• Composites Research
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• v.18 no.4
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• pp.14-20
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• 2005

To determine the effect of chemical structure of aromatic amino curing agents on thermal and mechanical properties, standard epoxy resin DGEBF (diglycidylether of bisphenol F) was cured with diaminodiphenyl methane (DDM) and diaminodiphenyl sulphone (DDS) in a stoichiometrically equivalent ratio. From this work the effect of aromatic amino curing agents on the thermal and mechanical properties is significantly influenced by the chemical structure of curing agents. In contrast, the results show that the DGEBF/DDS system having the sulfone structure between the benzene rings had higher values in the thermal stability, density, shrinkage ($\%$), thermal expansion coefficient, tensile modulus and strength, flexural modulus and strength than the DGEBF/DDM system having methylene structure between the benzene rings, whereas the DGEBF/DDS system presented low values in maximum exothermic temperature, conversion of epoxide, and grass transition temperature. These results are caused by the relative effects of sulfone group having strong electronegativity and methylene group having (+) repulsive property. The result of fractography shows that the grain distribution of DGEBF/DDS system is more irregular than that of the DGEBF/DDM system.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.312-317
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• 2018

In this study, activated carbon fibers (ACFs) were treated by oxy-fluorination to improve the adsorption property of benzene gas, one of the gases causing sick house syndrome. Surface properties and pore characteristics of oxyfluorinated activated carbon fibers were confirmed by X-ray photoelectron Spectroscopy (XPS) and Brunauer-Emmett-Teller (BET), and adsorption properties of benzene gas were evaluated by gas chromatography (GC). As a result of XPS data, it was confirmed that the fluorine functional groups on activated carbon fibers surface increased with increasing the fluorine partial pressure. The specific surface area of all samples decreased after the oxyfluorination treatment, but the micropore volume ratio increased when the fluorine partial pressure was at 0.1 bar. The oxyfluorinated activated carbon fibers adsorbed 100 ppm benzene gas for an 11 h, it was found that the adsorption efficiency of benzene gas was improved about twice as much as that of untreated ones.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.502-509
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• 1997

Aromatic pollutants(benzene, toluene, ethylbenzene and xylenes) were photodegraded by using a UV oxidation and the rates of degradation were investigated under various reaction conditions. Each of the solution containing 50 ppm benzene, 150 ppm ethylbenzene and 250 ppm xylenes was found UV-photodegraded over 90% in 1 hour of reaction time, wheras the only was 43 % degradation was obtained with 350 ppm toluene solution. A single component solution was more degradable than a mixed component solution and benzene was almost photodegraded at a pH 4.0, 6.4 and 10.0 after reaction time is 1 hr, ehtylbenzene was photodegraded about 92%(pH 4.0), 90%(pH 6.4) and 91%(pH 10.0), xylenes was photodegraded about 95%(pH 4.0), 90%(pH 6.4) and 92%(pH 10.0), but toluene was photodegraded about 80%(pH 4.0), 43%(pH 6.4) and 70%(pH 10.0), respectively. Kinetics studies show that the rate of decay in TOC(total organic carbon) were pseudo first-order rate except ethylbenzene, and then we could evaluate mineralization rate constants(k) of aromatics.

• Economic and Environmental Geology
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• v.35 no.2
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• pp.149-154
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• 2002

Column tests were carried out to examine the effect of surfactant solution conditions on surfactant-enhanced remediation of contaminated soil. The selected conditions of the surfactant solution were concentration and pH. 1,2,4-trichlo-robenzene (TCB) was chosen as the model hydrophobic organic substances. Sodium diphenyl oxide disulfonate (DOSL) and octylphenoxypoly ethoxyethanol (OPEE) surfactants were selected for this study. Two Iowa soils, Fruitfield sand and Webster clay loam, were leached with surfactant solution. The test results revealed that an optimum condition was achieved for 4 %(v/v) of concentration and 10 of pH, respectively. The maximum recoveries of added TCB (93-98%) were obtained when optimal conditions of each surfactant solution parameter were simultaneously met. The optimum conditions of these parameters may be useful for surfactant-assisted remediation in soil contaminated by TCB.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.379-383
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• 1988

