TNT Concentration Research Articles

Intermittent anaerobic-aerobic biopiling for remediating energetic compound-contaminated soils

Demolishing obsolete ammunition and live fire training, along with other military activities, contaminated military sites with energetic compounds (ECs), are raising human concerns. Biopiling is a green and sustainable technology for soil remediation due to its low cost and minimal secondary pollution. This study investigated the effects of various bio-stimulants in enhancing intermittent anaerobic-aerobic biopiling for ECs degradation in soil. The results showed that intermittent anaerobic-aerobic biopiling with municipal sludge, livestock and poultry manure, and agricultural and forestry wastes degraded 93.7 % 2,4,6-trinitrotoluene (TNT), 79.5 % hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and 92.0 % octahydro-1,3,5,7-tetranitro −1,3,5,7-tetrazocine (HMX) in 15 days. Correlation analysis of the energetic compounds showed that the TNT concentration and its reduction products changed conversely under anaerobic conditions, indicating a faster TNT reduction. Analysis based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database revealed an increase in the abundance of genes (nemA &porA) associated with nitrotoluene reduction. This study demonstrated that bio-stimulants composed of a mixture of municipal sludge, manure, and soil conditioner (SLA) could improve the physicochemical properties of the biopiling system and the microbial community structure, promoting the growth of Firmicutes that respond for the degradation of energetic compounds, including the influence of functional genes for TNT degradation.

Spatial structure and biodiversity of macrofauna around marine munition dumpsites – A case study from the Baltic Sea

Coastal German waters contain about 1.6 million tons of dumped munition, mostly left after World Wars. This study investigated the benthic macrofauna around the ‘Kolberger Heide’ munition dumpsite (Baltic Sea). A total of 93 macrofauna grab samples were obtained in the proximity of the munition dumpsite and in reference areas. Environmental variables analysed included the latitude/longitude, depth, terrain ruggedness, sediment grainsize distribution, TNT concentration in the bottom water and distance to the centre of munition dumpsite. The overall abundance, biomass and diversity varied among these groups, though demonstrated no clear differences regarding the proximity to munition and modelled near-bottom dissolved TNT. Among individual taxa, however, a total of 16 species demonstrated significant correlation with TNT concentration. Moreover, TNT may serve as a predictor for the distribution of three species: molluscs Retusa truncatula, Varicorbula gibba and polychaete Spio goniocephala. Possible reasons for the species distribution including their biological traits are discussed.

Investigating the Potential of Fusarium solani and Phanerochaete chrysosporium in the Removal of 2,4,6-TNT.

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 100mg/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 100mg/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.

Sensitive and selective impedimetric determination of TNT using RSM-CCD optimization

Detection of trace amounts of 2,4,6-Trinitrotoluene as a widely used explosive in the military and industrial sectors is of vital importance due to security and environmental concerns. The sensitive and selective measurement characteristics of the compound still is considered a challenge for analytical chemists. Unlike conventional optical and electrochemical methods, the electrochemical impedance spectroscopy technique (EIS), has a very high sensitivity, but it faces a significant challenge in that it requires complex and expensive steps to modify the electrode surface with selective agents. We reported the design and construction of an inexpensive, simple, sensitive, and selective impedimetric electrochemical TNT sensor based on the formation of a Meisenheimer complex between magnetic multiwalled carbon nanotubes modified with aminopropyl triethoxysilane (MMWCNTs @ APTES) and TNT. The formation of the mentioned charge transfer complex at the electrode-solution interface blocks the electrode surface and disrupts the charge transfer in [(Fe (CN) 6)] 3−/4- redox probe system. Charge transfer resistance changes (ΔRCT) were used as an analytical response that corresponded to TNT concentration. To investigate the influence of effective parameters on the electrode response, such as pH, contact time, and modifier percentage, the response surface methodology based on central composite design (RSM-CCD) was used. The calibration curve was achieved in the range of 1–500 nM with a detection limit of 0.15 nM under optimal conditions, which included pH of 8.29, contact time of 479 s, and modifier percentage of 12.38% (w/w). The selectivity of the constructed electrode towards several nitroaromatic species was investigated, and no significant interference was found. Finally, the proposed sensor was able to successfully measure TNT in various water samples with satisfactory recovery percentages.

