• Korean Chemical Engineering Research
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• 제50권6호
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• pp.952-959
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• 2012

환형 광촉매반응기 외경지지체의 반사막에 의한 광촉매반응기시스템의 광도를 제고함으로써 개선된 광촉매반응기에 의한 악취성분 및 휘발성 유기화합물을 동시 포함한 폐가스의 처리를 수행하였다. 그리고 광도 제고가 각 운전조건에서의 폐가스처리효율에 미치는 영향을 조사하였다. 광촉매 코팅된 nonporous glass bead 담체와 porous silica-based 담체를 각각 광촉매반응기에 충전하였을 때에 반사필름이 부착된 개선된 광촉매반응기 외경에서 측정한 광도는, 반사필름이 부착되지 않아서 광도가 제고되지 않은 광촉매반응기보다 각각 30.1%와 28.5% 증가하였다. Porous silica-based 담체를 충전한 개선된 광촉매반응기의 제거효율에 대한 제고효과는 약 2~3%이었다. 그러나 glass-bead 담체를 충전했을 때에 개선된 광촉매반응기의 제거효율 제고효과는 미미하였다. Porous silica-based 담체가 충전된 개선된 광촉매반응기인 최적화 광촉매반응기의 경우의 황화수소 및 톨루엔 제거효율은 nonporous glass bead가 충전되고 반사막이 없는 광촉매반응기 경우의 제거효율인 각각 19%와 53%보다 각각 약 26%와 약 60%의 증가율을 보였다. 반사막 필름표면의 roughness가 종래의 상업용 거울의 roughness보다 4배 정도 컸으나, 향후 개선된 광촉매반응기의 반사막의 roughness를 개선할 경우에 광도 개선효과가 더욱 커져서 이에 따른 악취 및 VOC를 함유한 광촉매 처리효율이 더욱 제고되리라 예상된다.

• 환경위생공학
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• 제19권2호
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• pp.1-6
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• 2004

In Bok-Jeong water treatment plant, chlorination is the only technique used for disinfection of drinking water. This disinfecting treatment leads to the formation of trihalomethanes (THMs). This study was carried out to investigate the possibility of improving removal efficiency of THM precursor in the conventional water treatment processes by $TiO_2$ photocatalytic oxidation. Removal efficiencies of DOC, $UV_{254}$, THMFP were low in the conventional water treatment processes. With application of $TiO_2$ photocatalyst, DOC, $UV_{254}$, THMFP were reduced more effectively. As the $TiO_2$ photocatalytic reaction time increased, the removal efficiencies of DOC, $UV_{254}$, THMFP were increased. The $TiO_2$ photocatalytic removal efficiencies of DOC, $UV_{254}$, THMFP were increased with increasing $TiO_2$ dosage. However, over 0.6g/l of $TiO_2$ dosage, the efficiency reached a plateau.

• Korean Chemical Engineering Research
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• 제51권1호
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• pp.80-86
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• 2013

본 연구에서는 광촉매담지 실리카담체 카트리지를 장착한 광촉매반응기시스템을 활용하여 악취 가스인 황화수소 및 휘발성유기화합물(VOC)인 에탄올 및 톨루엔이 함유된 폐가스처리를 수행하고, 그 연구결과를 상용 광촉매담지 부직포필터 카트리지를 장착한 광촉매반응기시스템을 활용한 연구결과와 비교 및 평가하였다. 광촉매담지 실리카담체 카트리지를 장착한 광촉매반응기시스템의 경우는 1단계 운전에서 에탄올 및 톨루엔의 제거율은 각각 80% 및 20% 값을 계속 유지하였으나, 에탄올의 제거율은 톨루엔과 다르게 점점 떨어져서 1단계 끝에는 제거율 40% 값을 보였다. 한편 황화수소의 제거율은 100%에서 90%로 감소하였다. 에탄올의 제거율은 2단계 운전에서 10% 값을 보여서 더욱 감소하였으나, 황화수소 및 톨루엔 제거효율은 처리대상 폐가스의 톨루엔 부하가 4배로 급격히 증가하였음에도 불구하고 제거효율이 각각 90% 및 20% 값을 그대로 유지하였다. 3단계 운전은 알루미늄 코팅된 반사막필름을 광촉매반응기에 사용한 결과로서, 에탄올 및 톨루엔의 제거율은 각각 약 5%가 증가한 15% 및 25%의 제거율을 보였다. 한편 광촉매담지 부직포필터 카트리지를 장착한 광촉매반응기시스템의 에탄올, 황화수소 및 톨루엔 제거율은 1단계 운전에서 각각 10%, 97% 및 100% 값을 유지하였다. 그러나 2단계 운전에서 에탄올, 황화수소 및 톨루엔 제거율은 각각 5%, 95% 및 2~3% 미만의 제거율을 보여서 에탄올과 황화수소는 제거율이 약간 저하되었으나 톨루엔의 경우에는 완전 제거에서 급락하였다. 또한 에탄올, 황화수소 및 톨루엔 모든 경우에서 반사막필름의 효과를 전혀 보지 못하였다. 따라서 상용 광촉매담지 부직포필터 카트리지를 장착한 광촉매반응기시스템에서 에탄올, 황화수소 및 톨루엔 제거는 부직포필터의 혐수성 VOC에 대한 흡착능에 주로 기인하였고, 광촉매 활성에 의한 제거는 광촉매담지 실리카담체 카트리지를 장착한 광촉매반응기시스템보다 훨씬 미미하였다.

