• Journal of Environmental Health Sciences
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• v.40 no.6
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• pp.477-483
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• 2014

Objectives: This study was carried out to investigate the characteristics of odors emitted from sewage in a sanitary sewer and its outlets. Methods: The concentration of mal-odorous sulfur was analyzed by gas chromatograph, and odor intensity was estimated by an on-site sensory test. Odor intensity calculated from instrumental analysis results was compared with odor intensity observed at field. Results: As a results, the concentration of $H_2S$ ranged from 2.4 ppb to 5,889 ppb (average 703 ppb), while $CH_3SH$, $(CH_3)_2S$, and $(CH_3)_2S_2$ showed from 10 ppb to 554 ppb (average 119 ppb) and from 20 ppb to 332 ppb (average 70 ppb) and from 2.7 ppb to 8.1 ppb (average 5 ppb) individually. Average odor intensity observed in the field was degree three. Odor intensity calculated from sulfur compound concentration was confirmed as similar to the observed odor intensity because the coefficient of variance between the observed and the calculated intensities was less than one. Conclusion: It was expected that the results of this study will be helpful to design a deodorizing device to reduce odor emissions from sewerage facilities in the future.

• Environmental Engineering Research
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• v.13 no.3
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• pp.119-124
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• 2008

Ammonia is an inorganic compound that may cause severe odor problem. In this study the effectiveness of applying natural neutralizer to destroy and remove the odor-causing compound from gas streams was studied. Experimental result evaluated with a bench-scale apparatus via the neutralization of gas phase. This indicates that the natural neutralization depends on the gas concentration, gas residence time, temperature and pH. Removal efficiency of ammonia from gas stream was achieved by 95% using theconvection in the packed bed. This study proved the chemical neutralization technology was effective for controlling inorganic odor-causing compound.

• Journal of Sensor Science and Technology
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• v.24 no.1
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• pp.29-34
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• 2015

This study aimed to evaluate the characterization of a metal oxide semiconductor and electrochemical gas sensor array for measuring wastewater odor. The sensitivity of all gas sensors observed in sampling method by stripping was 6.7 to 20.6 times higher than that by no stripping, except sensor D (electrochemical gas sensor). The average reduction ratio of sensor signal as a function of initial dilution rate of wastewater was in the order of food plant > food waste reutilization facility > plating plant. The sensitivity of gas sensors was dependent on both the type of wastewater and the dilution rate. The sensor signals observed by the gas sensor array were correlated with the dilution factor (OU) calculated by the air dilution sensory test with several wastewater ($r^2=0.920{\sim}0.997$), except the sensor signals of sensor D measured in the plating plant wastewater. It seems likely that the gas sensor array plays a role in the evaluation of odor in wastewater and is useful tool for on-site odor monitoring in the wastewater facilities.

• Journal of Biosystems Engineering
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• v.39 no.2
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• pp.76-86
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• 2014

Purpose: The objective of this study was to measure emissions of gases (ammonia ($NH_3$), hydrogen sulfide ($H_2S$) and carbon dioxide ($CO_2$)), volatile organic compounds (VOC) and odor from two shallow pit pig nursery rooms. Gas and odor reduction practices for swine operations based on the literature were also discussed. Methods: This study was conducted for 60 days at a commercial swine nursery facility which consisted of four identical rooms with mechanical ventilations. Two rooms (room 1 (R1) and room 2 (R2)) with different pig numbers and ventilation rates were used in this study. The pig manure from both the R1 and R2 were characterized. Indoor/outdoor temperatures, ventilation rates/duration, $NH_3$, $H_2S$, $CO_2$, and VOC concentrations of the ventilation air were measured periodically (3-5 times/week). Odor concentrations of the ventilations were measured two times on two days. Three different types of gas and odor reduction practices (diet control, chemical method, and biological method) were discussed in this study. Results: The volatile solids to total solids ratio (VS/TS) and crude protein (CP) value of pig manure indicated the pig manure had high potential for gas and odor emissions. The $NH_3$, $H_2S$, $CO_2$ and VOC concentrations were measured in the ranges of 1.0-13.3, 0.1-5.7, 1600-3000 and 0.0-1.83 ppm, respectively. The $NH_3$ concentrations were found significantly higher than $H_2S$ concentrations for both rooms. The odor concentrations were measured in the range of $2853-4432OU_E/m^3$. There was significant difference in odor concentrations between the two rooms which was due to difference in pig numbers and ventilation duration. The literature studies showed that simultaneous use of dietary control and biofiltration practices will be more effective and environmentally friendly for gas and odor reductions from pig barns. Conclusions: The gas and odor concentrations measured in the ventilation air from the pig rooms indicate an acute need for using gas and odor mitigation technologies. Adopting diet control and biofiltration practices simultaneously could be the best option for mitigating gas and odor emissions from pig barns.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.247-251
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• 2005

