간행물
한국환경과학회지 KCI 등재 Journal of Environmental Science International
- 발행기관 한국환경과학회
- 자료유형 학술지
- 간기 월간
- ISSN 1225-4517 (Print)2287-3503 (Online)
- 수록기간 1992 ~ 2023
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제22권 제3호 (2013년 3월) 13건
ORIGINAL ARTICLE
1.
2013.03
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In this study, non-point source(NPS) contribution was investigated based on flow rates and water qualities of streams into the lake during rainfall events. Event mean concentration(EMC) and the pollution loads were calculated to establish a database for NPS control measurement in the survey area, and so on. The runoff characteristics of NPS were investigated and estimated on the basis of the ratio of an agricultural to forest area in the stream of sub-catch basin during rainfall events. Non-point source pollution loads were also calculated to establish a database for NPS control measure in the upstream lake Chinyang. At a rainfall event, BOD concentrations rise sharply at the early peak time of runoff, however, peaks of TSS concentration were observed at the similar time of peak flow. This was a phenomenon shown at the watersheds caused by forest and geological types. The discharged EMC range was 2.9-4.8 mg/L in terms of BOD. The discharged EMC range was 6.2-8.2 mg/L in terms of SS. The discharged EMCs of T-N and T-P were 1.4-2.5 mg/L and 0.059-0.233 mg/L, respectively. Total BOD loading rate through the 3 tributaries to the lake Chinyang was 1,136 kg/d during dry weather. The upper watershed area of the Nam-river dam in this study was divided into 14 catchment basins based on the Korean guideline for total maximum daily load(TMDL) of water quality pollutants. The higher the agricultural land-use ratio, the more NPS loading rate discharged, but the more occupied a forest area, the lower more NPS loading rate discharged. In an agricultural land-use area more than 20%, the increase of NPS loadings might be dramatically diffused by increasing the integrated complex-use like vinyl-house facilities and fertilizer use etc. according to the effective land-use utilization. The NPS loading rates were BOD 0.3 kg/ha․day, SS 0.21 kg/ha․day, TN 0.02 kg/ha․day, TP 0.005 kg/ha․day under less than 10% agricultural land-use. In agricultural land-use of 20%-50%, these values were investigated in the range of 0.32 kg/ha․day-0.73 kg/ha․day for BOD, 0.92 kg/ha․day-3.32 kg/ha․day for SS, 0.70 kg/ha․day-0.90 kg/ha․day TN, 0.03 kg/ha․day-0.044 kg/ha․day for TP.
2.
2013.03
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In this paper, an environmental assessment was carried out on the whole process of industrial business activities to establish a basic plan for climate change mitigation and energy independency. The whole process was divided into each discharge process in terms of water, air, solid waste, green house gases and refractory organic compounds. The flowcharts and basic unit of process were analysed for three years (2008-2010), being utilized as basic information for the life cycle assessment. It was found that the unit loading for the whole process significantly depends on changes in the operation rate change and highly concentrated wastewater inflow. About 35% of solid waste production was reduced by improving the incineration method with co-combustion in coal boiler, generating about 57% of electricity used for the whole process, and consequently reducing the energy costs. As the eco-efficiency index was found to be more than 1, compared to the previous years, it can be said that improvement in general has taken place.
3.
2013.03
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For the purpose of evaluating the eco-efficiency(EE) on surplus heat generated from industrial process, techniques of life cycle assessment are adopted in this study. Because it can be indicated both environmental impacts and economic benefits, EE is well known as a useful tool for symbiosis network on the sustainable development of new projects and businesses. To evaluate environmental impacts, the categories were divided into two areas of resource depletion and global warming potential. It can be seen that environmental impact increased a little but much higher economic benefit on the company, environmental performance and economic value were improved on the apartment by the district heating, respectively. In result, eco-industrial park(EIP) project on surplus heat should be found sustainable new business because the EE was in the area of fully positively eco-efficiency and, moreover resource depletion was taken place than the reduction of greenhouse gas.
4.
2013.03
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Sediment from the upstream channel has been deposited near the Nakdong River Estuary Barrage (NREB) due to the mild slope and decreased velocity. The annual mechanical dredging to ensure the flood capacity has been performed to remove the deposited sediment. However, the dredging method is not considered as an effective countermeasure due to high cost and long time to operate. Therefore, many methods for sedimentation reduction have been proposed for NREB. Especially, the channel contraction method to mitigate sedimentation problem by changing the channel geometry from 2 km to 3 km upstream of NREB has been recently suggested as an effective countermeasure. However, there is the possibility that the channel contraction method induces flood level increase compared to original condition. Therefore, it is necessary to investigate quantitatively the flood level changes in the upstream and downstream section due to the channel contraction method for NREB. In this study, water level changes by 10% channel contraction of whole width has been evaluated using the HEC-RAS model and simulated with and without channel contraction for various flood discharge. As a result, water level in the section where the channel was contracted was decreased by 0.02 m and flood level at the upstream of channel contracted was increased up to 0.015 m for the 500-year flood.
