• Title/Summary/Keyword: photocatalyst

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A Study on the Removal of Organics and Cr(VI) Using Photocatalyst (광촉매를 이용한 유기물과 Cr(VI)의 제거에 관한 연구)

  • 김현용;김영규;양원호;조일형;이소진;정동균;이홍근
    • Journal of environmental and Sanitary engineering
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    • v.14 no.4
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    • pp.21-28
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    • 1999
  • This study was carried out the simultaneous removal or organics and Cr(VI) in aqueous suspensions of phtocatalyst under circular type reactor and UV light illumination. In this experiment, comparison on the removal of Cr(VI) by photoreduction using UV light, photocatalyst adsorption using TiO2, ZnO, and FeCl3 as photocatalyst, and phtocatalysis using UV light with photocatalysts as well as the effect of experimental parameters such as phtocatalyst dosage, a kinds of organics and their concentration was examined. The major results of this study were as follows; 1. It was found that photocatalyst adsorption and phtocatalysis were applicable to the removal of Cr(VI), and Cr(VI) was more effectively eliminated by TiO2 than ZnO, and FeCl3. 2. phtocatalytic removal efficiency of Cr (VI) increased with increasing phtocatalyst dosage. However, over 1.0g/l of phtocatalyst dosage, the efficiency reached a plateau. 3. phtocatalytic removal of Cr(VI) was enhanced by addition of organics such as salicylic acid, mandelic acid, EDTA, and citric acid, and phtocatalytic oxidation of organics were also observed. 4. It was found that the simultaneous removal of organics and Cr(VI) using phtocatalysis was possible.

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PVDF-TiO2 coated microfiltration membranes: preparation and characterization

  • Shon, H.K.;Puntsho, S.;Vigneswaran, S.;Kandasamy, J.;Kim, J.B.;Park, H.J.;Kim, I.S.
    • Membrane and Water Treatment
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    • v.1 no.3
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    • pp.193-206
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    • 2010
  • Organic fouling and biofouling pose a significant challenge to the membrane filtration process. Photocatalysis-membrane hybrid system is a novel idea for reducing these membranes fouling however, when $TiO_2 photocatalyst nanoparticles are used in suspension, catalyst recovery is not only imposes an extra step on the process but also significantly contributes to increased membrane resistance and reduced permeate flux. In this study, $TiO_2$ photocatalyst has been immobilized by coating on the microfiltration (MF) membrane surface to minimize organic and microbial fouling. Nano-sized $TiO_2$ was first synthesized by a sol-gel method. The synthesized $TiO_2$ was coated on a Poly Vinyl Difluoride (PVDF) membrane (MF) surface using spray coating and dip coating techniques to obtain hybrid functional composite membrane. The characteristics of the synthesized photocatalyst and a functional composite membrane were studied using numerous instruments in terms of physical, chemical and electrical properties. In comparison to the clean PVDF membrane, the $TiO_2$ coated MF membrane was found more effective in removing methylene blue (20%) and E-coli (99%).

A Study on the Dye Wastewater Treatment Using TiO2 Photocatalyst/Ozonation (광촉매/오존을 이용한 염색폐수처리에 관한 연구)

  • Kim, Chang-Kyun;Chung, Ho-Jin;Kim, Jong-Suk
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.6
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    • pp.663-670
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    • 2007
  • This study was performed to provide basic information for evaluating the efficiency and applicable extent of photocatalysis and ozonation for the treatment of dye wastewater. The treatability of dye wastewater by $UV/TiO_2$ and $UV/TiO_2/O_3$ advanced oxidation process (AOP) was investigated under various conditions. The experiments were conducted in a batch reactor of 50 liters equipped with twelve UV Lamps of 16W. In $UV/TiO_2$ AOP, the removal efficiency of TCODMn and Color increased to 58% and 67% respectively with increasing UV intensity. Also, The removal efficiency of TCODMn and Color increased to 97% and 99% respectively with increasing $H_2O_2$. Acid area was more efficient than neutral and alkalic areas in wastewater treatment, and pH 5 was the most effective and the treatment efficiency continually increased as the amount of photocatalyst was increased. When the photocatalyst was increased, TCODMn was removed faster than Color.

