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
제9권 제2호 (2000년 4월) 12건
1.
2000.04
서비스 종료(열람 제한)
Through numerical experiment using simplified OSU-ID PBL(Oregon State University One-Dimensional Planetary Boundary Layer) model and field measurement, we studied the impacts of vegetation canopy on heat island that was one of the characteristics of local climate in urban area. It was found that if the fraction of vegetation was extended by 10 percent, the maximum air temperature and the maximum ground temperature can come down about 0.9℃, 2.3℃, respectively. Even though the field measurement was done under a little unstable atmospheric condition, the canopy air temperature was lower in the daytime, and higher at night than the air and ground temperature. This result suggests that the extention of vegetation canopy can bring about more pleasant local climate by causing the oasis, the shade and the blanket effect.
2.
2000.04
서비스 종료(열람 제한)
The purpose of the present study is to develope the estimation scheme for sensible heat flux by semi-empirical approach using routine meteorological data such as solar radiation and air temperature. To compare observed sensible heat flux with estimated sensible heat flux, the sensible heat fluxes were measured by three dimensional sonic anemometer-thermometer. The field observation was performed during 1 year from December 1, 1995 to November 30, 1996 on a rice paddy field in Chunchon basin. The heat fluxes were measured at a heights of 5m and mean meteorological variables were obtained at two levels, 2.5m(or 1.5m) and 10m. Since condition of rice paddy field such as, wetness of the field, roughness length, vary widely, we devided annual data to 5 periods. Comparing with two sensible heat fluxes, the results showed that the correlation coefficients were more than 0.86. Thus, we can conclude that the estimation method of sensible heat fluxes using routine meteorological data is practical and reliable enough.
3.
2000.04
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The dynamics of water quality and phytoplankton population had examined by monthly sampling from the upper to the lower part of watergate in an artificial Shihwa Reservoir in which situated near newly cities and industrial complex on the west coast of Korea from January 1997 to December 1998. Among environmental factors, yearly average concentration of chl-a, TN and TP seemed to eutrophic or hypertrophic conditions that ranged 146.4∼245.8㎍/ℓ , 1.6∼2.7㎎ N/ℓ, 258∼448㎍ P/ℓ , 26.9∼80.7 ㎍/ℓ, 1.0∼2.4 ㎎ N/ℓ and 74∼239㎍ P/ℓ respectively. Water quality was extremely deteriorated to consistently accumulation into inner reservoir by load of pollutants from autochthonous and allochthonous until early July 1997 after embankment. Water pollution of Shihwa Reservoir was remarkble on the biological condition with largely persistent bloom of phytoplankton and increase rate of standing crops was 2.4/yr. The development trend of phytoplankton in water ecosystem were closely related to increse and decrease of physico-chemical factors and those scale seemed to control by nutrient contents. Inflow of seawater into reservoir to object of repair of water quality began on July 1997. This action was caused to variable of algal flora as well as improvement of water quality. As to see dominant species, composition of those composed to mostly freshwater algae before inflow of seawater such as Selenastrum capricornutum of green algae, Cyclotella atomus, C meneghiniana of diatom and Microcystis spp. of blue-green algae and the other hand brackish algae were dominated after inflow of seawater such as Chaetoceros dicipiens, Skeletonema costatum of diatom, Dinophysis acuminata, Gymnodinium mikimotoi, G. sanguineum, Gyrodinium spirale, Prorocentrum minimum of dinoflagellate and Eutreptiella gymnastics of euglenoid. Moreover, small flagellates including Chroomonas spp. of cryptomonad were abundant throughout the year. The cause of water deterioration during fill of the freshwater were complexly supported with extra and intra parameters. The variation pattern of phytoplankton were related to water temperature and salinity by inflow of seawater based to plentiful nutrients. The dynamics of phytoplankton were assessed to ecosystem that clearly condition of dominant by unique or a few algal species seasonally.
4.
2000.04
서비스 종료(열람 제한)
갯벌의 오염물질 정화능력 평가를 위한 기초조사로서 환경적 특성이 다른 3지점 갯벌을 채취하여 수직적인 물리, 화학적 특성을 조사하였다.
갯벌의 입도특성을 보면, 금강하구에 위치한 어은리 갯벌의 니질 함량이 98.89%를 보인 반면 충남 서천에 위치한 춘장대갯벌은 모래함량 97.99%를 나타내었다. 새만금지구 내 위치한 계화도 갯벌은 니질 32.81%, 사질 67.19%로 나타나났다.
갯벌의 화학적인 특성은 니질 함량이 높은 어은리 갯벌에서 유기물 관련인자(IL, COD, POC)가 다른 두 갯벌 보다 3∼4배 높았으며, 각 지점에서 층별 농도 분포는 아래로 갈수록 약간 증가하는 것으로 나타났다.
상관분석 결과 중 갯벌의 유기오염물질과 관련 있는 인자인 I.L., COD 및 POC, PON 사이에는 0.821∼0.940의 높은 상관성이 있었다. 또한 pH는 COD, PON 및 POC와 0.9 이상의 높은 상관성을 나타냈다.
