, the pristine surface properties of AC limit its ability to effectively remove 2,4,6-trinitrotoluene (TNT, a widely used explosive water contaminant). Modifying AC with Fe nanoparticles (NPs) can significantly improve the surface properties of the Fe/AC composite, thereby enhancing its adsorption capabilities. Commercial charcoal-based AC was modified with Fe NPs via wet impregnation followed by a one-step carbothermal synthesis (labeled Fe-AC-800). A detailed characterization of Fe-AC-800 and its counterparts, pristine AC and thermally modified AC (AC-800, without Fe NPs doping) was performed using XRD, Raman Spectroscopy, SEM, EDS, BET, XPS, and FTIR. Then, the adsorption characteristics and performances of Fe-AC-800 were analyzed to determine its effectiveness in removing TNT and compared to AC and AC-800, considering the impact of in-situ Fe-modification and carbothermal treatment. Fe-AC-800 displayed a higher adsorption capacity for TNT (387.74 mg/g) than the pristine AC (265.52 mg/g) but only slightly higher than AC-800 (339.64 mg/g). This was ascribed to the combined effect of the carbothermal treatment and Fe NPs doping, which constructed a richer porous structure that improved the Fe-AC-800 surface features and favored TNT removal. The optimal adsorption capacity of Fe-AC-800 was 464.13 mg/g under ambient conditions. TNT adsorption onto Fe-AC-800 and AC-800 conformed to only the Langmuir isotherm model, indicating uniform monolayer adsorption, whereas on the pristine AC, it satisfied both Langmuir and Freundlich isotherm models, respectively. The primary mechanism of TNT adsorption onto Fe-AC-800 was physical adsorption through pore filling, hydrogen bonding, and π-π EDA interactions, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

• PUC2 Luminescent Probe: utilizing MOF PUC2 for TNT detection. • Sensitivity: achieving a 0.145 μM detection limit. • pH Adaptability: effective in pH 4–11 aqueous environments. • Distinctive Blue Emission: vivid blue light enhances accuracy. • Quenching Mechanisms: PET and FRET for sensitivity. The existence of nitroaromatic compounds, specifically 2,4,6-trinitrotoluene (TNT), in water reservoirs poses significant health risks, necessitating robust detection and monitoring strategies. In this study, we leverage the exceptional properties of the previously synthesized metal-organic framework (MOF), PUC2 as a highly luminescent probe for selective and sensitive detection of TNT in aqueous media. PUC2 exhibits remarkable luminescence, emitting a vivid blue light, making it an ideal candidate for TNT detection. Our investigations reveal that PUC2 demonstrates outstanding sensitivity, achieving an impressive detection limit of 0.145 μM towards TNT which can be attributed to the robust probe-analyte interactions evident from the quenching constant (Ksv) value of 0.18 × 104 M −1. An intriguing aspect of PUC2 is its adaptability to a wide pH range, maintaining its sensing capabilities effectively in aqueous phase with pH levels ranging from 4 to 11. The predominant quenching mechanism in this context appears to be photoinduced electron transfer (PET), with an additional enhancement through Forster resonance energy transfer (FRET). The unique combination of structural features and exceptional sensing capabilities of PUC2 opens up new avenues for environmental monitoring and security applications, highlighting its potential as a highly effective luminescent sensor for detecting hazardous substances like TNT. [Display omitted] [ABSTRACT FROM AUTHOR]

• The glass transition of energetics is important for inert munitions developments. • The glass transition of TNT as a function of cooling rate is determined. • The glass transition of TNT is sensitive to mixing with a silver paste. • The glass temperature of TNT is approximately 10 K lower than prior reports. • TNT has a dynamic fragility index m of approximately 70. In prior work (N. Shamim, Y. P. Koh, S. L. Simon and G. B. McKenna, "The glass transition of trinitrotoluene (TNT) by Flash DSC," Thermochimica Acta, 620 , 36–39 (2015)) results for the glass transition temperature T g of TNT based on measurements using a rapid chip calorimeter were reported. In that work a silver paste was used to contain the liquid TNT on the chip sensor. In the present work we show that there was an interaction between the paste and the TNT that cause the reported T g to be approximately 10 °C higher than what we find for the material when placed directly on the chip calorimeter sensor. The reasons for the differences in T g values and similarities in the glassy fragility index m from the different sample preparations are presented and discussed. [ABSTRACT FROM AUTHOR]

