고도정수처리를 위한 관형 세라믹 정밀여과와 이산화티타늄(TiO2) 광촉매 첨가 PES (polyethersulfone) 구의 혼 성공정에서 주기적 물 역세척 시 유기물질의 영향 및 정밀여과(MF), PES 구 흡착, 광산화의 역할을 막오염에 의한 저항(Rf) 및 투과선속(J), 총여과부피(VT) 측면에서 기존의 질소 역세척 결과와 비교하였다. 휴믹산 농도가 증가함에 따라 급격한 막 오염으로 Rf는 증가하고 J는 감소하여, VT는 휴믹산 농도 2 mg/L에서 가장 높았다. 탁도 처리효율은 물과 질소 역세척 모 두 휴믹산 농도와 상관없이 비슷하였다. 유기물질 처리효율은 물 역세척 경우 최대 휴믹산 10 mg/L에서 최소 71.4%이었으나, 질소 역세척에서는 거의 일정하였다. 물과 질소 역세척 모두 MF 및 PES 구, 자외선의 혼성공정(MF + TiO2 + UV)에서 Rf가 최소이고, J와 VT는 최대였다. 탁도 및 유기물질의 처리효율도 물과 질소 역세척에 상관없이 MF + TiO2 +UV에서 최대였 고, 공정이 MF로 단순화될수록 처리효율도 점차 감소하였다. 하지만 물 역세척에서는 광산화 보다 흡착이, 질소 역세척에 서는 흡착 보다 광산화가 더 주요한 역할을 하였다.
고도정수처리를 위한 관형 세라믹 정밀여과와 이산화티타늄(TiO2) 광촉매 첨가 PES (polyethersulfone) 구의 혼성공정에서 유기물질의 영향 및 정밀여과(MF), PES 구 흡착, 광산화의 역할을 막오염에 의한 저항(Rf) 및 투과선속(J), 총여과부피(VT)를 통해서 비교 및 고찰하였다. 휴믹산의 농도가 증가함에 따라 급격한 막오염으로 인해 Rf 는 증가하고 J는 감소하였으며, VT는 휴믹산의 농도가 2 mg/L인 조건에서 가장 높았다. 광산화와 흡착의 영향을 알아보기 위해 휴믹산의 농도 4 mg/L와 6 mg/L에서의 결과를 비교하였다. 두 가지 조건에서 공통적으로 정밀여과(MF)만의 단독공정에서 막오염이 급격하게 진행되어 Rf값이 가장 높게 나타났고, 총여과부피(VT)는 광촉매와 자외선의 혼성공정(MF + TiO2 + UV)에서 가장 높은 값을 나타내었다. 탁도와 유기물질의 평균처리효율은 MF + TiO2 + UV 공정에서 가장 높은 값을 나타내었다.
탄소 한외여과막 및 광촉매 혼성 수처리를 위해 관형 여과막 외부와 원통형 막 모듈 내부 사이 공간에 광촉매를 충전하였다. 광촉매는 PP (polypropylene) 구에 이산화티타늄 분말을 플라즈마 화학증착 공정으로 코팅한 것이다. 휴믹산과 카올린 모사용액을 대상으로 막오염을 최소화하기 위해 10분 주기로 10초 동안 물 역세척을 시행하였다. 기존 결과와 동일하게 휴믹산을 10 mg/L부터 2 mg/L로 변화시킴에 따라, 막오염에 의한 저항(Rf)이 감소하여 2 mg/L에서 최대 총여과부피 (VT)를 얻었다. 탁도와 휴믹산의 처리효율은 각각 98.9%와 88.7% 이상이었다. UF 및 UF + TiO2, UF + TiO2 + UV 공정의 처리 분율 결과, 광촉매 흡착과 광산화에 의해 탁도는 거의 처리되지 않았으나, 광촉매 흡착 및 광산화에 의한 휴믹산 처리 분율은 각각 2.5%, 12.3%이었다. 기존 결과와 비교하면, 분리막의 재질과 기공의 크기에 따라 광촉매 흡착과 광산화에 의한 휴믹산의 처리 분율이 다르게 나타났다. 공정이 단순화될수록 180분 운전 후 막오염 저항(Rf,180)은 증가하였고, 최종 투과선속(J180)은 소폭 감소하였다.
본 연구에서는 정수처리용 세라믹 한외여과 빛 광촉매의 혼성공정에서 휴믹산 농도 및 광산화, 흡착의 영향을 알아보았다. 휴믹산 농도 각각 2mg/L와 4 mg/L 일 때 UF 단독 공정 및 광촉매를 투입한 공정, UV를 조사한 공정을 막오염에 의한 저항(Rf) 및 투과선속(J), 총여과부피 (VΤ) 측면에서 고찰하였다. 휴믹산 농도가 낮아질수록 Rf는 급격히 감소하고 J는 증가하여, 휴믹산 농도 2 mg/L에서 VΤ는 가장 높았다. 탁도의 평균 처리효율은 휴믹산 농도가 증가할수록 감소하였으나, 4 mg/L에서 휴믹산의 처리효율이 가장 높았다. 이러한 결과는 낮은 휴믹산 농도에서 휴믹산 대부분이 분리막에 의해 제거되고 막을 통과한 일부 휴믹산은 광촉매에 흡착 산화되어, 처리수의 수질이 휴믹산 2 mg/L 와 4 mg/L 에서 거의 같고 원수의 수질은 4 mg/L에서 더 높기 때문이다. 광산화와 흡착의 영향 실험에서 UF + TiO2 + UV 공정의 J가 가장 높게 유지되어, 180분 운전 후 VΤ가 가장 높았다. 휴믹산 및 탁도의 처리효율을 비교한 결과, 휴믹산 농도가 2 mg/L 에서 4mg/L로 증가하였을 때 광산화 보다 광촉매 흡착이 더 주요한 역할을 하였다.
