• 센서학회지
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• 제32권3호
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• pp.194-198
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• 2023

With the recent development of industrial technology, the problem of odor due to leakage of toxic gas discharged from industrial complexes is gradually increasing. Among them, hydrogen sulfide is a colorless representative odorous substance that can cause pain through irritation of the mucous membranes of the eyes and respiratory tract, and is a gas that can cause central nervous system paralysis and suffocation when exposed to high concentrations. Therefore, in order to improve the odor problem, research on a gas sensor capable of quickly and reliably detecting a leak of hydrogen sulfide is being actively conducted. A lot of research has been done on the existing metal oxide-based hydrogen sulfide gas sensor, but it has the disadvantage of requiring low selectivity and high temperature operating conditions. Therefore, in this study, a Pt/CNT-based electrochemical hydrogen sulfide gas sensor capable of detecting at low temperatures with high selectivity for hydrogen sulfide was developed. A working electrode capable of selectively detecting only hydrogen sulfide was fabricated by synthesizing Pt nanoparticles as a catalyst on functionalized CNT and applied to an electrochemical hydrogen sulfide gas sensor. It was confirmed that the manufactured Pt/CNT-based electrochemical hydrogen sulfide gas sensor has a current change of up to 100uA for hydrogen sulfide, and the both response time and recovery time were within 15 seconds.

• 한국산업보건학회지
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• 제16권1호
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• pp.36-43
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• 2006

The principal aim of this field study was to determine the concentrations and emissions of gaseous contaminants such as ammonia and hydrogen sulfide in the different types of pig buildings in Korea and allow objective comparison between Korea and the other countries in terms of pig housing types. This field study was performed from May to June and from September to October in 2002. Pig buildings investigated in this research were selected in terms of three criteria; manure removal system, ventilation mode and growth stage of pig. Measurements of concentration and emission of ammonia and hydrogen sulfide in the pig buildings were done in 5 housing types and the visited farms were 15 sites per each housing type. Concentrations of ammonia and hydrogen sulfide were measured at three locations of the central alley in the pig building and emission rates of them were estimated by multiplying the average concentration($mg/m^3$) measured near the air outlet by the mean ventilation rate($m^3/h$) and expressed either per pig of liveweight 75kg(mg/h/pig) or per area($mg/h/m^2$). Concentrations of ammonia and hydrogen sulfide in the pig buildings were averaged to 7.5 ppm and 286.5 ppb and ranged from 0.8 to 21.4 ppm and from 45.8 to 1,235 ppb, respectively. The highest concentrations of ammonia and hydrogen sulfide were found in the mechanically ventilated buildings with slats; 12.1 ppm and 612.8 ppb, while the lowest concentrations of ammonia and hydrogen sulfide were found in the pig buildings with deep-litter bed system(2.2 ppm) and the naturally ventilated pig buildings with manure removal system by scraper(115.2 ppb), respectively(p<0.05). All the pig buildings were investigated not to exceed the threshold limit values(TLVs) of ammonia(25 ppm) and hydrogen sulfide(10 ppm). The mean emissions of ammonia and hydrogen sulfide per pig(75kg in terms of liveweight) and area($m^2$) from pig buildings were 250.2 mg/h/pig and 37.8 mg/h/pig and $336.3mg/h/m^2$ and $50.9mg/h/m^2$, respectively. The pig buildings with deep-litter bed system showed the lowest emissions of ammonia and hydrogen sulfide(p<0.05). However, the emissions of ammonia and hydrogen sulfide from the other pig buildings were not significantly different(p>0.05). Concentrations and emissions of ammonia and hydrogen sulfide were relatively higher in the pig buildings managed with deep-pit manure system with slats and mechanical ventilation mode than the different pig housing types. In order to prevent pig farm workers from adverse health effect caused by exposure to ammonia and hydrogen sulfide in pig buildings, they should wear the respirators during shift and be educated sustainably for the guideline related to occupational safety.

• 치위생과학회지
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• 제10권2호
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• pp.101-107
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• 2010

