• Journal of Korean Society for Atmospheric Environment
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• v.17 no.E2
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• pp.35-42
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• 2001

Recent development of photocatalytic degradation method that is mediated by TiO$_2$ is of interest in the treatment of volatile organic compounds(VOCs). In this study, trichloroethylene(TCE) and acetone were closely examined in a batch scale of photo-reactor as a function of water vapor, oxygen, and temperature. Water vapor inhibited the photocatalytic degradation of acetone, while there was an optimum concentration in TCE. A lower efficiency was found in nitrogen atmosphere than air, and the effect of oxygen on photocatalytic degradation of acetone was greater than on that of TCE. The optimum reaction temperature on photocatalytic degradation was about 45$^{\circ}C$ for both compounds. NO organic byproducts were detected for both compounds under the present experimental conditions. It was ascertained that the photocatalytic reaction in a batch scale of photo-reactor was very effective in removing VOCs such as TCE and acetone in the gaseous phase.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.40-47
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• 2002

Because UV wavelength lights can activate photocatalysts, plasma is used as a light source of a photocatalytic reactor. Even though plasma has good intensity for photo reaction, substrate of catalyst coating was limited by the geometry of plasma generator. Usually bead type substrate was used for a pack bed type reactor. Honeycomb monolith type substrate was used with UV lamps instead plasma, due to the light penetration the honeycomb monolith length was too short to show good activity In this study a photocatalytic reactor, which is using a honeycomb monolith substrate, was investigated with plasma as an activation light source. As a parametric study the effects of 1311owing factors on plasma generation and power consumption are examined; supply voltage, substrate length, environment condition, catalyst loading and ratio. Using the test results, the practicability test was done with simulated synthetic gases representing bad smells and automotive exhaust gases.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.E3
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• pp.117-124
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• 2001

The present paper examined the kinetics of photocatalytic degradation of volatile organic compounds (VOCs) including gaseous trichloroethylene (TCE) and acetone. In this study, we examined the effects of the initial concentration of VOCs and the light intensity of ultra-violet (UV). A batch photo-reactor was specifically designed for this work. The photocatalytic degradation rate increased with the initial concentration of VOCs but remained almost constant beyond a certain concentration. It matched well with the Langmuir-Hinshelwood (L-H) kinetic model. When the effect of light intensity was concerned, it was found that photocatalytic degradation occurs in two regimes with respect to light intensity.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.382-390
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• 2010

In this research hydrogen sulfide, ammonia and toluene were designated as the representative source of malodor and VOC, respectively, frequently generated at the compost manufacturing factory and publicly owned facilities. The optimum operating condition to treat the waste air(2 L/min) containing malodor was constructed using photocatalytic reactor/biofilter process with humidifier composed of fluidized aerobic anf anoxic reactor. The ammonia(300 ppmv) of fed-waste air was removed by 22, 55 and 23% at the stage of photocatalytic reactor, humidifier and biofilter, respectively. The toluene(100 ppmv) of fed-waste air was removed by 20, 10 and 70% at the stage of photocatalytic reactor, humidifier and biofilter, respectively. Therefore the water-soluble ammonia and the water-insoluble toluene were treated mainly at the stage of humidifier and biofilter, respectively. In addition, hydrogen sulfide(10 ppmv) was almost treated at the stage of photocatalytic reactor and its negligible trace was absorbed in humidifier so that it was not detected before biofilter process. The nitrate concentration of the process water from anoxic reactor was found lower by 3 ppm than that from fluidized aerobic reactor. Besides, the dissolved ammonia-nitrogen concentration of the process water from humidifier remained at the high value of 1,500-2,000 ppm, which may be attributed to the existence of ammonium chloride and other source of ammonium nitrogen.

• Journal of Environmental Science International
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• v.12 no.12
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• pp.1277-1284
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• 2003

The photocatalytic oxidation of Rhodamine B (RhB) was studied using immobilized TiO$_2$ and fluidized bed reactor. Immobilized TiO$_2$ onto GF/C was employed as the photocatalyst and a 30 W germicidal lamp was used as the light source and the reactor volume was 4.8 L. The effects of parameters such as the amounts of photocatalyst, initial concentration, initial pH, air flow rate and anion additives (NO$_3$$\^$-/, SO$_4$$\^$2-/, Cl$\^$-/, CO$_3$$\^$2-/) competing for reaction. The results showed that the optimum dosage of the immobilized TiO$_2$ was 40.0 g/L. Initial removal rate of immobilized TiO$_2$ was expressed Langmuir - Hinshelwood equation.

• Journal of Energy Engineering
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• v.14 no.2 s.42
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• pp.105-111
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• 2005

In this study, the photocatalytic degradtion of D-glucose with the micro channel reactor was performed on the various experimental conditions. To apply the $TiO_2$ coating on the micro channel reactor, $TiO_2$ solution was synthesized by hydrolysis of titanium oxysulfate. The feeding rate was proportional to degradation rate of D-glucose solution over the micro channel reactor. Also, the reaction rate constant and Langmuir adsorption coefficient were calculated under various experimental conditions. And the results of these system photonic efficiencies were calculated. This study aims to understand the photocatalytic degradation characteristics on $TiO_2$ coating in the micro channel reactor experimented by the feed batch reaction system.

