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
제6권 제5호 (1997년 10월) 14건
1.
1997.10
서비스 종료(열람 제한)
The objective of this study is to supply basic data for large reservoir sedimentation research in future and make suggestions to maintain and operate the reservoir more efficiently. At first, previous studies about the estimation of sediment yield rate were reviewed in Korea. And the discharge rating curves of upstream stage gauging stations and the correlation between dam inflow and stage discharge were analyzed. With the analysis results, the specific sediment rate of Soyanggang dam was estimated as 608 ^m3/㎢/yr It was similar to that of Soyanggang dam feasibility study and 1994`s field surveys of the reservoir than that of 1983`s field surveys. Because the sediment rating curves were derived under the low discharge conditions, it needs to be checked under the flood conditions. However, the suggested methods such as flowrate analysis and sediment estimation will be useful to the sediment studies in future.
2.
1997.10
서비스 종료(열람 제한)
One - Dimensional Model for Simulations of Atmospheric Mixed Layer : Application to Dukyang Bay Area
One-dimensional thermodynamic mixed layer model to simulate variations of meteorological variables within the planetary boundary layer has been developed in this study. This model consists of 2 prognostic equations, which can predict the variations of potential temperature and mixing ratio and several diagnostic equations. Physics within the surface and mixed layers has been considered seperately in the model.
For the variations of the model, its result has been analysed and compared with observated data over the Dukyang Bay for one day, July 23, 1992. The simulated height of mixed layer is comparable to the observation and the variations of temperature and mixing ratio in the mixed layer are also reasonably simulated. Those imply that the model responds appropriately with given boundary conditions in spite of its simplified assumptions applied to the model and insufficient boundary and initial conditions.
3.
1997.10
서비스 종료(열람 제한)
To predict diffusion and movement of air pollutants in coastal urban region a numerical simulation shoud be consider atmospheric flow field with land-sea breeze, mountain-valley wind and urban effects. In this study we used Lagrangian particle dispersion method in the atmospheric flow field of Pusan coastal region to depict diffusion and movement of the pollutants emited from particular sources and employed two grid system, one for large scale calculating region with the coarse mesh grid (CMG) and the other for the small region with the fine mesh grid (FMG). It was found that the dispersion pattern of the pollutants followed local circulation system in coastal urban area and while air pollutants exhausted from Sasang moved into Baekyang and Jang moutain, air pollutants from Janglim moved into Hwameong-dong region.
4.
1997.10
서비스 종료(열람 제한)
This paper aims to describe the indoor-outdoor air quality in school environment through the analyses of heavy metal concentration by Inductively Coupled Plasma(ICP), which were observed at some school environment, such as traffic area, industrial area, seme-industrial area, and residence area.
The results are as follows ;
(1) Regardless indoor and outdoor, the area with the highest concentration of heavy metal is industrial area followed by traffic area, residence area and semi-industrial area in descending order of magnitude. And the heavy metal concentration of indoor is higher than that of outdoor.
(2) The main heavy metal components with more high level concentration of indoor than those of outdoor are Zn, Al, Ca and these heavy metal concentrations are higher in class than in corridor and outdoor.
5.
1997.10
서비스 종료(열람 제한)
This study was carried out to investigate the characteristics of chemical components and precipitation at Kimhae area from March, 1992 to June, 1994. The pH values, concentration of soluble ions(Cl^-, NO_2^-, NO_3^-, SO_4^2-, PO_4^3-, F^-, Mg^2+, Ca^2+, Mn^2+, K^+) and nonsoluble metals(Cr, Si, Zn, Pb, Cu, Fe, Mn, Mg, Al, V, Ca) were measured by pH meter, IC(Ion Chromatography) and ICP(Inductively Coupled Plasma). The data were analyzed by the daily, hourly distribution characteristics of acidity and chemical components, as well as the correlation between them.
The results are as follows.
1. The pH range of precipitation was from 3.45 to 6.80 in Kimhae area, and average value was pH 4.62 and main chemical components were SO_4^2-, Cl^-, NO_3^-. The highest pH value and concentration appeared in initial rain, which might result from urbanization and industrialization in this area and long term transportation from China.
2. The hourly correction distribution of main anions related to pH value in the rainwater showed SO_4^2- > NO_3^- > Cl^-. Hourly concentration of heavy metal and each ion was highly correlated with pH in the precipitation.
6.