본 연구는 구취의 원인을 분류하고, 각 성분들에 영향을 미치는 구강환경 요인들과 어떤 관련성이 있는지를 조사하여 구취환자 개개인의 구강건강을 증진시키고 구취관련의 올바른 보건교육에 활용하고자 실시하였으며, 2009년 3월 1일부터 2010년 3월 1일까지 1년간 대도시 소재 치과병원 외래환자 98명의 자료를 최종분석에 이용한 결과 다음과 같은 결론을 얻었다. 1. 구취의 각 성분인 Hydrogen sulfide, Methyl mercaptan, Dimethyl sulfide 및 Ammonia의 평균 수치는 Hydrogen sulfide 36.71 ppb, Methyl mercaptan은 31.46 ppb, Dimethyl sulfide는 54.33 ppb, Ammonia는 22.60 ppm로 나타났고, 정상과 역치 이상의 검출비교 결과 Dimethyl sulfide는 46.9%가 역치 이상으로 검출되었고, Ammonia는 연구대상자 중 52%가 역치 이상으로 검출되어 가장 높게 나타났다. 2. Hydrogen sulfide 성분의 양에 따라 Dimethyl sulfide 성분의 양, 설태의 양과 타액 분비율이 통계적으로 유의한 관계가 있는 것으로 나타났다(p<0.05). 3. Methyl mercaptan 성분의 양은 Dimethyl sulfide의 성분과 설태량, 타액 분비율과 통계적으로 유의한 관계가 있었다(p<0.05). 4. Dimethyl sulfide성분의 양은 Hydrogen sulfide성분, Ammonia성분과 관련이 있었으며, 설태의 양, 타액분비율, 타액내 수소이온농도지수와도 관계가 있었다(p<0.05). 5. Ammonia성분은 Methyl mercaptan성분과 Dimethyl sulfide성분, 치주필요지수(CPI), 타액 분비율이 통계적으로 유의한 관계가 있었다(p<0.05).

• 센서학회지
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• 제32권5호
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• pp.290-294
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• 2023

Among various types of harmful gases, hydrogen sulfide is a strong toxic gas that is mainly generated during spillage and wastewater treatment at industrial sites. Hydrogen sulfide can irritate the conjunctiva even at low concentrations of less than 10 ppm, cause coughing, paralysis of smell and respiratory failure at a concentration of 100 ppm, and coma and permanent brain loss at concentrations above 1000 ppm. Therefore, rapid detection of hydrogen sulfide among harmful gases is extremely important for our safety, health, and comfortable living environment. Most hydrogen sulfide gas sensors that have been reported are electrical resistive metal oxide-based semiconductor gas sensors that are easy to manufacture and mass-produce and have the advantage of high sensitivity; however, they have low gas selectivity. In contrast, the electrochemical sensor measures the concentration of hydrogen sulfide using an electrochemical reaction between hydrogen sulfide, an electrode, and an electrolyte. Electrochemical sensors have various advantages, including sensitivity, selectivity, fast response time, and the ability to measure room temperature. However, most electrochemical hydrogen sulfide gas sensors depend on imports. Although domestic technologies and products exist, more research is required on their long-term stability and reliability. Therefore, this study includes the processes from electrode material synthesis to sensor fabrication and characteristic evaluation, and introduces the sensor structure design and material selection to improve the sensitivity and selectivity of the sensor. A sensor case was fabricated using a 3D printer, and an Ag reference electrode, and a Pt counter electrode were deposited and applied to a Polytetrafluoroethylene (PTFE) filter using PVD. The working electrode was also deposited on a PTFE filter using vacuum filtration, and an electrochemical hydrogen sulfide gas sensor capable of measuring concentrations as low as 0.6 ppm was developed.

• 한국어병학회지
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• 제10권1호
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• pp.65-72
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• 1997

유용 갑각류인 꽃게, 중하 및 징거미새우의 유생과 성체에 대한 황화수소의 급성독성 실험 결과로부터 이들 갑각류에 대한 독성수준, 독성순위 및 유생과 성체와의 독성차를 검토하였다. 황화수소에 대한 꽃게, 중하 및 징거미새우 유생의 96시간 반수치사농도(96hr-$LC_{50}$)는 각각 7.3, 9.3 및 $9.0{\mu}g/\ell$으로 독성순위는 꽃게>징거미새우>중하순으로 나타났다. 한편, 성체에 대한 황화수소의 96hr-$LC_{50}$값은 꽃게 $42.5{\mu}gS/\ell$, 중하 $37.8{\mu}gS/\ell$, 징거미새우 $56.6{\mu}gS/\ell$로 독성순위는 중하>꽃게>징거미새우 순으로 유생과는 다른 경향을 나타내었다. 황화 수소는 꽃게, 중하 및 징거미새우의 유생에 대하여 성체에 비해 각각 5.8, 4.1, 6.3배의 강한 독성을 나타냈다.

• 한국환경과학회지
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• 제25권11호
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• pp.1555-1562
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• 2016

Concentrations of hydrogen sulfide in ambient air have been measured from January 2014 to June 2016 in a coastal area near the Ulsan National Industrial Complex. The measurement sites were 1 km, 2.6 km, 5.6 km, and 20 km away from a kraft pulp mill, which is located at the most southern edge of the complex. Concentrations above 0.4 ppb were monitored every 5 min and the highest concentration of the day was determined. From a total of 775 measurement days, hydrogen sulfide concentrations > 20 ppb were recorded on 36 and 38 days at the measurement site closest to the mill and the residential area 2.6 km away from the mill, respectively. At the site farthest from the mill, the concentrations were always 20 ppb lower than the malodor regulation for the residential area but sometimes higher than the odor recognition threshold for hydrogen sulfide. Although several emission sources of hydrogen sulfide have been published in the Pollutant Release and Transfer Register of Korea, the kraft pulp mill is considered to be the biggest contributor of atmospheric hydrogen sulfide in the southern coastal area of Ulsan.

