• 멤브레인
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• 제17권3호
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• pp.244-253
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• 2007

광촉매 반응이 자연유기물에 의한 나노여과막의 오염에 미치는 영향을 살펴보았다. 광촉매 분해공정은 자연유기물의 분해와 변형에 효율적이었으며 이산화티타늄과 고정화 비드를 광촉매로 사용하였다. 광촉매적 특성을 비교하기 위하여 칼슘 이온 존재 시의 휴민산의 광분해를 모델 반응으로 설정하였다. 광분해 전에는 치밀한 막오염층이 형성되어 막오염을 가속화시킨 반면, 광분해 후에는 막오염이 크게 감소하였다.

• Asian Journal of Atmospheric Environment
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• 제11권4호
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• pp.217-234
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• 2017

Indoor air pollutants can cause severe health problems, specifically in terms of toxicological impacts on human. Every day, a complex mixture of many air pollutants is emitted from various sources and subject to atmospheric processes that can create varied classes of pollutants such as carboxylic acids, aldehydes, ketones, peroxyacetyl nitrate, and hydrocarbons. To adhere to indoor air quality standards, a number of techniques such as photocatalytic oxidation of various volatile organic compounds (VOCs) have been employed. Among these techniques, titania ($TiO_2$) based photocatalytic reactions have proven to be the best benchmark standard approach in the field of environmental applications. Over the last 45 years, $TiO_2$-based photocatalytic reactions have been explored for the degradation of various pollutants. This review discusses the indoor air quality profile, types of indoor pollutants, available indoor air cleaning approaches, and performance of $TiO_2$-based catalysts. Finally, we have presented the perspectives on the progress of $TiO_2$ induced photocatalysis for the purification of indoor air.

• Asian-Australasian Journal of Animal Sciences
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• 제1권1호
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• pp.21-25
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• 1988

The rumen degradability of rice straw (untreated, urea-sprayed, urea-treated), grasses (Panicum maximum, Pennisetum clandestinum) and rice bran was compared. The mean in vivo organic matter digestibility of the untreated (US), urea-supplemented (SS) and urea-ammonia treated (TS) rice straw were 50.9, 53.9 and 57.4%, respectively. Rice bran contained extremely high levels of acid-insoluble ash (25.2% DM), and its OMD was 36.1%. Grasses had OMD values around 66%. Degradability measurements were performed with buffaloes using the nylon bag technique. The organic matter (OM) disappearance data were fitted to an model which was used to describe degradation pattern. The mean potentially degradable fraction for US, SS and TS was 61.5, 61.9 and 69.4%, respectively. Urea-ammonia treatment increased both the amount of OM degraded and the rate at which it was degraded in the rumen. Both grasses had similar values for degradable fraction (around 65%) and for rate constant for degradation (0.04). Rice bran contained high proportions of readily soluble material (23.9%), but the degradable OM fraction was only 13.2%. The low quality of rice bran is attributed to the contamination of rice hulls during processing.

• Preventive Nutrition and Food Science
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• 제20권2호
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• pp.102-109
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• 2015

In order to investigate the thermal degradation of glucose and maltose solutions after high temperature and high pressure (HTHP) treatment, the samples were treated at temperatures of 110, 120, 130, 140, and $150^{\circ}C$ for 1, 2, 3, 4, and 5 h in an apparatus for HTHP treatment. Glucose and maltose solutions (20% w/w) were prepared by weighing glucose and maltose and adding distilled water in the desired proportion. Chromaticity, pH, organic acids, 5-hydroxymethylfurfural (HMF), free sugar contents, electron donating ability (EDA), and ascorbic acid equivalent antioxidant capacity (AEAC) were evaluated. With increasing heating temperatures and times, the L-, a-, and b-values decreased. The pH and free sugar contents decreased, and organic acids and HMF contents increased with greater temperatures and times. EDA (%) and the AEAC of the heating sugars increased with the increases in temperatures and times.

• 유기물자원화
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• 제9권1호
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• pp.109-118
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• 2001

사후관리단계에 있는 폐기물매립지에서는 매립쓰레기의 안정화 정도를 실측조사하여 파악하기 어려운데 굴착조사를 하면 최종복토층이 손상되기 때문이다. 이러한 문제를 해결하고자 본 연구에서는 침출수 및 매립가스를 이용하여 매립쓰레기의 분해정도를 평가하는 방법을 개발하고 난지도매립지를 대상으로 적용해 보았다. 그 결과 난지도매립지의 매립쓰레기는 2000년까지 분해가능폐기물 기준 54%, 이분해성물질 기준 70%가 분해되었으며, 대부분이 가스상태로 전환된 것으로 분석되었다. 본 연구에서는 이러한 결과는 생화학적 안정화지수로 활용하고, 매립지의 생물학적 분해조건이 변화되었을 때 반영하는 방법도 제시하였다.

