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
제11권 제7호 (2002년 7월) 18건
1.
2002.07
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2.
2002.07
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Depth-area-duration(DAD) relations are important to hydrological plans and designs for the water resources as well as the flood defence. And these relations have been still in analysis and use today because they can be applied to readily available data. In this paper, rational and consistent DAD models were developed using the multiple regression analysis and basic relationships of area ratio-runoff volume about heavy rainfall occurring in the Im-Jin river basin, 1999. In addition, revised DAD models and curves that can convert a maximum point rainfall to mean area rainfall were developed and evaluated. As results, these models seem to have predictive value in order to plan and design hydrological structures of flood defence in the Im-Jin river basin.
3.
2002.07
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4.
2002.07
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This study presents an investigation of the changes of the currents in Kwangyang Bay due to the construction of harbor, reclamation and coastal developments. Currents were simulated by the numerical experiments with a diagnostic multi-level model and using the seasonal oceanographic data of temperature, salinity and ocean current. The values of kinetic and potential energies for the currents were calculated in cases of three topographical changes; before coastal developments, the existing state and after completion of the development project in Kwangyang Bay. The changes of currents due to the coastal developments are as follow; Kinetic energies of tide induced residual currents and wind driven currents decreased by 35～40 percent and 5 percent respectively, however those of density currents increased by 10 percent since the decrease of the coastal areas. Kinetic energy of residual currents including tide induced residual currents, density currents and wind driven currents reduced by 10 percent compared with before the coastal developments. Decrease of current velocity was greatest in summer. Therefore, in summer it was assumed that the Kwangyang Bay is more easily polluted by stratification and decrease of residual current than before the coastal developments carried out.
5.
2002.07
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Weather elements were observed by the AWS (Automatic Weather System) and dustfall particles were collected by the modified American dust jar (wide inlet bottle type) at 4 sampling sites in Busan area from March, 1999 to February, 2000. Thirteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Si, and Zn) were analyzed by AAS and ICP.
The purposes of this study were to estimate qualitatively various bulk deposition flux of dustfall and insoluble components by applying regional and seasonal wind intensity. Frequency of wind speed were found in order of low(1-3㎧), very low(<1㎧), medium(3-8㎧) and high(>8㎧), and annual mean had higher range at low(1-3㎧) for 56.3%. Strong negative linear correlation were observed between dustfall and wind direction (northeastern and eastern), but strong positive linear correlation were observed between dustfall and wind direction (western and northwestern) at industrial, commercial and coastal zone(p<0.05). While a negative correlation were observed between wind speed frequency of very low(<1㎧) and dustfall, and positive correlation were observed between wind speed frequency of low(1-3㎧) and dustfall in coastal zone(p<0.05). The correlation coefficient was observed 0.556 between wind speed frequency of low(1-3㎧) and Ni by commercial zone(p<0.05). The correlation coefficient show well-defined insoluble trace metals (Al, Ca, Cr, Cu, Fe, Pb, and Zn) and wind speed frequency of low(1-3㎧) at coastal zone, which was found significant difference(p<0.01).
6.
2002.07
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The aerodynamic resistance(Ra) to vertical transfer in the surface boundary layer can be formulated in terms of the friction velocity, height of observation, vertical heat flux and surface roughness. Unlike previous studies which focused on the role of Rc, present study perform additional tests using a variety of Ra formulae. Several Ra formulations available in the literature, suitable for unstable conditions, were tested for their influence on the dry deposition velocity. The canopy resistance(Rc) determines the shape of the diurnal pattern, while a small amplitude diurnal cycle in Vd was attributed to the aerodynamic resistance. The aerodynamic resistance is the major contributor to the formation of spikes in nighttime and Ra is relatively important at night because the canopy resistance is smaller. All formulations show similar diurnal cycle and yield good agreement with the observations. Although present Vd formulations are suitable for numerical air quality models, the research must continue for further improvements in resistance parametrizations.
7.
