• Title/Summary/Keyword: low-pollution

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Numerical Investigation of Low-pollution Combustion with applying Flue Gas Recirculation in Counterflow Flames: Part I. Combustion Characteristics of Low NOx (대향류 화염에서 FGR이 적용된 저공해 연소의 수치적 해석: Part I. 저 NOx 연소특성)

  • Cho, Seo-Hee;Lee, Kee-Man
    • Journal of the Korean Institute of Gas
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    • v.23 no.6
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    • pp.8-16
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    • 2019
  • One of the methods for low-pollution combustion, flue gas recirculation(FGR) is effective to reduce nitrogen oxides and it was applied in CH4/air premixed counterflow flames to identify the change of flame characteristics and NOx mechanisms. Considering that the mole fraction of the products varied depending on the strain rates, the major products: CO2, H2O, O2 and N2 were recirculated as a diluent to reflect the actual combustion system. With the application of the FGR technique, a turning point of maximum flame temperature under certain strain rate condition was found. Furthermore as the recirculation ratio increased, the tendency of NO was changed before and after the turning point and the analysis on thermal NO and Fenimore NO production was conducted.

Problems and their Counter-measures in Water Quality Preservation (수질보전상의 문제와 대책)

  • Ryu Jae Keun
    • Journal of environmental and Sanitary engineering
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    • v.2 no.2 s.2
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    • pp.69-78
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    • 1987
  • Due to the increase of population and development of industry, the demand of available water resources increased . Many reservoirs have been constructed in large scales to meet this urgent need , resulting in the increased amount of water resources. After the constructions, however, serious pollution-especially eutrophication-in some reservoirs become a socialaffair. Therefore, water quality control in these resources should be considered more intensively than any other environmental preservation policies. It also seems to be imminent to prepare the precautionary steps. Most water pollution in Korea-73 percent - can be traced to domestic sewage. It may rome as a surprise to Some, Industry is responsible for just 27 percent of ]Korea's water pollution. What he calls 'non-point' Sources, which may include agricultural Chemicals, Create only negligible amount of water pollution. Up to $15\%$ of domestic sewage is treated in Korea, which is quite low when compared with the waste processing in developed countries. So it is the most urgent matter to control the pollution sources. One of the precautionary plans, more urban domestic sewage treatment plants must be installed and operated efficiently. It is known that nutrients such as nitrogen and phosphorous are the major factors the process of eutrophication, which can be removed majorly by the tertiary or advanced treatment process.

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A Study on the Attitude in Recognition of Environmental Pollution and Safety of Laundry Detergents - centering around Jeonju.Gunsan - (의류용 세제의 환경오염 및 안전성에 대한 태도 연구 -전주 . 군산을 중심으로-)

  • 신인수;유복선
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.2
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    • pp.189-199
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    • 2004
  • This study analyed the results of the survey on the actual condition and the attitude in using laundry detergents of housewives in Jeonbuk region centering around Jeonju\ulcornerGunsan. The purpose of this study is to give more reasonable and scientific clothing management and to help to solve the problems of the environmental pollution caused by laundry detergents. Both Jeonju(71.4%) and Gunsan(71.0%) got informations about environmental pollution through mass media like TV and Radio. As for the degree of recognition of regenerated soap, comparing with the synthetic detergent, most people thought that the regenerated soap had better detergency, less water pollution, and less harm to the human being than the synthetic detergent. Accordingly, it showed they misconceived it. It showed that the aged consumers in Jeonju and Gunsan had all good attitudes for the practice. As roles of consumers toward the problems of environmental pollution, the respondents who thought that the consumers roles were important took high percentage(Jeonju 86.8% and Gunsan 84.5%). In conclusion, they showed high degree of concerns in the recognition of necessity about the proper use of detergent, however, low in their attitudes in real life applications.

