• 생명과학회지
• /
• 제30권9호
• /
• pp.743-748
• /
• 2020

제독유황은 황산염의 환원제로서 황화수소로 환원되면서 메탄생성과정에서 에너지 이용 경쟁을 통해 저감 할 수 있다. 본 연구는 유독성분이 제거된 유황을 in vitro를 통해 반추위 발효 성상 및 메탄 저감 효과를 평가하였다. 반추 위액은 케뉼라가 부착되어 있는 홀스타인 젖소에서 채취하여 이용하였으며, 기질 사료는 농후사료 1 g (DM)을 사용하였다. 처리구는 0% (대조구), 0.2% (처리구 1), 0.4% (처리구 2), 0.6% (처리구 3), 0.8% (처리구 4) 및 1.0% (처리구 5)로 실시하였다. pH, 총가스발생량 (TG), 메탄, 건물 소화율, 유기물 소화율 및 휘발성지방산을 분석하였다. 메탄생성량은 0.2% 처리구에서(13.78 ml) 가장 낮았으며, 대조구에서(20.16 ml)로 가장 높았다(p<0.05). 휘발성 지방산은 0.2% 처리구에서 64.28 mM 높았다. A/P 비율은 0.2% 처리구에서 1.90으로 가장 낮았으며, 0.8%에서 2.44로 유의성이 있었지만, pH, 총가스발생량, DM 소화율, OM 소화율, acetate, propionate 및 butyrate에서는 차이가 없었다. 총 세균의 DNA는 대조구보다 모든 처리구에서 낮았다. 이 연구를 통해 0.2% 처리구에서 반추위 발효 성상 및 메탄 저감에 효과가 있었다.

