In this study, the performances of H2S, NH3, and HCl sensors for real-time monitoring in small emission facilities (4, 5 grades in Korea) were evaluated at high concentration conditions of those gases. And the proper approach for the collection of reliable measurement data by sensors was suggested through finding out the effect on sensor performances according to changes in temperature and humidity (relative humidity, RH) settings. In addition, an assessment on sensor data correction considering the effects produced by environmental settings was conducted. The effects were tested in four different conditions of temperature and humidity. The sensor performances (reproducibility, precision, lower detection limit (LDL), and linearity) were good for all three sensors. The intercept (ADC0) values for all three sensors were good for the changes of temperature and humidity conditions. The variation in the slope value of the NH3 sensor showed the highest value, and this was followed by the HCl, H2S sensors. The results of this study can be helpful for data collection by enabling the more reliable and precise measurements of concentrations measured by sensors.

The present study estimated rumen fermentation characteristics and greenhouse gas emissions of different forages. Alfalfa, timothy, tall fescue, Italian ryegrass, and rice straw as the main forage sources for Hanwoo were used in the present study. Crude protein was highest in alfalfa but lowest in rice straw (p<0.05). Ether extract was higher in alfalfa and Italian ryegrass than in the other forages (p<0.05). Crude ash was highest in rice straw but lowest in tall fescue (p<0.05). Neutral detergent fiber was highest in tall fescue but lowest in alfalfa (p<0.05). Acid detergent fiber was highest in Italian ryegrass and rice straw but lowest in alfalfa (p<0.05). In vitro digestibilities of dry matter (DMD) and neutral detergent fiber (NDFD) were highest in timothy but lowest in rice straw (p<0.05). Rumen pH was highest (p<0.05) in alfalfa, while ammonia-N was higher (p<0.05) in alfalfa and Italian ryegrass than in the other forages. Total volatile fatty acid was highest (p<0.05) in timothy, while acetate and propionate were highest (p<0.05) in alfalfa and rice straw, respectively. Acetate to propionate ratio was higher (p<0.05) in alfalfa, timothy, and Italian ryegrass than in rice straw. Rice straw had lowest total gas (mL) (p<0.05) but highest its per DMD and NDFD. Rice straw had higher (p<0.05) CO2 (per DMD and NDFD) compared to alfalfa (per DMD and NDFD), timothy (per DMD and NDFD), tall fescue (per NDFD), and Italian ryegrass (per DMD). Again, rice straw had higher (p<0.05) CH4 (per DMD and NDFD) compared to timothy (per DMD and NDFD) and tall fescue (per NDFD). Therefore, this study indicates that timothy has a higher nutrient digestibility and volatile fatty acid in the rumen leading to a reduction of greenhouse gas emission.

수도권에 위치한 S매립장 내 3개의 매립장을 대상으로 매립가스 배출 및 주요 경로별 표면 발산과 관련된 분석을 하였다. 전체 매립가스 발생비율 10.9%인 LS1이 총 표면발산 비중은 49.4%를 차지하고 있었다. 3개 매립장에서의 메탄의 총 표면발산은 13.6 Nm3/min로서, LS1 8.4 Nm3/min (61.7%), LS2 4.0 Nm3/min(29.4%), LS3 1.2 Nm3/min(8.9%)이고, 발산경로별로는 상부 7.3 Nm3/min (53.2%), 사면 6.4 Nm3/min(46.7%), 다이크 0.02 Nm3/min(0.1%)이었다. 3개 매립장의 주요 배출경로 별 산화율은 다이크가 87.5%로 가장 크고, 상부 72.3%, 사면 71.8% 순이었다. 메탄을 기준으로 표면발 산 기여율은 매립장 별로 LS1이 전체의 61.7%로 가장 컸다. 주요 배출경로별로는 LS1의 사면이 전체의 41.7%, LS2의 상부 24.4%, LS1의 상부 20.0%로서 S매립장의 전체 메탄 표면발산량의 86.1%를 차지함 에 따라 향후 집중적인 관리가 필요할 것으로 판단되었다.

