• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.104-109
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• 2011

The removal efficiencies of 2-methylisoborneol (MIB) and geosmin were investigated to reveal removal characteristics of typical organic compounds causing disagreeable taste and odor at the conventional water treatment plant installed with pulsator clarifier patented by the French company $Degr{\acute{e}}mont$. The injection rate of Powdered Activated Carbon (PAC) into water was changed step wisely as we conducted jar tests in the laboratory and water treatment in the actual plant. 2-MIB concentration decreased linearly while geosmin did exponentially along with the injection rate of PAC at our jar tests. The removal efficiency of geosmin by PAC injection was considerably higher than that of 2-MIB. In the real pulsator clarifier, 2-MIB concentration started decreasing as the injection rate reached up to 10 mg/L of PAC. On the other hand, the concentration of geosmin in water decreased proportional to the injection rate of PAC. In the sand filtration, removal efficiencies of 2-MIB and geosmin on July were much higher than those on March. It was carefully suggested beforehand and found afterwards that general microorganisms notably existed in the sand filter with no chlorine in filter influent and backwash water and the sand filter biologically activated removed much more odor compounds. It was considered as the reason why the removal efficiency of 2-MIB and geosmin was increased. The microbial activity maybe increased in summer with water temperature rising and low filtration rate possibly increased contact time between odor compounds and general microorganisms.

• Particle and aerosol research
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• v.17 no.4
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• pp.115-123
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• 2021

The emission gas from meat grilled restaurants has unpleasant odor and sticky particulate matters (PM) in form of oil mist. This affects the residents living nearby. In oder to decrease the odor and PM, electrostatic precipitators (ESP) were installed at several restaurants by support of Seoul metropolitan government and emission characteristics of PM and odor were investigated. The removal efficiency of odor and PM at before- and after-ESP was that total hydrocarbon (THC), NH₃, H₂S, acetaldehyde, butyraldehyde were not much decreased. Total suspended particles (TSP) emitted from the vent was below the value of 7 mg/m³ regardless of the concentration of before-ESP and removal efficiency was in the range of 64 ~ 86%. The ratio of PM_1.0 to PM₁₀ of emission gas was over 0.9. So it was revealed that most PM of emission gas was PM1.0. The PM concentration in the air of the street near the vent was higher than another street due to the emission gas and the PM of indoor air of restaurant grilling meats was measured very high compared to outdoor air. So it needs more powerful ventilation of indoor air.

• KSBB Journal
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• v.20 no.5 s.94
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• pp.341-344
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• 2005

This research was performed for developing of biological treatment process of odor gas such as MEK, $H_2S$, and toluene, which was 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 1 st stage reactor and End 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.26 no.2
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• pp.237-247
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• 2012

This study assessed the removal characteristics of taste and odor causing compounds (2-methylisoborneol and geosmin) and organic matters, using a pilot-scale ozone/granular activated carbon ($O_{3}$/GAC) process treating surface water of Pal-dang reservoir in the Han river over a 3-month period. Experiments were conducted to verify the removal efficiency of $O_{3}$/GAC process which has two different empty bed contact time (EBCT) ($O_{3}$/GAC column 1 : 10 min and 2 : 15.1 min) with 10.86 min contact time of ozonation at 1.0 mg/L $O_{3}$. Spiking test using geosmin and 2-MIB was also conducted systematically to mimic the conditions when the algae appears, specifically at the levels similar to the concentrations experienced (geosmin: 250 ng/L) in the winter of 2011. In single ozonation process, organic materials, disinfection by-products (DBPs) and their precursors were disassembled but not removed completely. Meanwhile, it was verified that organic matters, taste and odor causing compounds, and DBPs were well removed when sequentially passing through the GAC process. The pilot results also showed that GAC column with larger EBCT achieved higher removal efficiency. Specifically, in spiking tests, single $O_{3}$ process showed approximately 89% removal efficiency of geosmin and 2-MIB. $O_{3}$/GAC combined process demonstrated excellent removal of geosmin and 2-MIB, which are higher than 95%.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.91-97
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• 2002

Removal of malodorous gases from swine manure by a polyurethane biofilter inoculated with heterotrophic and autotrophic bacteria was investigated. Ammonia, hydrogen sulfide and other gases could be efficiently treated at 3~3.6 second of empty bed retention time by the polyurethane biofilter. In the range of SV $200~l,200h^{-1}$ , the average removal efficiency of odor was about 89% when the odor unit of inlet gas was below 4100. Odor elimination capacity of the polyurethane biofilter was$ 1.8$\times$10^{5}$ $~5.0$\times$10^{7}$OUㆍm$^{-3}$ㆍ$h^{-1}$ that were 84~90% of the inlet load. The critical loads of $NH_3$ and $H_2$S, which mean 97% removal with respect to the inlet loads, were 31 and $27 g.m^{-3}$ ㆍ$h^{-1}$ , respectively. The maximum elimination capacities of $NH_3$ and $H_2$S were 56 and $157 gㆍm^{-3}$ ㆍh$^{-1}$ , respectively. Although the removability for$ NH_3$ and $H_2$S was not influenced by $H_2$S$NH_3$ ratio (ppmv/ppmv), the $H_2$S removability was inhibited by high $H_2$S concentration more than 80 ppmv.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.6
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• pp.703-710
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• 2011