2002.07
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This study was conducted to investigate the characteristics of role of transport on aerosol concentration at Crate Lake, Oregon USA for 1988.3～1999. 5. The IMPROVE program is a cooperative measurement effort governed by a steering committee composed of representatives from USA federal and regional-state organizations. Also IMPROVE sampler is designed to obtain a complete signature of the composition of the airborne particles affecting visibility. According to 10-day backward isentropic trajectory analysis, the frequency of local, marine and Asian trajectory showed 33.1%(335 cases), 47%(478 cases), 5.2%(53 cases) respectively. The monthly variation of nss SO42-, nss S, NO3-, K and C showed the double peak pattern, high in April～May and August～September and showed the lowest concentration in Winter. The other constituents concentration except for Cl-, Na, Mg was high in local trajectory than marine trajectory. A ratio nss SO42- to SO42- was 90.5% in marine trajectory and 98% in local trajectory. It suggest that the aerosol in Crater Lake was effected by salt. The annual mean concentration of nss SO42- and nss S decreased but the the springtime concentration increased.
8.
2002.07
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Turbulence greatly influence on atmospheric flow field. In the atmosphere, turbulence is represented as turbulent diffusion coefficients. To estimate turbulent diffusion coefficients in previous studies, it has been used constants or 2-level method which divides surface layer and Ekman layer.
In this study, it was introduced Smagorinsky method which estimates turbulent diffusion coefficient not to divide the layer but to continue in vertical direcrtion. We simulated 3-D flow model and TKE equation applied turbulent diffusion coefficients using two methods, respectively. Then we showed the values of TKE and the condition of each term to TKE. The results of Smagorinsky method were reasonable. But the results of 2-level method were not reasonable. Therefor, it had better use Smagorinsky method to estimate turbulent diffusion coefficients.
We are expected that if it is developed better TKE equation and model with study of computational method in several turbulent diffusion coefficients for reasonably turbulent diffusion, we will able to predict precise wind field and movements of air pollutants.
9.
2002.07
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Air quality monitoring data and meteorology data which had collected from 1995. 1. to 1999. 2. in six areas of Daegu, Manchondong, Bokhyundong, Deamyungdong, Samdukdong, Leehyundong and Nowondong, were investigated to determine the distribution and characteristic of ozone. A equation of multiple regression was suggested after time series analysis of contribution factor and meteorology factor were investigated during the day which had high concentration of ozone.
The results show the following; First, 63.6% of high ozone concentration days, more than 60 ppb of ozone concentration, were in May, June and September. The percentage of each area showed that; Manchondong 14.4%, Bokhyundong 15.4%, Deamyungdong 15.6%, Samdukdong 15.6%, Leehyundong 17.3% and Nowondong 21.6%.
Second, correlation coefficients of ozone, SO2, TSP, NO2 and CO showed negative relationship; the results were respectively -0.229, -0.074, -0.387, -0.190(p<0.01), and humidity were -0.677. but temperature, amount of radiation and wind speed had positive relationship; the results were respectively 0.515, 0.509, 0.400(p<0.01).
Third, R2 of equation of multiple regression at each area showed that; Nowondong 45.4%, Lee hyundong 77.9%, Samdukdong 69.9%, Daemyungdong 78.8%, Manchondong 88.6%, Bokhyundong 77.6%. Including 1 hour prior ozone concentration, R2 of each area was significantly increased; Nowondong 75.2%, Leehyundong 89.3%, Samdukdong 86.4%, Daemyungdong 88.6%, Manchondong 88.6%, Bokhyundong 88.0%. Using equation of multiple regression, There were some different R2 between predicted value and observed value; Nowondong 48%, Leehyundong 77.5%, Samdukdong 58%, Daemyungdong 73.4%, Manchondong 77.7%, Bokhyundong 75.1%. R2 of model including 1 hour prior ozone concentration was higher than equation of current day; Nowondong 82.5%, Leehyundong 88.3%, Samdukdong 80.7%, Daemyungdong 82.4%, Manchondong 87.6%, Bokhyundong 88.5%.
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2002.07
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In the present study, space allocation methods of pollutant emission from area and mobile sources are assessed by the actual application to air quality modeling of Pohang area. It is found that the TM-based modeling which allocates emission onto the 1km x 1km sized TM-grid system predicts almost the same mean ground-level concentration as that by the GIS-based modeling which uses geographical information of area and mobile sources directly, while maximum ground-level concentration by the TM-based modeling is predicted considerably lower than that by the GIS-based modeling. Moreover, the problem is found that the TM-based modeling causes deviation of mobile roads. In conclusion, it is anticipated to applying GIS-based modeling for a more accurate assessment of air quality in local scale.
11.