This study was conducted to determine the effects of dietary protein level and supplementation of protease on growth performance, nutrient digestibility, gut microflora, intestinal morphology and fecal noxious gas emission in weanling pigs. A total of 240 weaned pigs (Landrace×Yorkshire×Duroc, 5.82±0.3 kg) were used during 4 weeks in 2 phases (days 0-14, phase 1; and days 15-28, phase 2) feeding program based on age and initial body weight. Pigs were allocated to 2×2 factorial arrangement, including 2 protein levels (HP, high protein; LP, low protein) and 2 protease levels (with or without protease). The average daily gain in the LP treatment (357 g/d) was increased rather than the HP treatment (339 g/d). A greater avarage daily gain was observed in dietary suppiemented protease treatment (358 vs 339 g/d). Average feed intake was greater in the LP treatment (544 g/d) rather than the HP treatment (530 g/d). A greater average daily feed intake was observed in dietary supplemented protease treatment (552 vs 523 g/d). Dry matter and crude protein digestibility were increased in dietary supplemented protease treatment (82.62% and 76.08%, respectively) rather than non-supplemented treatment (81.74% and 75.13%, respectively). Ileal Lactobacillus spp. count increased in dietary supplemented protease treatment (7.42 vs 7.32 log10CFU/g). Emission of H2S was decreased in the LP treatment (4.41 ppm) rather than HP treatment (4.78 ppm). Emission of NH3 was decreased in dietary supplemented protease treatment (10.43 ppm vs 11.76 ppm). In conclusion, the decrease of dietary protein level and supplementation of protease had beneficial effects on growth performance, nutrient digestibility, gut microflora, and noxious gas emission in weanling pigs.

In this paper, we compare and analyze the injector defects of P-ENG and S-ENG with normal injectors by measuring current waveforms, voltage waveforms, exhaust gases and driving fuel economy. In the case of FTS failure, the S-ENG reduced the overall injection time by 3.7% and the main injection by 3.5% compared to the normal engines. In the case of AFS failure, the overall injection time increased by 45.7% and the main injection time increased by 24.1% compared to the normal engine. The rest data showed that fuel economy of S-ENG had 25.9% higher than P-ENG, NOX had 162.5% higher than that of P-ENG, and CO2 of S-ENG had 26.7% lower than P-ENG.

최근 지구의 기후변화는 온실가스가 원인으로 전 세계적 대기환경문제로 크게 부각되고 있다. 국내에서도 기후변화에 적극 대응하기 위한 기술개발이 꾸준히 진행되고 있다. 날씨의 이상고온으로 인한 환경에 미치는 영향과 갑작스런 집중호우가 환경에 미치는 영향을 대상으로 하였다. 우리생활 주변 대기온도가 상승하였을 때 온도변화에 의한 대기오염발생에 미치는 영향을 연구하고자 한다. 본 연구의 실험조건은 선박 디젤기관에서 회전수 1400 rpm, 1600 rpm 그리고 1800 rpm, 부하는 0 %에서 25 %씩 100 %까지 하였고, 흡기 온도변화 는 20℃에서 50℃까지 구분하여 연구하였다. 연구한 결과 흡기온도가 증가함에 따라 일산화탄소 및 탄화수소는 약간 감소하였으나 연료 소비율, 질소산화물, PM은 약간 증가하였다. 또한 연소온도는 큰 변화가 없었다.