• 한국대기환경학회지
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• 제25권3호
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• pp.211-218
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• 2009

Feasibility study of using $Ti0_2$ mist generated by ultrasonic atomization for photocatalytic degradation of gaseous toluene was attempted in this study. For this, the photocatalytic reactor consisting of mist generator and photo-reactor was designed. Most of experimental results showed that steady state reached about 30 minutes after the start of experiments. The effects of $Ti0_2$ concentration, toluene concentration, and UV wavelength on toluene removal ratio were investigated. It was found that the highest removal efficiency was obtained when $Ti0_2$ concentration was 0.6 g/L in slurry. At this condition, it was found that the toluene removal efficiency increased as toluene concentration in feed decreased. In order to investigate the effect of UV wavelength, experiments were carried out using three UV lamps with different UV wavelength. The results showed that the highest removal efficiency was achieved when the lamp with the shortest wavelength were employed.

• Environmental Engineering Research
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• 제13권4호
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• pp.197-202
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• 2008

This study evaluated the photocatalytic oxidation of BPA using the RPOD reactor under various conditions. This study found that the RPOD was effective for BPA degradation. It could reduce 1 mg/L of BPA by half within 5 min under the optimum conditions. According to the study results, $TiO_2$ coating was important for the BPA oxidation. As the coating thickness increased, the removal efficiency improved. The light source, the light intensity and the drum rotating speed were important for the oxidation. The UV light was more effective for the BPA degradation than the visible light. The removal efficiency improved with increasing intensity. As the drum speed increased, the removal efficiency improved. The maximum speed was 240 rpm in this study. Addition of air and nitrogen was not beneficial for the BPA degradation in this study probably due to enough oxygen in the water.

• Korean Chemical Engineering Research
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• 제53권1호
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• pp.71-77
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• 2015

D염색공단의 폴리에스테르 알카리 감량폐수가 혼합된 실제 혼합염색폐수를 처리하기 위하여 Pseudomonas sp. 및 Bacillus cereus/thuringiensis를 고정한 폐타이어담체를 충전한 유동상 바이오필터를 운전하였다. 또한 유동상 바이오필터와 450 W의 UV/광촉매반응기를 결합한 하이브리드 재순환시스템을 구축하여 stage I에서는 UV/광촉매반응기를 바이패스하고 유동상 바이오필터만을, stage II-i, ii, iii에서는 하이브리드 재순환시스템을 각각 운전하였다. 유동상 바이오필터만을 사용하였을 경우에 $COD_{Cr}$ 및 색도 제거효율은 각각 75~80% 및 67%를 나타내었다. 한편 하이브리드 재순환시스템 운전에서 stage I에서 stage II-i로 전환되었을 때에 UV/광촉매산화공정의 $COD_{Cr}$ 제거율이 20~30%에 달하여 총 $COD_{Cr}$ 제거율은 75%로부터 80~85%까지 제고되었다. 한편 stage I에서 stage II-i로 전환되었을 때에 UV/광촉매산화공정의 색도제거율은 0~5%에 불과하였으나 총 색도제거율은 45~65%로부터 65~70%까지 제고되었다. 색도 제거에서는 $COD_{Cr}$ 제거와 다르게 UV/광촉매산화공정에 의하여 유동상 바이오필터의 효율이 제고되어서 하이브리드 재순환시스템의 시너지효과가 나타났다. 또한 색도제거에서는 $COD_{Cr}$ 제거와 다르게 반송비 증가에 따른 광촉매 비활성화가 관찰되지 않았고, $COD_{Cr}$ 제거에서 반송비 증가에 따른 광촉매 비활성화는 비가역적으로 관찰되었다.