• Korean Chemical Engineering Research
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• 제51권5호
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• pp.568-574
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• 2013

퇴비공장 또는 공공시설에서 발생되는 악취폐가스의 대표적인 제거대상 오염원인 황화수소와 암모니아를 포함한 악취폐가스를 처리하기 위하여 여러 운전 조건 하에서의 Thiobacillus sp. IW 및 반송슬러지를 고정한 담체를 충전한 semi-pilot 바이오필터 시스템을 운전하였다. Semi-pilot 바이오필터 운전 초반 및 중반에서는 황화수소 제거효율은 암모니아 부하와 무관하였으나, 암모니아 제거효율은 황화수소 부하가 커짐에 따라서 감소하였다. 그럼에도 불구하고 semi-pilot 바이오필터 운전 후반에서는 황화수소 부하가 커짐에도 불구하고 암모니아 제거효율이 영향을 받지 않았다. 이것은 semi-pilot 바이오필터 운전 후반의 buffer solution의 지속적 투입으로 인하여 semi-pilot 바이오필터담체의 산성화가 크지 않음에 기인한다고 간주된다. Semi-pilot 바이오필터시스템으로 황화수소와 암모니아의 동시제거를 할 때에 황화수소와 암모니아의 최대 elimination capacity 값은 각각 약 58 및 $30g/m^3/h$이었다. 이와 같이 semi-pilot 바이오필터 운전에 의하여 황화수소와 암모니아를 동시 제거한 경우에는 실험실규모 바이오필터의 유사한 운전조건 하에서 둘 중의 하나만을 함유한 경우보다 제거용량이 각각 약 39와 46% 만큼 감소하여서, 황화수소와 암모니아를 동시 제거한 경우에 암모니아 최대제거용량이 황화수소 최대제거용량보다 7% 만큼 더 감소하였다.

• 한국대기환경학회지
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• 제31권2호
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• pp.173-180
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• 2015

The purpose of this study was to fabricate a ferric nitrate impregnated activated carbon, and the performance for hydrogen sulfide by adsorption was evaluated. Sodium hydroxide was utilized to control pH in the process during generation of ferric hydroxide on the surface of the carbon. Critical mixing duration for generation of ferric hydroxide on the carbon was 48 hrs at pH 1 of the solution, in which the chemical adsorption of hydrogen sulfide was enhanced. The adsorption capacity of the impregnated carbon increased up to 0.10 g hydrogen sulfide/g carbon, which was 4.3 times higher than that of the raw carbon. Presence of FeOOH on the surface of the impregnated carbon was examined by X-ray diffraction.

• 한국환경보건학회지
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• 제14권1호
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• pp.11-22
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• 1988

Calcium oxide, lithium oxide and titanium oxide were investigated as additives of zinc oxide for the removal of hydrogen sulfide at high temperature. This experiment was performed in the range of 1.0-2.0 vol.% H$_2$S concentration at 623-873 K reaction temperature, using a thermogravimetric analyzer. A pore blocking model was found to fit the reaction rate and the kinetics data were sucessfully expressed by this model. The reactions between additive sorbents and hydrogen sulfide were first order with respect to hydrogen sulfide concentration in a gaseous mixture with nitrogen. Among the used sorbents, ZnO-CaO 0.5 at.% and ZnO-TiO$_2$ 2.0 at.% sorbents had the best additive effects on the sulfidation reaction between additive sorbents and hydrogen sulfide, whereas the ZnO-Li$_2$O sorbents were ineffective.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.265-270
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• 1999

A three phase fluidized bed bioreactor immobilized with Thiobacillus sp. IW was tested to remove hydrogen sulfide and methylmercaptan with high loading rate. In a single gas treatment, the bioreactor removed 92- 98％ of hydrogen sulfide with loading rate of 15- 66 g/l/h and removed 87-98％ of methylmercaptan with loading rate of 14-60 gl/sup -1/h/sup -1/. In the mixed gas treatment, the removal efficiencies of hydrogen sulfide and methylmercaptan maintained at 89-99％ for various inlet loading rates and were not affected by the inlet loading ratio of both gases in low loading rates. When the inlet concentration of methylmercaptan increased 3.8 times and was maintained for 30 h to observe the response of the bioreactor to sudden environmental change, the removal efficiency of methylmercaptan was maintained at an average of 91％.