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
제5권 제1호 (1996년 2월) 11건
1.
1996.02
서비스 종료(열람 제한)
The genetic variabilities of second chromosomes of Drosophila melanogaster concealed in O^n-yang natural population have been analyzed by the Cy//Pm method and an allelism test during two years (1993-1994).
The mean frequencies of deleterious(lethal and semilethal) genes in O^n-yang natural population were estimated to be 23.97% in 1993 and 27.15% in 1994, respectively. The allelism rates between lethal genes in the population were 0.654%(1993) and 1.429%(1994). The mean values of elimination by frequencies of deleterious genes and allelism rates were 0.0004(1993) and 0.0010(1994), respectively. The frequencies of phenotypic sterility of males in 1994 were estimated to be 1.95%, and thoses of genotypic sterility of females and males were estimated to be 1.54% and 2.31%, respectively.
2.
1996.02
서비스 종료(열람 제한)
Two experiments were conducted to evaluate breathing zone air quality in Taegu, using automatic analyzers for four air quality standards(SO2, NO2, CO, and O3). First, air target compounds were measured for 8 to 12 hours in each of two commercial areas and five residential areas. Second, air target compounds were hourly measured for 24 hours in each of two commercial areas, two residential areas, and an industrial complex area. Based on the first experiment the breathing zone air was more polluted in the commercial area as compared to the residential area, while the second experiment showed that the breathing zone air was polluted rather in the residential area as compared to the commercial area. The second experiment also indicated that there was some variation of breathing zone air concentration with time and measuring sites. Diurnal variation of breathing zone air concentrations was consistent with previous studies which measured at building height. The highest breathing zone air concentration was shown in Seongseo industrial complex area. An unusual finding of this study was that SO2 concentration in the breathing zone air of Bisandong, a typical residential area of Taegu, was higher than that of other residential areas, even higher than that of Seongseo industrial complex area.
3.
1996.02
서비스 종료(열람 제한)
During the last two decades, many industrial complexes for heavy and chemical industries have been established along the Korean coastline, thereby increasing the pollution materials burden on the coastal environment of seawater. Masan Bay is one of the most polluted coastal areas in Korea and the main soures of pollutants are domestic and industrial wastewater from Masan, Changwon.
This study was aimed to evaluate relationships among the physicochemical parameters in the bottom water of Masan bay and to examine environmental factors affecting to pollutions of seawater by factor analysis.
The factor loading, 1 is showed higher increasing inclination after 1989 year in station 1. The variance of pollutant materials is showed 43.7% in which the coastal inflow water is indicated external loadings(factor 1 : NO3- -N, TN, factor 4 : SiO2-Si) corresponded to domestic sewage, industrial wastewater, and earth-sands in the bottom water of Masan bay. And the internal loadings(factor 2 : SS, salinity, factor 3 : W.T., DO) are explained 33.8% corresponded the phenomena of sedimentary layer and oxygen concentration. Therefore, The external loadings are explained by the higher factor pollutantal variance in Masan bay.
4.
1996.02
서비스 종료(열람 제한)
This study was conducted to investigate the biological treatment capability of MMCMAS(Movinig Media Complete Mixing Activated Sludge) reactor for high strength organic wastewater (Average BOD=800㎎/ℓ). And this experimental results were compared previous study for low strength organic wastewater (Average BOD=150㎎/ℓ) by the same reactor. In this study, we abtained following conclusions ;
(1) The laboratory MMCMAS reactor demonstrated that SBOD removal efficiencies of more than 90% can be achieved at organic loading rates of 30.9 gBOD/㎡/d for high strength organic wastewater and 39.4 gBOD/㎡/d for low strength organic wastewater, respectively.
(2) The nitrification rates of MMCMAS reactor was found same results of similiar organic loading rates.
(3) The ratio of attached biomass to total biomass on the moving media varied in the range of 40 to 63% and 32 to 94% for high and low strength organic wastewater, respetively. And it was varied at the various concentration of influents for the similiar organic loading rates. The sludge production rates was found approximately 0.37 gVSS/gBODrem. in MMCMAS reactor.
5.
1996.02
서비스 종료(열람 제한)
For studying of coagulation and sedimentation in estuarine clay, we obtained several flow curves with various concentrations of sea water by using Coutte type rotational rheometer. The initial shear stress on high concentration of sea water was observed big, but after this, its value is decreasing with increasing shear rate. The maximum pick of shear stress is decreasing with the decreasing of concentration of sea water. The trend is same totally above for viscosity. The sedimentation times with the concentration of sea water vary in ∞ ∼ 5 minutes.
The zeta potential is changed dramatically between 1/4 and 1/8 concentration of sea water. That is consistent with the sedimentation graph. From these results, the phenomena of coagulation and sedimentation can be explained with viscoelastic terms on structual formation among particles by the changes of surface potential affected from contacting sea water to dispersed particles.
6.
1996.02
서비스 종료(열람 제한)
Thiobacillus neopolitanus R-10, which produces a active thiosulfate oxidase, was isolated from nightsoil. The optimal culture conditions of Thiobacillus neopolitanus R-10 for the production of enzyme was determined as followed: 0.8% Na2S203, 0.2% KH2P04, 0.2% K2HP04, 0.04% Na2C03, 0.02% MgSO4·7H2O, 2ml trace elements solution, and pH 6.5 at 30℃ and 72hr cultivation. The oxidase was successively purified 83 folds yield by (NH2)2S04 fractionation, DEAE-Cellulose, Sephadex A-50 column chromatogrophy and gel Sephadex G-150 gel filteration with yield of 5.9%. The molecular weight of purified enzyme was estimated to be 43.000 dalton by SDS-polyacrylamide gel electrophoresis and gel filteration column chromatography.