Effect of Reduced Graphene Oxide in Photoanode on Photoelectrochemical Performance in Water Splitting for Hydrogen Production (수소생산을 위한 물 분해용 광전극에 도입된 환원된 산화그래핀이 광전기화학성능에 미치는 영향)

  • YOON, SANGHYEOK;DING, JIN-RUI;KIM, KYO-SEON
    • Journal of Hydrogen and New Energy
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    • v.27 no.4
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    • pp.329-334
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    • 2016
  • Hydrogen is eco-friendly alternative energy source and the photoelectrochemical water splitting is believed to be one of the promising methods for hydrogen production. Many researchers have studied several potential photocatalysts to increase the photoelectochemical performance efficiency for hydrogen conversion. In this study, the GO (graphene oxide) was prepared by Tour's method and was dispersed in precursor solutions of $WO_3$ and $BiVO_4$. Those precursor solutions were spin-coated on FTO glass and several photocatalyst thin films of $WO_3$, $BiVO_4$ and $WO_3/BiVO_4$ were prepared by calcination. The morphologies of prepared photocatalyst thin films were measured by scanning electron microscope. The photoelectrochemical performances of photocatalyst thin films with rGO (reduced graphene oxide) and without rGO were analyzed systematically.

Preparation of C Doped TiO2 Photocatalyst Activating to Visible Irradiation and Investigation of Its Photocatalytic Activity (유성 볼밀법을 이용한 탄소 도핑 가시광 활성 TiO2 광촉매 제조 및 이의 특성 평가)

  • Yeo, In-Chul;Kang, In-Cheol
    • Journal of Powder Materials
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    • v.17 no.4
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    • pp.281-288
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    • 2010
  • A carbon doped $TiO_2$ (C-$TiO_2$) photocatalyst, which shows good photocatalytic activity to Ultraviolet irradiation and visible irradiation, was successfully prepared by co-grinding of $TiO_2$ with ethanol or Activated Carbon(C), followed by heat treatment at $200^{\circ}C$ in air for 60 min. Ethanol and C were used as a representative agent of liquid and solid for carbon doping. Their influence on improving photocatalytic ability and carbon doping degree was studied with degradation of methyl orange and XPS analysis. The product prepared by co-grinding of $TiO_2$ with Ethanol had Ti-C and C-O chemical bonds and showed higher photocatalytic activity than the product prepared by co-grinding of $TiO_2$ with C, where just C-O chemical bond existed. As a result, mechanochemical route is useful to prepare a carbon doped $TiO_2$ photocatalyst activating to visible irradiation, where the solid-liquid operation is more effective than solid-solid operation to obtain a carbon doped $TiO_2$.

Hybrid Water/Wastewater Treatment Process of Membrane and Photocatalyst (분리막 및 광촉매의 혼성 정수/하수 처리 공정)

  • Park, Jin Yong
    • Membrane Journal
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    • v.28 no.3
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    • pp.143-156
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    • 2018
  • In this review article, hybrid water/wastewater treatment processes of membrane and photocatalyst were summarized from papers published in various journals. It included (1) membrane photoreactor (MPR), (2) fouling control of a membrane coupled photocatalytic process, (3) photocatalytic membrane reactors for degradation of organic pollutants, (4) integration of photocatalysis with membrane processes for purification of water, (5) hybrid photocatalysis and ceramic membrane filtration process for humic acid degradation, (6) effect of $TiO_2$ nanoparticles on fouling mitigation of ultrafiltration membranes for activated sludge filtration, (7) hybrid photocatalysis/submerged microfiltration membrane system for drinking water treatment, (8) purification of bilge water by hybrid ultrafiltration and photocatalytic processes, and (9) Hybrid water treatment process of membrane and photocatalyst-coated polypropylene bead.