1997.10
서비스 종료(열람 제한)
Microorganisms producing bioemulsifier were isolated from the sea water in Pusan coastal area. The isolated strain which had the highest emulsification activity and stability was identified as the genus Acinetobacter from the results of morphological, cultural and biochemical tests and named Acinetobacter sp. EL-C6 for convenience. The compositions of optimum medium for emulsification of crude oil by Actnetobacter sp. EL-C6 were crude oil 2.0%, NH_4NO_3 0.2%, K_2HPO_4 0.01%, MgSO_4·7H_2O 1.0%, CaCl_2·2H_2O 0.1% and NaCl 3.0% at initial pH 7.5 and 30℃, respectively. The cultivation for emulsification of crude oil was carried out in 500㎖ shaking flask containing 100㎖ of the optimum medium at 30℃. The highest emulsification was observed after 5 days. The utilization on the various hydrocarbon of the Acinetobacter sp. EL-C6 showed that utilization of n-alkane compounds were better than that of aromatic compounds. Among the petroleum compounds, crude oil was best utilized by the Actnetobacter sp. EL-C6.
7.
1997.10
서비스 종료(열람 제한)
Microorganisms capable of degrading trichloroethylene(TCE) using phenol as a induction substrate were isolated from industrial effluents and soil. The strain MS-64K which had the highest biodegradability was identified as the genus Micrococcus. The optimal conditions of medium for the growth and biodegradation of trichloroethylene were observed as follows; the initial pH 7.0, trichloroethylene 1,000ppm as the carbon source, 0.2% (NH_4)_2SO_4 as the nitrogen source, respectively. Lag period and degradation time on optimal medium were shorter than those on isolation medium. Growth on the optimal medium was increased. Addition of 0.1% Triton X-100 increased the growth rate of Micrococcus sp. MS-64K, but degradation was equal to optimal medium. Trichloroethylene degradation by Micrococcus sp. MS-64K was shown to fit logarithmic model when the compound was added at initial concentration of 1,000ppm.
8.
1997.10
서비스 종료(열람 제한)
The aim of this study is to determine harmful radioactive gas(Rn^222)-concentrations in soils and to suggest the anormalous regions of Rn^222 -concentration in Taejeon area. The range of Rn^222 -concentration in the soils (45 samples) of the survey area is 100 to 2,475 (pCi/L) and mean±δ of those values is 489±05 (pCi/L).
The 2% (4 samples) of soil-gas samples (45 ones) collected in the survey area is corresponded to high risk level, 53% (24 samples) to medium one and 43% (19 samples) to low one. Especially, The Rn^222-concentration is relatively higher in schistose granite region than in other rock units (two-mica granite and biotite granite) in the survey area.
The Rn^222-concentration is propotional to the uranium contents in the soils. The soil hardness among the various factors is correlative with Rn^222-concentrations. To prevent the damage from Rn^222 -concentrations, it is necessary to close the cracks of underground structure and to consider methods reducing Rn222-concentration for the anormalous regions.
9.
1997.10
서비스 종료(열람 제한)
This study was performed to investigate the utilization of waste concretes for neutralization and removal of heavy metals in plating wastewater, because waste concretes have been known to be very porous, to have high specific surface area and to have alkaline minerals such as calcium.
The results obtained from this research showed that waste concretes had a buffer capacity to neutralize an acidic alkali system in plating wastewater. Generally, neutralization and removal rate of heavy metals were excellent in the increase of waste concrete amounts and a small size. Because a coefficient of correlation was high, it seemed that removal of heavy metals could be explained by Freundlich and Langmuir isotherms. If we reflected the adsorption capacity(k) and adsorption intensity(l/n) of Freundlich isotherm, we couldn`t consider waste concretes as a good adsorbent, But, we could know that waste concretes were capable of removing a part of heavy metals. In point of building waste debris, if waste concretes substituted for a valuable adsorbent such as actviated carbon, they could look forward to an expected economical effect.
10.
1997.10
서비스 종료(열람 제한)
The interfacial characteristics between various heavy metals and hydrous FeS were investigated. Heavy metals which have lower sulfide solubilities than FeS undergoes the lattice exchange reaction when these metal ions contact FeS in the aqueous phase. For heavy metals which have higher sulfide solubilities than FeS, these metal ions adsorb on the surface of FeS. Such characteristic reactions were interpreted by the solid solution formation theory. The presence of ligand such as EDTA reduced largely metal removal efficiency due to formation of metal-ligand complex in the solution. In an attempt to elucidate the interfacial characteristics, zeta potential of the hydrous FeS in the absence and in the presence of various metal ions were measured and analyzed.