Submerged munitions are present in marine waters across the globe. They contain energetic compounds (ECs), such as TNT and metabolites thereof, which are considered carcinogenic, exhibit toxic effects in marine organisms, and may affect human health. The aim of this study was to investigate the occurrence of ECs and their trends in blue mussels from the annual collections of the German Environmental Specimen Bank sampled over the last 30 years at three different locations along the coastline of the Baltic and North Sea. Samples were analyzed by GC-MS/MS for 1,3-dinitrobenzene (1,3-DNB), 2,4-dinitrotoluene (2,4-DNT), 2,4,6-trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (2-ADNT), and 4-amino-2,6-dinitrotoluene (4-ADNT). The first signals indicating trace levels of 1,3-DNB were observed in samples from 1999 and 2000. ECs were also found below the limit of detection (LoD) in subsequent years. From 2012 onwards, signals just above the LoD were detected. The highest signal intensities of 2-ADNT and 4-ADNT, just below the LoQ (0.14 ng/g d.w. and 0.17 ng/g d.w., respectively), were measured in 2019 and 2020. This study clearly shows that corroding submerged munitions are gradually releasing ECs into the waters that can be detected in randomly sampled blue mussels, even though the concentrations measured are still in the non-quantifiable trace range.

The organic gunshot residues (OGSRs), specifically methyl centralite (MC; 1,3‐dimethyl‐1,3‐diphenylurea), ethyl centralite (EC; 1,3‐diethyl‐1,3‐diphenylurea), 2,4‐DNT (2,4‐dinitrotoluene), and TNT (trinitrotoluene), are characteristic compounds for which forensic analysts test determining if a person has discharged a firearm. A set of 200 samples from 50 shooters were collected as part of the validation study. Pistol 9 mm and special revolver.38 were fired at indoor and outdoor shooting ranges. The development of a methodology based on direct analysis of samples‐time of flight‐mass spectrometry (DSA‐TOF‐MS) made it possible to identify the main components of organic shot residues, which gave the possibility to introduce a new method of analysis of shot residues in the Chilean supply area. The DSA‐TOF‐MS provided extensive information on the composition of the shot residues: MC, EC, 2,4‐DNT, and TNT. Samples taken from the trigger hands required minimal sample preparation that reduced analyses time. With the implementation of new alternative analytical methodologies, a great step would be taken in the analysis of OGSRs, because now there is no such technique for its analysis in Chile, and the results would also complement the existing inorganic elemental analyses generated during a gunshot. [ABSTRACT FROM AUTHOR]

The adverse health effects of trinitrotoluene (TNT) include allergies, liver and blood damage, and carcinogenesis. The present study aimed to optimize the sono-Fenton and photo-Fenton processes for the removal of TNT from aqueous solutions. TNT removal was evaluated at various pH (acidic, neutral, and alkaline), pollutant concentrations (10, 30, 50, 100, and 120 mg/l), H2O2 concentration (10-80 mM), and ferrous ions (0.5-4 Mm). After the optimization of the parameters, the appropriate UV irradiation time and optimal time of ultrasonic waves were determined for the removal of this compound. TNT concentration was measured using high-performance liquid chromatography. Increased hydrogen peroxide from 10 to 40 mMole/l led to higher TNT degradation (45.3% to 88.4% and 40 to 80 mMole/l), while the removal rate decreased from 88.4% to 79%. At the optimal H2O2 concentration, increased pH (3±0.2 to 11±0.2) decreased TNT decomposition from 88.4% to 23.5%. In addition, increased time (5 to 60 minutes) led to the higher photo-Fenton process efficiency (68.6% to 89%). The maximum photo-Fenton efficiency was achieved in optimal conditions at the TNT concentration of 10 mg/L (97%) and 60 minutes, while the efficiency of the sono-Fenton process in optimal conditions was 100% at 20 minutes. Therefore, it was concluded that the sono-Fenton process was effective in the removal of TNT.