This research was performed for developing of biological treatment process of odor gas such as MEK, $H_{2}S$, and toluene, which is generated from the food waste recycling process. To establish the operational conditions of odor gas removal by small-scale biofiltration equipment, it was continuously operated by using toluene as a treating odor object. When the odor treating microorganisms were adhered to fibril form biofilter, high removal efficiency over 93% was obtained by biofilm formation. At 400 ppm of inlet odor gas concentration and 10 sec of retention time, the removal efficiency was 76% and 93% in 1st stage reactor and 2nd stage reactor, respectively. However, the removal efficiency remained over 97% at the operational conditions above 15 sec of retention time.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.3
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• pp.373-382
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• 2013

In this study, a biological odor treatment system was proposed to remove odor(foul smell) materials causing several problems in the closed sewage treatment plant. This odor treatment system was composed of a two-step biofilter system in one reactor. The two-step biofilter reactor was constructed with natural purification layer in upper part and artificial purification layer in lower part. The reed grasses of water purification plants were planted in the surface area and mixed porous ceramic media were filled with the lower part of biofilter reactor. By using the above experimental apparatus, the ammonia gas removal efficiency was attained to 98.3 % and the hydrogen sulfide gas removal efficiency was appeared more than 97.7 % which shows more effective than the conventional odor removal process.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.383-389
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• 2002

Odor sources of a chemical plant in Ulsan were surveyed and temperatures, humidities and flow rates of each exhaust gas were measured. The air samples collected from each source were transferred to the laboratory for sensory test and their odor concentrations were investigated. The odor emission rate of each source was estimated from the recorded results and assigned the sources expected to be needed for the odor prevention policy using the simple prediction equation of the affection by malodor to the nearest residential area. From the total odor emission rate of the examined plant and the relation table for expectable affection area it was concluded that total odor emission of this plant might be decreased for the prevention of residential complaint.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.8
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• pp.541-548
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• 2012

The objective of this study was to investigate emission characteristics of odorous compounds from the pneumatic waste collection plants (namely, A and B sites). The air samples were collected from each site, at a carrier gas inside the plant and an exhaust gas, to analyze complex odor and 22 odorous compounds. Ammonia, sulfur compounds, and acetaldehyde were the critical odorous components generated in the plants studied. Characteristics of odor at exhaust outlet varied according to the type of odor control engineering. In the analysis of the odor contribution degree of odor components based on odor threshold, site A shows that the odor contribution of dimethyl sulfide was found to be 26%, acetaldehyde 18%, and methyl mercaptan 14%. For site B, methyl mercaptan was 56% and both hydrogen sulfide and dimethyl sulfide were 15%.

• Journal of the Korean Institute of Gas
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• v.5 no.3 s.15
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• pp.36-44
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• 2001

In case of low odor level, accident probabilities are very high Otherwise, when the odorant concentration is too high, the deterioration of pipeline and governor facilities and the environmental problems may occur. Odorants fade in the pipeline and other equipment due to physical and chemical adsorption and reactions with odorant and materials. So, it is very important to maintain odorant concentration properly In this study, the current status of odorization technologies has been reviewed. And the characteristics of small odorant system have been analyzed. In case that the small odorant system Is introduced in our country, this paper is proposed the feasible management plan and showed feasibility results through the analysis of current available technology.

• 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.