• 환경위생공학
• /
• 제24권4호
• /
• pp.1-26
• /
• 2009

We conclude the following with air pollution data measured from city measurement net administered and managed in Gwangju for the last 7 years from January in 2001 to December in 2007. In addition, some major statistics governed by Gwangju city and data administered by Gwangju as national official statistics obtained by estimating the amount of national air pollutant emission from National Institute of Environmental Research were used. The results are as follows ; 1. The distribution by main managements of air emission factory is the following ; Gwangju City Hall(67.8%) > Gwangsan District Office(13.6%) > Buk District Office(9.8%) > Seo District Office(5.5%) > Nam District Office(3.0%) > Dong District Office(0.3%) and the distribution by districts of air emission factory ; Buk District(32.8%) > Gwangsan District(22.4%) > Seo District(21.8%) > Nam District(14.9%) > Dong District(8.1%). That by types(Year 2004~2007 average) is also following ; Type 5(45.2%) > Type 4(40.7%) > Type 3(8.6%) > Type 2(3.2%) > Type 1(2.2%) and the most of them are small size of factory, Type 4 and 5. 2. The distribution by districts of the number of car registrations is the following ; Buk District(32.8%) > Gwangsan District(22.4%) > Seo District(21.8%) > Nam District(14.9%) > Dong District(8.1%) and the distribution by use of car fuel in 2001 ; Gasoline(56.3%) > Diesel(30.3%) > LPG(13.4%) > etc.(0.2%). In 2007, there was no ranking change ; Gasoline(47.8%) > Diesel(35.6%) > LPG(16.2%) >etc.(0.4%). The number of gasoline cars increased slightly, but that of diesel and LPG cars increased remarkably. 3. The distribution by items of the amount of air pollutant emission in Gwangju is the following; CO(36.7%) > NOx(32.7%) > VOC(26.7%) > SOx(2.3%) > PM-10(1.5%). The amount of CO and NOx, which are generally generated from cars, is very large percentage among them. 4. The distribution by mean of air pollutant emission(SOx, NOx, CO, VOC, PM-10) of each county for 5 years(2001~2005) is the following ; Buk District(31.0%) > Gwangsan District(28.2%) > Seo District(20.4%) > Nam District(12.5%) > Dong District(7.9%). The amount of air pollutant emission in Buk District, which has the most population, car registrations, and air pollutant emission businesses, was the highest. On the other hand, that of air pollutant emission in Dong District, which has the least population, car registrations, and air pollutant emission businesses, was the least. 5. The average rates of SOx for 5 years(2001~2005) in Gwangju is the following ; Non industrial combustion(59.5%) > Combustion in manufacturing industry(20.4%) > Road transportation(11.4%) > Non-road transportation(3.8%) > Waste disposal(3.7%) > Production process(1.1%). And the distribution of average amount of SOx emission of each county is shown as Gwangsan District(33.3%) > Buk District(28.0%) > Seo District(19.3%) > Nam District(10.2%) > Dong District(9.1%). 6. The distribution of the amount of NOx emission in Gwangju is shown as Road transportation(59.1%) > Non-road transportation(18.9%) > Non industrial combustion(13.3%) > Combustion in manufacturing industry(6.9%) > Waste disposal(1.6%) > Production process(0.1%). And the distribution of the amount of NOx emission from each county is the following ; Buk District(30.7%) > Gwangsan District(28.8%) > Seo District(20.5%) > Nam District(12.2%) > Dong District(7.8%). 7. The distribution of the amount of carbon monoxide emission in Gwangju is shown as Road transportation(82.0%) > Non industrial combustion(10.6%) > Non-road transportation(5.4%) > Combustion in manufacturing industry(1.7%) > Waste disposal(0.3%). And the distribution of the amount of carbon monoxide emission from each county is the following ; Buk District(33.0%) > Seo District(22.3%) > Gwangsan District(21.3%) > Nam District(14.3%) > Dong District(9.1%). 8. The distribution of the amount of Volatile Organic Compound emission in Gwangju is shown as Solvent utilization(69.5%) > Road transportation(19.8%) > Energy storage & transport(4.4%) > Non-road transportation(2.8%) > Waste disposal(2.4%) > Non industrial combustion(0.5%) > Production process(0.4%) > Combustion in manufacturing industry(0.3%). And the distribution of the amount of Volatile Organic Compound emission from each county is the following ; Gwangsan District(36.8%) > Buk District(28.7%) > Seo District(17.8%) > Nam District(10.4%) > Dong District(6.3%). 9. The distribution of the amount of minute dust emission in Gwangju is shown as Road transportation(76.7%) > Non-road transportation(16.3%) > Non industrial combustion(6.1%) > Combustion in manufacturing industry(0.7%) > Waste disposal(0.2%) > Production process(0.1%). And the distribution of the amount of minute dust emission from each county is the following ; Buk District(32.8%) > Gwangsan District(26.0%) > Seo District(19.5%) > Nam District(13.2%) > Dong District(8.5%). 10. According to the major source of emission of each items, that of oxides of sulfur is Non industrial combustion, heating of residence, business and agriculture and stockbreeding. And that of NOx, carbon monoxide, minute dust is Road transportation, emission of cars and two-wheeled vehicles. Also, that of VOC is Solvent utilization emission facilities due to Solvent utilization. 11. The concentration of sulfurous acid gas has been 0.004ppm since 2001 and there has not been no concentration change year by year. It is considered that the use of sulfurous acid gas is now reaching to the stabilization stage. This is found by the facts that the use of fuel is steadily changing from solid or liquid fuel to low sulfur liquid fuel containing very little amount of sulfur element or gas, so that nearly no change in concentration has been shown regularly. 12. Concerning changes of the concentration of throughout time, the concentration of NO has been shown relatively higher than that of $NO_2$ between 6AM~1PM and the concentration of $NO_2$ higher during the other time. The concentration of NOx(NO, $NO_2$) has been relatively high during weekday evenings. This result shows that there is correlation between the concentration of NOx and car traffics as we can see the Road transportation which accounts for 59.1% among the amount of NOx emission. 13. 49.1~61.2% of PM-10 shows PM-2.5 concerning the relationship between PM-10 and PM-2.5 and PM-2.5 among dust accounts for 45.4%~44.5% of PM-10 during March and April which is the lowest rates. This proves that particles of yellow sand that are bigger than the size $2.5\;{\mu}m$ are sent more than those that are smaller from China. This result shows that particles smaller than $2.5\;{\mu}m$ among dust exist much during July~August and December~January and 76.7% of minute dust is proved to be road transportation in Gwangju.