Efficient adsorption of trinitrotoluene by isoxazoline‐based porous polymers prepared from room‐temperature stable bis(nitrile oxide)

AbstractA novel isoxazoline‐based porous adsorbent (PB‐TTNO) is prepared by click polymerization and freeze‐drying from a methyl‐containing bis(nitrile oxide) stable at room temperature. The introduction of four methyl groups around the nitrile oxide group reduces the activity of the bis(nitrile oxide) and make it react more mildly with polybutadiene, resulting in PB‐TTNO with a more uniform pore size. Meanwhile, the electron‐donating methyl groups further increase the π–π interaction between the polymer benzene ring and the TNT benzene ring. The π–π interaction enables one benzene ring in the polymer to interact with two TNT molecules to form a sandwich structure, which further improves the adsorption capacity. The synergistic effect of dual π–π interactions and dipole‐π interactions makes the maximum adsorption capacity of PB‐TTNO reach 235.3 mg g−1 within 12 h at 25°C. The factors such as pH value, adsorbent dosage, contact time, initial TNT concentration, and temperature are also discussed. The adsorption kinetics fit well with the pseudo‐second‐order model, and the Langmuir model exhibits better correlation for equilibrium data analysis. In addition, the adsorption data of PB‐TTNO in real water samples are similar to those in laboratory, and the maximum adsorption capacity decreases by only 15% after five adsorption–desorption cycles.

A flow-drop electrochemiluminescent design for portable detection of soil and skin 2,4,6-trinitrotoluene

An automatic miniaturized flow-drop electrochemiluminescence (ECL) technique was established by utilizing a coalescing drop as a wall-less electrolytic cell, a self-driven mixer, and a µL scale reactor. Cost-effective ECL detection of 2,4,6-trinitrotoluene (TNT) was proposed, by virtue of the finding of the enhancement on luminol ECL by trace TNT in alkaline aqueous medium. The mechanism of TNT intensifying luminol ECL was suggested as that the one-electron reduction of TNT yielded TNT anion radical converts dissolved oxygen into superoxide anion radical, which subsequently reacted with luminol to produce luminol anion radical, finally resulting in the acceleration of luminol oxidation. By optimizing all the experimental conditions, the intensified ECL was found to be linear to TNT concentration over the 5–100 nM range, with a limit of detection of 0.5 nM. The method’s precision and accuracy were examined via F and t tests. The feasibility of this portable ECL method was validated by determining unknown TNT contents in real soil and finger skin samples via parallel official method. All results support the technique as a robust alternative for on-site TNT detection for environmental and forensic purposes.

Smartphone-Assisted Sensing of Trinitrotoluene by Optical Array.

Here we report the design and fabrication of an array-based sensor, containing functionalized Carbon Dots, Bodipy’s and Naphthalimide probes, that shows high fluorescence emissions and sensitivity in the presence of low amounts of TNT explosive. In particular, we have fabricated the first sensor device based on an optical array for the detection of TNT in real samples by using a smartphone as detector. The possibility to use a common smartphone as detector leads to a prototype that can be also used in a real-life field application. The key benefit lies in the possibility of even a nonspecialist operator in the field to simply collect and send data (photos) to the trained artificial intelligence server for rapid diagnosis but also directly to the bomb disposal unit for expert evaluation. This new array sensor contains seven different fluorescent probes that are able to interact via noncovalent interactions with TNT. The interaction of each probe with TNT has been tested in solution by fluorescence titrations. The solid device has been tested in terms of selectivity and linearity toward TNT concentration. Tests performed with other explosives and other nitrogen-based analytes demonstrate the high selectivity for TNT molecules, thus supporting the reliability of this sensor. In addition, TNT can be detected in the range of 98 ng∼985 μg, with a clear different response of each probe to the different amounts of TNT.