대기오염에 대한 관심은 국내·외에서 점진적으로 상승하고 있으며, 자동차 및 연료 연구자들은 청정(친환경 대체연료) 연료와 연료품질 향상 등을 위해 새로운 엔진 설계, 혁신적인 후 처리 시스템 등의 많은 접근을 통하여 차량 배출가스와 온실가스를 감소시키려고 노력하고 있다. 이러한 연구들은 주로 차량 의 배출가스 (규제 및 미규제물질, PM 입자 배출 등)와 온실가스의 두 가지 이슈로 진행되고 있다. 자동차의 배출가스는 환경오염과 인체에 악영향을 주는 많은 문제를 일으키고 있다. 이러한 배출가스를 줄이기 위하여 각국에서는 배출가스 시험모드를 새로 만들어 규제하고 있다. 2007 년부터 UN ECE의 WP.29 포 럼에서 배출가스 인증을 위한 전 세계의 조화된 light-duty 차량 시험 절차 (WLTP)가 개발되었다. 이 시험 절차는 유럽과 동시에 국내 light-duty 디젤 차량에도 적용되어졌다. Light-duty 차량의 대기오염 물질 배 출량은 거리 당 무게로 규제되어 있어 주행주기가 결과에 영향을 미칠 수 있다. 차량의 배출가스는 주행 및 환경조건, 주행습관 등에 따라 크게 달라진다. 극단적인 외기온도는 배출가스를 증가시키는데, 이것은 더 많은 연료가 실내를 가열하거나 냉각해야하기 때문이다. 또한 높은 주행속도는 증가된 항력을 극복하기 위해 필요한 에너지로 인해 배출가스 량을 증가시킨다. 일반적으로 상승하는 차량속도와 비교할 때, 급격 한 차량가속도도 배출가스를 증가시킨다. 부가적인 장치 (에어컨 또는 히터)와 도로경사 또한 배출가스를 증가시킨다. 본 연구에서는 3대의 light-duty 차량을 가지고 light-duty 차량의 배출가스 규제에 사용되는 WLTP, NEDC 및 FTP-75로 시험을 하였으며, 배출가스가 다른 주행 사이클에 의해 얼마나 많은 영향을 받을 수 있는지를 측정하였다. 배출 가스는 통계적으로 의미있는 차이를 보이지 않았다. 최대 배출 가스는 주로 냉 각 된 엔진 조건에 의해 야기되는 WLTP의 저속 단계에서 발견된다. 냉각 된 엔진 상태에서 배출가스의 양은 시험 차량과 크게 다르다. 이는 WLTP 구동 사이클에 대처하기 위해 다른 기술적 솔루션이 필요하다는 것을 의미한다.

Fossil fuel combustion during fishing activities is a major contributor to climate changes in the fishing industry. The Tier1 methodology calculation and on-site continuous measurements of the greenhouse gas were carried out through the use of fuel by the coastal and offshore gillnet (blue crabs and yellow croaker) and trap (small octopus and red snow crab) fishing boats in Korea. The emission comparison results showed that the field measurements are similar to or slightly higher than the Tier1 estimates for coastal gillnet and trap. In offshore gillnet and trap fisheries, Tier1 estimate of greenhouse gases was about 1,644-13,875 kg CO2/L, which was more than the field measurement value. The CO2 emissions factor based on the fuel usage was 2.49-3.2 kg CO2/L for coastal fisheries and 1.46-2.24 kg CO2/L for offshore fisheries. Furthermore, GHG emissions per unit catch and the ratio of field measurement and Tier1 emission estimate were investigated. Since the total catch of coastal fish was relatively small, the emission per unit catch in coastal fisheries was four to eight times larger. The results of this study could be used to determine the baseline data for responding to changes in fisheries environment and reducing greenhouse gas emission.

The role played by reservoirs in the biogeochemical cycles of elements is a subject of ongoing debate. Recent research has revealed that reservoirs emit significant levels of greenhouse gases. To assess the importance of reservoirs in monsoon climate areas as a source of methane gas into the atmosphere, we investigated variations in organic carbon (OC) input into the reservoir, oxic state changes, and finally the amount of methane emitted (focusing on the ebullition pathway) in Lake Soyang, which is the largest reservoir in South Korea. Total organic carbon (TOC) concentrations were higher during summer after two years of heavy rainfall. The sedimentation rates of particulate organic carbon (POC) and particulate organic nitrogen (PON) were higher in the epilimnion and hypolimnion than the metalimnioin, indicating that autochthonous and allochthonous carbon made separate contributions to the TOC. During stratification, oxygen depletion occurred in the hypolimnion due to the decomposition of organic matter. Under these conditions, H2S and CH4 can be released from sediment. The methane emissions from the reservoir were much higher than from other natural lakes. However, the temporal and spatial variations of methane ebullition were huge, and were clearly dependent on many factors. Therefore, more research via a well-organized field campaign is needed to investigate methane emissions.