Enzymatic biotransformation stands as an eco-friendly strategy for eliminating toxic contaminants like 2,4,6-trinitrotoluene (TNT). Moreover, the application of immobilized biocatalysis is relevant for industrial applications due to the improved stability and reusability of the immobilized enzymes. In the present study, an enzymatic cocktail containing laccases from a native fungus from the northeastern of Mexico (Pycnoporus Ssanguineus CS43) was immobilized in nanofibers. The study explores three biopolymer mixtures—polyalcohol vinyl (PVA), PVA/alginate (PVA/SA), and PVA/chitosan (PVA/CS)—for nanofiber preparation and employs three distinct immobilization strategies: entrapment, adsorption, and covalent bonding. Among them entrapped laccases in PVA/SA nanofibers showed the highest immobilization rate (96.92%) and retained 77.85% activity after five cycles using 2,2-azino- bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) as substrate. Preliminary kinetic parameters and optimal pH/temperature were determined, comparing the cocktail of immobilized laccases to free ones. The application of this system resulted in a substantial 93.43% TNT removal at pH 7 and 25 °C within four days, preserving 24.13% activity after five cycles. Significantly, this study marks the pioneering use of immobilized laccase for TNT biotransformation, offering a promising eco-friendly strategy for tackling persistent pollutants such as TNT. [Display omitted] • Entrapment on PVA/SA yielded highest laccase immobilization rates on nanofibers. • PVA/SA/LE nanofiber-immobilized laccase was used for TNT biotransformation. • After 4 days of enzymatic treatment, 93.43% of TNT was removed. • Immobilization increased enzyme reusability up to 5 cycles. • Amino dinitrotoluene isomers were the biotransformation annotated products. [ABSTRACT FROM AUTHOR]

The results of field and experimental microbiological studies of water, soil, and rock samples in the influence zone of large landslide are presented. The landslide occurred in December 2018 and blocked the Bureya Reservoir from coast to coast. An artificial channel was created to restore the hydrological regime with the use of TNT (trinitrotoluene) and RDX (hexogen). A comparative analysis of the abundance of cultivated heterotrophic bacteria around the landslide body and in the artificial channel is carried out. The activity of microbial communities in relation to easily available (peptone, lactate, and starch) and difficult-to-mineralize humic compounds is also determined. With the use of spectrometry and gas chromatography, it is shown that an increase in the diversity of aromatic compounds in water is accompanied by an increase in the abundance of heterotrophic bacteria. A number of toxic substances, including methanol and methylated benzene derivatives, are found among the dominant components in the water. Its concentrations increased after the water drained through the landslide body and after imploding works. Many of the volatile organic compounds may have been products of microbial metabolism when water interacts with rocks. A hypothesis on the role of methanotrophic and methylotrophic bacteria in the genesis of methanol and toluene is discussed. [ABSTRACT FROM AUTHOR]

2,4,6-Trinitrotoluene (TNT) is a highly toxic nitroaromatic explosive known for its environmental consequences, contaminating soil and groundwater throughout its life cycle, from production to disposal. Therefore, the urgency of developing innovative and ecological strategies to remedy the affected areas is recognized. This study reports, for the first time, the enzymatic biotransformation of TNT by a cocktail of native laccases from Pycnoporus sanguineus CS43. The laccases displayed efficient TNT conversion under both oxygenic and non-oxygenic conditions, achieving biotransformation rates of 80% and 87% within 48 h at a temperature of 60 °C and pH 7. Preliminary kinetic constants were calculated with the laccase cocktail, being a V max of 1.133 μM min -1 and 0.2984 μM min -1 , and the K m values were 1586 μM and 458 μM, in an oxygenic and non-oxygenic atmosphere, respectively. High-performance liquid chromatography-mass spectrometry (HPLC/MS) confirmed the formation of amino dinitrotoluene isomers and hydroxylamine isomers as biotransformation products. In summary, this study suggests the potential application of laccases for the direct biotransformation of recalcitrant compounds like TNT, offering an environmentally friendly approach to address contamination issues., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The nitrated compounds 2,4-dinitrotoluene (2,4-DNT), 2,4,6-trinitrotoluene (TNT), and pentaerythritol tetranitrate (PETN) are toxic xenobiotics widely used in various industries. They often coexist as environmental contaminants. The aims of this study were to evaluate the transformation of 100 mg L−1 of TNT, 2,4-DNT, and PETN by Raoultella planticola M30b and Rhizobium radiobacter M109c and identify enzymes that may participate in the transformation. These strains were selected from 34 TNT transforming bacteria. Cupriavidus metallidurans DNT was used as a reference strain for comparison purposes. Strains DNT, M30b and M109c transformed 2,4-DNT (100%), TNT (100, 94.7 and 63.6%, respectively), and PETN (72.7, 69.3 and 90.7%, respectively). However, the presence of TNT negatively affects 2,4-DNT and PETN transformation (inhibition > 40%) in strains DNT and M109c and fully inhibited (100% inhibition) 2,4-DNT transformation in R. planticola M30b. Genomes of R. planticola M30b and R. radiobacter M109c were sequenced to identify genes related with 2,4-DNT, TNT or PETN transformation. None of the tested strains presented DNT oxygenase, which has been previously reported in the transformation of 2,4-DNT. Thus, unidentified novel enzymes in these strains are involved in 2,4-DNT transformation. Genes encoding enzymes homologous to the previously reported TNT and PETN-transforming enzymes were identified in both genomes. R. planticola M30b have homologous genes of PETN reductase and xenobiotic reductase B, while R. radiobacter M109c have homologous genes to GTN reductase and PnrA nitroreductase. The ability of these strains to transform explosive mixtures has a potentially biotechnological application in the bioremediation of contaminated environments. [ABSTRACT FROM AUTHOR]