Improved colorimetric detection of 2,4,6‑trinitrotoluene through γ-cyclodextrin complexation

Simple and convenient detection of 2,4,6‑trinitrotoluene (TNT) explosive is of great importance for public security and environmental protection. Herein we report the fabrication of a supramolecular visual colorimetric assay for TNT based on γ-cyclodextrin (γ-CD) molecular container. The hydrophobic cavity of γ-CD can encapsulate the hydrophobic TNT molecular because the molecular size of TNT is smaller than that of γ-CD. The γ-CD-TNT inclusion complex can react with NaOH to generate colored Meisenheimer complexes with enhanced absorption capacity, enabling highly sensitive colorimetric detection of TNT. Under optimal experimental parameters, the present visual colorimetric method displays a linear dynamic range of 0–200 μM with a detection limit of 0.8 μM, which shows 2-fold enhancement in the sensitivity compared with the γ-CD-free detection system. When the TNT concentration reaches 10 μM, it is discernible by the naked eye. Moreover, this assay is highly selective to TNT and applied for real water and soil samples. The spiked recoveries vary from 91.5% to 100%, demonstrating the potential practical applications.

Bacillus pumilus proteome changes in response to 2,4,6-trinitrotoluene-induced stress.

2,4,6-Trinitrotoluene (TNT) is the most widely used nitroaromatic compound and is highly resistant to degradation. Most aerobic microorganisms reduce TNT to amino derivatives via formation of nitroso- and hydroxylamine intermediates. Although pathways of TNT degradation are well studied, proteomic analysis of TNT-degrading bacteria was done only for some individual Gram-negative strains. Here, we isolated a Gram-positive strain from TNT-contaminated soil, identified it as Bacillus pumilus using 16S rRNA sequencing, analyzed its growth, the level of TNT transformation, ROS production, and revealed for the first time the bacillary proteome changes at toxic concentration of TNT. The transformation of TNT at all studied concentrations (20-200mg/L) followed the path of nitro groups reduction with the formation of 4-amino-2,6-dinitrotoluene. Hydrogen peroxide production was detected during TNT transformation. Comparative proteomic analysis of B. pumilus showed that TNT (200mg/L) inhibited expression of 46 and induced expression of 24 proteins. Among TNT upregulated proteins are those which are responsible for the reductive pathway of xenobiotic transformation, removal of oxidative stress, DNA repair, degradation of RNA and cellular proteins. The production of ribosomal proteins, some important metabolic proteins and proteins involved in cell division are downregulated by this xenobiotic.

2,4,6-trinitrotoluene (TNT) degradation by Indiicoccus explosivorum (S5-TSA-19).

2,4,6-trinitrotoluene (TNT), a nitro-aromatic explosive commonly used for defense and several non-violent applications is contributing to serious environmental pollution problems including human health. The current study investigated the remediation potential of a native soil isolate, i.e., Indiicoccus explosivorum (strain S5-TSA-19) isolated from collected samples of an explosive manufacturing site, against TNT. The survivability of I. explosivorum against explosives is indirectly justified through its isolation; thus, it is being chosen for further study. At a TNT concentration of 120mg/L within an optimized environment (i.e., at 30°C and 120rpm), the isolate was continually incubated for 30days in a minimal salt medium (MSM). The proliferation of the isolate and the concentration of TNT, nitrate, nitrite, and ammonium ion were evaluated at a particular time during the experiment. Within 168h (i.e., 7days) of incubation, I. explosivorum co-metabolically degraded 100% TNT. The biodegradation procedure succeeded the first-order kinetics mechanism. Formations of additional metabolites like 2,4-dinitrotoluene (DNT), 2,4-diamino-6-nitrotoluene (2-DANT), and 2-amino-4,6-dinitrotoluene (2-ADNT), were also witnessed. TNT seems to be non-toxic for the isolate, as it reproduced admirably in TNT presence. To date, it is the first report of Indiicoccus explosivorum, efficiently bio-remediating TNT, i.e., a nitro-aromatic compound via different degradation pathways, leading to the production of simpler as well as less harmful end products. Further, at the field-scale application, Indiicoccus explosivorum may be explored for the bioremediation of TNT (i.e., a nitro-aromatic compound)-contaminated effluents.