5.
2013.03
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This paper proposed a new method for estimating missing values in time series rainfall data. The proposed method integrated the two most widely used estimation methods, general linear model(GLM) and ordinary kriging(OK), by taking a weighted average of covariance matrices derived from each of the two methods. The proposed method was cross-validated using daily rainfall data at thirteen rain gauges in the Hyeong-san River basin. The goodness-of-fit of the proposed method was higher than those of GLM and OK, which can be attributed to the weighting algorithm that was designed to minimize errors caused by violations of assumptions of the two existing methods. This result suggests that the proposed method is more accurate in missing values in time series rainfall data, especially in a region where the assumptions of existing methods are not met, i.e., rainfall varies by season and topography is heterogeneous.
6.
2013.03
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This study was conducted for determining the influence of artificial structures on benthic macroinvertebrate communities in stream. Sampling was taken at upper(pool), down(riffle) and control(riffle) from two check dams, two weirs, one agricultural reservoir, and one multipurpose dam in northern part of Gyeongsangbuk-do. The benthic macroinvertebrate communities of these structures were surveyed during 2009 to 2011. The simple habitat of benthic macroinvertebrates occurred at the upper sites due to pooling effects from artificial structures. Specifically, Check dam1, Jusanji, Imha dam showed very low biological attribute values compared to the down and control sites, which have greater difference in substrate characteristics. However, in the upper sites of Check dam2, Weir1 and Weir2, the difference of values of biological attributes was relatively smaller. Also, proportion of functional feeding groups and functional habit groups were relatively simpler at upper stream and the degree of community differences was greater between upper and down, control sites. Spearman’s correlation between biological attributes and substrate characteristics, water quality parameters had significant correlations; particularly, the substrate characteristics were more significantly related. In conclusion, the pool caused by artificial structures had negative effects on benthic macroinvertebrate communities thus leading to simplified stream habitats at upper stream ecosystems.
7.
2013.03
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In this study, the cause of rapid intensity change of typhoon Nakri(0208) in view of point of a trough-typhoon interaction using diagnostic methods was examined based on 6-hourly GDAPS data from 10 to 13 July, 2002.
At 0000 UTC 13 July, high PV(Potential Vorticity) region moved southeastward, reaching to the western edge of the Korean peninsula and near typhoon center at surface and there shows an increasing value of EFC(Eddy Momentum Flux Convergence). Also, as the trough and typhoon approach one another at the same time, the vertical shear(850-200 hPa) increases to more than 15 m/s. Thus, it might be concluded that the trough-typhoon interaction made intensified significantly, providing the fact that typhoon Nakri(0208) underwent substantial weakening while moving northward to around Jeju island.
8.
2013.03
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Efforts were made to determine the activation energy and the reaction order by adopting Kissinger and Flynn-Wall-Ozawa analysis methods. All the data were acquired from TGA thermograms for the mixed fuels with different temperature heating rates. It could be known that both the coal and the mixed fuels decomposed thermally at temperature ranges of 300～700℃. The temperature at the maximum reaction rate, Tp, could be determined by DTG method, which could be obtained by differentiation of TGA thermogram. Kissinger analysis showed the linear relationship with experimental data, showing the activation energy of 319.64 ±4 kJ/mol. From Flynn-Wall-Ozawa analysis, it was shown that the activation energies and the reaction orders did not undergo any significant changes with both the conversions and the heating rates. It was considered from this facts that the combustion mechanism of the mixed fuels could not be affected by the extent of conversion and heating rate. In the present study, the activation energies showed different values according to the different analysis methods. The difference might be originated from the inconsistency of the mathematical data treatment method. In other words, while the activation energies obtained from the Kissinger method indicated the average values for overall reaction, that from Flynn-Wall-Ozawa method showed the average values for the each conversion around Tp.
9.
2013.03
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The purpose of this study was to assess the effects of Cordyceps militaris extract supplementation on the improvement of blood glucose, lipid compositions and hepatic functional enzyme activities in the serum of streptozotocin(STZ, 50 mg/kg BW, IP injection)-induced diabetic rats fed the experimental diets for 5 weeks. The concentrations of blood glucose and lipid compositions(total cholesterol, β-lipoprotein, free cholesterol, cholesteryl ester, triglyceride and phospholipid) and atherosclerotic index in serum were significantly lower in the DM+CM group than in the DM group, whereas the ratio of HDL-cholesterol concentration to total cholesterol in the DM+CM group were higher than in the DM group.
The activities of hepatic functional enzymes(aminotransferase, LDH and ALP) in serum were lower in the Cordyceps militaris extract administration group(group DM+CM) than in the hyperglycemic DM group. The results shown above suggested that Cordyceps militaris extract supplementation effectively improves blood glucose and atherosclerosis in the serum of diabetic rats.
