• Journal of Korean Society of Environmental Engineers
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• v.31 no.11
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• pp.965-974
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• 2009

This study evaluated the degradation efficiency of malodorous sulfurized-organic compounds by utilizing N- and Sdoped titanium dioxide under visible-light irradiation, and examined the catalyst deactivation and regeneration. Catalyst surface was characterized by employing Fourier-Transform-Infrared-Red (FTIR) spectra. The visible-light-driven photocatalysis techniques were able to efficiently degrade low-level dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) with degradation efficiencies exceeding 97%, whereas they were not effective regarding the removal of high-level DMS and DMDS, with degradation efficiencies of 84 and 23% within 5 hrs of photocatalytic processes. As compared with DMS, DMDS which containes one more sulfur element revealed quick catalyst deactivation. Catalyst deactivation was confirmed by the equality between input and output concentrations of DMD or DMDS, the obsevation of no $CO_2$ generation during a photocatalytic process, and the FTIR spectrum peaks related with sulfur ion compounds, which are major byproducts formed on catalyst surfaces. The mineralization efficiency of DMS at 8 ppm, which was a peak value during a photocatalytic process, was calculated as 144%, exceeding 100%. The catalyst regenerated by high-temperature calcination exhibited higher catalyst recovery efficiency (53 and 58% for DMDS and DMS, respectively) as compared with dry-air and humid-air regeneration processes. However, even the calcined method was unable to totally regenerate deactivated catalysts.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.1-8
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• 2005

The purpose of this study was to investigate the potential subacute toxicity of dimethyl disulfide by 3 weeks inhalation in F344 rats. The test article, dimethyl disulfide was exposed by inhalation to male and female rats at dose levels of 0, 5, 25, or 125 ppm/6 hrs/ day for 3 weeks. Five rats/ sex/ group were sacrificed on day 4 after the initiation of treatment, while 5 rats/ sex/ group were sacrificed at the end of treatment period. During the test period, clinical signs, mortality, body weights, food consumption, hematology, serum biochemistry, and gross findings were examined. Slight decreases in body weight gain were noted in both sexes of the highest dose group in a dose dependent manner but were only statistically different from the control animals in males of the group. A slight non-significant reduction in food consumption were also noted in the both sexes of the highest dose group. There were no adverse effects on mortality, clinical signs, hematology, serum biochemistry, and necropsy findings at any dose tested. Based on these results, it was concluded that the 3 weeks repeated dose of dimethyl disulfide by inhalation resulted in suppressed body weight gain and decreased food consumption at 125 ppm of both sexes. In the present experimental conditions, the target organ was not determined in rats. The no­observed-adverse-effect level (NOAEL) was considered to be 25 ppm/6 hrs/day for both sexes.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1998.10a
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• pp.150-151
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• 1998

• Analytical Science and Technology
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• v.15 no.1
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• pp.80-86
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• 2002

The simultaneous analysis of the odorous compounds designated by law in Korea and Japan was examined with the thermal desorber gas chromatography-mass spectrometry using one column. The approximate concentrations of trimethyl amine, acetaldehyde, methyl mercaptan and dimethyl sulfide were estimated. Styrene, dimethyl disulfide, propionaldehyde, n-butyl aldehyde, i-butyl aldehyde, n-valeraldehyde, i-valeraldehyde, ethyl acetate, toluene, xylene, methyl i-butyl ketone and i-butanol were detected at concentrations of the detection limits of their threshold values. As a typical example of simultaneous analysis of the odorous compounds, the volatile organic compounds emitted from compost procedure of food waste were concentrated and analyzed with thermal desorber/GC/MSD, and major malodorous compounds were estimated from the concentrations and threshold values of the detected components. From the result of analysis, 34 compounds were confirmed and among them, trimethyl amine, i-valeraldehyde, methyl mercaptan, methyl allyl sulfide, dimethyl sulfide, acetaldehyde, ethanol, n-butyaldehyde were expected to attribute to the odor in order of strength.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.257-258
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• 2003

사회가 고도로 발달하면서 현대인의 생활공간은 대부분 사무실이나 가정에서 보내는 시간이 하루의 80-90% 이상을 차지하므로 오히려 실외공기보다 실내환경의 공기오염이 수백 배 높은 실정이다1). 대부분의 시간을 특정공간에서 보내게 되므로 현대인의 건강과 편리함을 위해 실내공간에 설치되는 탈취제품(공기 청정기)이 많이 상품화 되고 있다. 본 연구에서는 암모니아(NH$_3$), 트리메틸아민(($CH_3$)$_3$N), 초산($CH_3$COOH), 황화수소(H$_2$S), 메칠멀켑탄($CH_3$SH), 황화메틸 ($CH_3$S$CH_3$), 이황화메틸($CH_3$SS$CH_3$), 아세트알데히드($CH_3$CHO), styrene(C$_{8}$H$_{8}$)등 9종의 악취물질을 대상으로 탈취제품의 객관적인 탈취 능력 평가를 위한 시험방법을 개발하고자 하였다.(중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.340-341
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• 2001