Predictors of unfavourable outcome in clinically stable, low risk acute pulmonary embolism patients (sPESI 0)

Abstract Introduction Nowadays one of the most challenging tasks is to identify, within the large group of normotensive and clinically stable acute pulmonary embolism (APE) patients, those who are at “sufficiently low” risk to permit early discharge and home treatment. Current ESC guidelines suggest, that troponin measurement is optional in sPESI 0 patients. Aim The aim of this study was to assess whether right ventricular dysfunction (RVD) in transthoracic echocardiographic examination (TTE) and/or elevated plasma troponin level improves in-hospital risk stratification in sPESI 0 patients. Methods Post-hoc analysis of a prospective study of 1191 patients with at least segmental APE confirmed in computed tomography (CT). Among this group 434 patients (208 F, age median = 52 yrs [39; 67]) were classified to low risk group according to sPESI. TTE and TnT concentration were assessed within the first 24-hours from admission. Echocardiographic criteria for RVD were RV/LV ratio≥1 or tricuspid regurgitant pressure gradient ≥31 mmHg. The sPESI score was calculated from patient records. The combined endpoint (CE) included in-hospital death of any cause and/or haemodynamic deterioration requiring catecholamines i.v., rescue thrombolysis, cardio-pulmonary resuscitation, cardiac surgical intervention or percutaneous catheter-directed treatment. Results Among 434 sPESI 0 patients, cardiac troponin plasma level was assessed in 409 individuals, 136 results were above the normal limit. CE occurred in 6 patients with elevated and 0 with non-elevated troponin concentration (p=0,0013). In 253 cases high-sensitive troponin (hsTnT) assays were used. Median hsTnT concentration was significantly higher in patients with CE (0,032 ng/ml [0,024; 0,127] vs 0,09 ng/ml [0; 0,025]) SPESI and hsTnT assessment showed AUC ROC=0.834 (0.727–0,941; p=0.000) for the CE with suggested threshold 0,024 ng/ml (Fig. 1). Interestingly, no statistically significant differences in RV/LV ratio or TRPG between CE and non-CE group were observed. Furthermore, CE did not occur more often in patients with RVD (7 vs 1; p=0,067). Conclusion SPESI combined with normal cardiac troponin plasma concentration may be used for predicting favourable outcome in patients with APE and thus select candidates for home treatment. We suggest to assess plasma troponin levels in all normotensive patients early, before discharge to home treatment. However, due to relatively low number of endpoints, these findings need to be confirmed in further studies enrolling more patients. Funding Acknowledgement Type of funding sources: None. Figure 1. hsTnT ROC

Degradation of 2, 4, 6-trinitrotoluene (TNT) from aqueous solution by coupled electrocoagulation process with persulfate salt.

The 2, 4, 6-trinitrotoluene (TNT) is the major explosive extensively applied in demolition of structure, military activity, and mining industry. This research was investigating the degradation rate of TNT in aqueous solution using electrochemical combined with persulfate anions. In this study, the effect of seven independent variables including pH, reaction time, current density, type (NaCl, Na2SO4, NaNO3) and concentration of salts, initial concentration of TNT, scavenger type, and persulfate concentration were studied on TNT removal. High performance liquid chromatography (HPLC) was applied to measure TNT concentration. The findings indicated that the optimum conditions for TNT reduction were pH = 5, time = 45min, current density = 1.75mA/cm2, initial concentration of TNT = 25mg/l, persulfate concentration = 0.3mg/l, and Na2SO4 concentration = 1.75mg/l which the removal rate of TNT was found to be 88.0 ± 4.4%. According to the findings, electrocoagulation procedure is suggested as an applicable method in TNT reduction from aqueous solution.

TNT sensor based on accumulation layer and effective distance of FRET mechanism with ultra-high sensitivity

Common methods of 2,4,6-trinitrotoluene (TNT) detection are based on direct detection to the concentration of TNT. If TNT can be accumulated first to increase partial concentration near the sensor and detected by sensing materials then, the detection performance can be significantly improved. As we know, fluorescence resonance energy transfer (FRET) is widely used as the sensing mechanism in TNT detection, which has an effective range of 10 nm. Based on this, we built an accumulation layer between sensing materials and TNT within effective range of FRET, where exists a large quantity of amino groups. The Amino groups can adsorb TNT and realize accumulation function. The accumulation and sensing layer played different roles in the detection of TNT based on distinct mechanism. Accumulation layer was realized by forming Meisenheimer complex between TNT and amino groups while sensing layer was realized by FRET. Via both two layers and mechanisms, the sensors achieved ultra-high sensitivity to TNT, with a limit of detection (LOD) of 0.6 nM and a linear range of 1–20 nM. Compared with pure graphene quantum dots (GQDs), the KSV of sensor in this work to TNT increased for about 14 times. The accumulation-detection path provides an effective method for the measurement of TNT with ultra-low concentration.