To evaluate the treatability of activated sludge induced by benzene with microorganisms, isolation and characterization of benzene-degrading microorganisms were carried out. Six bacterial isolates from the activated sludge were identified ; Pseudomonas fluorescens, Enterobacter agglomerans, Enterobacter cloacae, Klebsiella oxytoca, Citrobacter freundii and Klebsiella pneumoniae. P. fluorescens degraded 55% of benzene contained in the medium as a sole carbon source, E. cloacae 24%, E. agglomerans 41%, and K. oxytoca 32%. Optimal temperature, pH and benzene concentration for growth of P. fluorescens appeared to be 31$^{\circ}C$, pH 7.0, and 300mg benzene per liter. When the P. fluorescens was dominant in the activated sludge induced by benzene, the indicator protozoa was Aspidisca sp. When concentration of benzene was about 387mg per liter, the growths of Aspidisca sp. and Litonotus sp. were high. Protozoa, Litonotus sp. and Vorticella sp. did not grow over 1600mg of benzene per liter.

• Analytical Science and Technology
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• v.10 no.2
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• pp.139-145
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• 1997

Alkylbenzenes used as synthetic lubricant base oils have been analyzed to find the quantity of mono- and di-substituted alkyl aromatic hydrocarbon compositions and the number of carbon atoms in alkyl chains by $^{13}C$-NMR, near-infrared, and UV-Vis spectroscopy. Also, linear long chain alkylated benzene in the engine lubricants was analyzed quantitatively by infrared spectroscopy.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.244-248
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• 2001

사질 토양에서의 유기물 함량이 벤젠의 흡착과 생분해에 미치는 영향을 분석하기 위하여 다양한 분말 활성탄(PAC)함량 조건에서 비평형 배치 실험을 실시하였다. 비평형 배치실험에서 벤젠의 흡착과 생분해를 비교하기 위하여 BTEX 화합물에 대한 분해능이 우수한 Pseudomonas aeruginosam의 유무에 따른 두 가지의 실험 조건을 설정하였다. 실험 결과 반응 시간 1일까지 빠른 흡착양상을 보였으며, 2일부터 20일 까지는 매우 느린 흡착 양상을 보였다. 활성탄의 함량이 증가할수록 벤젠의 흡착은 증가하는 것으로 나타났으며, Pseudomonas aeruginosa가 첨가된 실험에서는 PAC 함량이 증가할수록 흡착은 증가하였으 나 bioavailability factor (B$_{f}$ ) 값이 감소하였다. 이는 bioavailability가 흡착에 의해 제한됨을 지시한다.

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.495-500
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• 2009

Activated carbon was used as an adsorbent to capture benzene vapor from gaseous stream of nitrogen in a fixed-bed to obtain the breakthrough data. The deactivation model is used to analyze the adsorption kinetics of benzene vapor using the experimental breakthrough data. The experimental breakthrough data are fitted very well to the deactivation model than the adsorption isotherm models in the literature.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.356-357
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• 2003

대기오염을 유발하는 가스 중 휘발성 유기오염물(VOC)의 가스성분에 대한 관심은 점점 높아지고 있다. 휘발성 유기오염물(VOC)가스 중 가장 대표적인 성분은 벤젠, 톨루엔, 자일렌으로서 주 발생원은 유해한 작업환경의 대기나 공장의 배기 가스, 또는 주변 주거 지역의 대기 등이다. 본 연구는 벤젠, 톨루엔, 자일렌을 측정하는데 있어서 표준가스로 사용하는 벤젠, 톨루엔 및 자일렌 교정용 혼합가스의 인증 값의 정확성 및 신뢰성을 유지하기 위하여 이들 성분을 조성으로 하는 혼합가스를 제조하고 단기 흡착성 정도 및 유효기간 설정을 위하여 안정도 조사를 수행하였다. (중략)

• Journal of the Korean Chemical Society
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• v.27 no.6
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• pp.419-423
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• 1983

Amounts of alkylbenzene sulfonate (ABS) in the mixtures of anionic and nonionic detergents were determined by nuclear magnetic resonance (NMR) method. In the NMR spectrum of anionic and nonionic detergents, benzene group showed peaks overlapping at 6.5∼8ppm, but after sampling, benzene group showed two doublet at 7∼8ppm. Calibration curve was obtained by relative ratio of area for benzene group in anionic detergent to that for methyl group in acetic acid(acetic acid was used as the internal standard).