Treatment characteristics of benzene were investigated by using a fixed bed reactor system applying a hybrid method over composites of photocatalyst and adsorbent. Various composites were made by mixing photocatalyst with adsorbent, such as activated carbon, activated carbon fiber, and sludge. Performance tests were conducted with benzene concentrations of 1,000～3,000 ppm, Benzene flow rates of 50～100cc/min, and packing weights of 14～24g for the various composite samples. The property of benzene treatment was analyzed concerning BET, SEM, pH, and the conversion efficiency. It was concluded by experimental results that the benzene conversion efficiency of a hybrid method was much higher than that of a photocatalyst only method showing a conversion efficiency range between 13% and 65%. It was also found that the comprehensive feasibility study of the hybrid method would be needed with consideration of various factors including additional expenses.

Aluminum was anodized in a H2SO4 solution, and titanium (IV) oxide (TiO2) was electrodeposited into nanopores of anodic porous alumina in a mixed solution of TiOSO4 and (COOH)2. The photocatalytic activity of the prepared film was analyzed for photodegradation of methylene blue aqueous solution. Consequently, we found it was possible to electrodeposit TiO2 onto anodic porous alumina, and synthesized it into the nanopores by hydrolysis of a titanium complex ion under AC 8-9 V when film thickness was about 15-20μm. The photocatalytic activity of TiO2-loaded anodic porous alumina (TiO2/Al2O3) at an impressed voltage of 9 V was the highest in every condition, being about 12 times as high as sol-gel TiO2 on anodic porous alumina. The results revealed that anodic porous alumina is effective as a substrate for photocatalytic film and that high-activity TiO2 film can be prepared at low cost.

A ventilation system comprising a dielectric barrier discharger and UV‐TiO2 photocatalyst filters was designed and tested for simultaneous removal of gaseous and particulate contaminants in a test chamber. The DBD was used as the 1st stage of ESP for particle charging and gas decomposition. Charged particles were collected in the 2nd stage of ESP by an applied DC electric field. The UV‐TiO2 photocatalyst filters were used for decomposing gaseous species including O3 which was inherently produced by the DBD. Particle removal efficiencies based on mass and number were approximately 83.0% and 88.8%, respectively, after the ventilation system was operating for 5 hours. HCHO removal efficiency was approximately 100% for 1∼5ppm of upstream concentration condition. TVOC removal efficiency was 99.0% and 99.6% for 1 ppm and 5 ppm of upstream concentration conditions, respectively.

Decomposition of ozone at room temperature was investigated by comparing between commercial monolithic ozone decomposition catalyst (ODC, MnO2) filter and monolithic photocatalyst (TiO2) filter. The effects of residence time, UV (ultraviolet, A type) irradiation, and upstream ozone concentration on the ozone conversion were discussed. UV ray was irradiated using four BLB (black light blue) lamps (λ: 310∼ 400nm) of constant intensity. The upstream concentration of ozone was controlled by an electrostatic ozone generator. For ODC performance, the presence of UV irradiation slightly affected initial ozone conversion compared with no UV irradiation condition. However, for photocatalyst, the ozone was highly decomposed in the presence of UV irradiation. Long time performances of the both catalysts were evaluated by a real-time ozone monitoring system during 120 hours. The results show that the UV irradiation enhanced the ozone conversion for the both catalysts.

In order to obtain the nano size composite powders by mechanical alloying method for useful composite catalysis, the effects of mechanical alloying time on the formationof composite powders were analyzed. The phase transformation behaviors were experimented as the heat treating temperature increased. Homogeneous 10wt% Cu-rutile type composite powders were synthesized in 40 hours by mechanical alloying. After 60 hours mechanical alloying 50 nm size powders were obtained. Both the phase of mechanically alloyed 10 wt% and pure powders were not transformed to anatase after annealing at the temperature range between 350 to 500 . The intermetallic compound of O was formed after 10 hours mechanical alloying, however it could be considered that this intemetallic phase dose not prevent the transformation of rutile to the anatase phase after heat treatment at the temperature between 350 and .