Voltammetric Detection of Explosives in Wet Environments with Ionic Liquids and Ionogels

2,4,6-Trinitrotoluene (TNT) is an explosive compound commonly used for industrial, military, as well as mining applications. It is also used by terrorists in homemade explosives, due to its insensitivity to shock and friction compared to other high explosives such as nitroglycerin. At mining sites where TNT is used for land clearing, if not completely removed after detonation, TNT and its reduction products may contaminate ground water and rivers — which is an environmental issue since they are known to be toxic and carcinogenic to humans. The development of sensors for explosives such as TNT is therefore of huge interest due to the wide range of security and environmental concerns. In recent years, room temperature ionic liquids (RTILs) have been investigated as a replacement solvent in sensors1 due to their favourable properties including wide electrochemical windows, intrinsic conductivity, high chemical and physical stability, and the ability to dissolve a wide range of analytes. However, RTILs are liquid and tend to flow, which makes the sensor not sufficiently robust for portable applications due to electrolyte spillage. To overcome this, we have mixed a RTIL with a cheap and widely available methacrylate polymer to produce a non-flowing ionogel, which we refer to as a gel polymer electrolyte (GPE).2 It was observed that the electrochemical signal in the GPE was significantly less affected in humid environments compared to the neat RTIL, where water molecules can act as proton donors, altering the mechanism of electrochemical reactions leading to sensor instability.2 Notably, the voltammetry of TNT in a hydrophobic RTIL was found to be unaffected by the presence of oxygen, which allows for selectivity over oxygen and moisture for the detection of TNT in real environments.4 With the choice of a hydrophobic RTIL/polymer mixture and the use of a cheap commercially available thin-film electrode, we have developed a new electrochemical system that enables direct detection and quantification of TNT in aqueous solutions (see Figure 1).3 The RTIL acts to preconcentrate TNT into the GPE and provides ionic conductivity, while the hydrophobic polymer serves to increase viscosity to ensure mechanical stability of the GPE while immersed in water, in addition to blocking water from reaching the electrode surface. Using square wave voltammetry, linear plots of peak current vs. concentration of TNT were obtained, and the sensor device was able to quickly and easily quantify TNT concentrations at typical ground water contamination levels via. liquid/liquid extraction mechanism. The low-cost and portability of the sensor device, along with the minimal amounts of GPE materials required, makes this a viable platform for the onsite monitoring of explosives, which is currently a significant operational challenge. Our GPEs may further allow for rapid and easy forensic surveying and detection of explosives in real-environments with simple and portable equipment — which we are presently developing; negating the need for the samples to be transferred to a lab to be analysed with expensive bulky instruments, and the need for careful pre-processing of the samples. The ability to immediately detect explosives onsite also reduces the chances of residue decomposition and possible contamination of samples during transport.Our polymer/RTIL based materials can readily be extended to the sensing of other redox active explosive materials, and other analyte species as well. The ease of mass production and low cost of our electrode/GPE system, along with the minimal amounts of RTIL and polymer required for the GPE, make this a viable electrochemical sensing device to be applied on a bulk scale, in a wide range of environmental conditions.

\u201cDon\u2019t Blast\u201d: blast-in-place (BiP) operations of dumped World War munitions in the oceans significantly increase hazards to the environment and the human seafood consumer