Pproperties of formaldehyde and CO2 adsorption type matrix using TiO2 photocatalysis (광촉매를 활용한 흡착형 경화체의 포름알데히드 및 CO2 특성)

  • Lee, Won-Gyu;Pyeon, Su-Jeong;Kyoung, In-Soo;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.11a
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    • pp.153-154
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    • 2018
  • As the air pollution progresses, the pollution degree of the indoor air quality is increased, and when the pollution degree of the indoor air quality is increased, it causes respiratory diseases and skin diseases. In addition, volatile organic compounds are released from the materials used for architectural interior decoration, and volatile organic compounds are the main cause of polluting indoor air quality. In order to improve indoor air quality, we tried to secure indoor air quality pollution by using photocatalyst which has the function of decomposing harmful substances. photocatalyst is a material that promotes chemical reaction by absorbing light. The photocatalyst used in the experiment was TiO2, In this study, an adsorption type hardener for reducing volatile organic compounds was prepared by photocatalytic reaction. the formaldehyde and CO2 concentrations of the cured products were analyzed according to the TiO2 content.

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A study on the Functional Properties of Polyester Fiber Treated Titanium Dioxide Photocatalyst (이산화티타늄 광촉매를 처리한 Polyester 섬유의 기능성 연구)

  • Choi, Sei Young
    • Elastomers and Composites
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    • v.49 no.4
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    • pp.336-340
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    • 2014
  • The functionality such as deodorant, antibacterial, ultraviolet shielding of titanium dioxide self-actuated photocatalyst $Weltouch^{TM}$ treated polyester fiber was characterized in conditions without light. The deodorizing capacity was maintained more than 97% reduction irrespective of before washing and after 20 times repeated washing, and antimicrobial capacity was also retained more than 99.9% reduction. Titanium dioxide self-actuated photocatalyst was still maintained to the surface of polyester fiber without separation even after 20 times repeated washing. According to washing durability of polyester fiber, the reduction effect for ammonia was still retained even after 20 times repeated washing as much as before washing. The ultraviolet shielding capacity was still maintained at least 83% irrespective of before washing and 20 times repeated washing.

Developing a Testing Method for Antimicrobial Efficacy on TiO2 Photocatalytic Products

  • Kim, Jee-Yeon;Park, Chang-Hun;Yoon, Je-Yong
    • Environmental Engineering Research
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    • v.13 no.3
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    • pp.136-140
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    • 2008
  • $TiO_2$ photocatalyst has been known to exhibit a notable disinfecting activity against a broad spectrum of microorganisms. A lot of commercial $TiO_2$ photocatalyst products have been developed for antimicrobial purposes. However, a standard method has not yet been proposed for use in testing antimicrobial activity. In this study, we developed a $TiO_2$ photocatalytic adhesion test method with film as the standard testing method for the evaluation of antimicrobial activity. This method was devised by modifying the previous antimicrobial products test method, which has been widely used, and considering the characteristics of $TiO_2$ photocatalytic reaction. The apparatus for testing the antimicrobial activity was composed of a Black Light Blue (BLB) lamp as UV-A light source, a Petri dish as the cover material, and a polypropylene film as the adhesion film. The standard $TiO_2$ photocatalyst sample, Degussa P25 $TiO_2$ - coated glass, could only be used once. The optimal initial concentration of the microorganism, proper light intensity, and light irradiation time were determined to be $10^6$ CFU/mL, 1.0 mW/$cm^2$, and 3 hr, respectively, for testing and evaluating antimicrobial activity on the $TiO_2$ surface.

Development of air-sterilization purification system of fusion and composite structure using broadband-to-active photocatalyst (광대역대 활성광촉매를 활용한 융·복합 구조 공기살균정화장치 개발)

  • Yoon, Sueng-Bae;Hwang, Yun-Jung;Kim, Seung-Cheon
    • Journal of the Korea Convergence Society
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    • v.10 no.4
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    • pp.147-151
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    • 2019
  • Modern people spend most of their daily lives in their homes, schools, or workplaces, hospitals, shopping malls, subway stations, rooms, and parking lots. According to the survey, air quality management at the multi-use facility is less than 50% satisfied. In this study, a photocatalytic filtration system is developed by utilizing a broadband-to-active photocatalyst that utilizes a media photocatalyst filter that removes airborne germs from indoor air as well as indoor air quality and operates on visible light as well as ultraviolet light.