• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.56-65
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• 2014

Contamination of explosive compounds in the soils of military shooting range may pose risks to human and ecosystems. As shooting ranges are located at remote places, active remediation processes with hardwares and equipments are less practical to implement than natural solutions such as bioremediaton. In this study, a series of experiments was conducted to select a suitable carbon source and to optimize dosing rate for the enhanced bioremediation of explosive compounds in surface soils and sediments of shooting ranges with indigenous microorganisms activated by external carbon source. Treatability study using slurry phase reactors showed that the presence of indigenous microbial community capable of explosive compounds degradation in the shooting range soils, and starch was a more effective carbon source than glucose and acetic acid in the removal of TNT. However, at higher starch/soil ratio, i.e., 2.0, the acute toxicity of the liquid phase increased possibly due to transformation products of TNT. RDX degradation by indigenous microorganisms was also stimulated by the addition of starch but the acute toxicity of the liquid phase decreased with the increase of starch/soil ratio. Taken together, the optimum range of starch/soil ratio for the degradation of explosive compounds without significant increase in acute toxicity was found to be 0.2 of starch/soil.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.73-84
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• 2015

Nine plant species were selected through vegetation survey at three military shooting ranges at northern Gyeonggi Province. Plants were germinated in normal soil and three seedlings were transplanted to a bottom sealed pot containing sandy loam soils contaminated with either RDX (291 mg/kg) or TNT (207 mg/kg). Planted, blank (without plant), and control (without explosive compound) pots were grown in triplicate at a green house for 134 days. During cultivation, transplanted plants exhibited chlorosis and necrosis in flower and leaf by explosive toxicity and stress. Only three plants, Wild soybean, Amur silver grass, Reed canary grass, survived in TNT treated pot, while seven plant species except for field penny cress and jimson weed, thrived in RDX treated pot. Appreciable amount of TNT (61.6~241.2 mg/g-D.W.) was detected only in plant roots. Up to 763.3 mg/g-D.W. along with 4-amino-2,6-dinitrotoluene, an intermediate of TNT, accumulated in the root of wild soybean. In addition, azoxy compounds, abiotic intermediates of TNT, were detected in TNT treated soils. RDX absorbed average 1,839.95 mg/kg in shoot and 204.83 mg/kg in root. Most of TNT in plant was accumulated in underground part whereas RDX was localized in aerial part. Material balance calculation showed that more than 95% of the initial TNT was removed in the planted pots whereas only 60% was removed in the blank pot. The amount of RDX removed from soil was in the order of Amur Silver Grass (51%) > Chickweed (43%) > Evening primrose (38%). Based on the results of pot cultures, Amur silver grass and Reed canary grass are selected as tolerant remedial plants for explosive toxicity.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.82-93
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• 2014

A starch ball was devised to conveniently supply carbon source to indigenous microorganisms and to enhance biotransformation of explosive compounds(TNT and RDX) in the sediments of settling basins installed in military shooting ranges. To identify optimum dose/sediment ratio for degradation of explosives in the basin, a series of bench scale settling basin experiments were performed for 30 days while monitoring supernatant pH, DO, concentrations of nitrite, nitrate, sulfate, explosive compounds, and acute toxicity measured by bacterial luminescence. Addition of starch ball induced changes in oxidation conditions from oxic to anoxic in the benthic zone of the basin, which resulted in subsequent reductive degradation of both TNT and RDX in the liquid and solid phase of basin. However, fermentation products of excess starch, acetic acid and formic acid, caused acute toxicity in the liquid phase. The optimum ratio of starch ball/sediment for explosive compounds degradation by inducing changes in bio-geochemical environments without increase in acute toxicity, was found to be 0.009~0.017.

