• Clean Technology
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• v.13 no.1 s.36
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• pp.1-15
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• 2007

Biological treatment is a relatively recent air pollution control technology in which off-gases containing biodegradable odors and volatile organic compounds(VOCs) are vented through microbes. It is a promising alternative to conventional air pollution control methods. Bioreactors for air pollution control have found most of their success in the treatment of dilute and high flow waste air streams containing VOCs and odor compounds. They offer several advantages over traditional technologies such as incineration or adsorption. These include lower treatment costs, absence of formation of secondary pollutants, no spent chemicals, low energy demand and low temperature treatment. The three most widely used technologies are described, namely biofiltration, biotrickling filtration, bioscrubbing. The most widely used bioreactor for air pollution control is biofilter, but it has several limitations. In the past years major progress has been accomplished in the development of vapor phase bioreaction systems, for solving problems of biofilter. Biotrickling filters are more complex than biofilters, but are usually more effective, especially for the treatment of compounds which are difficult to degrade or compounds that generate acidic by-products. This, paper reviews fundamental and theoretical/practical aspect of air pollution control in biofilter, biotrickling filter and bioscrubber, focusing more extensively on biotrickling filtration. Special emphasis is given to the operating parameters and the factors influencing performance for air pollution control, and cost estimation in biotreatment technologies.

• Analytical Science and Technology
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• v.17 no.2
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• pp.145-152
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• 2004

In this study, analytical characteristics of S gas detection technique were investigated against four major reduced S compounds (including hydrogen sulfide; methyl mercaptan; dimethyl sulfide (DMS); and dimethyl disulfide (DMDS)). To analyze such properties, an analytical system was constructed by combining the GC/PFPD system with the loop injection method. The results of our analysis indicated that response behavior of S gases differs greatly between compounds; H2S exhibited the weakest sensitivity of all compounds, while DMDS with two S-atom compounds the strongest sensitivity. To learn more about their response behavior on GC/PFPD method, their calibration patterns were compared using the three arbitrarily set concentration ranges of low, intermediate, and high. The results showed that calibration patterns of each compound are distinguished because of different factors. There was a line of evidence that calibration of $H_2S$ was affected noticeably by adsorptive loss within the system, whereas those of DMS and DMDS were influenced most sensitively by such factor as the linearity response at a given PMT voltage setting. The overall results of our study suggest that quantification of malordorous S compounds require a better knowledge of compound-specific response behavior against GC detection.

• Analytical Science and Technology
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• v.22 no.6
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• pp.488-497
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• 2009

In this study, analytical methodology for several organic fatty acids (OFA: propionic acid (PA), butyric acid (BA), isovaleric acid (IA), and valeric acid (VA)) designated as new offensive odorants in Korea (as of year 2010) was investigated along with some odorous VOCs (styrene, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, and isobutyl alcohol). For this purpose, working standards (WS) containing all of these 13 compounds were loaded into adsorption tube filled with Tenax TA, and analyzed by gas chromatography (GC) system thermal desorber interfaced with. The analytical sensitivities of organic fatty acids expressed in terms of detection limit (both in absolute mass (ng) and concentration (ppb)) were lower by 1.5-2 times than other compounds (PA: 0.24 ng (0.16 ppb), BA: 0.19 ng (0.11 ppb), IA: 0.15 ng (0.07 ppb), and VA: 0.28 ng (0.13 ppb)). The precision of BA, IA, and VA, if assessed in terms of relative standard error (RSE), maintained above 5%, while the precison of other compounds were below 5%. The reproducibility of analysis improved with the aid of internal standard calibration (PA: $1.1{\pm}0.4%$, BA: $10{\pm}0.46$, IA; $12{\pm}0.3%$, VA: $4{\pm}0.1%$), respectively. The results of this study showed that organic fatty acid can be analyzed using adsorption tube and thermal desorber in a more reliable way to replace alkali absorption method introduced in the odor prevention law of the Korea Ministry of Environment (KMOE).

• Journal of Korean Society of Environmental Engineers
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• v.30 no.3
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• pp.278-285
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• 2008

This research was performed to evaluate the landfilling method of organic sludge from mix of pre-treated organic sludge (OS) and municipal solid waste(MSW). Organic sludges were dried, composted, and solidified as pre-treatment and the OS and MSW were mixed in ratios of 2 to 8 and 4 to 6. Approximately 1,800$\sim$2,500 L of landfill gas(LFG) was generated in the lysimeter with solidified-OS, which was higher than 1,150$\sim$1,650 L of the dried- and composted- ones. Maximum H$_2$S concentration was found in the following order : Composted-20(80 ppmv) > Composted-40(55 ppmv) > Dried-20(30 ppmv) > Dried-40 $\fallingdotseq$ Solidified-20 $\fallingdotseq$ Solidified-40 (20 ppmv). BOD$_5$ at initial leachate generation period was 38,000 mg/L for Composted-40, 28,000 mg/L for Dried-40, 26,000 mg/L for Dried-20, 21,000 mg/L for Composted-20 and Solidified-40, and Solidified-20 for 17,000 mg/L. In the final period of experiment, BOD$_5$ was low as 300$\sim$500 mg/L in the lysimeter with solidified-OS and MSW and showed 2,000$\sim$3,500 mg/L in dried- and composted- ones. As the results, landfilling by mix of solidified-OS and MSW was evaluated as the most appropriate method for biodegradable organics. Direct landfilling of OS is permitted for landfill site with CDM facility. Therefore, mixed landfilling of solidified-OS and MSW should be considered for much more LFG generation as methane.

