• Clean Technology
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• v.23 no.1
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• pp.113-117
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• 2017

We prepared sodium carbonate impregnated activated carbon fiber and evaluated its availability for hydrogen sulfide removal by the comparison with the counterpart, sodium carbonate granular impregnated activated carbon. The sodium carbonate impregnated concentration and immersion duration were chosen as two primary parameters. First, the hydrogen sulfide adsorption capacity increased in proportion to the impregnated concentration up to 3 wt%, above which the sodium carbonate impregnated amount rarely showed an increase due to the pore filling effect for both cases. The optimal impregnated concentration was thus set to 3 wt%. Meanwhile, impregnated activated carbon fiber required only half of the immersion duration compared with granular impregnated activated carbon, while showing a 30% increase on the hydrogen sulfide removal capacity. The greater specific area of impregnated activated carbon fiber explained it. In conclusion, we evaluated advantage of preparation time and improved hydrogen sulfide adsorption capacity by impregnate sodium carbonate, which is capable of reacting with hydrogen sulfide chemically, onto the activated carbon fiber with improved specific area.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.6
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• pp.397-405
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• 2012

In this study, performance evaluation of newly developed technology for the economical and safe removal of volatile organic compounds (VOCs) coming out from electronic devices washing operation and offensive odor induction materials was made. Metal oxidization catalyst has shown 50% of removal efficiency at the temperature of $220^{\circ}C$. Composite metal oxidization catalyst applied in this study has shown that the actual catalysis has started at the temperature of $100^{\circ}C$. Comprehensive analysis on the catalyst property using Mn-Cu metal oxidization catalyst in the pilot-scale unit was made and the removal efficiency was variable with temperature and space velocity. Full-scale unit developed based on the pilot-scale unit operation has shown 95% of removal efficiency at the temperature of $160^{\circ}C$. Optimum elimination effective rates for the space velocity was found to be $6,000hr^{-1}$. The most appropriate processing treatment range for the inflow concentration of VOCs was between 200 ppm to 4,000 ppm. Catalyst control temperature showed high destruction efficiency at $150{\sim}200^{\circ}C$ degrees Celsius in 90~99%. External heat source was not necessary due to the self-heat reaction incase of VOCs inflow concentration is more than 1,000 ppm. Equipment and fuel costs compared to the conventional RTO/RCO method can be reduced by 50% and 75% respectively. And it was checked when there was poisoning for sulfide and acid gas.

• Clean Technology
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• v.13 no.2
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• pp.122-126
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• 2007

When ammonia ($NH_3$) gas was supplied to a biofilter packed with bio-carrier made of waste polyurthane and worm cast. No odor gases were detected at the outlet of the biofilter when $NH_3$ gas was supplied to the biofilter at the space velocity(SV) of $50\;h^{-1}$ until the inlet $NH_3$ concentration increased to $4\;{\sim}\;454\;ppmv$. The gradual inlet $NH_3$ concentration was set and the removal efficiency of $NH_3$ gas was measured at each condition, while the SV of $NH_3$ increased step by step from 100 to $400\;h^{-1}$. The maximum possible inlet $NH_3$ loading was $11.38\;g-NH_3{\cdot}m^{-3}{\cdot}h^{-1}$ and $34.42\;g-NH_3{\cdot}m^{-3}{\cdot}h^{-1}$ while maintaining the removal efficiency of 100% when the SV was $50\;h^{-1}$ and $100 \;h^{-1}$, respectively. The maximum $NH_3$ loading was $71.28 \;g-NH_3{\cdot}m^{-3}{\cdot}h^{-1}$ with the $NH_3$ removal efficiency of 99.85% at SV $300\;h^{-1}$.

• Culinary science and hospitality research
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• v.12 no.1 s.28
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• pp.93-110
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• 2006

Eumsik-dimibang is the oldest and first cooking recipe book in Korean language ever published in Korea. It was examined in order to find out food ingredients being used as side dishes and its cooking methods used at that time. As side dishes, there were many foods which used dogs as food ingredients for making Gae Jang Jim and Gae Jang etc. as well as Dong A such as Dong A Nurumi and Dong A sun. Also, there were many foods prepared by Nurumi cooking method for making Gae Jang Guk, Nurumi, eggplant Nurumi etc. From cooking methods for food ingredients for side dishes at that time, following characteristics could be found. First, there was a cooking method of broiling meat on fire after blanching it in water. Second, many cooking methods were used to remove fetid smells and fishy smells (using ginger, pepper, cheoncho etc). Third, there was a method which demanded much attention and devotion in the course of cooking. Fourth, use and cooking method of flour were diversified.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.6
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• pp.674-681
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• 2008

Silver as a metal catalyst has been used to remove odorous compounds. In this study, silver particles in nano sizes ($5{\sim}30nm$) were prepared on the surface of $NaHCO_3$, the supporting material, using a sputtering method. The silver nano-particles were dispersed by dissolving $Ag-NaHCO_3$ into water, and the dispersed silver nano-particles in the aqueous phase was applied to remove inorganic odor compounds, $NH_3$ and ${H_2}O$, in a scrubbing reactor. Since ammonia has high solubility, it was removed from the gas phase even by spraying water in the scrubber. However, the concentration of nitrate (${NO_3}^-$) ion increased only in the silver nano-particle solution, implying that the silver nano-particles oxidized ammonia. Hydrogen sulfide in the gas phase was rapidly removed by the silver nano-particles, and the concentration of sulfate (${SO_4}^{2-}$) ion increased with time due to the oxidation reaction by silver. As a result, the silver nano-particles in the aqueous solution can be successfully applied to remove odorous compounds without adding additional energy sources and producing any harmful byproducts.