Sensitivity Analysis of Air Pollutants Dispersion Model in the Road Neighboring Area Due to the Line Source -The Object on ISCST3, CALINE4 Model- (선 오염원에 의한 도로변 지역으로의 대기확산모델의 민감도 분석 - ISCST3, CALINE4 모델을 중심으로 -)

  • Ahn, Won-Shik;Park, Myung-Hee;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.16 no.6
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    • pp.715-723
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    • 2007
  • The air pollutant emission is mainly caused by line sources in urban area. For example, the annually totaled air pollutant emission is known to consist of about 80% of line sources in Daegu. Hence, the appropriate assessment on the air pollutants of line sources is very important for the atmospheric environmental management in urban area. In this study, we made a comparative study to evaluate suitable dispersion model for estimating the air pollution from line sources. Two air pollution dispersion models, ISCST3 and CALINE4 were the subject of this study. The results were as follows; In the assessment of air pollution model, ISCST3 was found to have 4 times higher concentration than CALINE4. In addition, actual data obtained by measurement and estimated values by CALINE4 were generally identical. The air pollution assessment based on ISC3 model produced significantly lower values than actual data. The air pollution levels estimated by ISCST3 were very low in comparison with the observational values.

Nonpoint Source Pollution Loadings from Land Uses on Small Watersheds (소유역의 토지이용에 따른 비점원오염 부하량)

  • 박승우;류순호;강문성
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.39 no.3
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    • pp.115-127
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    • 1997
  • Nonpoint source (NPS) pollution from small watersheds has recently been brought into attention as a potential pollutant to streams and tnbutaries, as majority of them are experiencing water quality degradation. This necessiates the quantification of NPS loadings from agricultural and forested lands. And this study attempts to quantify daily loadings from forested and farm lands using hydrologic and water quality monitoring. The hydrologic monitoring program consists of five water level gauging stations along creeks and stream at the Banweol reservoir watershed having 1220 hectare in size. Water sam pies were taken and analyzeel periodically at the streamf low gaging sites and tributaries. Soil samples were also taken and the chemical constitutes analyzed. The primary results indicate that the major sources of pollution were small villages and dairy farms on the watersheds, constituting two-third of total nutrient loadings to the reservoir. However, the loadings from paddies and upland areas may cause a problem to the water quality of the reservoir and stream as the measured levels of total nitrogen and phosporus are not low enough to ignore. Further studies are needed to quantify the effects of landuses and treatments at a watershed scale.

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Air Pollution History, Regulatory Changes, and Remedial Measures of the Current Regulatory Regimes in Korea (우리나라 대기오염 역사, 규제의 변천, 현행 규제제도의 개선방안)

  • Kim, Dong-Sool
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.4
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    • pp.353-368
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    • 2013
  • All Koreans had suffered heavily from municipal and industrial air pollution problems since 1960's to 1980's. However the levels of $SO_2$, CO, and Pb have been dramatically decreased since 1990's due to various air pollutants' reduction policies under the provisions of the 1978 Environmental Preservation Act and the 1990 Air Quality Preservation Act such as increasing the supply of low-sulfur fuel, the use of cleaner fuel, no use of solid fuel, and so on. Even though the national ambient air quality standard has been strengthened to protect public health and welfare, the levels of $NO_2$, $O_3$, and $PM_{10}$ frequently exceed the corresponding standards; for example, only 4 stations (1.7%) out of 239 nationwide monitoring stations satisfied the 24-hr based PM10 standard in 2011. Moreover, upto the present time, since there are serious underlying policies of economism and growth-first which can not be solely solved by the environmental laws, it is difficult to root out undesirable social evils such as public indifference, passive academic activities, complacent government bureaucracy, insufficient social responsibility of enterprise, and radical activities of environmental groups. The paper initially reviewed air pollution history of Korea with surveying various environmental factors affecting in/out-door air pollution in the past Korea. Further this study extensively investigated legal and political changes on air pollution control and management for the last 50 years, and then intensively discussed the present environment-related laws and policies unreasonably enforced in Korea. It is necessary to practically revise many outdated legal policies based on health-oriented thinking and on our current economic levels as well.

Spatial Characterization of Water Pollution in the Urban Stream Watershed (Gap Stream), Korea (도시하천(갑천) 유역에서 수질오염의 공간적 특성)