• 공업화학
• /
• 제5권5호
• /
• pp.836-842
• /
• 1994

가스분사반응기(Jet bubbling reactor)에서의 가스분사관의 최적 설계조건과 $SO_2$ 제거효율에 미치는 운전변수들의 영향을 검토하였다. 효과적인 기-액 접촉을 위한 가스분사관의 설계에 있어서 가장 중요한 인자는 Reynolds number로서 Reynolds number를 12,000 이상으로 하고 가스분사관과 가스분사구멍에서의 Reynolds number가 동일하게 되도록 가스분사관을 설계하는 것이 가스분사관 설계의 최적조건인 것으로 판단된다. ${\Delta}P$, pH, 유입 $SO_2$농도, 석회석 입자크기 등 공정의 운전변수 중에서 $SO_2$ 제거효율에 가장 큰 영향을 미치는 변수는 ${\Delta}P$였으며 pH 4.0하에서 90% 이상의 $SO_2$ 제거효율을 얻기 위해서는 ${\Delta}P$를 230mmAq 이상으로 유지시켜야 하였다. 실험결과 3.0 정도의 낮은 pH 하에서도 높은 $SO_2$ 제거효율이 얻어졌으며 이러한 이유는 강제산화에 의해 흡수액내의 $HSO{_3}{^-}$이온이 $SO{_4}{^{2-}}$ 이온으로 거의 완전한 산화가 일어나 흡수액 내의 $SO_2$ 평형분압이 매우 낮은 상태로 유지되었기 때문으로 생각된다. 또한 흡수액의 pH 5.0 이하의 조건에서는 $SO_2$ 흡수에 사용된 석회석의 입자크기에 관계없이 모두 99.5% 이상의 높은 석회석 이용률을 나타내었다.

• 청정기술
• /
• 제18권2호
• /
• pp.209-215
• /
• 2012

분말활성탄과 제올라이트가 담지된 폴리우레탄 담체를 충진한 파일롯 규모의 바이오필터를 이용하여 암모니아와 황화수소의 처리 성능을 평가하였다. 약 10개월간 하수처리장 슬러지 농축조에서 발생하는 악취를 대상으로 바이오필터 유입 암모니아 농도는 0.1~1.5 $ppm_v$, 황화수소 농도는 2~20 $ppm_v$ 범위에서 운전되었다. 바이오필터의 공탑체류시간 3.6~5초 범위에서 초기 순응기간을 제외하고는 거의 모든 경우 100%에 가까운 악취 제거율을 보여주었다. 바이오필터에서의 기체흐름에 의한 압력손실도 매우 낮아 10개월 동안 최대 31 mm $H_2O$ 정도의 차압이 발생하였다. 이것은 본 연구에 이용된 바이오필터의 막힘이나 담체의 압착 현상이 거의 일어나지 않아 장기간의 운전에도 안정성을 확인할 수 있었다. 담체에 부착하여 서식하는 미생물군집은 바이오필터의 처리 성능에 중요한 영향을 미치는데 특히 암모니아나 황화수소를 제거하기 위한 암모니아 산화균과 황산화균의 분포가 중요하다. FISH (Fluorescence in Situ Hybridization) 방법으로 확인한 결과 질산화를 주관하는 암모니아 산화균인 Nitrosomonas sp.와 황산화균인 Thiobacillus ferroxidans가 검출되었다. 또한 바이오필터의 운전기간이 길어질수록, 그리고 악취의 유입부분이 유출부분에 비해 미생물 분포량이 더 많음을 확인하였다.

• 멤브레인
• /
• 제26권3호
• /
• pp.220-228
• /
• 2016

비용매 유도 상분리(NIPS) 법으로 제조된 폴리이미드 전구체를 이용하여 탄소분자체 중공사 분리막을 제조하였으며, 온도변화에 따른 열처리 조건이 탄소분자체 중공사막의 기체 분리 특성에 미치는 영향을 고찰하였다. 열처리 온도 $250{\sim}450^{\circ}C$에서 승온 속도, 안정화 시간을 조정하여 최적화 하였을 때, 중공사 분리막의 단일기체 $N_2$, $SF_6$, $CF_4$ 투과도는 각각 20, 0.32, 0.48 GPU이었고, $N_2/SF_6$ 선택도는 62, $N_2/CF_4$ 선택도는 42로 가장 높은 값을 나타내었다. $SF_6/CF_4/N_2$ 혼합기체 평가에서는 0.5 MPa에서 stage cut이 0.2일 때, $SF_6$, $CF_4$ 회수율이 각각 99, 98% 이상으로 높게 나타났고, 농축농도는 stage cut 0.8에서 주입농도의 4.5배 이상이었다. 이로부터 제조된 탄소분자체 중공사 분리막은 불화가스 회수용 분리막으로써 우수한 소재임을 확인할 수 있었다.