• 한국환경보건학회지
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• 제25권3호
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• pp.64-69
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• 1999

This study was carried out the removal of Cr(VI) which was known to the toxic pollutant in industry using the process of UV and TiO$_2$ photocatalyst in a circular type reactor. In this experiment, the series of photocatalytic process for the removal of Cr(VI) has been selected as a model reaction in a circular type reactor in order to obtain the basic data on the influence of various experimental parameters such as circulation flow rate, pH of solution, initial Cr(VI) light illumination and TiO$_2$ dosage, and salicylic acid concentration. The results of this study were as follows; 1. With both UV light illumination and TiO$_2$ present, Cr(VI) was more effectively eliminated than with either UV or TiO$_2$ alone. 2. As the circulation flow rate of solution increased, the removal efficiency of Cr(VI) was increased. However, over 2.4 l/min of circulation flow rate, the efficiency wa limited. 3. A increase in the photocatalytic removal of Cr(VI) was noticed with decreasing pH. 4. An increase in the photocatalytic removal of Cr(VI) was noticed with decreasing Initial Cr(VI) concentration and first order kinetics was observed from the result at different initial concentration of Cr(VI). 5. Photocatalytic removal efficiency of Cr(VI) increased with increasing TiO$_2$ dosage. However, over 1.0 g/l of TiO$_2$ dosage, the efficiency reached a plateau. 6. As low concentration of saliculic acid were added, there was an increase in the removal efficiency of Cr(VI). However, over 300 mg/l of salicylic acid, the efficiecy was decreased. It eas found that application of photocatalysis to water treatment that contains both Cr(VI) and salicylic acid was possible.

• Korean Chemical Engineering Research
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• 제50권6호
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• pp.945-951
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• 2012

광촉매반응기의 충전제로서 glass bead-광촉매담체를 control로 하고 다공성의 silica-based 광촉매담체를 사용하였을 때의 악취 및 VOC를 함유한 폐가스의 광촉매 처리효율에 대한 광촉매담체 다공성의 영향평가를 수행하였다. 다공성의 silica-based-광촉매담체의 광촉매 코팅량은 $1,716.3{\mu}g/cm^2$로서 nonporous glass bead(control)에 담지된 광촉매코팅량인 $670{\mu}g/cm^2$ 값의 약 250%이었다. Porous silica-based 담체가 충전된 광촉매반응기의 황화수소 및 톨루엔 제거효율은 각각 22% 및 82%로서, glass-bead 담체가 충전된 UV/광촉매반응기의 경우의 황화수소 및 톨루엔 제거효율인 각각 19% 및 53%와 비교하였을 때에 황화수소의 경우는 약 16% 증가하였고 톨루엔의 경우는 약 55% 증가하였다. 따라서 다공성의 silica-based 광촉매담체를 사용함으로써 황화수소와 톨루엔의 동시처리효율을 각각 제고하였고, 처리효율의 제고율은 황화수소보다 톨루엔의 경우가 3.4배 높았다.

• 한국환경과학회지
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• 제11권7호
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• pp.757-763
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• 2002

The objective of this study is to delineate removal efficiency of the Linear alkylbenzene sulfonates(LAS) in solution by $TiO_2$ photocatalytic oxidation as a function of the following different experimental conditions : initial concentration of LAS, $TiO_2$ 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 $TiO_2$ concentration but was almost the same at $TiO_2$ 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 $TiO_2$ concentration of 0.5 g/L but 100% after 150 min in the case of $TiO_2$ concentration of 1 g/L, 100% after 110 min in the case of $TiO_2$ 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.

• 한국재료학회지
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• 제32권4호
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• pp.223-229
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• 2022

A porous photocatalyst concrete filter was successfully produced to remove NOx, by mixing TiO₂ photocatalyst with lightweight aerated concrete. Ultra Fine Bubbles were used to form continuous pores inside the porous photocatalytic concrete filter, which was mixed via a bubble generation experiment. The optimal mixing condition was determined to be with 4 % of the bubble generation agent B. NO removal specimens were prepared for various photocatalytic loading conditions, and the specimen containing 3 % P-25 removed NO at a concentration of 1.03 µmol in 1 h. The NO removal rate of the porous photocatalytic concrete filter prepared in this study was 10.99 %. This photocatalytic filter performance was more than 9 times the amount of NO removed by a general photocatalytic filter. The porous photocatalyst concrete filter for removing NOx developed in this study can be applied to various construction sites and the air quality can be solved by reducing NOx contributing to the formation of fine particles.