In order to investigate the effect to antioxygenic substances in Pine Needles on the photooxidation of linoleic acid (linoleic acid 100mg/10ml ethanol) added antioxidants and antioxygenic substances in Pine Needles was irradiated by the tungsten lamp attached with red fitter. The Photo oxidation of linoleic acid (LA) was conformed with Lea method and rhodan method. The following results were obtained: 1. Photooxidation of LA was greatly increased the presence of photosensitizer. However the Photo oxidation of LA without photosensitizer was smoothly increased by the irradiation. 2. The Photo oxidation of LA without irradiation occured quite lately whether photosensitizer was present or absent. 3. Photooxidation of LA under the presence of photosensitizer was inhibited by the addition of dl-α-tocopherol and the acetone fraction of methanol extract of Pine Needles but inhibited by BHT. Photooxidation of LA increased gradually as the addition of BHT increased but decreased gradually as that of acetone fraction increased.
To investigate the protective action of various antioxidants on the photooxidation of rice bran oil, it was irradiated with red and visible light in presence and absence antioxidants with or without sensitizer (methylene blue). 1. Rice bran oil with and without sensitizer in chloroform-ethanol (4:1, v/v) media was largely oxidized under visible light irradiation. on the other hand, rice bran oil without sensitizer was hardly oxidized under red light irradiation. 2. Rice bran oil with sensitizer was oxidized much faster than that without. And the absorbance of it irradiated with visible was increased more than that with red light. 3. The effectiveness of antioxidants on the rice bran oil photooxidation was same order as follows: Irradiation with visible light, no addition of sensitizer β-carotene 〉 dl-α-tocopherol 〉 BHT 〉 BHA Irradiation with visible light, addition of sensitizer β-carotene 〉 BHT 〉 dl-αtocopherol 〉 BHA Irradiation with red light, addition of sensitizer β-carotene 〉 BHA 〉 BHT 〉 dl-α-tocopherol From these results, we concluded that rice bran oil was largely oxidized under visible light irradiation, therefore it must be protected from photooxidative deterioration by the addition of antioxidants.
This study introduces a method to eliminate formaldehyde and benzene, toluene from indoor air by means of a photocatalytic oxidation reaction.
In the method introduced, for the good performance of the reaction, the effect and interactions of the TiO2 catalyst and ultraviolet in photocatalytic degradation on the reaction area, dosages of catalysts, humidity and light should be precisely examined and controled. Experiments has been carried out under various intensities of UV light and initial concentrations of formaldehyde, benzene and toluene to investigate the removal efficiency of the pollutants. Reactors in the experiments consist of an annular type Pyrex glass flow reactor and an 11W germicidal lamp. Results of the experiments showed reduction of formaldehyde, benzene and toluene in ultraviolet /TiO2/ activated carbon processes (photooxidation-photocatalytic oxidation-adsorption processes), from 98% to 90%, from 98% to 93% and from 99% to 97% respectively. Form the results we can get a conclusion that a ultraviolet/Tio2/activated carbon system used in the method introduced is a powerful one for th treatment of formaldehyde, benzene and toluene of indoor spaces.
In this study, The decomposition of gas-phase Benzene and Toluene, Xylene in air streams by direct UV Photolysis, UV/TiO2 and UV/TiO2/A.C process was studied. The experiments were carried out under various UV light intensities and initial concentrations of B.T.X to investigate and compare the removal efficiency of the pollutant. B.T.X was determined by GC-FID of gas samples taken from the a glass sampling bulb which was located at reactor inlet and outlet by gas-tight syringe.
From this study, the results indicate that UV/TiO2/A.C system (photooxidation-photocatalytic oxidation-adsorption process) is ideal for treatment of B.T.X from the small workplace. Although the results needs more verifications, the methodology seems to be reasonable and can be applied for various workplace (laundry, gas station et al.).
In this study, the decomposition of gas-phase TCE, Benzene and Toluene, in air streams by direct UV Photolysis and UV/TiO2 process was studied.
For direct UV Photolysis, by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene and Benzene in this work were determined to be 0.00392s-1, 0.00230s-1 and 0.00126s-1, respectively. And the adsorption constant K of TCE, Toluene and Benzene in this work were determined to be 0.0519mol-1 ,0.0313mol-1 and 0.0084mol-1, respectively. For UV/TiO2 system by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene, and Benzene in this work were determined to be 5.74g/ℓ․min, 3.85g/ℓ․min, and 1.18g/ℓ․min, respectively. And the catalyst adsorption constant K of TCE, Toluene, and Benzene in this work were determined to be 0.0005m3/mg, 0.0043m3/mg and 0.0048m3/mg, respectively.
Industrial waste water which was highly loaded by halogenide phenols was photooxidized by laboratory-scale photooxidation of these organic impurities in the presence of aerotropic and titaniumdioxide as photocatalyst.
The disappearance of organic compounds was determined as a function of the irradiation time. Some contaminants such as 2-chlorophenol, 2-bromophenol, 3-bromophenol, 4-bromophenol, 2,4-dibromophenol and 2,6-dibromophenol were photodegraded separately to obtain information on the reaction rates, reactivities, and reaction mechanisms of the photooxidation, and on the stoichiometric correlation between organic reactant and inorganic products concentration in the course of the photocatalytic photoreaction.