• Journal of Environmental Science International
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• v.23 no.10
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• pp.1763-1773
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• 2014

It is known that mackerel and pork belly release a strong odor in the process of roasting. We evaluated a dilution factor of odor arising during roasting mackerel or pork belly and the relative odor strength using several cooking tools and analyzed compounds causing odors with gas chromatograph/mass detector. Roasting pans used were grill with lid, electric grill without lid and general roasting pan, and a grill with lid can attach the activated carbon charcoal deodorant at the inside of lid. And all electric grills have a drip tray under the heater. We investigated characteristics of odor emission depending on the presence of water and deodorants in these cooking tools. Study has shown that roasting mackerel produces approximately 36 time more odors than roasting pork belly, and the reduced odor emission when roast with water. And it shows the reduced deodorant effect when cooked with water after attaching activated carbon charcoal in the cooking pan. Major odor causing compounds arising when cooking mackerel and pork belly were aldehydes with high boiling point such as octyl aldehyde with a low odor threshold value.

• Analytical Science and Technology
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• v.18 no.6
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• pp.552-558
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• 2005

A type of dimethyl sulfide gas CRM in the ppb level was developed for the analysis of trace-level odorous gas in environmental atmosphere. The concentration of dimethyl sulfide ($(CH_3)_2S$) was 10 umol/mol level in the cylinder filled with nitrogen, 1500 psi. And the variability of the concentration for 3 years was about 0.1% due to the adsorption or instability of $(CH_3)_2S$. The gas standards produced simultaneously in 4 bottles and examined by GC-FID were shown with 0.4%, reproducibility of preparation and 0.25%, standard uncertainty due to weighing and purity. The relative expended uncertainty of 1.1% (95% of confidence level, k=2) was assigned to the certified value of 10 umol/mol level of $(CH_3)_2S$ after quantitative evaluation on the purity, mixing, weighing, analysis, adsorption and stability of dimethyl sulfide gas.

• Analytical Science and Technology
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• v.19 no.6
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• pp.498-503
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• 2006

A type of dimethyl disulfide gas CRM in the ppb level was developed for the analysis of tracelevel odorous gas in environmental atmosphere. The concentration of dimethyl disulfide($(CH_3)_2S_2$) was $10{\mu}mol/mol$ level in the cylinder filled with nitrogen, 1500 psi. And the variability of the concentration for 2 years was about 0.14% due to the adsorption or instability of $(CH_3)_2S_2$. The gas standards produced simultaneously in 4 bottles and examined by GC-FID were shown with 0.4%, reproducibility of preparation and 0.25%, standard uncertainty due to weighing and purity. The relative expended uncertainty of 1.1%(95% of confidence level, k=2) was assigned to the certified value of $10{\mu}mol/mol$ level of $(CH_3)_2S_2$ after quantitative evaluation on the purity, mixing, weighing, analysis, adsorption and stability of dimethyl sulfide gas.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.4
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• pp.257-262
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• 2013

This study investigates the effect of fermentable carbohydrate on the concentration of odorous compounds in pig slurry. Four types of pig diet were studied: control, peanut hull (crude fiber 29.87, NDF 44.02%), golden fiber (crude fiber 48.77, NDF 65.88%), and almond hull (crude fiber 44.30, NDF 64.44%). Pigs (average BW 37.0 kg) were fed diets that met the Korean Feeding Standard (2012) and their excreta samples were collected from the slurry pits. Levels of volatile organic compounds (phenols and indoles) and volatile fatty acids were analyzed by gas chromatography. Phenol level was the lowest (p<0.05) in golden fiber (33.26 ppm) group and the highest in control (97.29 ppm). The concentration of indoles in the peanut hull (1.27 ppm), almond hull (1.20 ppm), and golden fiber (1.02 ppm) groups was lower (p < 0.05) than that of control (1.79 ppm). Levels of short chain fatty acid (SCFA) were lower (p < 0.05) in golden fiber (1,319 ppm) and almond hull (1,433 ppm) groups than in control (1,893 ppm). Concentration of branched chain fatty acid (BCFA) in the golden fiber group (74 ppm) was lower (p < 0.05) than that of control (98 ppm). Taken together, the concentration levels of phenols, indoles, and VFAs decreased on addition of peanut hull, golden fiber or almond hull to the diet, suggesting that fermentable carbohydrate may contribute to reducing odorous compounds in pig slurry.

• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.612-617
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• 2007

This research was performed to evaluate the effect of 'Food Wastes (FW) Direct Landfilling Prohibition' on characteristics of landfill gas (LFG) and leachate and the appropriateness of current legislation. Approximately 45% (Exp.45) and 15% (Exp.15) of FW were filled in two lysimeters. During 570 days, 1400 L of LFG was generated from Exp.45%, which was much more than 906 L of Exp.15. There was no significant difference of LFG composition between Exp.15 and Exp.45. 2~30 ppmv of odorous hydrogen sulfide was detected in Exp.45, while 2~7 ppmv was in Exp.15. There was also no significant difference in the leachate generation between the two. On day 570, $BOD_5$ of Exp.45 and Exp.15 were 37000 mg/Land 25630 mg/L and $COD_{Cr}$ of Exp.45 and Exp.15 were 45480 mg/L, 30294 mg/L. TOC of Exp.45 was 2~3 times higher than Exp.15. Higher portion of FW in landfilling increased LFG generation. However, it generated more odor and made the quality of leachate. Therefore, 'FW direct Landfilling Prohibition' was evaluated as an appropriate legislation.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.5
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• pp.615-624
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• 2013

In this study, the emission patterns of reduced sulfur compounds (RSC) were investigated using four different types of food samples (boiled egg, milk, canned meat and strawberry) between fresh and decaying stages. To this end, the concentrations of RSCs were measured at storage days of 0, 1, 3, 6, and 9 under room temperature. Four sulfur compounds ($H_2S$, $CH_3SH$, DMS and DMDS) were selected as target compounds along with two reference compounds ($CS_2$ and $SO_2$). Their concentrations were quantified using GC-PFPD equipped with thermal desorption (TD) system. The boiled egg showed the highest concentration of $H_2S$ (3,655 ppb) at D-1, while $CH_3SH$ reached its maximum value of 64.4~78.5 ppb after 3 days. In milk samples, concentration of $CH_3SH$, DMS, and DMDS went up to 487, 16.3, and 578 ppb, respectively with the progress of decay (D-9). In case of canned meat, concentration of $H_2S$ and $CH_3SH$ peaked in the beginning (D-0) such as 345 and 66.6 ppb. In case of strawberry, $CH_3SH$ and DMDS showed the maximum concentrations 135 and 50.5 ppb at D-1, respectively. The olfactometry dilution-to-threshold (D/T) ratio by air dilution sensory (ADS) test showed similar patterns when sum of odor intensity (SOI) was derived via conversion of odorant concentration data. The results of this study confirm that the time of strong RSC emissions is distinguished for each food type between fresh (e.g., strawberries) and decaying conditions (e.g., milk).

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.399-405
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• 2005

In this study, we investigated the gas chromatography (GC) and pulsed flame photometric detection (PFPD) system for the analysis of four major reduced S compounds including hydrogen sulfide ($H_2S)$; methyl mercaptan ($CH_3SH$); dimethyl sulfide (DMS); and dimethyl disulfide(DMDS) contained in environmental samples. To analyze these compounds in high concentration range (above ppb level), we developed a high mode analytical setting with the loop-injection system. By contrast, we also established a low mode setting for the analysis of low concentration samples (ppt-level samples from ambient air) by the combination with thermal desorption unit(TDU). Comparative analysis of both settings revealed that relative detection properties of four S compounds are systematic enough. The results of high mode analysis indicated that the patterns were systematic among compounds: H2S exhibited the lowest sensitivity, while DMBS showed the strongest one. The results were also compared in terms of sensitivity reductions for all compounds by dividing slope ratios between low and high mode system. Although low mode system exhibited significant reductions on the order of a few tens times, their detection characteristics were highly consistent as it was shown in the high mode setting. To learn more about absolute and relative relations between two different modes of S analysis, future studies may have to be directed to cover more complicated nature of GC/PFPD performance. Hydrogen sulfide($H_2S$) was over in summer about low level of olfactory sense 410 ppt, Methyl mercaptan(C$H_3SH$) was over in apring and summer about low level of olfactory sense 70, Dimethyl sulfide(DMS) was not over in four season about low level of olfactory sense 2,200 ppt. Carbon disulfide($CS_2$) was not over in four deason about Tow level of olfactory sense 210,000, Dimethyl disulfide(DMDS) was not over in summer about low level of olfactory sense2,000.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.470-477
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• 2007

