• Journal of Korean Society of Transportation
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• v.29 no.2
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• pp.25-35
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• 2011

In order to reduce Green House Gas(GHG) reduction in the road freight sector and thus establish green logistics, running efficiency of goods vehicles is of paramount importance. Providing effective transportation infrastructure can contribute to achieve the green logistics by reducing empty running of heavy goods vehicles and van, increasing the average payload on the vehicle, and shifting the transportation mode. In order to reduce the environmental impact from the road freight sector, it is essential to quantify the amount of environmental loading from the sector. However, any systematic survey on the environmental loading from the logistics companies has not been carried out in Korea. In this study, the environmental index for the road freight sector is defined as the amount of $CO_2$ emission per ton km generated from goods vehicles. The computational analysis shows that the average $CO_2$ emission per ton km generated by the logistics companies in Korea is $363g-CO_2/ton{\cdot}km$. Compared to UK (=$130g-CO_2/ton{\cdot}km$) and France (=$97g-CO_2/ton{\cdot}km$), the efficiency of logistics in Korea is 2.8 and 3.7 times as low as in the advanced countries. It also indicates that the main reasons for the low efficiency are mainly due to the high rate of empty operation of goods vehicles and the low payload.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.3
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• pp.3-12
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• 2000

The field surveys and the measurements of seawater temperatures were conducted every month from 1997 to 1999, and the distributions of seawater temperature were simulated and reproduced by a three dimensional hydrodynamic numerical model over the southern waters of Cheju island. In order to estimate the marine environmental capacity for the reception of the heat loads of cooling water discharged from Hwasoon Thermal Power Plant(HTPP) in the study area, the simulations for predicting the situation of unfavorable environment in which marine organisms might not be satisfied with change in seawater temperature were peformed using a three dimensional hydrodynamic numerical model by controlling quantitatively the heat loads of cooling water from HTPP Currently, HTPP discharges cooling water of 35.9℃ into the sea as much as 112,800m³/day in summer. As the results of simulations, the more the heat loads from the power plant increase, the more increase the seawater temperatures around the water areas adjacent to the power plant. In case the heat loads of cooling water from HTPP become about 5 times as high as the present loads, seawater temperatures at near-shore waters adjacent to HTPP appear to be increased to the extent of 0.5℃ above the existing seawater temperature in summer. The marine environmental capacity for the reception of thermal discharge from HTPP is estimated to be about 530×10/sup 6/kcal/day which is equivalent to the increase of a factor of 2 in the temperature of cooling water without any change in the discharge rate of cooling water or which is equivalent to the increase of a factor of 4.6 in the discharge rate of cooling water without any change in the temperature of cooling water. Comparing the case of the increase in the discharge rate of cooling water with the case of the increase in the temperature of cooling water on the basis of the same heat loads of 530×10/sup 6/kal/day, the former case is expected to increase seawater temperature a little higher and to extend the area affected by heat loads a little broader.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.565-565
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• 2016

농림부는 농업지역에서 발생하는 비점오염원을 관리하기 위해 다양한 최적관리기법(BMP)에 대해 연구를 수행하여 효과를 검증하였으나 이를 광역 단위로 보급하여 실제 영농지역에서 BMP의 효과를 측정한 연구는 부족한 실정이다. 따라서 본 연구에서는 논 지역을 대상으로 물관리기술(물꼬)과 시비관리기술(완효성 비료) BMP를 보급하고 광역 단위로 BMP의 효과를 측정하고자 하였다. 연구대상지구는 새만금 지역에 위치한 전라북도 부안군 용계리 일대에 위치하고 있으며, 벼농사가 활발하게 이루어지고 있는 지역을 선정하였다. 논에 보급된 BMP의 효과를 측정하기 위해 BMP 참여 농가를 선정하여 물꼬와 완효성 비료를 보급하였으며, 용수로와 배출구 3지점을 선정하여 관개량을 측정하고 유출량을 측정하였다. 또한 관개수와 대조구, 처리구별(대조구, 물꼬, 완효성, 물꼬+완효성) 수질을 분석하여 배출구 별로 단위면적당 오염부하량을 산정하고 이를 통해 대조구 대비 처리구의 저감율을 분석하였다. 분석 결과, 대조구 대비 처리구의 단위면적당 오염부하량의 저감율은 SS 63.6%, BOD 45.5%, $COD_{Mn}$ 26.5%, $COD_{Cr}$ 40.1%, T-N 16.0%, T-P 12.9%, TOC 11.4%로 나타났다. 또한 연구대상지구를 SO#1(완효성 비료 95%, 비참여 농가 5%), SO#2(완효성 비료 2%, 물꼬 8%, 완효성 비료+물꼬 40%, 비참여 농가 40%), SO#M(완효성 비료 96%, 비참여 농가 4%) 3개의 배출구로 구분하여 BMP 보급 효과를 측정한 결과, 대조구 대비 SO#1에서는 수질항목별로 10.6 ~ 85.5%, SO#2는 8.1 ~ 45.9%, SO#M은 10.7 ~ 86.2%의 범위로 저감된 것으로 분석되었으며, 특히 SS의 단위면적당 오염부하 저감율이 가장 큰 것으로 나타났다. 하지만 본 연구는 7월부터 10월까지 측정된 데이터를 활용하여 산정하였기 때문에 써레질, 이앙기간에 발생한 단위면적당 오염부하량은 포함되지 않은 결과이며, 각 배수구역별 유입량의 경우 정확한 측정에 어려움이 있어 전체 관개량 대비 관개 면적을 이용하여 단위면적당 유입량을 산정하였기 때문에 추가적인 연구를 통해 효과를 검증할 필요가 있을 것으로 판단된다.