본 연구에서는 빛 감성친화형 콘크리트에 광촉매를 적용하여 대기질 및 실내공기질을 개선하기 위한 LEFC 블록을 개발하고자 하였다. LEFC에 광촉매를 적용하게 되면 자외선 입사면 반대편에서도 투과로 인한 자외선이 존재하여 광촉매가 반응함으로써 일반 건축 자재를 적용한 경우보다 광촉매 반응효율이 크게 상승한다. 따라서 광촉매를 LEFC에 적용하기 위해 슬럼프, J-ring, L-box 테스트를 통한 자기충전성능을 평가하여 최적 배합을 결정하였고, 압축 및 휨 강도 시험을 통해 역학성능을 평가하였다. 그리고 TiO2 분포도를 확인하기 위해 SEM과 EDS 분석을 실시하였다. ALC골재와 단열재 적용으로 광촉매 사용량을 줄이고 단위중량을 감소시키는 방안을 활용하여 광촉매 효율을 증가시키는 빛투과 콘크리트 블록을 제작하였고, 향후 건조수축 등의 문제점 개선 및 NOx 제거 실험을 통한 LEFC 블록 성능 평가를 진행하고자 한다.

본 연구에서 광촉매 종류 및 혼입율에 따른 역학적 특성 및 질소산화물 제거 특성을 평가하였고 보다 경제적이고 효율적인 광촉매 콘크리트 제조를 위해 분할 타설하는 방법에 대해 검토하였다. 그 결과 광촉매 혼입률이 5%일 때 가장 높은 압축강도와 탄성계수가 측정되었다. 광촉매 반응에 의한 질소산화물 제거 성능평가 결과 광촉매 혼입률이 증가함에 따라 질소산화물 제거율이 증가하였다. 이때 광촉매 P-25의 질소산화물 제거성능은 NP-A보다 우수하였다. 경제성을 고려하여 콘크리트 표면의 일정 두께를 광촉매 콘크리트로 타설하는 분할 타설 방안을 제안하였고, 이때의 일체화 성능을 평가하였다. 그 결과 역학적 성능 및 내구성능이 Plain에 비해 동등 이상으로 나타나 일체화 거동을 만족하는 것으로 판단된다.

The effect of fine dust on indoor and outdoor atmospheric environment in Korea is getting larger and it is tried to solve this problem by incorporating photocatalyst. Conventional light transparent concrete (LEFC) arranges plastic rods to ensure light transmittance. However, it is difficult to secure sufficient fluidity due to the heterogeneity and spacing of the materials. In addition to the flow test, J-ring test and L-box test, which are ASTM standards or EN standards, are used to evaluate the fluidity and to find out the optimum mix design of light transparent concrete with self-consolidating performance.

This study provides a simple introduction to photo-catalyst technology to self-clean the organic dirts and degrade the air pollution in urban environment. Moreover, it shows the spray coating technique was applied to effective coating on the surface of concrete specimen by using as-developed integral photocatalyst solution. In order to examine photo-catalytic activity and degradation effectiveness on the surface of the concrete specimen, the UV-LED lamp was used as a light source to activate the photo-catalysis. Methyl-orange dye was used as an indicating method to speculate the photo-catalytic reaction and UV-VIS spectrometer to determine the molar content of the organic dye.

콘크리트는 장기간 사용환경에 노출되면서 다양한 표면열화과정을 거친다. 실리케이트 기반 함침제는 콘크리트 표면에 적용되어 불용성 수화물을 형성하는데, 이 과정에서 다양한 공학적 장점을 기대할 수 있다. 본 연구는 분산형 실리케이트를 사용하여 표면의 내구성능을 강화하고 이후 광촉매를 분무함으로서 표면 함침된 콘크리트의 자기정화능력을 평가하는 것이다. 이를 위해 실리케이트 함침 콘크리트에 대하여 압축강도 뿐 아니라, 흡수성, 건조 수축, 염소이온저항성, 황산저항성, 동결융해 저항성 등과 같은 내구성 실험이 수행되었다. 또한 아세트 알데이드 및 메틸렌블루 반응 평가를 통하여 독성카스의 제거와 자기정화성능을 평가하였다. 실리케이트 함침 후 광촉매 도포를 함으로서 광촉매의 부착성을 확보할 수 있었으며, 콘크리트의 내구성 개선과 광촉매 고유의 정화성능을 유지할 수 있었다.

