• 멤브레인
• /
• 제29권6호
• /
• pp.299-307
• /
• 2019

광촉매는 물에서 유기 염료를 분해하는 친환경적 기술이다. 산화 텅스텐은 이산화 티타늄에 비해 더 작은 밴드갭을 지니고 있어 광촉매 나노물질로서 활발히 연구되고 있다. 계층적 구조의 합성, 백금 도핑, 나노 복합물 또는 다른 반도체와의 결합 등이 광촉매 분해 효율을 향상시키는 방법들로 연구되고 있다. 이들 방법들은 광 파장의 적색편이를 유도하여 전자 이동, 전자-정공 쌍의 형성과 재결합에 영향을 미친다. 산화 텅스텐의 형태 개질을 통해 앞서 언급한 광촉매 분해 효율을 향상시키는 방법들과 합성에 대해 분석하였으며 금속 산화물과 탄소 복합재를 결합하는 방법이 새로운 물질의 합성이 필요없으며 가장 효율적인 방법으로 조사되었다. 이러한 광촉매 기술은 수처리 분리막기술과 모듈화하여 정수처리 목적으로 사용될 수 있다.

• 청정기술
• /
• 제8권3호
• /
• pp.141-149
• /
• 2002

본 연구에서는 공기청정 시스템의 최적설계에 필요한 자료를 획득하기 위하여, 광촉매 필터 부분을 포함한 전체 시스템의 유동저항 특성을 수치해석 방법으로 연구하였으며, 이를 위해 광촉매 필터의 압력 강하량을 예측한 후, 이 결과를 바탕으로 광촉매 필터를 다공성 매질로 대체하여 전체 시스템의 해석에 이용하였다. 연구과정 중에 사용된 광촉매 필터는 원관형 필터로서 내경 6 mm와 20 mm의 두 가지 모델이 고려되었다. 내경 6 mm의 원관형 촉매는 내경 20 mm의 촉매에 비해 약 3배 높은 압력 강하량을 보였으며, 여러 개의 원관을 체결하기 위해 사용되는 촉매 하우징이 장착된 경우에 대해서도 해석을 수행하였다. 하우징이 있는 경우 압력 강하는 하우징이 없는 경우에 비해 약 8배 증가하였다. 전체 시스템의 유동장을 계산하기 위해 모사된 다공성 매질은 광촉매 필터의 특성을 1% 미만의 오차로 정확히 모사하고 있으며, 이를 이용하여 전체 시스템을 해석할 수 있었다.

• Korean Chemical Engineering Research
• /
• 제51권3호
• /
• pp.297-302
• /
• 2013

악취 유발 물질인 $H_2S$를 처리하기 위한 UV/photocatalysis의 성능 향상에 관한 연구를 수행하였다. 광촉매 물질을 선정하기 위하여 EtOH을 기준물질로 사용하였으며, 광촉매 반응기의 광활성은 광촉매 반응기의 표면에 코팅된 광촉매의 표면특성과 높은 상관성을 나타냄을 확인하였다. PS 광촉매(STS-01)가 코팅된 광촉매 반응기는 기체선속도가 0.01 m/s, 상대습도가 40%의 조건에서 약 80%의 $H_2S$ 산화효율을 보였으나, 그 이상의 선속도에서 반응활성은 급격히 감소하였다. 광촉매 반응기의 성능유지를 위하여 백금을 광촉매에 담지하였는데 이는 같은 실험조건에서 95% 이상의 우수한 $H_2S$ 전환율을 나타내었다.

• 한국도로학회논문집
• /
• 제15권6호
• /
• pp.1-9
• /
• 2013

PURPOSES : About 35% of air pollutant is occurred from road transport. NOx is the primary pollutant. Recently, the importance of NOx removal has arisen in the world. $TiO_2$ is very efficient for removing NOx by photocatalytic reaction. The mechanism of removing NOx is the reaction of photocatalysis and solar energy. Therefore, $TiO_2$ in concrete need to be contacted with solar radiation to be activated. In general, $TiO_2$ concrete are produced by substitute $TiO_2$ as a part of concrete binder. However, 90% of $TiO_2$ in the photocatalysis can not contacted with the pollutant in the air and solar radiation. Coating and penetration method are attempted as the alternative of mixing method in order to locate $TiO_2$ to the surface of structure. METHODS : The goal of this study was to attempt to locate $TiO_2$ to the surface of concrete, so we can use the concrete in pavement construction. The distribution of $TiO_2$ along the depth were confirmed by basing on the comparison of $TiO_2$ compare by using the EDAX(Energy Dispersive X-ray Spectroscopy). RESULTS : $TiO_2$ were distributed within 3mm from concrete surface. This distribution of $TiO_2$ is desirable, since the $TiO_2$ induce photocatalysis are located to where they can be contacted with the air pollutant and solar radiation. CONCLUSIONS : Nano size $TiO_2$ is easily penetration in the top 3mm of concrete surface. By the penetration $TiO_2$ concrete can be produced with the use of only 10% of $TiO_2$, by comparing the mixing types.