• Journal of Environmental Impact Assessment
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• v.22 no.2
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• pp.157-170
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• 2013

수질오염총량관리제 시행 하천에 대해서는 객관적이고 과학적 방법으로 유역내 각 지역의 오염부하량을 할당할 필요가 있다. 본 연구에서는 대도시에서 배출되는 오염부하의 영향을 크게 받는 영산강수계의 중상류부를 대상으로 오염부하량 할당 방법에 대해 검토하였다. 오염부하량 할당을 위한 수질모델링은, 수질관리에 흔히 적용되어온 QUAL2E의 최근 판인, QUAL2Kw를 이용해서 수행하였다. 모델 적용 대상 지역의 각 reach의 수질매개변수는 QUAL2Kw의 자동보정 기능을 이용해서 추정하였다. 오염부하량 할당의 최적화는 유전알고리즘(genetic algorithm)을 이용하였고, 최소부하량 삭감법(least waste load removal allocation), 일정 부하량 이상 최소부하량 삭감법(least waste load removal over a certain value), 동일삭감률 할당법(equal removal rate)의 세가지 방법을 적용하고 비교 검토하였다. 동일삭감률 할당법은 다른 방법보다 유역 전체 부하량 삭감량이 훨씬 크기 때문에 효과적이지 않았고, 이 방법을 쓰기 위해서는 부하량 삭감대상인 각 소유역과 하수처리장을 그 규모와 특성에 따라 세분화할 필요가 있다. 동일삭감률 할당법의 적용시 세가지 범주로 나누어서 삭감률을 적용하였다. 오염부하량 삭감의 효율성을 감안할 때 최소 부하량 삭감법보다 일정 부하량 이상 최소부하량 삭감법이 더 적절한 것으로 검토되었다.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.418-424
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• 2015

Marine Environment Protection Committee of the International Maritime Organization has decided to reinforce the NOx emission standards for ships passing an ECA(Emission Control Area) with Tier III standards from January 1, 2016. In this study, real-time measurements of the exhaust gas, cylinder pressure and fuel consumption were conducted at each load of a T/S Hanbada main engine of Korea Maritime and Ocean University, which is controlled by single injection and double post injection for reducing NOx emissions. The results showed that the quantity of CO2 and NOx increased in proportion to the engine load, whereas the CO concentration was inversely proportional to the engine load. In addition, double post injection decreased 10 % of P-max and reduced 25~30 % of the NOx emissions compared to single injection, whereas there was a trade-off relation, such as increase 3~5 % of SFOC (Specific Fuel Oil Consumption).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.4
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• pp.263-273
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• 2016

The effect of recirculated exhaust gas on performance and exhaust emissions with FGR rate are investigated by using a natural circulation, pressurized draft and water tube boiler with FGR system operating at several boiler loads and over fire air damper openings. The purpose of this study is to apply the FGR system to a power plant boiler for reducing $NO_x$ emissions. To activate the combustion, the OFA with 0 to 20% is supplied into the flame. When the suction damper of two stage combustion system installed in the upper side of wind box is opened by handling the lever between $0^{\circ}$ and $90^{\circ}$, also, the combustion air supplied to burner is changed. It is found that the fuel consumption rate per evaporation rate did not show an obvious tendency to increase or decrease with rising the FGR rate, and $NO_x$ emissions at the same OFA damper opening are decreased, as FGR rates are elevated and boiler loads are dropped. While a trace amount of soot is emitted without regard to the operation conditions of boiler load, OFA damper opening and FGR rate, because soot emissions are eliminated by the electrostatic precipitator with a collecting efficiency of 86.7%.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.166-174
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• 2001