This study provides a simple introduction to photo-catalyst technology to degrade the air pollution in urban environment, in particular, NOx gases from automobiles. Moreover, it shows the spray coating technique was applied to effective coating on the surface of asphalt roads by using as-developed integral photocatalyst solution. In order to examine the slip resistance of asphalt surfaces, the BPT (British Pendulum Test) was used under drying and wetting conditions.

In the case of VOCs, it is known that the removal can be realized through the use of titanium dioxide (TiO2) photocatalyst. The experimental results reveal that VOCs removal efficiency for Mortar with Photocatalyst powder was effective and It was different depending on the Photocatalyst types.

This research intends to develop a photocatalytic concrete enabling to decompose the nitrogen oxides (NOx) using a titanium oxide photocatalyst for reducing the cost. In details, this research develops the mix composition of the photocatalytic concrete exhibiting photolytic characteristics and establish the technology enabling to reduce the emission of air pollutant caused by nitrogen oxides.

In order to reduce roadside and indoor air pollution for volatile organic compounds VOC), it may be necessary to apply photocatalyst-coated construction materials. This study evaluated the technical feasibility of the application of TiO2 photocatalysis for the removal of VOC present in roadside or indoor air. The photocatalytic removal of five target VOC was investigated: benzene, toluene, ethyl benzene and o,m,p-xylenes. Variables tested for the current study included ultraviolet(UV) light intensity coating materials, relative humidity (RH), and input concentrations. Prior to performing the parameter tests, adsorption of VOC onto the current experiment was surveyed, and no adsorption was observed. Stronger UV intensity provided higher photocatalytic destruction(PCD) efficiency of the target compounds. For higher humidity, higher PCD efficiency was observed. The PCD efficiency depended on coating material. Contrary to certain previous findings, lower PCD efficiencies were observed for the experimental condition of higher input concentrations. The current findings suggested that the four parameters tested in the present study should be considered for the application of photocatalyst-coated construction materials in cleaning VOC of roadside or indoor air.

This study aimed at improving the TiO2 photocatalytic degradation of HA. ·In this study, the Degradation of Humic Acid using Jeju Scoria Coated with WO3/TiO2 in the presence of UV irradiation was investigated as a function of different experimental condition : photocatalyst dosage, Ca2+ and HCO3- addition and pH of the solution. Photodegradation efficiency increased with increasing photocatalyst dosage, the optimum catalyst dosage is 2.5 g/L and Photodegradation efficiency is maximized to WO3/TiO2=3/7. This indicates that WO3 retains a much higher Lewis surface acidity than TiO2, and WO3 has a higher affinity for chemical species having unpaired electrons. The addtion of cation(Ca2+) in water increased the photodegradaion efficiency. But the addtion of HCO3- ion in water decreased a photodegradation efficiency. Photodegradation efficiency increased with decreasing pH. At pH < pzc, the electrostatic repulsion between the HA and the surface of TiO2 decreased.

The objective of this study is to delineate removal efficiency of the Linear alkylbenzene sulfonates(LAS) in solution by TiO2 photocatalytic oxidation as a function of the following different experimental conditions : initial concentration of LAS, TiO2 concentration, UV wavelength and pH of the solution. It was increased with decreasing initial concentration of LAS and with decreasing pH of the solution. Removal efficiency increased with increasing TiO2 concentration but was almost the same at TiO2 concentration of 2 g/L and 3 g/L, i.e., for initial LAS concentration of 50 mg/L. It was removal efficiency was 85% at 150 min in the case of TiO2 concentration of 0.5 g/L but 100% after 150 min in the case of TiO2 concentration of 1 g/L, 100% after 110 min in the case of TiO2 concentration of 2 g/L and 3 g/L. UV wavelength affection on the removal efficiency of LAS decreased in the order of 254, 312 and 365 nm as increasing wavelength. But the removal efficiency of LAS was nearly the same at UV wavelength of 254 nm and 312 nm.