• Journal of Animal Environmental Science
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• v.18 no.1
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• pp.25-34
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• 2012

Noxious gases with malodorous substance concentrations in each stages of pig buildings were determined at a typical 400sow-scale farm to improve piggery environment. Using IAQ-300 and pDR-1000AN, continuous records for the concentration of $NH_3$, CO, $CO_2$, $NO_2$, $SO_2$, $H_2S$, $O_2$, and along with temperature, humidity, dust concentrates from individual pig pens were collected to analyze every 6 hours' condition of indoor environment for 24 hours' period. In most pig houses, the air quality at noon was good, while at night (00:00~06:00), air composition became noxious in all buildings. The order of buildings' air quality for 24 hrs was pregnant > farrowing > nursery > growing > finishing. The cause of air quality differences was presumed to be the differences of stocking density, defecating amount and the length of exposure time of slurry in indoors. In conclusion, well-designed building structure, proper control of stocking density, quick removal of excreta from pig pens and continuous ventilation are prerequisites to improve pig housing environment.

• 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 $300\;h^{-1}$.

• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.9-17
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• 2013

Butanethiol is known as a typical odorant with hydrogen sulfide, methyl mercaptan, methyl sulfide, but on the physical and chemical properties and biological hazard assessment, including inhalation toxicity data are very scarce. Butanethiol as a colorless transparent liquid, and has physic-chemical characteristics with flash point as $-23^{\circ}C$ and strong fire risk, boiling point $84-85^{\circ}C$, vapor pressure 80.71 mmHg ($25^{\circ}C$), freezing point $-140.14^{\circ}C$. From whole body exposure with SD rats, the $LC_{50}$ is above 2,500 ppm (9.22mg/L), and then it is classified as the acute toxic chemical (inhalation) category 4 according to the governmental notification No. 2012-14.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.327-332
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• 1997

This study was conducted to find out the effect for removal of $NH_3$ gas, one of the offensive odor. The removal efficiencies of $NH_3$ gas through zeolie column increased with the decreased percolation velocity. The effect of zeolite colum in removing $NH_3$ gas was influenced by the water content of zeolite and the added amount of zeolite, but was not influenced by the setting method of zeolite. The $NH_3$ gas removing sequence of saturated cation species on zeolite was in order of Ca->Na->$NH_4$ ->Natural->K-zeolite. Consequently the effect of zeolite on $NH_3$ gas removal efficiency is consided by the water content, added amount and saturated cation of the zeolite.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.212-212
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• 2020

도시하천의 경우 비 강우시 하천의 유지용수가 부족하고, 도시지역에서 유입되는 오염물질로 인하여 수질악화, 악취 등의 문제가 발생하고 있다. 최근 생태하천 및 친수 공간에 대한 관심이 증가하고 있고, 이에 정부는 도시하천 복원사업을 적극적으로 추진하여 수환경개선을 위한 많은 노력을 기울이고 있다. 굴포천은 인천 부평구에서 경기도 김포시로 이어져 있는 국가하천으로서 수질 향상 및 유지용수 확대를 위한 굴포 하수처리수의 재이용수 활용 계획이 수립되었다. 이에 2019년 3월 자연생태하천 조성사업이 준공되었고, 굴포하수처리수에 오존처리과정을 거친 유지용수가 굴포천 상류부에 공급되고 있다. 본 연구에서는 굴포천 내 오존처리 재이용수 공급 전·후의 수질 개선 효과를 분석하기 위하여 하천수 수질기준을 활용하여 계절 별 주요 수질인자의 농도를 정량적으로 비교하였다. 유지용수 방류지점과 굴포하수처리수 방류 위치를 기준으로 굴포천 내 해석구간을 나누고, 재이용수 공급전·후 각 1년에 대하여 주요 수질을 분석하였다. 하천수 수질환경기준에 사용되는 DO, BOD, COD, TOC, SS, T-P를 중심으로 분기별 수질 분석을 한 결과, 굴포천 모든 지점에서 DO 농도는 평균적으로 증가하였고, 다른 주요 수질 인자의 농도는 감소되어 수질 개선 효과가 높은 것으로 나타났다. 분기별 하천수 수질등급 비교 결과 재이용수 공급 전 '매우 좋음(1a)'였던 수질인자는 재이용수 공급 후에도 동일 등급을 유지하였고, 모든 수질 항목에서 계절에 따른 편차가 있었지만 재이용수 공급 이후 모든 수질등급이 향상된 것으로 나타났다.

• Journal of Animal Science and Technology
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• v.52 no.1
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• pp.23-28
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• 2010

This study was conducted to evaluate the effects of probiotics supplementation on growth performance, nutrient digestibility, fecal concentrations of Lactobacillus and Escherichia coli, emission of noxious gases from the feces, and circulating concentrations of the blood cells in early-finishing pigs. A total of sixty pigs [(Landrace ${\times}$ Yorkshire) ${\times}$ Duroc] (initial body weight 56.48 ${\pm}$ 1.66 kg) were used for the 28 days feeding trial. Dietary treatments included 1) CON (basal diet), 2) P1 (CON + 0.1% Agariemycetes) and 3) P2 (CON + 0.2% Agariemycetes). There were three dietary treatments with five replicate pens per treatment and four pigs per pen. There was no significant difference in ADG (average dairy gain) among the treatments (P>0.05). The gain/feed ratio was higher in P2 than CON (P<0.05). The P2 showed the highest digestibility of dry matter and energy (P<0.05). No significant difference was observed in the fecal Lactobacillus counts but fecal Escherichia coli population of P2 was lower than that of CON (P<0.05). The ammonia, $H_2S$ and total mercaptan was higher in P1 and P2 than CON (P<0.05). Blood characteristics were not affected by probiotics (P>0.05) supplementation. In conclusion, the results showed that dietary supplementation of probiotics at 0.2% level affected gain/feed ratio, dry matter and energy digestibility; reduced fecal Escherichia coli and emission of fecal noxious gases in finishing pigs.