  • Lee, Heung-Soo;Hur, Jin;Jeong, Seon-A;Hwang, Soon-Jin;Shin, Jae-Ki
    • Journal of Korean Society on Water Environment
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    • v.22 no.5
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    • pp.943-951
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    • 2006
  • Spatial distribution of water pollution in the Gap Stream was investigated from October to November, 2005. Sampling was conducted three times including effluents discharged from a wastewater treatment plant (WWTP) and a dam reservoir during the low-flow period. As a typical urban stream, total nitrogen and inorganic nitrogen concentrations increased toward downstream. Ammonia concentration was the highest in the treated water of the wastewater treatment plant and the lowest nitrate concentration was found in the effluent of the dam reservoir. A part of soluble reactive phosphorous (SRP) in total phosphorous was 22~54% in the upstream reach of WWTP in the Gap Stream whereas 68~73% in the downstream reach. Mean chlorophyll-a concentration ranged from 1.6 to $11.0{\mu}g/L$ and it tends to increase toward downstream except for WWTP effluent. As expected, untreated wastewater and WWTP effluent were suggested as the major sources of water pollution in the Gap Stream. In this study, the water pollution of the Gap Stream is a significant undergoing typical eutrophication, caused by excessive phosphorus and nitrogen nutrients from WWTP located in the watershed. As a result, the critical factor for the water pollution was evaluated to dissolved inorganic nitrogen and phosphorus nutrients. Particularly, SRP is a most important for the eutrophication. It suggest that may occur in the most urban streams of Korean peninsula. Therefore, because the necessity of water pollution management in the urban stream, inorganic N and P nutrients should be included as an essential component of water quality criteria in the advanced water quality project of Korean Government by enforcing of water quality assessment and total maximum daily loads (TMDLs).

Limnological Studies in Branch of Han River(Anyang River, Kockneung River) during Spring Season (춘기 한강지류(안양천, 곡릉천)의 육수학적 연구)

  • 홍사욱
    • Journal of Plant Biology
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    • v.11 no.4
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    • pp.1-8
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    • 1968
  • The persent paper discusses the relation between water pollution and aquatic organisms resulted from the study of the water quality and the kinds of algea and aquatic insects both of the An-yang River from Mt. Kwan-ak to the Han River and of the Kock-neung River from Mt. Puk-han to the Han River during the spring of 1965 and 1966. According to the change of water quality, the An-yang River might be divided into three areas. In the first area, from Mt. Kwan-ak to near An-yang town, water quality is not so polluted that may aquatic organisms such as Anisogamarus ryotoensis, Epeorus, Cambaroides, Zygnem, Batrachospermum moniliform, Draparnaldia glomerata are found. In the second area where water is polluted by the inflow of sewerage water from An-yang town, the concentration of chloride, COD, ammonia-N, nitrate-N, alkali degree increased. Therefore, few aquatic insects and algea are found. In the third area, it is much polluted by the industrial sewerage water frojm Yeong-dong-po; and so the aquatic organisms that indicate strong pollution such as Oscillatoria, Euglena, Tubifex are found in this area. It is also significant that the Nereis japonica that indicates the pollution of brackish water is discorved in the some area. In the case of the Kock-neung River, however, it is not clearly divided into areas, as in the case of the An-yang Riber, according to the pollution of water; but because of villages and towns along the river the gradual pollution of water; but because of villages and towns along the river the gradual pollution of water is observed and accordingly, a considerable change in aquatic organisms is also found in this river. In the area near II-yeung town, for instance, the concentration of the chloride, hardness, nitrite, nitrate is very low, and ammonia-N is not detected; and accordingly the aquatic insects that generally inhabit in mountain stream, such as Anisogamarus ryotoensis, Cambaroides, Epeorus, Thraubs, Hydropsyche are found here. In the down stream of the river, from Kock-chon, the quality of water is considerably polluted and fine sands are found laid on the bottom of the stream; therefore, the aquatic insects are very few, but the algea such as Navicula, Pleusigma, Oscillatoria that indicate water pollution are found in this area.

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Evaluation of the Effectiveness of Low Impact Development Practices in an Urban Area: Non-point Pollutant Removal Measures using EPA-SWMM (EPA-SWMM을 이용한 LID 기법의 비점오염 저감효과 분석)

  • Cho, SeonJu;Kang, MinJi;Kwon, Hyeok;Lee, JaeWoon;Kim, Sangdan
    • Journal of Korean Society on Water Environment
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    • v.29 no.4
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    • pp.466-475
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    • 2013
  • Non-point source pollution management is one of the most important issues in Korean water quality/watershed management. In recent years, Low Impact Development (LID) has emerged as an effective approach to control stormwater in an urban area. This study illustrates how to design and evaluate the effect of non-point pollutant management using EPA-SWMM LID module and suggests design parameters for modeling LID facilities. In addition, optimal installation locations of LID can be determined by a simple distributed hydrologic model by using SWMM for a long-term.