갯벌의 층별 투수실험 결과 춘장대 갯벌은 평균 투수 계수가 0.01584㎝/s로서 투수량이 18.66ml/min이었다. 하지만 어은리 및 계화도 갯벌은 거의 투수되지 않았다.
5.
2000.04
서비스 종료(열람 제한)
국립수산진흥원의 한국 연안 어장환경 오염조사 결과 보고서를 사용하여, 인천 연안역의 수온 및 염분의 계절변화의 특성을 살펴 보았다. 수온의 연변화는 인천항과 소래에 이르는 조간대 해역이 만의 바깥쪽 해역보다도 수온의 연평균이 높고, 진폭도 크며, 위상도 빨랐다. 염분의 연변화는 인천항과 소래에 이르는 조간대 해역이만의 바깥쪽 해역보다도 연평균은 낮고, 진폭은 크며, 위상은 느리게 나타났다. 이러한 특성은 T-S도를 이용하여 나타낸 수괴의 계절 변화에서도 뚜렷하게 볼 수 있었다. 즉, 인천 연안역의 수괴는 수온과 염분의 연교차가 큰 인천과 소래에 이르는 조간대 해역과 염분 변동에 영향을 주는 강수나 증발, 담수 유입의 계절적 변화에 비교적 영향을 적게 받는 만의 바깥쪽 해역으로 구분할 수 있었다. 또한 얕은 수심과 강한 조류로 인하여 수층이 연중 거의 혼합된 분포를 보이고 있었다.
6.
2000.04
서비스 종료(열람 제한)
The observations on the seasonal fluctuation and distributional characteristic of organic matters on surface sediments and its origin were carried out at the 25 stations in Keogeum-sudo, southern coast of Korean Peninsula from February to October in 1993. I made an analysis on the environmental factors for surface sediments such as temperature, ignition loss, chemical oxygen demand, pheopigment, total sulphide, water content, mud content in grain size, COD/IL ratio and COD/sulphide ratio.
The results are as follows ;
1) The range of temperature on the surface sediments was between 6.2℃ and 24.6℃. The highest mean temperatuer of mud was 24.0℃ in summer, the lowest 6.6℃ in winter.
2) Ignition loss(IL) fluctuated between 1.2% in winter and 16.8% in spring, that is to say, the seasons of increasing in temperature were very high ignition loss.
3) Chemical oxygen demand(COD) showed the highest mean value of 20.52 ㎎/g dry in summer within the range of 15.46∼32.78 ㎎/g dry, while showed the lowest of 5.79 ㎎/g dry in winter within the range of 7.4∼17.39 ㎎/g dry.
4) Pheopigment concentrations showed the highest mean value of 4.85 ㎍/g dry in autumn within the range of 0.84∼9.21 ㎍/g dry, while it did the lowest mean value of 1.97 ㎍/g dry in summer within the range of 0.23∼4.83 ㎍/g dry.
5) Total sulphide (H2S) fluctuated between no detect(ND) in spring, and 2.43 ㎎/g dry in autumn. The highest mean value was 0.68 ㎎/g dry in autumn, the lowest was 0.16 ㎎/g dry in spring.
6) Water content(WC) and mud content in grain size showed the mean value of 43.2% within the range of 26.5∼59.7% and 91.0% within the range of 57.8∼99.2%, respectively.
7) By the analytical results on the source of organic matter, it had been dumped from the seaweed farms in Keogeum-sudo coastal waters.
7.
2000.04
서비스 종료(열람 제한)
The purpose of this study was to determine whether Vermi Cast could be used effectively to remove SO2 from flue gas, and then to investigate optimum adsorption conditions. The Vermi Cast used as adsorbent was mechanically screened with 8∼20 mesh sieve. The adsorption data for S02 were regressed using the Freundlich isotherm. The fit was generally satisfactory (R2=0.945∼0.982). With the temperature changes from 20℃ to 40℃, the constant k in Freundlich isotherm qe = kCe(1/n), decreased from 1.409 at 20℃ to 0.297 at 40℃, and the exponent 1/n were decreased from 0.343 to 0.134. With the bed depth changes from 10㎝ to 30㎝, the adsorption capacity expressed as m㏖ of SO2 adsorbed per g of Vermi Cast increased from 0.247 to 0.381. Moisture content is an important parameter in the SO2 adsorption efficiency. When the moisture content ranging 23∼53% temperature 28℃ the amount of SO2 adsorbed were observed over 0.3m㏖ SO2/g Vermi Cast. The best adsorption capacity was 0.487m㏖ SO2/g Vermi Cast, and it was obtained with moisture content 37%, temperature 20℃. From the above results, it might be concluded that Vermi Cast is effectively available as a good adsorbent to remove SO2 from flue gas.
8.
2000.04
서비스 종료(열람 제한)
Considerable interest has been shown in recent years towards utilizing TiO2 particles as a photocatalyst in the degradation of harmful organic contaminants.