The development of an optochemical sensor for colorimetric determination of trinitrotoluene (TNT) from aqueous samples is described. The optode film was formed based on the immobilization of trioctylmethylammonium chloride (Aliquat 336) on a triacetylcellulose membrane, which acts as a fixed carrier and anion‐exchanger. When the colorless and transparent optochemical sensor are employed in TNT solution samples, a red‐orange color with maximum absorption wavelength at 530 nm develops in consequence of formation of TNT‐Aliquat 336 ion pair in the sensor membrane. The optical response of this optode is being proportional to concentration of TNT in aqueous solution. Various experimental parameters such as pH, optode composition, response time and reversibility have been studied and optimized. The analytical performance of the optode was evaluated, obtaining a linear response over the range of 1.0 to 16.0 mg/L, a limit of detection of 0.14 mg/L, good reproducibility and selectivity. The sensor was seen to exhibit a fully reversible response. The developed optode in the present work was applied to the determination of TNT in water and soil samples with satisfactory results. [ABSTRACT FROM AUTHOR]

There is great interest in detection of the level of 2,4,6-trinitrotoluene (TNT) explosive due to its importance in public security and environmental protection fields. The conventional chemical sensors do not simultaneously realize simple, rapid, sensitive, selective, and direct detection of TNT in different medium without sample pretreatment. Here we present a modified wood-based chemical sensor for visual colorimetric detection of TNT in water, air, and soil. The natural wood undergoes a delignified process, which is further functionalized by 3-aminopropyltriethoxysilane (APTES). When TNT solutions are introduced, the wood-based sensor shows a colorimetric transition from light yellow to brown for naked-eye readout because of the generation of Meisenheimer complex between APTES and TNT. The photographs are collected by smartphone camera, and the RGB components are extracted to calculate the adjusted intensity for qualitative detection of TNT. This visual colorimetric sensor for TNT solution displays a linearity in the range of 0.01–5 mM with a limit of detection of 3 μM. In addition, by taking advantage of its inherent mesostructure, the wood-based sensor can be employed for visual detection of TNT vapor as well. Furthermore, it is also able to directly detect TNT in wet soil samples based on capillary action, in which TNT carried by water transports upward along the wood microchannel, triggering the generation of Meisenheimer complex. [ABSTRACT FROM AUTHOR]

[Display omitted] • AIE-a-V as fluorescent nanoprobe exhibited robust stability and could be stored for a long time. • AIE-a-V as fluorescent nanoprobe could quickly and sensitively detect TNT in water. • AIE-a-V as fluorescent nanoprobe could selectively detect TNT in water. Trinitrotoluene (TNT) in water will damage biological tissues and organs of the human body due to its high toxicity and risk. However, the simple and rapid detection of TNT in water is always a challenging task. Herein, we reported a novel aggregation-induced emission-a vesicle (AIE-a-V) as fluorescent nanoprobe for the detection of TNT in water by π-π self-assembly of π-π stacking induced aggregation-emission. The AIE-a-V was spherical in shape with a hydrodynamic diameter of ∼106 nm and possessed robust stability. In addition, the AIE-a-V showed strong fluorescence and its fluorescence would quickly disappear after contact with TNT. Based on this, without any cumbersome operation, the AIE-a-V could detect the presence of TNT in water within 60 s, and its minimum detectable concentration was as low as 50 nM. Moreover, the AIE-a-V could selectively detect TNT in water and would not be affected by other components, including other aromatic compounds, toxic metals, and acid-base. Therefore, the new AIE-a-V with simplicity, rapidity, sensitivity and selectivity have great application potential in the detection of TNT in water. [ABSTRACT FROM AUTHOR]