The seas worldwide are threatened by a “new” source of pollution: millions of tons of all kind of warfare material have been dumped intentionally after World War I and II, in addition to mine barriers, failed detonations as well as shot down military planes and sunken ship wrecks carrying munitions. For example, in the German parts of the North and Baltic Sea approximately 1.6 million metric tons of toxic conventional explosives (TNT and others) and more than 5000 metric tons of chemical weapons are present. Such unexploded ordnance (UXO) constitutes a direct risk of detonation with increased human access (fisheries, water sports, cable constructions, wind farms and pipelines). Moreover, after more than 70 years of resting on the seabed, the metal shells of these munitions items corrode, such that chemicals leak out and distribute in the marine environment. Explosive chemicals such as TNT and its derivatives are known for their toxicity and carcinogenicity. In order not to endanger today's shipping traffic or the installation of pipelines and offshore plants by uncontrolled explosions, controlled blast-in-place (BiP) operations of these dangerous relics is a common practice worldwide. However, blast-in-place methods of in situ munitions disposal often result in incomplete (low-order) detonation, leaving substantial quantities of the explosive material in the environment. In the present free field investigation, we placed mussels (Mytilus spp.) as a biomonitoring system in an area of the Baltic Sea where BiP operations took place and where, by visual inspections by scientific divers, smaller and larger pieces of munitions-related materials were scattered on the seafloor. After recovery, the mussels were transferred to our laboratory and analyzed for TNT and its derivatives via gas chromatography and mass spectroscopy. Our data unequivocally demonstrate that low-order BiP operations of dumped munitions in the sea lead to multiple increases in the concentration of TNT and its metabolites in the mussels when compared to similar studies at corroding but still encased mines. For this reason, we explicitly criticize BiP operations because of the resulting environmental hazards, which can ultimately even endanger human seafood consumers.

Circulating miRNA 208a Reflect Early Myocardial Injury and Recovery after Heart Transplantation

Is the studied expression level of micro RNA208a a good, reliable and early marker in the diagnosis of early myocardial injury in patients who underwent heart transplantation METHODS: The study involved 45 donors, 45 patients who underwent heart transplantation. Six blood samples were tested: before heart transplant surgery - from the donor and recipient, just before the surgery and four more taken from the recipient: 1, 6, 12, 24 hours after the surgery. TnT levels were assessed at the same time intervals. Plasma was centrifuged from peripheral blood. MiR208a was determined by real-time PCR using TaqMan molecular probes. Correlations between miR208a, TnT and perioperative parameters were analyzed. Spearman rank correlation and correlation for repeated measurements were used. Levels of miR208a and TnT were measured in the donor and recipient before surgery and in the control group. In the control group, in recipients and donors, no miR208a was detected in the plasma before surgery. Troponin T levels measured in donors and recipients prior to surgery were above the norm for this marker. A significant increase in miR208a levels and troponin T levels was observed as early as the first hour after surgery. The time for maximum level of miR208a and TnT levels was much shorter for miR208a - 6.8 hours, 10.5 hours for TnT. Death due to cerebrovascular disease (intracranial bleeding or ischemic stroke) and death due to craniocerebral trauma did not affect the level of miRNA. Depending on the cause of death, changes in TnT concentration were noted one hour after operation (p=0.025). The extracorporeal circulation time had a significant impact on changes in the level of miRNA already in the first hour after surgery (p<0.019). TnT showed significant changes at 6, 12, 24 hours after surgery (p<0.036, p<0.005, p<0.004). For haemodynamic evaluation of the heart, we included central venous pressure (CVP), wedge pressure (PCWP), heart index (CI) and Intropscore. MiR208a showed positive correlations with CVP, PCWP and Inotropscore, as well as negative correlations with CI. TnTshowed a correlation with CVP and Inotropscore at the only time point. current research suggests that miR208a is a new sensitive marker that reflects hemodynamic function of the heart. It can be used to monitor the work of the heart, its dysfunction and regeneration after heart transplantation.

Electrochemical determination of nitroaromatic explosives at boron-doped diamond/graphene nanowall electrodes: 2,4,6-trinitrotoluene and 2,4,6-trinitroanisole in liquid effluents

The study is devoted to the electrochemical detection of trace explosives on boron-doped diamond/graphene nanowall electrodes (B:DGNW). The electrodes were fabricated in a one-step growth process using chemical vapour deposition without any additional modifications. The electrochemical investigations were focused on the determination of the important nitroaromatic explosive compounds, 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitroanisole (TNA).The distinct reduction peaks of both studied compounds were observed regardless of the pH value of the solution. The reduction peak currents were linearly related to the concentration of TNT and TNA in the range from 0.05–15 ppm. Nevertheless, two various linear trends were observed, attributed respectively to the adsorption processes at low concentrations up to the diffusional character of detection for larger contamination levels. The limit of detection of TNT and TNA is equal to 73 ppb and 270 ppb, respectively. Moreover, the proposed detection strategy has been applied under real conditions with a significant concentration of interfering compounds – in landfill leachates.The proposed bare B:DGNW electrodes were revealed to have a high electroactive area towards the voltammetric determination of various nitroaromatic compounds with a high rate of repeatability, thus appearing to be an attractive nanocarbon surface for further applications.

