• KSBB Journal
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• 제25권1호
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• pp.103-107
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• 2010

Oil degradation agent was developed with organic sludge and modified peat moss (MPM) to recover oil contaminated soil. Waste sludge discharged from wastewater treatment plant of chemical plant in Ulsan National Industrial Park was used as organic sludge, and MPM was purchased. Organic sludge was adequate to use as growth medium for microorganism, the surface of MPM had porous structure which could enhance the cultivation condition of oil degradation microorganisms. Water contents and TPH variation with time were observed to investigate the degradation capacity of developed degradation agent. Water contents were rapidly decreased with higher contents of MPM, however, in case of TPH, high MPM content decreased the degradation capacity. Therefore, it was recommended that the content of MPM was controlled to below 10% in degradation agent as mixing organic sludge with MPM.

• Carbon letters
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• 제6권3호
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• pp.158-165
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• 2005

Room temperature kinetics of degradation of nerve agent simulants and sarin, an actual nerve agent at the surface of different carbon based adsorbent materials such as active carbon grade 80 CTC, modified whetlerite containing 2.0 and 4.0 % NaOH, active carbon with 4.0 % NaOH, active carbon with 10.0 % Cu (II) ethylenediamine and active carbon with 10.0 % Cu (II) 1,1,1,5,5,5-hexafluoroacetylacetonate were studied. The used adsorbent materials were characterized for surface area and micropore volume by $N_2$ BET. For degradation studies solution of simulants of nerve agent such as dimethyl methylphosphonate (DMMP), diethyl chlorophosphate (DEClP), diethyl cyanophosphate (DECnP) and nerve agent, i.e., sarin in chloroform were prepared and used for the uniform adsorption on the adsorbent systems using their incipient volume at room temperature. Degradation kinetics was monitored by GC/FID and was found to be following pseudo first order reaction. Kinetics parameters such as rate constant and half life were calculated. Half life of degradation with modified whetlerite (MWh/NaOH) system having 4.0 % NaOH was found to be 1.5, 7.9, 1206 and 20 minutes for DECnP, DEClP, DMMP and sarin respectively. MWh/NaOH system showed maximum degradation of simulants of nerve agents and sarin to their hydrolysis products. The reaction products were characterized using NMR technique. MWh/NaOH adsorbent was also found to be active against sulphur mustard.

• KSBB Journal
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• 제25권1호
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• pp.73-78
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• 2010

In this study, recovering agent was produced with organic sludge and modified peat moss (MPM) in pilot plant mixer to recover oil contaminated soil, and field test of it was estimated using landfarming method. Oil contaminated soil recovering agent was thought to contain more microorganisms than raw waste sludge and was no problem to come onto the market because there were not any items of specified wastes. According to the results of TPH variation with time, it was observed the initial degradation velocity of oil with produced recovering agent was rapid up to 50% after 4 days, remarkably. Because the microorganisms in the organic sludge discharged from chemical plant already acclimated with oil, therefore, it could be estimated initial degradation velocity of recovering agent might be rapid. It was concluded that the oil contaminated soil recovering agent produced in this study have high marketability because of its two aspects on recycling of wastes and initial rapid degradation capacity.

• 한국전기전자재료학회논문지
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• 제27권12호
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• pp.841-846
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• 2014

It found that the maximum temperature of the arc discharge occurred on the Silicone rubber sample significantly decreased with increasing the reinforcing agent. It was confirmed that the current value decreased with increasing the aluminium trihydrate($Al(OH)_3$) and the current value increased with reducing the primary resistance over time. Regarding these results, may be it is because the degradation due to the electro-conductive carbonization was improved and the properties of dielectric breakdown was reduced by the flame retardant reinforcing agent. It found that the electro-conductive carbonized road has not happened by increasing the flame retardant reinforcing agent. Regarding to the arc discharge, this study show that the arc arising near the lower electrode of sample has disappeared.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.360-363
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• 2003

Bioremediation is often used for in situ remediation of petroleum-contaminated site. We studied the microbial degradation of hydrocarbon in an artificially diesel contaminated soil in laboratory microcosm. In control soil, about 30% of the initial TPH was diminished and the degradation of diesel oil was significantly enhanced by the addition of bioremediation agent (70% of TPH reduction).

• 폴리머
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• 제28권4호
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• pp.291-297
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• 2004

수용성 키토산의 농도와 가교제 (글루타알데히드)의 양을 변화시키면서 미네랄오일 내에서 키토산용액의 유화법에 의해 수용성 키토산 미세구를 제조하였다. 그러고 약물이 봉입되어진 수용성 키토산 미세구의 분해에 따른 형태의 변화, 약물의 봉입효율, 약물 방출 거동과 같은 물리화학적 특성을 규명하였다. Norfloxacion 이 봉입된 수용성 키토산 미세구는 표면의 약물에 의해 나타나는 과량의 약물 방출이 없는 높은 약물 봉입 함량을 보였다. 표면에 약물이 존재하지 않음을 선 회절 분석으로 확인하였다. 수용성 키토산 미세구의 분해 특성과 약물방출 거동을 관찰한 결과 가교제의 양이 약물의 봉입량, 방출, 그리고 분해에 중요한 역할을 하는 것을 확인하였다. 수용성 키토산 미세구는 가교제의 양이 증가함에 따라 분해속도가 느렸으며, 이와 동시에 약물이 천천히 방출되었음을 확인하였다.