• 환경위생공학
• /
• 제18권2호
• /
• pp.52-59
• /
• 2003

This study was progressed in photocatalysis of VOCs using $UV/TiO_2$ which was a benign process environmentally. The experiments were peformed to know photodegradation characteristics as crystalline structure of $TiO_2$ which had anatase, rutile and P-25 (anatase : rutile = 70 : 30). The main purpose of this study was to identify photocatalytic characteristics as inlet concentration of reactants, $H_2O$, and residence time. The inlet concentration of VOCs was changed 50, 100 and 200 ppmv, and amount of $H_2O$ was changed 0, 500 and $1000{\;}mg/m^3$, respectively. The deep conversion was increased as the inlet concentration decreased, and the amount of $H_2O$ increased. The deep conversion of benzene had the highest value at $1000{\;}mg/m^3${\;}H_2O$ and 50 ppmv of inlet concentration. The reactivity of reactants was decreased in order benzene > toluene > m-xylene. Also, the photocatalytic deep conversion was increased as residence time increased, because the contact time between reactants and catalyst was increased. In this study, intermediates had not found by GC/MSD analysis. Therefore, the reactants were completely converted to $H_2O{\;}and{\;}CO_2$.

• 한국태양에너지학회 논문집
• /
• 제21권2호
• /
• pp.45-54
• /
• 2001

In this study, the characteristics of optical fibers for the application in photocatalytic system was investigated using the intentionally designed accessories for spectrometer and radiometer to resolve the problems associated with the conventional system such as cost and structural restrictions from artificial lamp usage, to broaden the application fields into underground, and to utilize solar light in the future. To do this two kinds of optical fibers, plastic optical fiber (POF) and quartz optical fiber (QOF) were compared in terms of characteristics related with light transmittance and absorption and reactivity in TCE degradation.

• 설비공학논문집
• /
• 제16권1호
• /
• pp.1-7
• /
• 2004

This study has been numerically conducted to investigate the removal efficiency of Volatile Organic Compound (VOC) for different photocatalytic honeycomb filters. Recently, the photocatalysis is being applied to air-cleaner, air-conditioner and vacuum-cleaner with the capability of air-purification, sterilization and antibiosis. However, photocatalysis is less efficient than other methods for removing VOC except in the case of low concentration. So far most of studies have focused on an improvement of the photocatalytic materials, but this study have placed emphasis on the improvements of shape of photocatalytic honeycomb filter. UV irradiation, concentration profile and pressure drop have been investigated for different cross sections of filters and for different filter lengths. Light intensity is dropped sharply with increasing distance from the UV-lamp, and becomes very low in the middle of the filters. Since photocatalytic reaction rate is a function of light intensity, VOC concentration gradient might be small in the middle of long filters. Thus, most of reaction have risen within only three times of dimensionless axial distance. These results can be used effectively for the design of advanced photocatalytic honeycomb filters.

• 멤브레인
• /
• 제28권3호
• /
• pp.143-156
• /
• 2018

본 총설은 다양한 저널 게재 논문으로부터 분리막 및 광촉매의 혼성 정수/하수 처리 공정을 요약하였다. 이 총설에는 (1) 분리막 광촉매 반응기(membrane photoreactor, MPR), (2) 분리막 결합 광촉매 공정에서 막오염 관리, (3) 유기 오염물의 분해를 위한 광촉매 분리막 반응기, (4) 정수처리용 막분리 공정과 광촉매 분해의 결합, (5) 휴믹산 분해를 위한 광촉매 및 세라믹 막여과의 혼성공정, (6) 활성슬러지 여과를 위한 한외여과의 막오염에 이산화티타늄 나노입자의 영향, (7) 정수처리용 광촉매 및 정밀여과의 혼성시스템, (8) 선박 평형수 처리용 한외여과 및 광촉매의 혼성공정 및 (9) 분리막 및 광촉매 코팅 프로필렌 구의 혼성수처리 공정이 포함되어 있다.

• 기계와재료
• /
• 제11권3호통권41호
• /
• pp.131-146
• /
• 1999

• Advances in materials Research
• /
• 제2권1호
• /
• pp.65-75
• /
• 2013

Heterogeneous photocatalysis is a rapidly developing field in environmental engineering. It has a great potential to cope with the increasing pollution in the air. The addition of a photocatalyst to ordinary building materials such as tiles, concrete, paints, creates environmental friendly materials by which air pollution or pollution of the surface itself can be controlled and diminished. This work reports the results of the laboratory research, especially carried out towards air purifying action and self-cleaning measurements. In particular the research was focused on the study of the photocatalytic behavior of industrially prepared tiles produced starting from commercial micro-sized $TiO_2$. Air purification action has been investigated through NOx degradation tests. On the contrary, the degradation of pollution at the surface, also called as self-cleaning action, is verified by the degradation of two different organic dyes: Rhodamine B (red color) and Metanil yellow (yellow).