This research was conducted to evaluate the effect of moisture content on direct landfilling prohibition of organic sludge. Organic sludges with moisture content (Me) of 75 and 85% were filled in two lysimeters. The lysimeters were named as Exp.75 and Exp.85, respectively. LFG of 2,064 l was generated greatly for Exp.85, compared to 1,500 l for Exp.75. LFG generations in Exp.75 and Exp.85 were 64.1 l/kg and 157.1 l/kg as dry TS basis, and 113.6 l/kg and 266.2 l/kg as dry VS basis. Total $CH_4$ generation in LFG for Exp.85 was 1,238 l, while 1,050 l for Exp.75. $H_2S$ of $3{\sim}150$ ppmv was generated from Exp.85, which was 5 times higher than $2{\sim}30$ppmv from Exp.75. Leachate was not generated from Exp.75 during operation time. However, 420 ml of leachate was generated from Exp.85. From the results of gas generation, composition, odorous compounds, and leachate generation, landfilling of organic sludge with high MC was more harmful to the environment in spite of great LFG generation. However, direct landfilling of organic sludges without great difference of MC made a severe odor problem. Therefore, it was thought that current direct landfilling prohibition law for all organic sludge was appropriate.

• Journal of Environmental Health Sciences
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• v.46 no.2
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• pp.170-183
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• 2020

Objectives: This study was conducted to estimate a technology to reduce hydrogen sulfide (H₂S) in sewage odor using microbial deodorant. Methods: After injecting five commercially available microbial deodorants into fresh sewage, the concentration of hydrogen sulfide over time was measured using the headspace method. H₂S concentration in odor samples was measured using gas chromatograph/FPD. Calculated odor concentration and calculated odor intensity by H₂S concentration remaining after treatment with microbial deodorant were evaluated theoretically. Results: The rate of H₂S abatement by microbial deodorant differed depending on the experimental conditions and the type of deodorant, but it was found to range from 63 to 82%. Especially, two deodorants showed high H₂S reduction rates of over 80% on average. However, based on the best deodorant, the theoretically calculated odor concentration by H₂S after microbial deodorant treatment was 4,400 OU_k, and the theoretical odor intensity was also rated at 4 degrees or higher. Conclusions: In conclusion, microbial deodorant is considered to have a relatively high effect on reducing H₂S in sewage odor. However, even after treatment with microbial deodorant, calculated odor concentration and calculated odor intensity were relatively high. This is thought to be caused by other odorous substances besides H₂S.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.2
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• pp.249-257
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• 2006

In this work, the adsorptive and desorptive behavior of reduced sulfur compounds (RSC) was investigated using the combination of the Peltier cooling (PC)/thermal desorption (TD) unit with the gas chromatographic (GC) detection technique. To examine the adsorptive characteristics of RSC on clothing materials, a total of nine experiments were conducted in a stepwise manner. Once small towel pieces are exposed to significant quantities of RSC standards with high concentrations (10 ppm), the desoprtion stage was then induced by deloading RSC with ultrapure $N_2$ at three different flow rates (FR) of 20, 40, and 60 mL/min. At each FR, the total deloading volume of 400, 800, and 1,600 mL were maintained. These results were then compared in terms of odoring efficiency by dividing the total amount of desorption with the total amount used for exposition or RSC loading. The results indicated that desorption reaction of certain compounds ($CH_3SH$ and DMS) can be influenced significantly with the reducing FR, while they are not affected directly by the total deloading volume. In addition, when the extent of adsorption was compared for most S compounds by the odoring efficiency term, the extent of absorption generally occurred at approximately 1/1000 level of original exposition.