2,4,6-Trinitrotoluene (TNT) production processes generate a substantial amount of toxic wastewater. Therefore, it is crucial to identify efficient and sustainable methods for treating this wastewater. This paper explores the application of sustainable biomass-derived carbon produced from rice straw for the adsorption of 2,4,6-trinitrotoluene (TNT) red water. The rice straw-derived biochar (SBC) materials were synthesized by two-step reactions through hydrothermal carbonization and chemical activation with KOH. Characterization of the fabricated biochar was conducted using various techniques. Here, the chemical oxygen demand (COD) was used as an evaluation index for adsorption efficiency. The adsorption kinetics showed a good fit with the pseudo-second-order model, and the adsorption equilibrium was achieved in 30 min. The biochar's high surface area (1319 m 2 /g) and large pore volume (1.058 cm 3 /g) gave it a large adsorption capacity. The Langmuir model exhibited better correlation for equilibrium data analysis, with a maximum adsorption capacity of 173.9 mg/g at 298 K. The SBC was found to have a high removal effect over a wide pH range (from 1 to 13) and showed remarkable stability after undergoing five desorption-adsorption cycles using ethanol and acetone as eluent. The results provide a simple and low-cost method for the efficient treatment of TNT red water., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

To determine the amount of the explosives 1,3-dinitrobenzene, 2,4-dinitrotoluene, 2,4,6-trinitrotoluene, and its metabolites in marine samples, a toolbox of methods was developed to enhance sample preparation and analysis of various types of marine samples, such as water, sediment, and different kinds of biota. To achieve this, established methods were adapted, improved, and combined. As a result, if explosive concentrations in sediment or mussel samples are greater than 10 ng per g, direct extraction allows for time-saving sample preparation; if concentrations are below 10 ng per g, techniques such as freeze-drying, ultrasonic, and solid-phase extraction can help to detect even picogram amounts. Two different GC-MS/MS methods were developed to enable the detection of these explosives in femtogram per microliter. With a splitless injector, limits of detection (LODs) between 77 and 333 fg/µL could be achieved in only 6.25 min. With the 5 µL programmable temperature vaporization—large volume method (PTV-LVI), LODs between 8 and 47 fg/µL could be achieved in less than 7 min. The detection limits achieved by these methods are among the lowest published to date. Their reliability has been tested and confirmed by measuring large and diverse sample sets.

Unwanted compounds in 2,4,6-trinitrotoluene (TNT) explosive, such as dinitrotoluene (DNT) and TNT isomers, can lead to exudation defects in the ammunition. For this reason, separation and analysis of impurities are valuable. Chemical treatment with sulfite solution is an important method for the purification of TNT. In this paper, TNT was purified by sodium sulfite solution with putting flaked TNT in digestion condition to remove existing impurities, and the effect of four main factors, digestion temperature, digestion time, concentration of sulfite solution and reaction time of sulfite with impurities on this purification process, was statistically investigated and optimized using central composite design of experiment (CCD) by Minitab software. Also, the qualification of final product was characterized by gas chromatography–electron capture detector method. Here, some conventional compounds such as 2,6-DNT, 2,4-DNT, 3,4-DNT, 2,4,5-TNT (γ-TNT), 2,3,4-TNT (β-TNT) and aniline derivatives were identified by standard solutions; then their concentrations were quantitatively determined by internal standard calibration method. [ABSTRACT FROM AUTHOR]

We present sub‐ppt level detection of explosive trinitrotoluene by constructing a fast‐response electrochemical sensor using nitrogenized porous carbon spheres (NPCS). NPCS with nitrogen doping and amino functionalization accelerates charge transfer and trinitrotoluene accumulation. A high sensitivity of 60.2 μA cm−2 ppb−1 and a detection limit of 0.15 ppb are achieved on NPCS, among the best of recently reported trinitrotoluene electrochemical sensors. Moreover, response time of NPCS is greatly reduced by two times comparing with nitrogen‐free sample. NPCS also offers high selectivity, repeatability and stability, rendering new opportunities to fast detect trinitrotoluene for home security and environment protection. [ABSTRACT FROM AUTHOR]