• 한국치위생학회지
• /
• 제8권1호
• /
• pp.119-131
• /
• 2008

This study was peformed in order to find out the relationship between the causing factors and the production of each gas 01 oral malodor, to contribute the oral malodor control at dental clinic as well as to establish the effective application of malodor control project for public oral health program 127 patients from 20 to 40 years old who had been visited for preventive dental cares were participated for the study. Such items as caries status, periodontal status, salivary flow, viscosity, pH. Snyder test, plaque deposit and tongue plaque were checked through the oral examination in order to find out the contributing factors Hydrogen sulfide, Methyl mercaptan, Di-methyl sulfide and Ammonia gas components were checked with Oral-Chroma and Attain, the oral malodor check units. Not only the corelation coefficiencies but also the multi-way variance analysis were calculated between each causing factor and each component of oral malodor gases to estimate the contributing factors of the oral malodor. 1. There was no relationship between the caries status and each component pf the oral malodor such as sulfur compound or Ammonia, both in laboratory test and VAS test (pF0.05). It revealed negative relationship between Hydrogen sulfide and FT(rM-0.1904. pE0.05) as well as the VAS and FT (rM-0.210. pE0.05). S0, it was estimated that the less oral malador was recognized when caries state changed to filled state in Hydrogen sulfide laboratory test or VAS test 2. High relationship was showed between salivary flow and Hydrogen sulfide (rM-0.183, pM0.039), Methyl mercaptan(rM-0.234, p-0.008). Dimethyl sulfide(rM-0.234, pM0.008) and Ammonia(-0.361. pM0.001) gas(pE0.05). 3. There was a high relationship between M-PHP(Modified-Patient Hygiene Performance Index) and tong plaque all kinds of sulfide(rM0.249. pM0.005). Ammonia gas component(rM0.232, pM0.009). 4. It was found that considerable relationship was appeared between the periodontal status and Ammonia gas (rM0.274, pM0.002), so, it should be needed to control Ammonia. Such dental Cares as the prevention or early treatment of periodontal disease and the accelerating the salivary flow as well as reducing the amounts and activities of filament or spiral typed oral micro-organism were recommended for adults, not only for dental care program at the dental clinics but also for public health programs, in order to promote the oral health and quality of file for individual and community peoples.

• 대한환경공학회지
• /
• 제34권8호
• /
• pp.541-548
• /
• 2012

본 연구에서는 생활폐기물 자동집하시설에서의 악취물질 배출특성을 파악하고자 2개소(A시설, B시설)의 시설을 선정하여 공기관로 내의 이송가스와 최종배출가스를 대상으로 복합악취와 22종의 지정악취물질을 조사하였다. 생활폐기물 자동집하시설에서 배출되는 주된 악취물질은 암모니아, 황 화합물, 아세트알데하이드이었으며, 악취처리공정의 종류에 따라 최종배출구의 악취 배출특성이 상이하였다. 이송가스를 대상으로 한 악취기여도 평가에서는 A시설의 경우, 디메틸설파이드 26%, 아세트알데하이드 18%, 메틸머캅탄 14%의 악취기여도를 보였으며, B시설의 경우에는 메틸머캅탄 56%, 황화수소와 디메틸설파이드가 각각 15%이었다.