• KSBB Journal
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• 제14권3호
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• pp.315-321
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• 1999

The relationships between the explosive 2,4,6-trinitrotoluene (TNT) degradation by Stenotrophomonas maltophilia and several relevant physicochemical environmental parameters were examined. At neutral pH of the cultures, the degradation of TNT proceeded to completion, whereas only about 50% of TNT was utilized when the cultures were adjusted to acidic pH. The effect of various co-substrates (e.g., glucose, fructose, acetate, citrate, succinate) on the degradation of TNT by the test culture of S. maltophilia was evaluated. The results indicated that, among the various co-substrates studies, the test culture that received 2 mM fructose degraded 100 mg/L of TNT completely within 20 days of incubation at ambient temperature, whereas partial degradation of TNT was observed in the test culture with acetate, citrate, or succinate as a co-substrate, respectively. In fact, fructose was the best co-substrate for TNT degradation in this experiment. The effect of supplemented nitrogens [e.g., (NH$_4$)$_2$,SO$_4$, NH$_4$Cl. urea] on the TNT degradation was monitored. All supplemented nitrogens in this study were inhibitory to TNT degradation. Addition of 1% Tween80 accelerated TNT degradation, and showed complete degradation of TNT within 8 days of incubation. Addition of yeast extract resulted higher growth yields, based on turbidity measurement, but it inhibited TNT degradation.

• 분석과학
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• 제28권5호
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• pp.347-352
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• 2015

밀도함수 이론을 이용하여 메틸나이트로이미다졸 유도체의 생성열, 밀도 등의 화학적 특성치들을 예측하고 분석하였다. 이미다졸 링에 나이트로기를 계속적으로 치환하면 생성열과 밀도값은 증가한다. 예측된 화학적 특성치들을 이용하여 치타 프로그램으로 화약적 성능을 분석하고, 현재 널리 사용되는 TNT, RDX, HMX 등과 비교하였다. C-J 압력과 폭발 속도 등을 사용하여 화약 성능을 분석하면 메틸다이나이트로 유도체들은 TNT 보다는 성능이 약간 우수하며, 메틸트라이나이트로이미다졸은 RDX에 거의 버금가는 수준이다. 메틸나이트로이미다졸계 화약들은 용융점이 낮아 용융 충전이 가능하다는 장점이 있으므로 군수나 민수 등 다양한 방면이 사용이 가능할 것으로 예측된다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 춘계 학술대회논문집
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• pp.1-14
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• 1998

Underwater explosion properties for TNT, an ideal explosive, and DXD-04, a nonideal explosive, were numerically modeled with a one-dimensional Lagrangian hydrodynamic code. The equation of state parameters for detonation products for TNT and DXD-04 were obtained from the BKW code, assuming complete reaction. Burn of TNT was modeled by using the Chapman-Jouguet(CJ) volume burn technique, a programmed-burn technique, assuming instantaneous detonation reaction. Burn of DXD-04 was modeled by using the same technique and by using the reaction rate calibrated from two-dimensional steady-state detonation experiments. The calculations for TNT reproduced the experimental peak pressure of the shock wave propagating through water with an error of $3.0\%$ and the experimental oscillation period of the bubble formed of detonation products with an error of $2.3\%$. For DXD-04, the CJ volume burn technique could not reproduce the experimental observations. When the reaction rate calibrated from two-dimensional steady-state detonation experimental data, the calculated peak pressure was slightly higher by $7.3\%$ than the experimental data, but the calculated shock profile was in good agreement. The bubble period was reproduced with an error of $1.8\%$. These results demonstrated that underwater explosion properties for an ideal explosive can be predicted by using a programmed burn technique, and that, however, those for a nonideal explosive can be predicted only when a well-calibrated reaction rate is used.

• 화약ㆍ발파
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• 제36권4호
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• pp.26-34
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• 2018