The enzyme activity was highest at 40℃ and pH 7.0 The enzyme activity was relatively high by β-mercaptoethanol but strongly inhibited by cysteine.
7.
1996.02
서비스 종료(열람 제한)
The purpose of this study was to evaluate the partial oxidation of the biological treatment plant effluents using Fenton`s reagent as a pretreatment step prior to a tertiary biological oxidation of these effluents. Fenton`s reagent was evaluated as a pretreatment process for inhibitory or refractory organics. Based on the Fenton oxidation system, the petrochemical wastewater treatment plant effluent was shown to have significant improvement in toxicity after oxidation with hydrogen peroxide. For example, at range of 42∼184 ㎎/L COD of petrochemical plant effluents, the COD removal efficiencies were from 38.2% to 60.1% after reaction with hydrogen peroxide 200 ㎎/L and Fe^2+ 100 ㎎/L and reaction time was 30 minutes. The total TOC reduction were about 15.8∼22.4% with same test condition and difference between the overall removal rate and BOD/COD ratio after Fenton`s oxidation estabilished in the biodegradation and otherwise meets the discharge standard or reuse for cooling tower make-up water.
8.
1996.02
서비스 종료(열람 제한)
The combined wastewater of municipal landfill leachate and municipal sewage was treated using several sets of bench-scale aerated circulating system including porous media. Investigated items in this experiment were the dominant protozoa and metazoa in this system, the variation of microfauna relationship between operating condition and dominant genera. Also considered the factors determining dominant genera and their role.
The outcome of this research is as follows;
1. Aspidisca, Vorticella, Trachellophyllum, Lecane, Philodina, Cyclops were mainly appeared prior to combinding leachate, while Trachelocerca, Bodo, Glaucoma were the dominant genera after combinding leachate.
2. As to metazoa, Nematode and Philodina were not influenced by 5% leachate mixing ratio, meanwhile Crustacea has high sensitivity for increased leachate mixing ratio and it was not appeared in 5% leachate mixing ratio.
3. The appropriate treatability could`nt be expected at the above 10% leachate mixing ratio. Especially, in the condition of 20% leachate mixing ratio, all of the microfauna were affected damage seriously on their existence. Meanwhile hydraulic retention time, substrate loading rate and sludge production rate didn`t give notable influence on increasing the number of microfauna.
4. As to protozoa, saprozoic and holozoic species were appeared commonly and polysaprobic species were dominent.
5. Filamentous organsms were nearly not affeced by leachate mixing. It seems that they could live without any trouble at the 10% leachate mixing ratio, if the substrate is sufficient.
6. Diversity of microfauna had a reducing trernd as the sewage was mixed with leachate.
9.
1996.02
서비스 종료(열람 제한)
Direct Sky Blue-5B is an Azo dye known as general for staining of textile and leather, etc., and as materials which are difficult to be biodegraded in nature. The bacterium strain which could degrade direct Sky Blue-5B was isolated from activated sludge of dyeing factory and identified as Proteus sp. by experiment on morphological, cultural and biochemical characteristics, and so named Proteus sp. ST-1. The optimum condition of the strain for degradation of Sky Blue-5B were at about 35℃ and pH 7∼8. The strain had been capable of degradation with organic nitrogen effectively and had completely degraded 200㎎/ℓ of the dye within 12hrs at 37℃. The enzyme system related to degradation of Azo dye may be intracellular, and so degraded the dye after absorption into cell. The degradation products of Sky Blue-5B by Proteus sp. ST-1 were analyzed by Gas Chromatography /Mass Spectrometry and Spectrophotomer, from this observation, it may be infered that the strain degraded the dye directly without any mediate.
10.
1996.02
서비스 종료(열람 제한)
A recycling soap was prepared from non-cooking oils. The effects of physical and chemical properties of the recycling soap on biodegradation are expected to be different due to the thermal histories of the non-cooking oils.
Therefore, the biodegradation rate of the recycling soap was studied by using Klebsiella pneumoniae(K. pneumoniae), and the growth rate of K.pneumoniae in soap solution was observed.
The biodegradation rate of the recycling soap appeared to be slower as the thermal histories of the non-cooking oils became larger. This might be resulted from hydrolysis, in which the ester bonds in the oils are broken to produce hydroxyl group. It was also observed that the growth rate of the microorganism decreased with the increase in the thermal histories of the oils. As a result, it is desired that recycling soap should be produced from the non-cooking oils with the proper ranges of thermal histories to reduce water contamination. The non-cooking oils with larger thermal histories are considered to be recycling through the cracking process before used.
11.
1996.02
서비스 종료(열람 제한)
Hydrodynamic characteristics such as gas holdup, liquid circulation velocity and bed expansion in a hexagonal inverse fluidized bed were investigated using air-water system by changing the ratio (Ad/Ar) of cross-sectional area between the riser and the downcomer, the liquid level(Hl/H), and the superficial gas velocity(Ug).
The gas holdup and the liquid circulation velocity were steadily increased with the superficial gas velocity increasing, but at high superficial gas velocity, some of gas bubbles were carried over to a downcomer and circulated through the column. When the superficial gas velocity was high, the Ad/Ar ratio in the range of 1 to 2.4 did not affect the liquid circulation velocity, but the maximum bed expansion was obtained at Ad/Ar ratio of 1.25.
liquid circulation velocity was expressed as a model equation below with variables of the cross-sectional area ratio(Ad/Ar) between riser to downcomer, the liquid level(H1/H), the superficial gas velocity(Ug), the sparger height[(H-Hs)/H], and the draft plate level(Hb/H).
Uld=11.62g^0.75(Hl/H)^10.30(Ad/Ar)^-0.52(H-Hs/H)^0.91(Hb/H)^0.13