• The Journal of Industrial Distribution & Business
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• v.10 no.12
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• pp.15-23
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• 2019

Purpose : We will develop the distribution method of wide oil extract technology to develop repellent using this technology and study mosquito repellent persistence. Research design, data and methodology : A positive control group containing purified water, ethanol and picaridin was prepared, and the experimental control group was prepared in the same proportion as the positive control group, and 0.6% of broad oil was added. The results were summarized using the calculation method according to the avoidance effect and statistically tested by t-test using the excel statistics program. Results : Experiments on skin surface area and voice control of participants showed that men had 8.9% wider skin surface area than women, and voice control tests showed that women were bitten by mosquitoes five times more than men. Both the positive and the experimental control groups had a valid duration of up to three hours, but from the time of five hours, the positive control group had 77% and the experimental control had 90%, indicating a difference of 14.4% over the positive control group. Conclusions : The mosquito repellents developed in this study on the basis of safety and continuity are cost-effective in terms of mosquito repellent, and in addition fragrance, odor removal, perfume, ink, skin care and massage effect.

• KSBB Journal
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• v.22 no.5
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• pp.336-340
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• 2007

Supercritical carbon dioxide was used to remove coffee odors. The odor removal efficiency was tested with coffee drink prepared by the espresso extraction method. Five typical odors in coffee were analyzed with GC and these odors in deodorized coffee were compared to those in control. Supercritical carbon dioxide extraction conditions were optimized as 350 bar and 70$^{\circ}C$ because the solvating power of supercritical fluid is depend on the density which is determined by temperature and pressure. A modified head space method was applied to collect coffee odors in coffee drink prepared by the espresso extraction method. Odors generated in coffee drink made with deodorized coffee powder were reduced by 73% in total mass of typical five coffee odors.

• Journal of Environmental Science International
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• v.18 no.4
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• pp.445-450
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• 2009

In this study, the fundamental experiments were performed for catalytic oxidation of NO (50 ppm) on $MnO_2$ in the presence of ozone. The experiments were carried out at various catalytic temperatures ($30-120^{\circ}C$) and ozone concentrations (50-150 ppm) to investigate the behavior of NO oxidation. The honeycomb type $MnO_2$ catalyst was rectangular with a cell density of 300 cells per square inch. Due to $O_3$ injection, NO reacted with $O_3$ to form $NO_2$, which was adsorbed at the $MnO_2$ surface. The excessive ozone was decomposed to $O^*$ onto the $MnO_2$ catalyst bed, and then that $O^*$ was reacted with $NO_2$ to form $NO_3^-$. It was found that the optimal $O_3$/NO ratio for catalytic oxidation of NO on $MnO_2$ was 2.0, and the NO removal efficiency on $MnO_2$ was 83% at $30^{\circ}C$. As a result, NO was converted mainly to $NO_3^-$.

• Journal of Animal Environmental Science
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• v.11 no.1
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• pp.17-24
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• 2005

Aerobic sequencing batch reactor (SBR) was used to treat screened dairy wastewaters. The study examined the production of volatile organic compounds (VOCs) and volatile fatty acids (VFAs) in the aerobic SBR and raw manure effluent storage over 35 days. The reduction of total VFAs in the aerobic SBR was over $59\%$ removal than that of the raw manure. Acetic acid production in the aerobic SBR and the raw manure effluent storage were kept 138 and 286 mg/L. The propionic acid in the aerobic SBR was 1.9 mg/L, while the raw manure effluent storage was 68 mg/L, respectively. The concentrations of VOCs in the aerobic SBR reactor and effluent fill down remarkably than the raw manure storage. The results confirmed that the aerobic biological treatment is an essential requirement for minimizing odor problems.

• Journal of odor and indoor environment
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• v.17 no.4
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• pp.396-403
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• 2018

In this study, volatile organic compounds (VOCs) emitted from printing industries were analyzed, and an inorganic adsorbent, ${\gamma}-alumina$, was selected for the effective control of the VOC emissions. Printing processes commonly require inks, thinners, and cleaners, and they were mixed organic solvents containing aromatic compounds, ketones, and alcohols. Therefore, toluene, methyl ethyl ketone (MEK), and isopropyl alcohol (IPA) were selected as model compounds for this study. The adsorptive properties using ${\gamma}-alumina$ were determined for the model compounds. Both batch isotherm and continuous flow column tests demonstrated that the adsorption capacity of MEK and IPA was 3~4 times higher than that of toluene. The column test performed at an inlet toluene concentration of 100 ppm showed that an 80% breakthrough for toluene was observed after 3 hours, but both MEK and IPA were continuously adsorbed during the same time period. A numerical model simulated that the ${\gamma}-alumina$ could remove toluene at a loading rate of 0.4 mg/min only for a 4-hour period, which might be too short of a duration for real applications. Consequently, lifetime enhancement for ${\gamma}-alumina$ must be implemented, and ozone oxidation and regeneration would be feasible options.