• Journal of Environmental Science International
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• v.1 no.2
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• pp.105.1-113
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• 1992

The present study was performed to develop the removal system of the offensive gases, including hydrogen sulfide of acid gas, ammonia or amice of base gas, from the nightsoil treatment plant. In order to remove the offensive gases, the Fe-EDTA system liquid phase catalytic oxidation method with the bubble lift column reactor was employed. From the results obtained, it was confirmed that the offensive gases can be deodorized simultaneously and also hydrogen sulfide of acid gas, ammonia of base gas completely removed at pH 6.45. In addition, as input gases feed rate the efficiency of acid gas did not change but the efficiency of base gases decreased to approximately 90 % at pH 6, 0. From the result of particle size analyzer, it was found that the particle sizes including sulfur and other impurites grew up to $21{\mu}m$ over 72hour reaction time.

• Journal of information and communication convergence engineering
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• v.6 no.1
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• pp.38-42
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• 2008

Highly sensitive and mechanically stable gas sensors have been fabricated using the microfabrication and micromachining techniques. The sensing materials used to detect the offensive $CH_3SH$ and $(CH_3)_3N$ gases are 1 wt% Pd-doped $SnO_2$ and 6 wt% $Al_2O_3$-doped ZnO, respectively. The optimum operating temperatures of the devices are $250^{\circ}C$ and $350^{\circ}C$ for $CH_3SH$ and $(CH_3)_3N$, respectively and the corresponding heater power is, respectively, about 55mW and 85mW. Excellent thermal insulation is achieved by the use of a double-layer membrane: i.e. $0.2{\mu}m$-thick silicon nitride and $1.4{\mu}m$-thick phosphosilicate glass. The sensors are mechanically stable enough to endure the heat cycles between room temperature and $350^{\circ}C$, at least for 30 days.

• The Korean Journal of Ceramics
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• v.6 no.3
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• pp.304-308
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• 2000

WO$_3$/SnO$_2$ceramics has been suggested as an effective sensing material for monitoring offensive odor or pollutant gases. This work was focussed on improving long-term stability, which has been a principal problem generally taking place in SnO$_2$semiconductor gas sensor. Miniaturized thick film gas sensors were fabricated by screen printing technique. Two types of sensor materials, W doped SnO$_2$and WO$_3$mixed SnO$_2$, were comparatively investigated on those long-term stability and sensitivites to several gases. Small amount of W doping(0.1 mol%) into SnO$_2$largely improved the long-term stability. The W(0.1 mol%) doped SnO$_2$gas sensor had higher sensitivities to both acetone and alcohol compared with WO$_3$(5 wt%) mixed SnO$_2$gas sensor. On the contrary, WO$_3$(5 wt%) mixed SnO$_2$gas sensor showed more superior sensitivity to cigarette smoke due to larger W content.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.6
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• pp.545-554
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• 2014

In general, odorant was added to fuel gases, such as LPG, LNG and city gas, to prevent gas poisoning, ignition, explosion, or other accident caused by fuel gases, and to enable immediate and easy detection of fuel-gas leakage by emitting an offensive smell. This study describes a study on the exhaust emissions characteristics and fuel economy of liquefied petroleum gas (LPG) vehicle using LPG fuel with new sulfur free odorant. New sulfur free odorant was added to LPG to reduce sulfur content of the LPG. Its performance and exhaust emission were compared to those of LPG with sulfur containing odorant (EM, ethyl mercaptan). Engine performance using LPG with sulfur free odorant was similar to that with sulfur-containing odorant. Exhaust emissions from the LPG vehicle with LPG including sulfur free odorant were also similar to those with LPG including sulfur containing odorant in the FTP 75 and NEDC mode. There experimental results suggest that the sulfur free odorant may substitute for the sulfur containing odorant in LPG fuel.

• Korean Journal of Organic Agriculture
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• v.8 no.2
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• pp.89-96
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• 2000

To reduce loss of nitrogen and generation of ammonia gas during composting, poultry manure and sawdust were mixed at the equivalent ratio and calcium chloride, fused superphosphate and vermiculite were added. Ammonia and sulfurous gas during composting, and NH4-N and NO3-N contents of composts were periodically measured. With the treatments of 0.5∼3% calcium chloride and 3% fused superphosphate, ammonia and sulfurous gas during composting significantly decreased, and especially generation of gases sharply reduced and a increase of calcium chlorde. Extractable NH4-N content in composts treasted with calcium chloride and fused superphosphate were high but extractable NO3-N markedly decreased. In conclusion, the results suggest that it is necessary the additon of 1∼3% calcium chloride or 3% fused superphosphate to reduce loss of nirogen and generation of offensive odor during composting of poultry manure mixed with sawdust.

• Journal of the Korean Society of Groundwater Environment
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• v.2 no.1
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• pp.1-8
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• 1995

Wastes produce groundwater contamination, offensive odor, and hazardous gases. This study investigates the contamination of groundwater at the Seokdae waste landfill area and seeks the desirable ways to minimize the groundwater contamination. Groundwater levels, water chemistry and aquifer characteristics of wells were examined around the Seokdae waste landfill. The water chemistry of the Dong stream, the groundwater distribution and flow were also studied. The results of this research show that the estimated quantity of the percolation from the landfill base to the ground is 520 ㎥/day and the extent of groundwater contamination is about 1-1.5 km from the center of the waste landfill. The groundwater contains heavy metals and other toxic elements. The conservation and management of the groundwater of the waste landfill need several monitoring wells to check the quantity and quality of groundwater, pumping wells to extract the contaminated groundwater, and slurry walls to protect the movement of contaminated groundwater.