• 한국산학기술학회논문지
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• 제7권6호
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• pp.1284-1291
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• 2006

기상 휘발성 유기화합물인 아세톤과 포름알데히드에 대한 분해반응을 $TiO_2$ 광촉매에 귀금속을 혼합 담지하여 분해능을 연구하였다. 아세톤의 경우 $TiO_2$에 팔라디움 혼합담지에 의하여 분해 반응성이 개선되었으며, 일반적인 광촉매 반응에 있어서 수분의 첨가시 OH기의 형성에 따른 분해반응성의 증가를 실험한 결과 아세톤의 경우 수분의 흡착에 의하여 분해반응성이 감소하는 것으로 나타났다. 아세톤의 경우 $45^{\circ}C$가 최적으로 나타났으며, 포름알데히드의 경우는 $75^{\circ}C$가 최적으로 나타났다. 귀금속 담지에 의한 영향에서는 아세톤의 경우 Pd를 $TiO_2$의 중량비 1wt%를 첨가한 경우 반응성의 향상을 보았으며, 포름알데히드의 경우 Pt가 반응성의 향상을 나타내었다.

• Membrane and Water Treatment
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• 제13권2호
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• pp.97-104
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• 2022

With a small particle size, specific surface area and chemical nature, Pd/Cu-Fe nanocomposites can efficiently remove the organic compounds. In order to understand the applicability for in situ remediation of contaminated groundwater, the degradation of p-nitrophenol by Pd/Cu-Fe nanoparticles was investigated. The degradation results demonstrated that these nanoparticles could effectively degrade p-nitrophenol and near 90% of degradation efficiency was achieved by Pd/Cu-Fe nanocomposites for 120 min treatment. The efficiency of degradation increased significantly when the Pd content increased from 0.05 wt.% and 0.10 wt.% to 0.20 wt.%. Meanwhile, the removal percentage of p-nitrophenol increased from 75.4% and 81.7% to 89.2% within 120 min. Studies on the kinetics of p-nitrophenol that reacts with Pd/Cu-Fe nanocomposites implied that their behaviors followed the pseudo-first-order kinetics. Furthermore, the batch experiment data suggested that some factors, including Pd/Cu-Fe availability, temperature, pH, different ions (SO42-, PO43-, NO3-) and humic acid content in water, also have significant impacts on p-nitrophenol degradation efficiency. The recyclability of the material was evaluated. The results showed that the Pd/Cu-Fe nanoparticles have good recycle performance, and after three cycles, the removal rate of p-nitrophenol is still more than 83%.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.623-624
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• 2004

The coating and estimation of gas and moisture barriers on polymer and glass substrates are receiving very much attention in passivation of organic light emitting devices (OLEDs). In this study, the encapsulation and lifetime measurement techniques of OLEDs were presented. The degradation mechanisms of bare and encapsulated OLEDs were investigated by the visual lifetime measurement (VLM) system with the parameters such as a pixel luminance(L), a luminance rms roughness(dL), a brightness area ratio(R), an edge degradation depth(D), etc.

• 환경위생공학
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• 제11권2호
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• pp.33-41
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• 1996

This study was performed to examine the factors influencing on the degradation of TCE, Benzene and 2,4 DCP in aqueous solution using ultrasonic irradiation. The TCE,Benzene and 2,4 DCP, which are hazard compounds causing environmental pollution, were not decomposable pollutants by convientional treatment. The results shows that the generation of H$_{2}$O$_{2}$, H$^{+}$ and OH$^{-}$ radical was formed by the oxidation and reduction reaction of ultrasound, and then theses decomposed the refractory pollutants of TCE, Benzene & 2,4 DCP in aqueous solution. we conformed that the ultrasonic irradiation was excellent in removal efficiency of the refractory pollutants any other than Advanced Oxidation Processes(AOP), utilized the treatment of organic compounds in the industrial wastewater. Consequently, these results suggest that ultrasonic irradiation may be extremely useful for the treatment of wastewaters contaminated organic pollutants, which is difficult to treat economically by conventional process.

• Journal of Electrochemical Science and Technology
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• 제3권1호
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• pp.44-49
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• 2012

Electrochemical and photochemical techniques have been proved to be effective for the removal of organic pollutants in textile wastewater. The present study deals with degradation of synthetic textile effluents containing reactive dyes and assisting chemicals, using electro oxidation and photo catalytic treatment. The influence of various operating parameters such as dye concentration, current density, supporting electrolyte concentration and lamp intensity on TOC removal has been determined. From the present investigation it has been observed that nearly 70% of TOC removal has been recorded for electrooxidation treatment with current density 5 mA/$dm^2$, supporting electrolyte concentration of 3 g/L and in photocatalytic treatment with 250 V as optimum lamp intensity nearly 67% of TOC removal was observed. The result indicates that electro oxidation treatment is more efficient than photocatalytic treatment for dye degradation.