2002.07
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In order to determine the factors causing Microcystis spp. bloom in the lower Nakdong River (Mulgum), we prepared wide ranges of pH, nutrient(N, P) concentration and the light through an enclosure experiment for 10 days (pH gradient: 6.5, 7.5, 8.5, 9.5; gradient of N, P: ½DW＋½River Water (RW), RW only; four different levels of nutrient addition/day; light: 100, 85, 60, 30, 15% of full sun light). From three days, the difference of Microcystis density in each enclosures was observed. The high density of Microcystis was maintained in the treatments over pH 9.5 and 85% of full sun light. However, in all nutrient treatments, relatively lower cell density than that of pH and light treatments was observed. These results suggested that pH and light input may play more important roles than nutrients in the early development of Microcystis bloom in the eutrophic lower Nakdong River.
12.
2002.07
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In order to provide the basic information on the environmental pollution of Kyungsan province, the contents of Pb, Cd, Cr, Cu, Mn and Zn in soil, stream water, aquatic sediment and groundwater were investigated, and also the values of pH, COD, KMnO4-C, NH3-N, NO2-N, NO3-N and Cl- of stream water and groundwater were determined.
The results were as follows.
The values of COD, NH3-N, NO2-N and NO3-N of the stream waters were very low. The contents of Pb, Cd, Cr, Cu and Zn in the stream waters were respectively at range of 0.014～0.063 ㎎/ℓ, 0.004～0.007 ㎎/ℓ, 0～0.045 ㎎/ℓ, 0～0.008 ㎎/ℓ and 0.001～0.175 ㎎/ℓ, and these values were much lower than those of contaminated stream water in Korea. The contents of Cd, Cr, Cu and Zn in the soils were respectively at range of 0.12～0.71 ppm, 0.88～2.65 ppm, 2.86～22.33 ppm and 3.89～26.39 ppm, and these values were much lower than those of ordinary polluted areas in Korea. The contents of Cd, Cr, Cu, As, Zn and Mn in the aquatic sediments were respectively at range of 3.05～3.81 ppm, 14.6～70.6 ppm, 13.74～61.59 ppm, 76.8～465.5 ppm, 12.56～190.83 ppm and 333.3～1188.3 ppm. The values of pH, KMnO4-C, NH3-N and NO3-N of the groundwaters were respectively at range of 7.6～8.4, 0～3.95 ㎖, 0.05～0.15 ㎎/ℓ and 0.05～0.42 ㎎/ℓ. The contents of Pb, Cd and Cr in the groundwaters were respectively at range of 0.015～0.061 ㎎/ℓ, 0.006～0.009 ㎎/ℓ and 0.005～0.045 ㎎/ℓ.
13.
2002.07
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The characteristics of drinking groundwater quality at Chung Cheong Nam Do was analyzed by investigating the 3,086 groundwater data which were carried out the water quality inspection from Jan. 1998 to Dec. 1998. It was found that all the mean concentration of items was not over the drinking water quality standard except Zn at Yeongee area. The highest mean concentration of nitrate was 8.2 ㎎/ℓ at Hongsung area. And the mean concentrations of nitrate and ammonium at Sucheon, Yesan, Yeongee were relatively higher. It was considered that the groundwater of that area was contaminated by breeding livestock as farm pollutants. The mean concentrations of chloride, hardness and evaporation residual at coastal regions were higher than inland regions. Especially the mean concentration of chloride was 2.5 times higher. It was considered that the groundwater at coastal regions was affected by seawater. It was found that the correlation between Fe and Mn was relatively high(r=0.776) and the correlation between hardness and evaporation residual was very high(r=0.983). The rainfall series and detection rate of E-coli had the hydrologic persistence. The correlation between the detection rate and rainfall series over 150 mm was very high (r=0.9146). Therefore it is surely required to control the groundwater sanitation in the rainy season.
14.