대기중의 악취물질의 분석은 현행 우리나라 악취공정시험법에 고시되어 있으나 복잡한 농축장치를 필요로하고 조작법이 복잡하고 시간이 많이 소요된다. 주요 악취물질로서 암모니아, 메틸머캅탄, 황화수소, 이황화메틸, 아세트알데히드등은 극미량에서(pub) 악취를 발생시키는 악취 주요물질이다. 그러나 이 물질들은 흡착, 반응성이 커서 정확한 분석이 어렵다. 본 연구에서는 간단한 장치로서 시료농축이 가능하며, 간단히 GC injection에 주입, 분석할 수 있는 SPME법을 이용하여 악취물질을 신속하게 분석할 수 있는 분석법을 개발하고저 하였다. 분석방법에 대한 분석재현성, 분석한계를 조사하였으며, 이 분석방법이 앞으로 악취물질분석방법으로 활용될 수 있도록 기본 분석법을 확립하고자 하였다. (중략)

• Journal of the Korean Chemical Society
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• v.33 no.5
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• pp.545-550
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• 1989

When (3R,4R)-1-(1-benzyloxycarbonyl-2-methyl-1-propenyl)-4-mercapto-3-phenylacetamidoazetidin-2-one(8) was reacted with carbon disulfide and alkyl halides in the presence of triethylamine, the ${\beta}$-lactam ring was cleaved to give (Z)-and (E)-1-alkylthio-5-benzyloxycarbonyl-6-methyl-2-phenylacetamido-4-aza-1,5-heptadien-3-one (13-16) or 2-benzyl-4-(3-benzyloxycarbonyl-4-methyl-1-oxo-2-aza-3-pentenyl)thiazole(17).

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.8
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• pp.671-675
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• 2002

The gas adsorption efficiency for various surfaces with three different characteristics has been reviewed. The dimethyl disulfide gas has been used to investigate characteristics of gas adsorption for different surface characteristics such as plasma treated, lacquer coated and untreated. Three different surfaces were evaluated in dry conditions initially and tested at wet surface conditions with spraying water to evaluate the gas adsorption efficiency which usually occurred at defrost cycles. The results show that the gas adsorption of the plasma treated sample has better performance than others. The lacquer coated and untreated samples showed the similar result, but the lacquer coated sample showed a slightly better performance.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.277-285
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• 2014

The usage of efficient microorganism (EM) is increasing in concern for server purposes including odor removal during carcasses degradation. In this study, we have studied the type of soil and its effect on efficient microorganisms for the removal of odorous gases during buried carcasses degradation in lab-scale reactor. The carcasses are buried in the reactor with various soil types such as normal soil, 20% sandy and 20% clay soil with the efficient microorganism KEM. The efficient microorganisms KEM have the ability to stabilize the degradation of carcasses of the burial site. We have focused on the analysis of odorous gases such tri-methylamine (TMA), hydrogen sulfide ($H_2S$), methyl mercaptan (MM), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), carbon dioxide ($CO_2$), and methane ($CH_4$) along with the changes of microbial community changed during complete degradation of buried carcasses for a year. The results suggested that the 20% sandy soil contain lesser level of $H_2S$ and MM (0.09 and 0.35 mg) but 20% clay has higher nitrogen compound removing effect and leave only less amount of ammonia and TMA (0.31 and 2.06 mg). The 20% sandy soil also has the ability to breakdown the carcasses more quality compared with other types of soil. Based on the data obtained in this study suggesting that, the use of 20% sandy soil can effectively control sulfur compounds whereas 20% clay soil controls nitrogen compounds in the buried soil. Depending on the type of the soil, the dominant of microbial communities and the distribution was change.

• Clean Technology
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• v.17 no.1
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• pp.48-55
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• 2011

The application of fibrous activated carbon (FAC)-titanium dioxide ($TiO_2$) hybrid system has not been reported yet for the control of malodorous dimethyl sulfide (DMS) at residential environmental levels. Accordingly, the current study was designed not only to characterize this hybrid system using x-ray diffraction method, particulate surface measurement and Fourier transform Infrared (FTIR) method, but also to evaluate its adsorptional photocatalytic activity (APA) for the DMS removal. The physical/surface characteristics of FAC-$TiO_2$ which was prepared in this study suggested that the hybrid material might have certain APA for DMS. The Brunauer-Emmett-Teller (BET) specific area, total pore volume, micropore volume and mesopore volume decreased all as the $TiO_2$ amounts coated on FAC increased, whereas the reverse was true for average pore diameter. $TiO_2$ coated onto FAC did not influence the adsorptional activity of FAC for the DMS input concentration of 0.5 ppm. The APA test of the hybrid material presented that the initial removal efficiencies of DMS were 93, 78, 71 and 57% for the flow rates of 0.5, 1.0, l.5 and 2.0 L/min, respectively, and they decreased somewhat 2 h after the experiment started and kept almost constant for the rest experimental period. Under this pseudo-equilibrium condition, the DMS removal efficiencies were 78, 58, 53 and 36% for the four flow rates, respectively. Meanwhile, there were no significant byproducts observed on the surfaces of the hybrid material. Consequently, this study suggests that, under the experimental conditions used in the present study, the hybrid material can be applied for DMS at residential environment levels without being interfered by any byproducts.