The objective of this study was to determine the effect of various roughage sources on nutrient digestibility and enteric methane (CH4), and carbon dioxide (CO2) production in goats. Four castrated black goats (48.5 ± 0.6 kg) were individually housed in environmentally controlled respiration-metabolism chambers. The experiment design was a 4 × 4 balanced Latin square design with 4 roughage types and 4 periods. Alfalfa, tall fescue, rice straw, and corn silage was used as representative of legume, grass, straw, and silage, respectively. Dry matter digestibility was higher (p < 0.001) in corn silage than in alfalfa hay. Dry matter digestibility of alfalfa hay was higher than those of tall fescue or rice straw (p < 0.001). Neutral detergent fiber digestibility of tall fescue was lower (p < 0.001) than those of alfalfa, rice straw, or corn silage. Daily enteric CH4 production and the daily enteric CH4 production per kilogram of BW0.75, dry matter intake (DMI), organic matter intake (OMI), digested DMI, and digested OMI of rice straw did not differ from those of tall fescue but were higher (p < 0.001) than those of alfalfa or corn silage. Roughage type had no effect on enteric CO2 emission in goats. Straw appeared to generate more enteric CH4 production than legume or silage, but similar to grass.

This study was conducted to investigate effects of feeding fermented milk on growth, intestinal microorganisms and fecal noxious gas emission in suckling pigs. A total of a hundred birth piglets (Landrace×Yorkshire×Duroc) were randomly assigned into feeding group and control group during suckling period that ten pigs per sow. Fermented milk contained 3.0×108/g of Bacillus and 3.5×108/g of Lactobacillus, and was supplied by top dressing method. Fermented milk fed to the sulking pigs indicated tendency to increase weaning body weight (p=0.052) and average daily gain (p=0.094). Total microbial flora and Escherichia coli in the feces were lower (p<0.05) in the feeding group than the non-feeding group. Reversely, Lactobacillus was higher (p<0.01) in feces of the pigs fed fermented milk than the pigs of the control group. Hydrogen sulfide emitted in feces was decreased in feeding group compared with control group (p<0.05). Similarly, fecal total mercaptans was diminished in the feeding group than the control group (p<0.01). Therefore, the fermented milk fed to the sulking pigs may improved growth and can influence positively intestinal microorganisms and fecal noxious gas emission.

This study was carried out to investigate the effect of malodor and VOCs reduction that could be achieved through the installation of a vapor recovery system (VRS) in a gas station. It was revealed that the reduction efficiencies of malodor by running VRS were about 93% around the oil feeder, 32% in the office and 45% in the site boundary. Specifically, it was remarkable that reduction efficiencies of BTEX over 90% were recorded through VRS operation. In addition, the results of continuous monitoring of THC around the oil feeder device provided good evidence of the inhibition of oil mist diffusion after running VRS.

This study investigated the effects of LactoPlanta® (Lactobacillus plantarum (L. plantarum), 2.0 × 109 colony forming units (CFU)/kg) on reduction of noxious gas emission in pig houses as well as improvement of carcass weight and quality in finishing pigs. A total of 850 finishing pigs were assigned to four treatment groups: control (CON, basal diet) (n=190), LP-0.1, 0.1% LactoPlanta® (n=210), LP-0.2, 0.2% LactoPlanta® (n=230), and LP-0.4, 0.4% LactoPlanta® (n=220). Ammonia and hydrogen sulfide concentrations were significantly reduced in all treatment groups compared to CON. Mercaptan contents and carcass weights of LP-0.2 and LP-0.4 were significantly decreased compared to CON, whereas there were no significant differences between LP-0.1 and CON. Carcass weight of LP-0.1 was slightly higher than that of CON, but there was no significant difference. However, carcass weights of LP-0.2 and LP-0.4 were significantly higher than that of CON (P<0.05). The prevalence of grade A carcasses in groups administered with L. plantarum (46.7~63.3%) was higher than that in CON (43.3%) and increased in a dose-dependent manner. Based on the results of this study, L. plantarum could be an effective candidate to reduce noxious gas emissions in finishing pig houses as well as improve carcass weight and quality in finishing pigs.