2002.07
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In order to examine the inhibition effect of other heavy metal ions on the removal of heavy metal ions by crab shell in aqueous solution, 10 heavy metal ions (Cr3+, Cd2+, Ni2+, Zn2+, Hg2+, Cu2+, Mn2+, Fe2+, Fe3+, Pb2+) were used as single heavy metal ions and mixed heavy metal ions, respectively. In single heavy metal ions, Pb2+, Cr3+, Cu2+ were well removed by crab shell, however, Cd2+, Ni2+, Zn2+, Mn2+ were not. The heavy metal removal increased as the increase of covalent index (Xm2r), and the relationship classified heavy metal ions as 2 heavy metal groups (Fe3+, Fe2+, Cu2+, Cr3+, Mn2+, Ni2+, Zn2+ group and Pb2+, Hg2+, Cd2+ group). In mixed heavy heavy metal ions, the removals of Fe2+, Fe3+, Pb2+, Cu2+ as 0.49 mmol/g, regardless of the existence of other heavy metal ions, were similar to the result of single heavy metal ions experiment. The removals of Mn2+, Cd2+, Ni2+ decreased as the existence of other heavy metal ions, however, the removal of Zn2+, Cr3+, Hg2+ increased.
15.
2002.07
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Sorption and desorption is an important phenomenon to determine the fate of halogenated aliphatic hydrocarbons in the aqueous phase. This study was conducted to develope a predictive equation capable of estimating the sorption and desorption potentials of halogenated aliphatic hydrocarbons onto the sludge from activated process, sediment, and clay. It has shown that the sorption and desorption parameters can be accurately estimated using Quantitative Structural Activity Relationship(QSAR) models based on molecular connectivity indexes of test compounds. The QSAR model could be applied to predict the sorption and desorption capacity of the other halogenated aliphatic hydrocarbons. The QSAR modeling would provide a useful tool to predict the sorption and desorption capacity without time-consuming experiments.
16.
2002.07
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UV photolysis process is little known in parts of air pollution treatment, so there are not many applications in field. Therefore we have to do more experiment and study application possibility for treatment of VOCs(Volatile organic compounds). To solve these problems, we have been studying for simultaneous application of this technology.
It has shown that concentration of TCE and B.T.X., diameter of reactor and wavelength of lamp have effected on decomposition efficiency. Analysis of TCE and B.T.X. concentration was carried out by GC-FID.
A cylinderical reactor consisting of a quartz tube and a centrally located lamp(ψ25mm) was used. The length and diameter of reactor were 1800mm, 75mm. It has shown that the generated ozone concentration goes up 250ppm when using 64watt ozone lamp. When using Photolysis process only, the rates of fractional conversion of each material are TCE 79%, Benzene 65%, Toluene 68%, Xylene 76%. This phenomenon can be rationalized in terms of the different bond energy that indicates how easily VOCs species can be decomposed.
17.
2002.07
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The effects of noble gas (such as helium, neon, argon, krypton, and xenon) on the sonolytic decomposition of water and 2-methyl-2-propanol(t-butanol) with 200 kHz high power ultrasound were investigated. The physical properties of the noble gas have an effect on the formation rate of products (H2O2, H2, O2) and the decomposition rate on the sonolytic decomposition of water. The pyrolysis products, such as methane, ethane, ethylene, and acetylene are formed during the sonolytic decomposition of t-butanol. From the estimation of the ratio [C2H4 + C2H2] / [C2H6], the cavitation temperature would be varied by the used noble gas. In all cases for the sonolytic decomposition of water, t-butanol, and diethyl phthalate, the decomposition rates were xenon > krypton > argon > neon > helium with a significant difference and were closely correlated with the formation rate of OH radical and high temperature inside the cavitation bubble under each noble gas.
18.
2002.07
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The objective of this study is to delineate removal efficiency of the Linear alkylbenzene sulfonates(LAS) in solution by TiO2 photocatalytic oxidation as a function of the following different experimental conditions : initial concentration of LAS, TiO2 concentration, UV wavelength and pH of the solution.
It was increased with decreasing initial concentration of LAS and with decreasing pH of the solution. Removal efficiency increased with increasing TiO2 concentration but was almost the same at TiO2 concentration of 2 g/L and 3 g/L, i.e., for initial LAS concentration of 50 mg/L. It was removal efficiency was 85% at 150 min in the case of TiO2 concentration of 0.5 g/L but 100% after 150 min in the case of TiO2 concentration of 1 g/L, 100% after 110 min in the case of TiO2 concentration of 2 g/L and 3 g/L. UV wavelength affection on the removal efficiency of LAS decreased in the order of 254, 312 and 365 nm as increasing wavelength. But the removal efficiency of LAS was nearly the same at UV wavelength of 254 nm and 312 nm.