• 한국대기환경학회지
• /
• 제30권4호
• /
• pp.301-310
• /
• 2014

Country-specific data for net calorific values and carbon emission factors requires for a higher tier estimate of greenhouse gas emissions in the energy sector. The objective of this study is to develop country-specific net calorific values and carbon emission factors for petroleum energy produced in Korea. Calorific values and carbon contents of the fuels were measured using the oxygen bomb calorimeter method and the CHN elemental analysis method, respectively. Sulfur and hydrogen contents, which were used to calculate the net calorific value, were also measured and then net calorific values and carbon emission factors were determined based on the measurement results. The net calorific values and carbon emission factors determined for the petroleum produced in Korea 2012 and 2013 were compared to those in the 2006 IPCC Guidelines. Most of the values were different compared with the default values of the 2006 IPCC Guidelines although those were placed within their upper and lower limits. Time series analysis results showed inconsistent seasonal variation for the net calorific values and carbon emission factors.

• 대한한방내과학회지
• /
• 제35권4호
• /
• pp.532-545
• /
• 2014

Objectives: The purpose of this study was to evaluate the clinical effect of Korean medical treatments such as herbal medicine, acupuncture, and electroacupuncture by using the portable gas chromatograph OralChroma$^{TM}$ (Abimedical, Japan) in halitosis patients. Methods: We surveyed 30 halitosis patients who had visited the Oral Diseases Clinic in the Korean Medical Hospital of Kyunghee University from October, 2013 to November, 2014. Before starting Korean medical treatment, the subjects were evaluated on sociodemographic characteristics, severity of discomfort using visual analogue scale (VAS), unstimulated salivary flow rate (USFR), and halitosis associated life-quality test (HALT) score. To evaluate the therapeutic effect, we measured the volatile sulfur compounds (VSCs) in breath by using OralChroma$^{TM}$ before and after 3 weeks treatment. Results: The concentration of total VSCs measured by OralChroma$^{TM}$ significantly decreased (p=0.001). Furthermore, the level of hydrogen sulfide and methyl mercaptan also significantly decreased (p<0.05). However, although the level of dimethyl sulfide decreased as well, there was no significance(p>0.05). Conclusions: Korean medical treatment was effective in treating halitosis by decreasing VSCs. Further study, with well-designed randomized controlled trials with larger number of cases will be needed in the future.

• Journal of Oral Medicine and Pain
• /
• 제26권3호
• /
• pp.243-252
• /
• 2001

본 연구에서는 구강 내 공기 중 설태 제거 전후의 휘발성 황화합물 농도를 gas chromatography를 이용하여 비교 분석하였다. 피검자로는 서울대학교 치과병원 구취클리닉에 내원한 환자 중에서 치주 건강 상태가 양호하며 구취를 호소하는 환자 18 명(평균연령 31.4세; 남자 8명, 여자 10명)을 대상으로 하였으며 구취를 측정하기 전에 모든 피검자들은 실험 전날 취침 전부터 실험 당일 실험시작 전까지 음식 섭취나 양치질 등의 모든 구강 활동을 금지하였다. 구취 시료는 채취 전에 피검자로 하여금 3분간 입을 다물게 한 후 입을 약 2cm정도 벌린 상태에서 시행하였으며 시료 채취 후 설태를 제거하였다. 설태 제거 후에 구강 내 공기를 다시 채취한 후 gas chromatography를 통하여 휘발성 황화합물의 각 성분별 농도를 분석하였다. 분석과정에서는 과거에 휘발성 황화합물의 검출 시 사용되어진 sampling loop와 isothermal run condition 대신 좀더 효율적인 직접표본주입방법과 oven temperature programmed analysis를 시행하였다. 1. 전체 휘발성 황화합물은 Hydrogen sulfide (59.96%), Methyl mercaptan (25.08%), Dimethyl sulfide (14.96%)로 구성되었다. 이 중 Hydrogen sulfide는 전체 휘발성 황화합물중 약 60%를 차지하여 치주상태가 양호한 구취환자에서의 주요한 구취 구 성 성분이었다. 2. 설태 제거 후 전체 휘발성 황화합물의 농도감소는 제거 전에 비하여 41.71%로 유의 하게 감소하였다(p<0.01). 3. 설태 제거 후에 Hydrogen sulfide의 농도감소는 43.62% (p<0.01), Methyl mercaptan 의 농도감소는 38.88% (p<0.05), 그리고 Dimethyl sulfide의 농도감소는 30.21% (p<0.01)로 각각 유의하게 감소하였다. 4. 전체 휘발성 황화합물의 구성비율은 설태 제거 전후에 유의한 차이가 없었다 (p>0.05).