11.
1997.10
서비스 종료(열람 제한)
This study was performed to investigate the riverbed structure and the pollution type in Nakdong River, Western Nakdong River, and Suyoung Stream. Sediment and water samples were collected at 15 in Nakdong River, 7 in Western Nakdong River, and 8 sites in Suyoung Stream from February 20, 1997 to June 15, 1997. The depth distributions of sampling sites in the three streams were measured and heavy metals(Cd, Pb, Cr, Cu) and pesticides in sediments and COD, BOD, and total nitrogen(T-N) in water samples were analyzed.
The deepest and the shallowest sites were site 11(11.58m) and 9(3.35m) in Nakdong River, site 7(6.25m) and 4(2.06m) in Western Nakdong River, and site 8(2.89m) and 1(0.61m) in Suyoung Stream, respectively. The mean concentration of Cd(45.79ppm) was higher in the sediment of Western Nakdong River than in other two streams and those of Pb(76.25ppm), Cr(48.13ppm), and Cu(77.50ppm) were higher in the sediment of Suyoung Stream than in other two streams. Pesticides(1 kind of organophosphonis and 3 kinds of organochlorine pesticide) were detected only in the sediment of Western Nakdong River. The mean concentrations of COD(20.26ppm), BOD(25.36ppm), and T-N(18.05ppm) were higher in the water sample of Suyoung Stream than in other two streams.
12.
1997.10
서비스 종료(열람 제한)
In the study, we investigated the behavior and removal efficiency of organics, nitrogen, phosphorus with operating conditions in SBRs. Substrate used was synthetic wastewater in which the ratio of COD_cr : N : P was 100 : 12 : 2. The cycling time in SBRs was adjusted at 6 hours and 8 hours, and then certainly included anaerobic and aerobic conditions. Also, for each cycling time, we performed 2 series of experiment simultaneously which was set up 10 days and 20 days as SRT. The removal efficiency of COD_cr, was over 97% in all operating conditions. In the 6 hours cycling time, the removal efficiency of PO_4^3- -P reached almost 100% in steady state. And then we could observe a typical phenomena of phosphorus release and uptake, and the removal efficiency of N was 67%. Residual N source was almost TKN and most of the rest remained as NO_2^- -N. Also the difference in both SRTs was not observed practically. In the 8 hours cycling time, dissolution of sludge appeared. and, PO_4^3- -P was not nearly removed but nitrogen was removed up to 75%. And the residual nitrogen was accumulated as NO_2^- -N.
13.
1997.10
서비스 종료(열람 제한)
In the study, we investigated the behavior and removal efficiency of organics, nitrogen, phosphorus with operating conditions in SBRs. Substrate used was synthetic wastewater in which the ratio of COD_cr : N : P was 100 : 12 : 2. The cycling time in SBRs was adjusted at 6 hours and 8 hours, and then certainly included anaerobic and aerobic conditions. Also, for each cycling time, we performed 2 series of experiment simultaneously which was set up 10 days and 20 days as SRT. The removal efficiency of COD_cr, was over 97% in all operating conditions. In the 6 hours cycling time, the removal efficiency of PO_4^3- -P reached almost 100% in steady state. And then we could observe a typical phenomena of phosphorus release and uptake, and the removal efficiency of N was 67%. Residual N source was almost TKN and most of the rest remained as NO_2^- -N. Also the difference in both SRTs was not observed practically. In the 8 hours cycling time, dissolution of sludge appeared. and, PO_4^3- -P was not nearly removed but nitrogen was removed up to 75%. And the residual nitrogen was accumulated as NO_2^- -N.
14.
1997.10
서비스 종료(열람 제한)
A least-square regression analysis is applied for the estimation of velocity streamfunction field based on discretely sampled current meter data. The coefficients of a streamfunction that is expanded in terms of trigonometric basis function are obtained by enforcing the horizontal non-divergence of two-dimensional flow field. This method avoids interpolation and gives a root-mean-square (rms) residual of fit which includes the divergent part and noisiness of oceanic data. The implementation of the method is done by employing a boundaryfitted, curvilinear orthogonal coordinate which facilitates the specification of boundary conditions. An application is successfully made to the Texas-Louisiana shelf using the 32 months current meter data (31 moorings) observed as a part of the Texas-Louisiana Shelf and Transport Processes Study (LATEX). The rms residual of the fitting is relatively small for the shelf, which indicates the field is well represented by the streamfunction.