In this study, photocatalytic degradation of diazinon which is extensively used as a pesticide in the agriculture field, has been investigated with UV-illuminated TiO2 in aqueous suspension as a function of the following different experimental parameters : initial concentration of diazinon, TiO2 weight, UV wavelength, pH of the solution.
Photodegradation rate increased with decreasing initial concentration of diazinon and with increasing pH of the solution. Photodegradation rate increased with increasing TiO2 weight, but was nearly the same at TiO2 weight of 1 g/ℓ , 2 g/ℓ , i.e., for initial diazinon concentration of 5 ㎎/ℓ . UV wavelength affecting on the degradation rate of diazinon decreased in the order of 254 nm > 312 nm > 365 nm. For TiO2 weight of 1 g/ℓ and initial diazinon concentration of 5 ㎎/ℓ , the photodegradation removal of diazinon was 100% after 130 min in the case of 254 nm, but 95% in the case of 312 nm, and 84% in the case of 365 nm, after 180 min. The photodegradation of diazinon followed a first order or a pseudo-first order reaction rate. For initial diazinon concentration of 5 ㎎/ℓ , the rate constants(k) in UV and TiO2(1g/ℓ )/UV system were 0.006 min-1 and 0.0252 min-1 at 254 nm, 0.0055 min-1 and 0.0104 min-1 at 312 nm, and 0.004 min-1 and 0.0092 min-1 at 365 nm respectively.
9.
2000.04
서비스 종료(열람 제한)
For the purpose of development of a liquid membrane permeator which separates metal ions from aqueous solutions continuously and effectively, a continuous membrane permeator with the membrane solution trapped between extraction and stripping phases by two micro-porous hydrophilic films was manufactured.
Experimental researches on the separation of zinc ion from aqueous solutions were performed in the liquid membrane permeator with 30 vol % D2EHPA solution in kerosine as liquid membrane. As results, the liquid membrane permeator separates zinc ion from aqueous solutions continuously and effectively in the wide range of operating conditions. A simple mass transfer rate model using equilibrium constant of the extraction reaction for the system used were proposed, and the model was compared with experimental results of separation of zinc ion in the permeator. And the effects of operating factors, such as space time, pH of extraction solution, extraction temperature, on the separation rate of zinc ion in the permeator were experimentally examined.
10.
2000.04
서비스 종료(열람 제한)
A kinetic study for anion exchange was performed for commercially available Cl- type anion exchange resin in use to remove nitrate in water. The obtained results from the batch reactor were applied to the Langmuir and Freundlich models. The constants for Langmuir model were qmax=29.82 and b=0.202, and for Freundlich model were K=5.509 and n=1.772. Langmuir model showed better fit than Frendlich model for the experimental results. Ion exchange reaction rate was also calculated and the approximate first-order reaction, rate constant k1 was 0.16 L/㎎·hr. Effective diffusion coefficient was obtained in the range from 9.67×10 exp (-8) to 1.67×10 exp (-6) ㎠/sec for initial concentration change, and from 6.09×10 exp (-7) to 3.98×10 exp (-6) ㎠/sec for reaction temperature change. Activation energy during the diffusion was calculated as 36 ㎉/㏖.
11.
2000.04
서비스 종료(열람 제한)
This study was carried out to investigate the filtration characteristics of membrane modules according to hollow fiber dispersion for direct solid-liquid separation of activated sludge. 2 bundle, 4 bundle, and 10 bundle module used in this experiment according to hollow fiber dispersion was manufactured at laboratory and permeate flux and transmembrane pressure(TMP) of each module were observed under a suction pressure of 0.5㎏f/㎠.
As the hollow fibers were dispersed, permeate flux was increased and TMP was decreased. Permeate flux and TMP of each module was 15.0 ℓ/㎡·h and 31.8 ㎝Hg for 2 bundle, 16.0 ℓ/㎡·h and 17.4 ㎝Hg for 4 bundle, and 20.4 ℓ/㎡·h and 13.8 ㎝Hg for 10 bundle.
In conclusion, the membrane fouling is expected to be decrease by maintaining lower TMP with hollow fiber dispersion.
12.
2000.04
서비스 종료(열람 제한)
This study is focused on the industrial symbiosis based on industrial ecosystem theory. At first, the concept of industrial ecosystem was introduced. Industrial symbiosis is a good tool in order to make a harmony between industry and natural ecosystem. The good example of industrial symbiosis is the case of Kalundborg in Denmark, where 11 networks are working in four enterprises and one community nearby. It was proved that savings of natural resources and economic benefit are achieved by use of industrial symbiosis. Moreover, the control of pollutant emission was also done by use of advanced technology and investments. Based on this case, It was shown that industrial symbiosis through eco-industrial complex in Korea was confronted with many difficulties. First of all, loose emmision criteria, recycling system on wastes, and the absence of will for industrial symbiosis should be solved in Korea.