• Journal of environmental and Sanitary engineering
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• v.24 no.2
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• pp.17-30
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• 2009

In Iksan city, there have been a lot of complaints caused by offensive odor from residents living near the public environmental infrastructures and the Iksan industrial complex. To solve these problems, it is important to know the present condition of odor pollution level in these areas, the emission characteristics of malodorous gases in temporal and spatial variations in addition to meteorological components, and the facilities of major sources emitting malodorous compounds. The objectives of this study is to make the odor monitoring network for 20 people who lived and worked in areas where the environmental infrastructures and the Iksan industrial complex are located and their neighboring areas for six months from June 1st to October 31st in 2008 in Iksan and to monitor the temporal and regional frequency and characteristics of odor intensity using direct olfactory methods. As a result of odor monitoring, the highest frequency of sensed odor per month and 20 people for six months was found to be 107 in July, followed by 84 in September, 80 in August, 54 in June, 38 in October, respectively. Odor intensity trend showed a regional trend in the decreasing order of Dongsan-dong, Busong-dong, and Palbong-dong. Odor was widely perceived from night through next morning and considered as the sense of excreta, chemicals, sewage, compost, waste, etc. When high odor intensity was sensed, there were constant meteorological characteristics: relative humidity was 80~90%, wind speed was less than 0.5~1 m/sec, and main wind directions were from the east, the southeast, and the south.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.88-95
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• 2014

In general, odorants are added to fuel gases, such as LPG, LNG and city gas, to prevent gas poisoning, ignition, explosion, or other accident caused by fuel gases, and to enable immediate and easy detection of fuel-gas leakage by emitting an offensive smell. This study describes a study on the performance and exhaust emissions (CO, THC, $CO_2$, $NO_x$, $SO_2$) characteristics of liquefied petroleum gas (LPG) engine using LPG fuel with new sulfur free odorant (K-Petro S-Free). New sulfur free odorant (40 mg/kg) was added to 2 type LPG fuels for summer, and winter and it was used in performance and exhaust emissions, compare to LPG fuel with sulfur containing odorant (EM, ethyl mercaptan). Engine performance using LPG with sulfur free odorant was similar to LPG with sulfur-containing odorant. Exhaust emissions (CO, THC, $CO_2$, $NO_x$) of LPG with sulfur free odorant were also similar characteristics, compare with sulfur containing odorant. Especially, $SO_2$ emission using LPG with K-Petro S-Free odorant was more reduced 83 % than LPG with sulfur containing odorant(EM) at 2000 rpm.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.386-390
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• 2005

This study was conducted to develop the biofilter fur reducing ammonia $(NH_3)$ and hydrogen sulfide $(H_2S)$ gas emission from a pig house. A biofilter was designed and constructed by a type of squeeze air into the column type of air flow upward. Its column size was ${\Phi}260{\times}360mm$. It was used pressure drop gauge, turbo blower, air temperature, velocity sensor and control program that was programed by LabWindows CVI 5.5. Mixing materials were consisted with composted pine tree bark and perlite with 7:3 ratio (volume). The biofilter media inoculated with ammonia (Rhodococcus equi A3) and hydrogen sulfide (Alcaligenes sp. S5-5.2) oxidizing microorganisms was installed in a commercial pig house to analyzed the effectiveness of biogas removal for 10 days. Removal rates of ammonia and hydrogen sulfide gases were 90.8% and 81.5%, respectively. This result suggests that the pine compost-perlite mixture biofilter is effective and economic for reducing ammonia ana hydrogen sulfide gases.

• Journal of the Korean Institute of Gas
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• v.18 no.5
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• pp.52-59
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• 2014

In general, sulfur containing odorants are added to fuel gases, such as LPG, and city gas, to prevent gas poisoning, ignition, explosion, or other accident caused by fuel gases, and to enable immediate and easy detection of fuel-gas leakage by emitting an offensive smell. In this study, sulfur free odorant for low sulfur fuel and prevention of metal corrosion were developed to replace current sulfur containing odorant for gas fuel. They were selected from 12 odorant containing non-sulfur organic compounds and evaluated by odor olfactory method (odor quality, odor intensity). Finally, selected mixture odorants were methyl isovalerate, methyl acrylate, 2-ethyl-3-methyl pyrazine with blending ratio of 50% : 40% : 10%. Final Sulfur free odorant was added 40 wt ppm in LPG fuels and evaluated fuel quality characteristics, metal corrosion test and long term stability of LPG fuel. It were limit in current LPG fuel standard in fuel quality characteristics. Final Sulfur free odorant also had no influence on metal corrosion and long term stability test with 60 days by adding in LPG fuels. Finally, they were shown to be warning agent candidates to reduce sulfur content and metal corrosion for LPG fuel.