10.
2013.03
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The aerosol number concentration have measured with an aerodynamic particle sizer spectrometer(APS) at Gosan in Jeju Island, which is known as background area in Korea, from March 2010 to February 2011. The obtained results of asian dust events and non-asian dust period have been compared.
The results show that the entire averaged aerosol number concentration from APS measurement during asian dust events and non-asian dust period are about 341 particles/㎝3 and 240 particles/㎝3, respectively. During asian dust events, the number concentration in small size ranges(≤0.4 ㎛) are similar to non-asian dust period, however, those in large size ranges(≥0.7 ㎛) are very higher than non-asian dust period.
The contributions of the size resolved number concentration(23 channel in 0.25∼10.0 ㎛) to total number concentration in that range are dramatically decreased with increased particle size. The contributions of smaller size ranges(≤0.4 ㎛) during asian dust events are very low compared with non-asian dust period, on the other hand, those of larger size ranges(≥0.4 ㎛) are higher than non-asian dust period.
total aerosol number concentration are depended on the number concentration in range of smaller than 0.58 ㎛ during non-asian dust period and asian dust events. On the other hand, PM10 mass concentration has mainly affected with the number concentration in range of smaller than 1.0 ㎛ during non-asian dust period, however, during asian dust events, the mass concentration has mainly affected with the number concentration in range of 0.65∼3.0 ㎛.
11.
2013.03
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Chronic effects such as reproduction and population dynamics with elevated CO2 concentration were evaluated using two representative marine benthic species, copepod (Tisbe sp.) and amphipod (Monocorophium acherusicum) adopting long-term exposure. Juvenile copepod and amphipod individuals were cultivated in the seawater equilibrated with control air (0.395 mmol CO2/air mol) and high CO2 air having 0.998, to 3.03, 10.3, and 30.1 mmol CO2/air mol during 20 and 46 days, respectively. After the exposure period, the number of benthic invertebrate was counted with separate larval and juvenile stage such as naupliar, copepodid and adult for copepod, or neonate and adult for amphipod, respectively. The individual number of both test species at each life-stage was significantly decreased in seawater with 10.3 mmol CO2/air mol or higher. Recently, the technology of marine CO2 sequestration has been developed for the reduction of CO2 emission, which may cause climate change. However, under various scenarios of CO2 leaks during the injection process or sequestrated CO2 in marine geological structure, the potential risk to organism including various invertebrates can be expected to exposure. So the results of this study suggested that the detailed consideration on the adverse effect with marine ecosystem can be prerequisite for the marine CO2 sequestration projects.
12.
2013.03
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After identifying species by collecting the suspended and attached algae mat inhabiting in the slow sand-filter, Spirogyra sp., Mougeotia sp. and Closterium sp. were main green algae and Synedra sp. was diatom algae. Among them green algae Spirogyra sp. was dominant species. A result of observing the life mode of apple snail for a month after introducing into the slow sand-filter, apple snail eggs were discovered on the filter walls 2 weeks after introducing, 4 weeks later lots of eggs were observed all of the slow sand-filter walls, it means there is no problem for apple snail to live in the slow sand-filter. The observation result for algae removal potential by introduced apple snail after 2 months later, slow sand-filter where apple snail were introduced, a few algal mat were observed. On the other hand, no introduced apple snail into the slow sand-filter, lots of suspended algal mats were formed in the water and attached algal mats on the sand surface as well, these algal mat induced much of operating problems.
NOTE
13.
2013.03
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This study was conducted to investigate the changes in nitrogen and soluble reactive phosphorus(SRP) contents from hanwoo manure using probiotics to feed and manure additives during 5 weeks. A total of 45 hanwoo(24 months old) with averaging 580±20 kg in weight were randomly assigned to 3 dietary treatments with 3 replicates per treatment(5 hanwoo per pen, 5 x 8 m). The treatment were supplemented, control, T1(10 kg roughage + 2 kg concentrate(2% probiotics as-fed basis)), and T2(10 kg roughage + 2 kg concentrate(2% probiotics as-fed basis) + 7 kg probiotics on the surface of hanwoo manure (top-dressing)). During the experimental period, there were statistically significant differences(P<0.05) in pH values at 3 and 5 weeks; TN contents at 5 weeks; and SRP contents at 5 weeks in all treatments. Adding probiotics to feed or feed and manure increased manure pH in comparison with controls. As time increased, changes in TN contents decreased in the order: T2 > Control > T1. Especially, the reduction in SRP contents in all treatments at 5 weeks was in following order: T1 > T2 > Control. This result suggests that it is possible to make efficient use of probiotics as feed and manure additives for reducing environmental pollution or to provide fundamental information on livestock managements to producers.