• Journal of Environmental Science International
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• v.12 no.12
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• pp.1255-1260
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• 2003

Plasma-photocatalytic oxidation process was applied in the decomposition of Triethylamine(TEA) and Methyl ethyl ketone(MEK). Plasma reactor was made entirely of pyrex glass and consists of 24mm inner diameter, 1,800mm length and discharge electrode of 0.4mm stainless steel. And initial concentrations of TEA and MEK for plasma-photocatalytic oxidation are 100 ppm. Odor gas samples were taken by gas-tight syringe from a glass sampling bulb which was located at reactor inlet and outlet, and TEA and MEK were determined by GC-FID. For plasma process, the decomposition efficiency of TEA and MEK were evaluated by varying different flowrates and decomposition efficiency of TEA and MEK increased considerably with decreasing treatment flowrates. For photocatalytic oxidation process, also the decomposition efficiency of TEA and MEK increased considerably with decreasing treatment flowrates. The decomposition efficiency of MEK was 57.8％, 34.2％, 18.8％ respectively and the decomposition efficiency of TEA was reached all 100％. This result is higher than that of plasma process only, From this study, the results indicate that plasma-photocatalytic oxidation process is ideal for treatment of TEA and MEK.

• Journal of Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.358-365
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• 2004

The photocatalytic oxidation of Rhodamine B(RhB) was studied using photocatalytic reactor filled with module of quartz tube. Module of quartz tube consisted of small quartz tube (inner diameter, 1.5 mm; outer diameter, 3 mm) bundle coated with powder $TiO_2$ and uncoated large quartz tube (inner diameter, 20 mm; outer diameter, 22 mm). Two 30 W germicidal lamp was used as the light source and the reactor volume was 0.5 l. The effects of parameters such as the coating materials and numbers, initial concentration, $H_{2}O_2$ dose and metal deposition (Ag, Pt and Fe) and simultaneous application of $H_{2}O_2$ and metal deposition. The results showed that the initial reaction constant of quartz module coated with powder $TiO_2$ was higher 1.4 time than that of the $TiO_2$ sol and optimum coating number is twice. In order to increase reaction rate, simultaneous application of photocatalytic and photo-fenton reaction using Fe coating and dose $H_{2}O_2$ dose increased reaction rate largely.

• Journal of Environmental Science International
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• v.13 no.9
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• pp.767-777
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• 2004

This study evaluated the technical feasibility of the application of $TiO_2$ photocatalysis for the removal of volatile hydrocarbons(VHC) at low ppb concentrations commonly associated with non-occupational indoor air quality issues. A series of experiments was conducted to evaluate five parameters (relative humidity (RH), hydraulic diameter (HD), feeding type (FT) of VHC, photocatalytic oxidation (PCO) reactor material (RM), and inlet port size (IPS) of PCO reactor) for the PCO destruction efficiencies of the selected target VHC. None of the target VHC presented significant dependence on the RH, which are inconsistent with a certain previous study that reported that under conditions of low humidity and a ppm toluene inlet level, there was a drop in the PCO efficiency with decreasing humidity. However, it is noted that the four parameters (HD, RM, FT and IPS) should be considered for better VHC removal efficiencies for the application of $TiO_2$ photocatalytic technology for cleansing non-occupational indoor air. The PCO destruction of VHC at concentrations associated with non-occupational indoor air quality issues can be up to nearly 100%. The amount of CO generated during PCO were a negligible addition to the indoor CO levels. These abilities can make the PCO reactor an important tool in the effort to improve non-occupational indoor air quality.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.E4
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• pp.157-168
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• 2003

This study evaluated the technical feasibility of the application of titanium oxide (TiO$_2$) photocatalysis for the removal of VOCs in low ppb concentrations commonly associated with non -occupational indoor air quality issues. A series of experiments were conducted to evaluate four parameters (relative humidity (RH), hydraulic diameter (HD), photocatalytic oxidation (PCO) reactor material (RM), and inlet port size (IPS) of PCO reactor) for the PCO destruction efficiencies of the selected target VOCs. None of the target VOCs presented significant dependency on the RH, which is inconsistent with a few previous studies. However, it is noted that the three parameters (HD, RM and IPS) should be considered for better VOCs removal efficiencies for the application of TiO$_2$ photocatalytic technology for cleansing non -occupational indoor air. The PCO destruction of VOCs at concentrations associated with non-occupational indoor air quality issues can be up to nearly 100％. The amount of CO generated during PCO would be negligible in comparison to the indoor CO levels. These results can make the PCO reactor an important tool in the effort to improve non-occupational indoor air quality.