• Analytical Science and Technology
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• v.18 no.1
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• pp.66-73
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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 S compounds: $H_2S$ exhibited the lowest sensitivity, while DMDS 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.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.9
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• pp.526-532
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• 2015

A bioreactor filling with pellets and stones was equipped to the swine manure treatment system, which is expected to emit high concentration of odor in the process of the organic wastewater treatment system, and in comparison with the activated sludge process as the control process, the reactor operation state, treatment water quality and odor emission concentration were measured. The reactor using the bioreactor proved to be much more stable in the bubble condition, treatment water transparency, etc, and BOD removal efficiency was also much better. The removal efficiency of T-N and T-P, however, showed little difference in the two reactors. Odor, as a result of examining $NH_3-N$, $NH_3$ concentratio, and complex odor, was 4 times to 24 times less emitted in the system using bioreactor than in the activated sludge system. $H_2S$, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide were not found or were found in only 5 ppbs in each reactor and showed little difference between the two reactors. In the bioreactor process, Bacillus sp./ Pseudomonas sp. species were mainly found and in the activated sludge process, acterium sp. Chryseobacterium sp. species were mainly found.

• 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.

• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.28-36
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• 2018

Adsorption experiments of three target gases such as acetone, benzene, and methyl mercaptan (MM) were carried in a continuous reactor using the activated carbon prepared from waste citrus peel. In a single gas system, the breakthrough time obtained from using the activated carbon (WCAC) prepared from waste citrus peel. In a single gas system, the breakthrough time obtained from the breakthrough curve decreased with increasing the inlet concentration and flow rate, but increased with respect to the aspect ratio (L/D). Adsorbed amounts of the target gases by WCAC increased as a function of the inlet concentration and aspect ratio. However, adsorbed amounts with the increase of the flow rate were different depending upon target gases. Results from the breakthrough time and adsorbed amount showed that the affinity for WCAC was the highest in benzene, followed by acetone and then MM. On the other hand, in the binary and ternary systems, the breakthrough curve showed a roll-up phenomenon where the adsorbate having a small affinity for WCAC was replaced with the adsorbate with a high affinity. The adsorption of acetone on WCAC was more strongly affected when mixing with the nonpolar benzene than that of using sulfur compound MM.

• Journal of Life Science
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• v.22 no.8
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• pp.1071-1076
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• 2012

To investigate the antimicrobial and anti-halitosis effects of Alnus firma extracts and gallic acid (GA) isolated from A. firma, we measured their antimicrobial activities against oral pathogens and their inhibitory effects on the cell adhesiveness and acid production of oral pathogens. In addition, the levels of volatile sulfur compounds were determined by using oral chroma. The dichloromethane (DCM) fraction has broad antimicrobial activity, and the ethylacetate (EA) fraction showed a relatively high level of antimicrobial activity against Streptococcus mutans and Porphyromons gingivalis. Especially, the GA and DCM fractions had significant inhibitory effects on the attachment and acid production of S. mutans and Streptococcus salivarius, respectively. The 2% MeOH extract of A. firma showed a significant inhibitory effect on the production of volatile oral compounds, such as hydrogen sulfide, methyl mercaptan, and dimethyl sulfide, which can cause bad breath and halitosis. Two percent GA also had a significant inhibitory effect on the production of hydrogen sulfide. Our study showed that the active fractions and GA of A. firma could be suitable resources for development as a natural antibiotic agent for the treatment of infectious oral diseases.

• Journal of Oral Medicine and Pain
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• v.34 no.1
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• pp.11-21
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• 2009

This study was conducted to investigate the relationship between systemic diseases and oral malodor. The author measured the volatile sulfur compound(VSC) of the patients who visited Pusan National University Health Promote Center for a comprehensive medical testing. The patients were examined gingival bleeding on probing, CPI index, tongue coating. Their systemic diseases were diagnosed by the specialist. 182 patients consisted of 112 males and 70 females. In this study, Oral $Chroma^{(R)}$ was used to measure oral malodor. This equipment could measure the concentration of intraoral VSC (hydrogen sulfide, methyl mercaptan, dimethyl disulfide). All data were analylized using Statistical Package for the Social Science $12.0^{(R)}$. The result of this study was the followings. 1. There was significant difference of numbers of patient who visited health care center according to the VSC concentration level and the Community Periodontal Index, bleeding on probing, tongue coating. 2. The subjects with hyperlipidemia showed the high level of $CH_3SH$ concentration (p=0.036). The concentration of $H_2S$ tends to be high in the group with abnormal findings on pulmonary fuction test(p=0.086). The concentration of $CH_3SH$ in the groups with abnormal findings on lipid profile test(p=0.130) and bone mineral density test(p=0.099) and abdominal ultrasonograpy(p=0.088) tends to be higher than the other group. 3. The concentration of $(CH_3)_2S$ in the group with abnormal findings on blood pressure test(p=0.113), hepatitis B virus serology(p=0.069), Abdominal ultrasonograpy(p=0.091) tend to be higher than the other group.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1769-1775
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• 2016