In this study, bacterial strains that can use TNT as a nitrogen source isolated from TNT contaminated pink water. We isolated 5 bacterial strains and the isolated bacteria were cultured in medium containing TNT and TNT degradation capacities of isolates were determined by spectrophotometric analysis. According to the results of the analysis that have done, 3 bacterial isolates that have high TNT degradation capacity were selected and the isolates were identified with firstly Gram-staining then with 16S rRNA sequence analysis method. According to the sequence of 16S rRNA, water isolates were identified as Stenotrophomonas maltophilia (SU K2), Klebsiella pneumoniae (SU K3), Raoultella planticola (SU K4). During the TNT degradation studies, at the end of 24 h incubation time, in the medium containing 100 mg/L TNT, TNT degradation rate for SU K2, SU K3 and SU K4 were determined 70%, 96% and 93% respectively. 4-aminodinitrotoluene and 2-aminodinitrotoluene accumulations were detected in the culture medium of all isolates as intermediate products formed during the degradation of TNT by HPLC analysis. Additionally, nitrite accumulation was detected in the culture medium of all isolates and the influence of temperature and pH on the degradation of TNT was also investigated. It was determined that SU K2 isolates have the highest TNT degradation capacity at 35 °C, the others have at 30 °C and all isolates degraded TNT fastest at pH 7. The results of the study show that the new isolates can be useful for the removal of TNT in a wastewater treatment system. [ABSTRACT FROM AUTHOR]

We demonstrate deep ultraviolet (UV) photoacoustic spectroscopy (PAS) of trace explosives using a sensitive microphone at meter standoff distances. We directly detect 10 μg/cm2 of pentaerythritol tetranitrate (PETN), 2,4,6-trinitrotoluene (TNT), and ammonium nitrate (AN) with 1 s accumulations from a 3m standoff distance. Large PAS signals for standoff detection are achieved by exciting into the absorption bands of the explosives with a 213 nm laser. We also investigate the impact of the deep UV photochemistry of AN on the PAS signal strength and stability. We find that production of gaseous species during photolysis of AN enhances the PAS signal strength. This deep UV photochemistry can, however, limit the PAS signal lifetimes when detecting trace quantities. [ABSTRACT FROM AUTHOR]

Here, a spectroscopic investigation of the interaction between bovine serum albumin protein and thioglycolic acid capped cadmium selenide (CdSe) quantum dots is presented. Luminescent water-soluble CdSe quantum dots were synthesized at room temperature by a one-step proctocol. Selenium powder and thioglycolic acid were used as the precursor and stabilizer, respectively. The synthesized thioglycolic acid capped CdSe quantum dots were activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide treatment and conjugated with bovine serum albumin protein. The fluorescence signal of CdSe quantum dots was enhanced proportionally with the bovine serum albumin concentration from 0.25 to 5 µg/mL. This nano-bioconjugate was employed for the determination of trinitrotoluene with a detection limit of 5.65 ppm trinitrotoluene across a linear range of 4.4 × 10−6 M to 35.2 × 10−6 M. [ABSTRACT FROM AUTHOR]

Abstract In Aerodynamic Breakup Droplet ionization (ABDI) mass spectrometry the dimer/monomer (I 2 /I 1) and trimer/dimer (I 3 /I 2) ratios are considered for compounds ionized in various ways. The following test compounds were selected: morphine (gives protonated ion, (M+H)+); hexogen, RDX (forms adducts with anion of chlorine or nitrate ion); and trinitrotoluene, TNT (gives deprotonated ion, (M-H)-). The test compounds were dissolved in water, acetonitrile or ethanol. It is shown that in the ABDI mass spectra of a number of compounds (protonated morphine ions in water and RDX adducts with chlorine in acetonitrile), the ratios I 2 /I 1 and I 3 /I 2 linearly depend on the analyte concentration in the solution. This is evident throughout the range of measured concentrations, when monomers and dimers are simultaneously visible in the mass spectrum. The phenomenon can be roughly explained by the dimerization of analyte molecules in singly charged parent drops during ABDI ionization. The linearity of the I 2 /I 1 and I 3 /I 2 on the concentration can be used for estimation of the analyte concentration in a sample without using an internal or external standard. This can be useful for routine analysis when standards are not commercially available or very expensive. Graphical abstract fx1 Highlights • Semi-quantitative analysis using Aerodynamic Breakup Droplet ionization is shown. • Compounds, ionized in various ways are considered. • Linear dimer/monomer, trimer/dimer ratios are shown for a number of compounds. [ABSTRACT FROM AUTHOR]