• Journal of the Korean Wood Science and Technology
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• 제45권2호
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• pp.168-181
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• 2017

Whole cell of Phanerochaete chrysosporium with reducing agent was applied to verify the degradation mechanism of aromatic compounds derived from lignin precisely. Unlike the free-reducing agent experiment, various degraded products of aromatic compounds were detected under the fungal treatment. Our results suggested that demethoxylation, $C_{\alpha}$ oxidation and ring cleavage of aromatic compounds occurred under the catabolic system of P. chrysosporium. After that, degraded products stimulated the primary metabolism of fungus, so succinic acid was ultimately main degradation product of lignin derived-aromatic compounds. Especially, hydroquinone was detected as final intermediate in the degradation of aromatics and production of succinic acid. In conclusions, P. chrysosporium has an unique catabolic metabolism related to the production of succinic acid from lignin derived-aromatic compounds, which was meaningful in terms of lignin valorization.

• 구강회복응용과학지
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• 제19권4호
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• pp.309-315
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• 2003

When the exposure surface of restoration is brushed with various toothpaste in the mouth, wear or undesirable surface deposit of restoration can occur. Surface change of gallium alloys according to brushing and toothpaste may directly affect oral hygiene. The aim of this study was to evaluate the surface alterations of Gallium alloys during tooth brushing with different prophylactic agents. Two gallium-alloys and an amalgam as a control were investigated. Without and with brushing were applied with three kinds of prophylactic agents on the sample for 0, 1, 5, 10, 60 and 360 minutes. At each time interval, surface roughness was recorded by a profilometer and some pictures were taken by a SEM. All results were analyzed by the one-way ANOVA, followed by Tukey multiple comparisons and the simple linear regression analysis. The results indicate that gallium alloys are more susceptible to surface degradation during tooth brushing than amalgam with respect to the specific prophylactic agent used.

• 펄프종이기술
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• 제47권6호
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• pp.66-72
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• 2015

This study was conducted to investigate the effects of optical brightening agents (OBA) on the chemical degradation characteristics of paper cellulose during humid heating aging. Three different types of OBAs were applied to a filter paper by dipping it in OBA solutions whose concentrations were controlled to 1% and 2%. The filter papers with an OBA were artificially aged at $80^{\circ}C$ and 65% RH, and the changes in pH of paper and viscosity of cellulose were evaluated. Their functional groups were also analyzed by ATR-FTIR (at-tenuated total reflectance fourier transform infrared spectroscopy). It was found that OBAs influenced the chemical degradation of paper cellulose during humid heating aging. Higher concentration of OBA solutions accelerated the degradation of paper cellulose. Especially, after aging for 12 days, the paper cellulose treated with the tetra-type OBA were the most significantly aged among the three types of OBAs. It was assumed that pH of OBA solutions affected the aging characteristics.

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권2호
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• pp.26-32
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• 2009

본 연구에서는(Fe$^{3+}$+chelating agent)/H$_2$O$_2$ 공정 [Fe(III) 1mM, ocalate 6mM, H$_2$O$_2$ 3%, pH 6]과 UV/(Fe$^{3+}$+chelating agent)/H$_2$O$_2$ 공정 [UV dose 17.4kWh/L, Fe(III) 1mM, oxalate 6mM, H$_2$O$_2$ 1%, pH6]에서 BTEX(benzene, toluene, ethylbenzene, xylene)를 분해하기위해 다양한 착제를 토입, 그 분해효율을 비교하였다. 착제의 종류는 catechol, NTA, gallic, acetyl acetone, succinic, acetate, EDTA, citrate, malonate, 그리고 oxalate,총 10가지 종류의 착제를 사용하였으며, 그 중,acetate를 착제로 사용한 경우, 가장 높은 분해효율을 나타내었다. 또한, UV를 조사한 경우, 모든 착제에 대한 BTEX의 분해효율이 UV를 조사하지 않은 (Fe$^{3+}$+chelating agent)/H$_2$O$_2$ 공정의 분해효율보다 높은 것으로 나타났다. 또한BTEX와 무연 휘발유의 첨가제로 사용되고 있는 MTBE(methl tert-butylether)의 혼합복합물(각각의 농도는 200mg/L)에 대해서도 acetate를 착제로 사용한 UV/(Fe$^{3+}$+chelating agent)/H$_2$O$_2$공정에서 높은 분해효율을 보였다. 이 경우, BTEX는 반응시간 180분 만에 완전 분해되었으며, MTBE의 경우, 85%의 분해효율을 보였다. 이러한 실험 결과는 acetate를 착제로 사용한 UV/(Fe$^{3+}$+chelating agent)/H$_2$O$_2$공정은 BTEX 분해효율뿐만 아니라, BTEX와 MTBE복합오염물의 분해효율도 증가시킬수 있음을 입증하고 있다.