Aerial parts (leaves and stems) of radish are usually discarded due to the distinct undesirable flavors associated with inappropriate preparations, despite their many health benefits. In this study, we examined the role of extrusion process in the removal of off-flavors and elevation of antioxidant activity in radish (Raphanus sativus L.) leaves and stems. To optimize the extrusion conditions, we changed the barrel temperature (110, 120, and $130^{\circ}C$), screw speed (150, 200, 250, and 300 rpm), and moisture content (20, 25, and 30%). The polyphenol and flavonoid contents significantly increased in extruded radish leaves and stems (ER) under optimum extrusion conditions ($130^{\circ}C$, 250 rpm, and 20%). Under extrusion conditions, we compared off-flavors (as amount of sulfur-containing compound) levels between ER and non-extruded radish leaves and stems (NER) by an electronic nose. A total of six peaks (sulfur-containing compound) were similarly detected in both ER and NER, whereas the ER showed reduced off-flavors. Levels of glucosinolate (${\mu}g/g$), which can be hydrolyzed into off-flavors during mastication or processing, were significantly decreased in the ER. From these results, extrusion processing can be an effective method to increase anti-oxidant activity and removal of off-flavors in radish leaves and stems.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.453-466
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• 2006

To comply with stricter regulations provoked by increasing odor nuisance, it is imperative to practice effective odor control for sustainable livestock production. This study was conducted to assess odor and odorous compounds emitted from liquid animal manure with different treatment methods such as Fresh Manure(without treatment, FM), Anaerobic Digestion(AD) and Thermophilic Aerobic Digestion(TAD) and their application to soil. Air samples were collected at the headspace of liquid manure, upland and paddy soil, and analyzed for odor intensity and offensiveness using an olfactometry; odor concentration index using odor analyser; nitrogen-containing compound such as ammonia(NH3) using fluorescence method; and sulfur containing compounds such as hydrogen sulfide(H2S), methyl mercaptan(MeSH), dimethyl sulfide(DMS) and dimethyl disulfide(DMDS) using gas chromatography-pulsed flame photometric detector, respectively. Odor intensity, offensiveness and concentration index from TAD liquid manure was statistically lower than those from FM and AD(p<0.01). Mean concentrations of H2S, MeSH, DMS, DMDS and NH3 were 65.93ppb, 18.55ppb, 5.26ppb, 0.33ppb and 10.57ppm for liquid manure with AD; and 5.15ppb, 0.97ppb, 0.80ppb, 0.56ppb and 1.34ppm for liquid manure with TAD, respectively. More than 60% of malodorous compounds related to nitrogen and sulfur were removed by heterotrophic microorganisms during TAD treatment. When liquid manure was applied onto upland and paddy soil, NH3 removal efficiencies ranged from 51 to 94% and 22 to 91% for AD and TAD liquid manure, respectively. The above results show that liquid manure with TAD is superior to AD and FM with respect to the odor reduction and odor problem caused by land applied liquid manure is directly related to the degree of odor generated by the manure treatment method.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.4
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• pp.118-126
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• 2012

In this study, two types of ozone generating experimental instrument were installed in commercial livestock manure fertilization facility, which can treat hundred tons of pig manure in a day. Gas samples to be treated were collected from the upper part of the liquid fertilization system and composting system of the commercial livestock manure fertilization facility. The gas sample was flowed to oxidation reactor through pipe line by suction blower, therefore, contacted with ozone. Ammonia and sulfur compounds of gas samples collected from the inlet and outlet point of the experimental instrument were analyzed. The oxidation effect by the contact with ozone was higher in sulfur compounds than ammonia. Ammonia content was reduced about 10% by ozone contact. Sulfur compounds, on the other hand, reduced significantly while treated with ozone. In case of gas sample collected from liquid fertilization system, the concentrations of hydrogen sulfide ($H_2S$), methyl mercaptan (MM), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS) of inlet gas were 50.091, 4.9089, 27.8109 and 0.4683 ppvs, respectively. After oxidized by ozone, the concentrations of sulfur compounds were 1.2317, 0.3839, 14.7279 and 0.3145 ppvs, respectively. Another sample collected from aerobic composting system was oxidized in the same conditions. The concentrations of $H_2S$, MM, DMS and DMDS of the sample collected from inlet point of the reactor were 40.6682, 1.3675, 24.2458 and 0.8289 ppvs, respectively. After oxidized, the concentrations of $H_2S$, MM, DMS, and DMDS were reduced to 3.013, ND, 8.8998 and 0.3651 ppvs, respectively. By application of another type of ozone, the concentrations of $H_2S$, MM, DMS and DMDS of inlet gas were reduced from 43.397, 1.4559, 3.6021 and 0.4061 to ND, ND, ND, and 0.21ppvs, respectively.