Abstract A 1:1 co-crystal of TNT and 2,6-diaminotoluene were prepared by solvent evaporation method. The structure of the co-crystal was determined via single crystal and powder X-ray diffraction techniques. The diffraction data analysis revealed that the co-crystal is mainly formed by hydrogen bonding (amino-nitro) and donor-acceptor Π-Π stacking. Besides, Hirshfeld surfaces and associated fingerprint plots of the co-crystal were examined and the results showed that the structures are stabilized by H⋯H, O⋯H, O⋯O and C⋯C (Π-Π) intermolecular interactions. The TNT: 2,6-diaminotoluene co-crystal shows significantly reduced impact sensitivity relative to pure TNT. The difference between the impact sensitivity of co-crystal and the impact sensitivity of TNT is due to having different intermolecular interactions observed in the co-crystal structure. This comprehensive study about the formation of co-crystal has resulted in alteration of vital properties including density, oxygen balance, melting point, decomposition temperature, crystal packing and detonation performance (sensitivity, velocity, pressure). The obtained results highlight that co-crystallization provides the newly discovered energetic material with attractive properties, and is an effective way to modify existing energetic material. As a consequence, the advanced and safer energetic material can be created without chemical synthesis. Graphical abstract Image 1 Highlights • Co-crystallization of Trinitrotoluene. • Structure analysis and characterization of new formed co-crystal (TNT-ATL). • Showed detonation performance of TNT-ATL co-crystal by calculation of theoretical method. • Explanation of Structure relationship with sensitivity. [ABSTRACT FROM AUTHOR]

Abstract Rapid, reliable, onsite approaches for detection trace level of trinitrotoluene (TNT) is a pressing necessity for both homeland security and environmental protection. To this end, hydrophilic amine(-NH 2) protected Au@Ag nanoparticles (NPs) were developed and fabricated as colorimetric paper sensor for delicate detection of TNT. The as-developed nanoprobe selectively reacts with TNT through classic Meisenheimer complex formation by means of charge transfer process from an electron-rich NH 2 group of β-cysteamine to an electron-deficient nitro group on TNT. Due to the absence of this particular interaction of other nitroaromatics, the proposed probe is highly selective for TNT detection with a better linear range (0–20 μg/mL) and limit of detection (LOD) of 0.35 μg/mL. The present work provides a novel and facile strategy to fabricate colorimetric paper sensors with rapid and selective recognition ability for label free analysis of TNT. Graphical Abstract Unlabelled Image Highlights • A colorimetric paper sensor for delicate detection of TNT using Au@Ag NPs was constructed. • A very low detection limit of around 0.35 μg/mL was achieved. • It is a highly rapid and reliable approach which did not require expensive instruments. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Graphite as a sensor for identification of TNT using 1064 nm wavelength. • The PA study with respect to different weight percentage of graphite in TNT matrix. • Identification of acoustic and optical phonons waves transfer mechanism between GP and TNT using 785 nm wavelength. • Development of a new tool for detection and identification of explosive molecules using commercially available laser systems. Abstract The optical phonon waves transfer mechanism between pure graphite (GP) and trinitrotoluene (TNT) using 1064 nm as an excitation wavelength based on the double resonant Raman effect and the pulsed photoacoustic (PA) technique has been investigated. The study was carried out at a different weight percentage of GP within TNT with respect to the two excitation wavelengths of 532 nm and 1064 nm (30 ps, 10 Hz, Q-switched Nd: YAG laser). The equal and double proportional matrix of the GP and TNT (solid samples) generate a strong PA signal with high quality factor (Q-factor) due to the interaction of optical phonons of GP and TNT in the same phase. The Raman spectra, recorded at 785 nm wavelength provides an insight on the pi-electron coupling between the GP and TNT. The obtained experimental results confirm that the pure GP and its derivatives, which have a SP2/SP3 hybridization, can be used to develop a new sensing optode for the detection and identification of explosive molecules in the visible and near-IR wavelengths range. [ABSTRACT FROM AUTHOR]