The autochthonous and allochthonous organic carbon loading were measured in Lake Soyang, to estimate the amount of carbon loading into the lake and the contribution of their sources to tile lake's carbon loading. Autochthonous carbon loading was estimated from phytoplankton primary production with the extracellular organic carbon (EOC). Allochthonous loading was determined by measuring dissolved organic carbon (DOC) and particulate organic carbon (POC) concentration in the main inflowing Soyang River. Both autochthonous and allochthonous organic carbon loading were high during the svmmer, from July to September, and accounted for 43.2% and 71.7% of the annual loading, respectively. Primary productivity was elevated up to $1,000\;mgC\;m^{-2}\;d^{-1}$ during summer and lowest in winter. EOC production from phytoplankton was also large in summer, resulting in a high DOC concentration in the lake water. Primary production of phytoplankton and allochthonous organic matter loading from the watershed contributed to 53.6% and 46.4% of total loading, respectively. The EOC production accounted far $4.4{\sim}21.2%$ of POC primary production, implying that EOC production of phytolankton must be considered in estimation of primary production.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.111-117
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• 2011

In the wake of increased concerns on reduction of greenhouse emission which started with United Nation's Framework Convention on Climate Change (UNFCCC) and Kyoto protocol, Korean government is making various efforts under the represented slogan "Low Carbon, Green Growth". Therefore, it is inevitable that construction industry also follow the Korea government's slogan and the international trend in environmental problems. This study identified several main construction materials and equipments of civil construction projects and suggested a environmental cost estimation method and related estimation standards (Public and private owners are distinguished). A case analysis of a real road construction project is also performed and characteristics according to the owner type is compared. This study analyzed the environmental impact to total construction cost variations. In the result, public owner required 11~16% of extra budget and private owner required 19~22% of extra costs. This study is limited in consideration of environmental factors and carbon trading prices.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.480-487
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• 2012

The field study was carried out to investigate runoff characteristics of non-point source (NPS) by cultivation activity in river district. Two sites were selected mainly as G region (paddy field, green house), located in Kwangju, Gyeonggi Province, and S region (ordinary field), located in Namyangju, Gyeonggi Province, those belong to Paldang reservoir watershed. The paddy field with water storage capacity showed a slow increase in runoff as rainfall intensity increases. Meanwhile, both green house and ordinary filed revealed a rapid increase. The average BOD runoff concentration of paddy field, green house, and ordinary field was 2.0 mg/L, 2.8 mg/L, 7.9 mg/L, respectively. It indicates that ordinary field shows the highest value in BOD, SS, T-N, and T-P concentration due to the soil loss during rainfall. As a result of runoff load estimation according to the field, a T-N runoff load of paddy field was 1,793.9 kg/year, higher than that of ordinary field. It was estimated that a SS runoff load of ordinary field was 69,704 kg/year and accounts for more than 70% of overall runoff load.

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.52-60
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• 2018

In the construction industry, attempts to evaluate the environmental impact of products through life cycle assessment (LCA) approach has been on the rise. However, the domestic construction industry needs to make rapid decisions due to limited budget and schedule, so it is difficult to carry out a review of the environmental load on all resources. The decision-making process requires information on the major influence factors that should be focused on to reduce environmental load. And this information should be quantified so that it can be linked to environmental impact assessment. In this study, the LCA results of road construction cases were analyzed to provide such information. As a result, diesel, ready-mixed concrete, urethane-based paint, aggregate, and asphalt concrete were found to be the main factors that generated 93.17% of the environmental load in the earthwork type of road project. The total environmental cost caused by these affecting factors when constructing 1 km of earthwork type of road project is 242 million won. The analysis also shows that a 10% reduction in the amount of ready-mixed and asphalt concretes can reduce carbon emissions by 5.02% and 2.28% while reducing environmental costs by 11 million won per kilometer. In order to reduce carbon emissions of the earthwork type of road project, it is necessary to actively develop and introduce new methods and eco-friendly materials to reduce the overall use of ready-mixed concrete and asphalt concrete.