Odor emission from domestic sewer systems has become a serious environmental problem. An investigation on a sewer manhole revealed that anaerobic decay of sediment organic matters (SOMs) and related declines of oxidation reduction potential (ORP) in the sediment layer were the main reason of the production of volatile sulfur compounds. In addition, as the anaerobic decaying period continued, the odor intensity rapidly increased with increasing concentrations of $H_2S$ and dimethyl sulfide. As a feasible method to control SOMs and to minimize odor emission potentials, an electrolytic oxidation process has been employed to the sediment sludge phase. In this study, voltages applied to the electrolytic oxidation process were varied as a main system parameter, and its effects on odor removal efficiencies and reaction characteristics were investigated. At the applied voltages greater than 20 V, the system efficiently oxidized the organic matter, and the ORP in the sludge phase increased rapidly. As a consequence, the removal efficiency of hydrogen sulfide was found to be >99% within 60 minutes of the electrolytic oxidation. Overall, the electrolytic oxidation process can be an alternative to control odor emission from sewer systems, and a threshold input energy needs to be determined to achieve effective operation of the process.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.385-386
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• 2004

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.615-622
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• 2017

This study was conducted to evaluate the odor reduction efficacy of the dip injection wet scrubber (DIWS) using tap water as washing fluid. The $NH_3$ and $H_2S$ removal efficiency of 7 day batch operated DIWS was evaluated twice over a total of 14 days of experiment. The $NH_3$ removal efficiency ranged from 26 to 37%. The $H_2S$ removal efficiency was between 22 and 30%. The pH of the washing fluid maintained below 8 and the $NH_4{^+}$ concentration tended to keep constant around 350 ppm after 5 days of washing-fluid replacement. Therefore, the 5-day washing fluid replacement interval is more preferable than the 7-day interval. The $NH_4{^+}$ concentration and the electrical conductivity (EC) showed a high correlation. The EC measurement can be used as an alternative to conventional $NH_4{^+}$ concentration measurement method for real time monitoring of washing fluid condition.

• Applied Chemistry for Engineering
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• v.22 no.1
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• pp.48-55
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• 2011

It was found that the absorbent mixed with 2-aminoethanol and others has been applied to remove them via chemical neutralization. The absorbent of natural second metabolites was achieved by a removal efficiency of 20~30% by itself depending on treatment conditions, but the complex absorbent mixed with 0.2% amine chemical provides the removal efficiency of over 98%. Optimal removal efficiencies have been examined against two major parameters of the temperature and pH to remove ammonia and hydrogen sulfide gases. The chemical analysis was also performed to analyze the composition of an essential oil by GC-MS. The monoterpenes in an essential oil reacted with odorous compounds by neutralization and their reaction mechanism was partially elucidated.

• Journal of Wellbeing Management and Applied Psychology
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• v.7 no.3
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• pp.67-72
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• 2024

This study developed a dry composite module-type deodorization facility with Twisting airflow changes and two forms (catalyst, adsorbent) within one module. Experiments were conducted to evaluate the reduction efficiency of odor substances C₈H₇N and C₉H₉N. The device combines UV oxidation using TiO₂, catalytic oxidation using MnO₂, and adsorption using A/C in five different methods. Data analysis of experimental results utilized the statistical package program Python 3.12. The program applied frequency analysis of odor removal efficiency, one-way ANOVA, and post-hoc tests, with statistical significance determined by p-value to ensure reliability and validity of the measurements. Results indicated that the highest removal efficiency of C₈H₇N and C₉H₉N was achieved by the UV+A/C method, suggesting the superior effectiveness and efficiency of the developed device. Combining multiple processes and technologies within one module enhanced odor treatment efficiency compared to using a single method. The device's modularity allows for flexibility in adapting to various sewage treatment scenarios, offering easy maintenance and cost-effective deodorization. This composite reaction module device can apply multiple technologies, such as biofilters, plasma, activated carbon filters, UV-photocatalysis, and electromagnetic-chemical systems. However, this study focused on UV-photocatalysis, catalysts, and activated carbon filters. Ultimately, the research demonstrates the practical applicability of this innovative device in real sewage treatment operations, showing excellent reduction efficiency and effectiveness by integrating UV oxidation, TiO₂ photocatalysis, MnO₂ catalytic oxidation, and A/C adsorption within a modular system.