• 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.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.107-114
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• 2017

The performance of polymer electrolyte membrane fuel cell (PEMFC) could be deteriorated when fuel contains contaminants such as carbon monoxide (CO) or hydrogen sulfide ($H_2S$). Generally, $H_2S$ is introduced in hydrogen by steam reforming of hydrocarbon which has mercaptan as odorant. $H_2S$ poisoning effect on PEMFC performance was examined on this study. Pure hydrogen injection, voltage cycling and water circulation methods were compared as performance recovery methods. The PEMFC performance was analyzed using electrochemical methods such as polarization curve, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Pure hydrogen injection and voltage cycling methods showed low recovery ratio, however, water circulation method showed high recovery ratio over 95%. Because anode was directly poisoned by $H_2S$, anode water circulation showed higher recovery ratio compared to the other methods. Water circulation method was developed to recover PEMFC performance from $H_2S$ poisoning. This method could contribute to PEMFC durability and commercialization.

• 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.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.520-520
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• 2016

석유 화학공장에서 발생하는 spent sulfidic caustic (SSC) 폐수는 액화석유가스(LPG)나 천연가스(NG)의 정제과정에서 발생되는 것으로 고농도의 sulfide와 cresylic, phenolic 그리고 mercaptan 등이 포함된 독성과 냄새를 유발하는 물질이다. 이러한 물질들은 LPG나 NG의 정제과정에서 높은 산도를 가진 휘발성 황화합 물질들을 제거하기 위해 사용된 NaOH가 $H_2S$와 반응하여 발생하는 것이다. 진한 갈색 또는 검은색을 띄는 SSC 폐수는 12 이상의 높은 pH를 가지고 있으며 5~12 wt%의 높은 염분도를 가지고 있다. 또한 강한 부식성과 독성을 가진 황화합물의 농도가 1~4 wt%이며, 방향족 탄화수소 물질 (i.e. methanethiol, benzene, tolune and phenol)들도 다량 함유되어 있다. 따라서 이러한 유해 물질들은 기존의 하수처리 공정으로 방류하기 전에 완벽하게 처리해야만 하수처리 공정의 오염 부하량을 줄일 수 있다. 습식산화공정은 SSC 폐수를 처리하기 위해 흔히 사용되고 있는 물리-화학적 처리 공정이지만 고비용, 고에너지가 필요하며, 고온 및 고압에서만 작동되어 안전상의 문제점을 갖고 있다. 또한 습식산화공정을 거친 폐수는 배출허용기준을 만족하기 위해 생물학적 2차 처리가 반드시 필요하다. 철-과산화수소를 이용하는 펜톤산화 공정, 그리고 sulfide를 sulfate로 전환시키는 생물학적 처리 공정은 황화합물의 완전한 무기물화가 힘들며, 현장 적용 시 기술적 경제적 부담이 크다. 이러한 단점을 극복하고, SSC 폐수를 효과적으로 처리하기 위해 본 연구는, 높은 흡착력과 광산화력을 가진 흡착광산화 반응 시스템(Adsorption Photocatalysis System, APS)을 개발하였다. APS는 SSC 폐수를 시스템 내부로 유입하여 수중의 오염물질을 흡착광산화제로 구성된 반응구조체가 흡착하고, 흡착된 오염물질을 UV에너지와 이산화티타늄 광촉매의 광화학반응에 의해 최종적으로 무해한 물질로 환원시키는 폐수처리시스템이다. APS의 반응구조체는 태양에너지 및 인공에너지원에 의해 활용 가능하며, 난분해성 유기화합물질을 물과 이산화탄소로 분해할 수 있는 친환경적이고 경제적인 소재로서 널리 쓰이고 있는 이산화티타늄 광촉매와 화력발전소의 높은 소성온도에 의해 연소된 후 발생되는 bottom ash를 이산화티타늄의 지지체로 사용하여 높은 흡착력과 광촉매 산화력을 가진 복합물이다. 개발된 APS에 의해 SSC 폐수를 처리한 결과, COD 86.1%, 탁도 98.4%, sulfide 99.9%의 높은 처리효율을 보여주고 있다. 따라서 본 연구를 통해 개발된 APS는 강한 부식성과 독성 그리고 높은 농도를 가지고 있는 SSC 폐수를 효과적으로 처리할 수 있다.

• 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.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.3
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• pp.23-33
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• 2016

The characteristics of ammonia generated from alkaline stabilization facilities was investigated which are for organic sewage sludge from wastewater treatment plants. The highest concentration of ammonia was found in mixing and curing process in alkaline stabilization facility and ammonia mainly showed a range of 87.78 ppm($66.62mg/m^3$) to 1,933 ppm($1,467.01mg/m^3$) by detection tube. This is presumed to occur because nitrogen oxides are converted into ammonia as the sewage sludge is mixed with lime. In some facilities, hydrogen sulfide and methyl mercaptan were detected in relatively high concentrations, but odor materials except ammonia were not detected in most of the facilities. The concentration of ammonia caused by process was generally high in the order of "mixing > curing > output > storage > drying > input." It was found that odor compounds are removed by wet absorption using sulfuric acid and sodium hypochlorite in the 5 alkaline stabilization facilities currently in operation. Each facility was designed to meet the concentration of after-treatment emission in 1 ppm($0.76mg/m^3$), 50 ppm($37.95mg/m^3$) or 100 ppm($75.89mg/m^3$), but no facility satisfied the design standard for their emssion limit. In case of ammonia, some workplaces in alkaline stabilization facilities exceeded the exposure limits established by the Ministry of Labor. It appears that proper ventilation should be provided for the safety of workers in future. No odor compound including ammonia was found by detection tubes in the border of the facilities, but trace amounts of odor compounds are expected to exist, given the current operational status of facilities.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.527-539
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• 2010

This study was conducted to determine the effect of probiotics as an alternative for antibiotics on growth performance, nutrient digestibility, noxious gas emission and fecal microbial population in growing piglets. A total of 96 piglets ($22.5{\pm}1.3$kg average body weight) were allotted to 3 different treatment groups and replicated 4 times with 8 piglets per replicate in randomized complete block design. Treatments were T1) (Control, basal diet+0.2% antibiotics), T2) 0.2% probiotics complex and T3) 0.3% Bacillus probiotics. During the whole experiment period, there were no differences (p>0.05) in average daily gain (ADG), average daily feed intake (ADFI) and feed efficiency. However, digestibility of dry matter, crude protein, ether extract, nitrogen free extract and crude ash were showed higher in probiotics groups (T2 and T3) than those of control. In noxious gas emission, ammonia, amine, hydrogen sulfide and mercaptan were significantly (p<0.05) reduced in T2 and T3 treatments compared to those in control. Moisture content of feces was not significantly different among treatments. The colony forming units (CFU) of total bacteria, E. coli and thermoduric bacteria in feces were significantly different among treatments. The CFU of total bacteria, E. coli and thermoduric bacteria in T3 treatment were reduced by feeding probiotics B. From this study, we suggest that probiotics A and B are likely able to improve the growth performance and nutrients digestibility, reduce noxious gas emission and change the fecal microbial composition in growing piglets.