A 1:1 co-crystals of Picric Acid with 1-Bromopyrene and TNT with 1-Bromopyrene were prepared by a solvent evaporation method, and the structure of the co-crystals were determined by single-crystal and powder X-ray diffraction, Mass spectrometry, Infrared spectroscopy techniques. The diffraction data analysis revealed that the co-crystals are primarily formed through donor-acceptor π…π stacking interactions. The TNT:1-Bromopyrene and Picric Acid:1-Bromopyrene co-crystals indicates significantly reduced impact sensitivity relative to pure TNT, Picric Acid. A detailed study of the cocrystals formed reveals a modification of crucial properties including density, oxygen balance, melting point, decomposition temperature detonation performance (velocity, pressure). The acquired results highlight that co-crystallization provides the newly discovered energetic material with attractive properties, and is an effective way to alter existing energetic material. [ABSTRACT FROM AUTHOR]

Abstract: The review covers the strategies for the biodegradation of a dangerous pollutant of the environment, an explosive 2,4,6-trinitrotoluene. The characteristics of the metabolism of this compound in microorganisms under aerobic and anaerobic conditions and the main enzymes involved in the transformation are described. The main class of enzymes involved in the destruction of trinitrotoluene are nitroreductases; oxidases, hydrogenases, and peroxidases may also be involved in degradation. Several approaches to the biodegradation of trinitrotoluene in the environment have been singled out and discussed: bioaugmentation of the biomass of TNT-destructor strains and consortia of microorganisms that degrade this compound; stimulation of the autochthonous microflora of polluted natural environments via the introduction of additional substrates for microorganism growth and electron donors for the reduction of trinitrotoluene; pollutant biodegradation by immobilized cells of microorganisms in bioreactors and biofilters; phytoremediation and the application of preventive measures consisting of the introduction of spores and lyophilisates of bacteria with biodegradation activity in a mixture containing nitroaromatic compounds. [ABSTRACT FROM AUTHOR]

• New energetic compounds formed between picric acid, trinitrotoluene and acridine. • Structure analysis and characterization of trinitrotoluene:acridine and picric acid, acridine. • Covalent and noncovalent interactions in crystal engineering. • Visual analysis of short contacts was achieved through Hirshfeld surface analysis and associated fingerprint plots. • DFT studies were executed to investigate the frontier orbital energies, non-covalent interactions, and electrostatic potential maps. Trinitrotoluene (TNT) and picric acid (PIC) suffer from suboptimal thermal and impact sensitivities, which severely hinder their real-world use. We here demonstrate how co-crystallization with acridine (ACR) can improve these properties of TNT and PIC without detrimentally affecting their explosive performance. Remarkably, while PIC:ACR formed readily, attempts to co-crystallise TNT with ACR led to formation of new covalent bonds between the co-formers, thereby creating a new molecular entity. The structure and energetic behaviour of both novel solid forms (PIC:ACR and TNT-ACR) were characterised using a range of experimental and computational tools, indicating that both materials have improved thermal and mechanical stability but explosive performance has decreased to some extent. These findings will increase the likelihood of rational energetic material design in the future and open a new chapter in this discipline. [ABSTRACT FROM AUTHOR]

Coastal marine environments are contaminated globally with a vast quantity of unexploded ordnance and munitions from intentional disposal. These munitions contain organic explosive compounds as well as a variety of metals, and represent point sources of chemical pollution to marine waters. Most underwater munitions originate from World Wars at the beginning of the twentieth century, and metal munitions housings have been impacted by extensive corrosion over the course of the following decades. As a result, the risk of munitions-related contaminant release to the water column is increasing. The behavior of munitions compounds is well-characterized in terrestrial systems and groundwater, but is only poorly understood in marine systems. Organic explosive compounds, primarily nitroaromatics and nitramines, can be degraded or transformed by a variety of biotic and abiotic mechanisms. These reaction products exhibit a range in biogeochemical characteristics such as sorption by particles and sediments, and variable environmental behavior as a result. The reaction products often exhibit increased toxicity to biological receptors and geochemical controls like sorption can limit this exposure. Environmental samples typically show low concentrations of munitions compounds in water and sediments (on the order of ng/L and μg/kg, respectively), and ecological risk appears generally low. Nonetheless, recent work demonstrates the possibility of sub-lethal genetic and metabolic effects. This review evaluates the state of knowledge on the occurrence, fate, and effect of munition-related chemical contaminants in the marine environment. There remain a number of knowledge gaps that limit our understanding of munitions-related contaminant spread and effect, and the need for additional work is made all the more urgent by increasing risk of release to the environment.