Instantaneous detection of explosive and toxic nitroaromatic compounds via donor–acceptor complexation

A porous membrane-type detection platform, fabricated with a carbazole-based fluorophore, was effective even at a 1.0 ppb TNT concentration.

EXPERIMENTAL ASSESSMENT OF TOXIC EFFECTS OF TROTYL (TNT) ON SOIL MICROFLORA

An experimental assessment of the hazard of trotyl content in the soil has been carried out according to one of the most significant sanitary indicators of harm - the microbiocenosis. E. coli, micromycetes, actinomycetes and saprofitny bacteria grown up in the specific to each microflora medium were used as test organisms. It was found that the content of the toxicant in the soil at the levels of 20.0 and 10.0 mg/kg during the experiment revealed a significant growth of E. coli (up to 458.87 % relative to the control) indicating the inhibition of the process of self-purification of the soil. In addition, TNT in these concentrations contributed to a significant growth of micromycete colonies (up to 200.00%) indicating its accumulation in the soil, where fungi act as indicators (toxin accumulators). At the same time the substance at the level of 20.0 mg/kg caused inhibition of vital activity of actinomycetes reaching 50.27 %. The number of colonies of saprophytic microflora also significantly decreased in the soil mixture with the content of the chemical at the levels of 20.0 and 10.0 mg/kg. According to this type of general health hazard indicator the concentration of TNT – 10.0 mg/kg has been accepted as a threshold, and the value of 2.0 mg/kg – as inactive. The data obtained are taken into account in the subsequent development of the hygienic standard for this explosive compound.

TREATMENT OF WASTEWATER CONTAINING AROMATIC NITRO COMPOUNDS USING THE A2O-MBBR METHOD

2,4,6-Trinitrotoluene (TNT) is widely used in explosives production. Since it is toxic and mutagenic to humans and animals, decontamination of TNT wastewater is necessary. Wastewater, containing TNT, from four factories in Vietnam producing industrial explosives were collected. The samples had different characteristics and varied widely, especially in terms of TNT concentration, depending on the technology and production management method at each plant. The TNT concentration ranged from 25 to 128 mg/l, chemical oxygen demand (COD) ranged from 128 to 650 mg/l, BOD5 ranged from 28 to 67 mg/l, NH4+ranged from 23 to 325 mg/l, T-P ranged from 0.13 to 0.38, and pH ranged from 6.5 to 8.2. In Vietnam, removal of TNT is carried out using granular activated carbon adsorption and an incineration method. This method is expensive and generates secondary pollution. To overcome these drawbacks, the combination of an anaerobic-anoxic-oxic and moving bed biofilm reactor (A2O-MBBR) for treating TNT wastewater was investigated in this study. Reaction tanks of the A2O-MBBR system were supplemented with activated sludges, from a wastewater treatment station in Chemical and Electrical Engineering Company 15, containing biological preparations of nitrifying and denitrifying bacteria. The results showed that after 30 days under operating conditions of COD of 200-250 mg/l, MSLL of 1800-3000 mg/l, and DO of 5 mg/l, COD removal efficiency reached approximately 70-83%, the TNT concentration decreased by 91-99.7% (to approximately 0.5- 2 mg/l), and the ammonium concentration fell to 15-17 mg/l (reaching 42.8–66% removal efficiency after 24 h of treatment).&#x0D; For citation:&#x0D; Nhan Vu Duy, Tu Nguyen Van, Nhan Nguyen Thi, Huong Le Mai, Tsarev Yu.V., Huong Le Thi Mai Treatment of wastewater containing aromatic nitro compounds using the A2O-MBBR method. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 113-119