인화성 물질을 보유하고 있는 시설물에서 인화성 물질이 유출되어 형성된 증기운의 폭발이 국내와 해외에서 자주 발생하고 있다. 본 연구에서는 증기운 폭발에 따른 폭풍 효과를 모사하기 위해서 TNT 등가법과 다중에너지법을 적용하였다. TNT 등가법은 단순하고 직접적인 적용이 가능하기 때문에 증기운 폭발을 해석하기 위해서 지금까지 널리 사용되고 있다. 그러나 TNT 등가법은 증기운 폭발로부터 발생하는 연소에너지와 이를 TNT 등가량으로 환산하는데 필요한 적절한 상관관계를 선택하는 것이 어렵다는 근본적인 단점을 가지고 있다. 다중에너지법에서는 증기운 폭발의 강도가 증기운이 확산되는 지역에서의 확산 경로의 레이아웃에 따라 달라진다고 가정한다. 즉 증기운의 잠재적 폭발력은 혼잡지역의 혼잡정도에 따라 달라진다. 본 연구에서는 TNT 등가법과 다중에너지법의 적용성을 평가하기 위해서 Flixborough 폭발사고를 사례연구로 분석하였다. 분석 결과 TNT 등가계수와 폭발강도계수를 현장상황에 맞게 적절히 선택하는 경우 TNT 등가법과 다중에너지법은 증기운 폭발 사고를 분석하는데 적합할 것으로 예상된다.

• 한국군사과학기술학회지
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• 제8권4호
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• pp.120-129
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• 2005

To analyze a blast effect of developed explosives, three different kinds of aluminized tastable explosives and melted cast explosive TNT were used. Conventional explosive TNT was used as a reference. Each tested explosive charge of 340mm diameter spherical type was initiated at the charge center with DXD-65(${\sim}750g$) booster and RP-87 EBW detonator. Thirteen piezo type pressure sensors were located at a range from 4 to 50m away from the charge. From the blast wave profiles, we calculated a peak blast pressure and impulse of the explosion. The calculated pressures and in pulses were converted to TNT Equivalent Weight(TEW) factor by the scaling ]aw method. The average TEW factors based on the blast pressure of TX-01, TX-02, TX-03, TX-04 were 1.298, 1.05, 1.266, 1.274 and the average TEW factors based on impulse were 1.504, 1.686, 1.640, 1.679. From the results, we concluded that TEW factors based on blast pressure and based on impulse of aluminized explosives were superior to TNT. This results are owing to the high contents of aluminum in formulations.

• Advances in concrete construction
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• 제5권5호
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• pp.493-512
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• 2017

Blast loads may considerably affect the response of structures. In previous years, before computer analysis programs, the parameters of blast effects were calculated with empirical methods, consequently some researchers had proposed equations to find out the phenomenon. In recent year's computer analysis programs have developed already, so detailed solutions can be made numerically. This paper describes the blasting response of the structures using numerical and empirical methods. For the purpose, a reinforced concrete retaining wall is modelled using ANSYS Workbench software, and the model is imported to ANSYS AUTODYN software to perform explicit analyses. In AUTDYN software, a sum of TNT explosive is defined 5,5 m away from the wall and solution is done. Numerical results are compared with those of obtained from empirical equations. Similar study is also considered for equal explosive which is the 4 m away from the wall. The results are represented by graphics and contour diagrams of such as displacements and pressures. The results showed that distance of explosive away from the wall is highly affected the structural response of it.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권2호
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• pp.105-111
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• 2002

The biological removal of 2,4,6-trinitrotoluene (TNT) was studied in a bench-scale bioreactor using a bacterial culture of strain OK-5 originally Isolated from soil samples contaminated with TNT. The TNT was completely removed within 4 days of incubation in a 2.5 L bench-scale bioreactor containing a newly developed medium. The TNT was catabolized in the presence of different supplemented carbons. Only minimal growth was observed in the killed controls and cultures that only received TNT during the incubation period. This catabolism was affected by the concentration ratio of the substrate to the biomass. The addition of various nitrogen sources produced a delayed effect for the TNT degradation. Tween 80 enhanced the degradation of TNT under these conditions. Two metabolic intermediates were detected and identified as 2-amino-4, 6-dinitrotoluene and 4-amino-2, 6-dinitrotoluene based on HPLC and GC-MS analyses, respectively. Strain OK-5 was characterized using the BIOLOG system and fatty acid profile produced by a microbial identification system equipped with a Hewlett Packard HP 5890 II gas chromatograph. As such, the bacterium was identified as a Stenotrophomonas species and designated as Stenotrophomonas sp. OK-5.