Sustainable development has been the key concept, both in economic policies and in environmental management since 1970s. In the view of systems ecology, sustainable resource use strategies are considered to be essential in achieving sustainable development. During the last three decades, the discipline of systems ecology has applied ecological energetic analysis to the evaluation of the contribution of natural environments to economic systems.
EMERGY analysis of main energy flows driving the economy of humans and life support systems of a city was made including environmental energies, fuel, and inputs, all expressed as solar emjoules. Total EMERGY use of Pusan was 3.89 E22 sej/yr, about 90 percent of it was purchased sources from outside during eleven years from 1985 to 1995. EMERGY flows from the environment were less than 10 percent. EMERGY yield ratio and environmental loading ratio were 1.10 and 10.45, respectively. EMERGY sustainability index is therefore less than one, which is indicative of highly developed consumer oriented economies. Development of a city has been achieved in the short run by the economic growth, but it can be sustained in the long run by the use of renewable resource systems.
This study is carried out the analysis of the runoff characteristics for the design of the interior drainage systems by SWMM in urbanization basin. The basin analyzed in this study is Bumuh-chun basin which is located in Susung-gu of Taegu city. Huff method is used for rainfall distribution analysis. The optimal rainfall duration in Bumuh-chun basin is analyzed as about 90 minutes decided from comparison of arrival time and critical duration. Flood flow variation pattern is proposed through the comparison of the results of peak flow and peak time analyzed by SWMM about pre-urbanization and post-urbanization of Bumuh-chun basin. It is known that the variation of arrival time caused by the rapid increase of pavement rate in the upper area shows about 20∼25 minutes faster than pre- urbanization.
Therefore, the management of surface water for design of water supply and drainage, and channel alteration has to considered the variation of geological factors according to urbanization.
PCBs and DDE were determined in the soil samples and the Korean striped field mice, Apodemus agrarius, collected at six localities in Changwon and one locality in Gaduck Island from August 1997 to May 1998. The residual level of PCBs in soils, in which the concentrations of high chlorinated compounds were much higher than those of low chlorinated ones, was highest in the industrial area(IA) in Changwon(60.7 ng/g in average), whereas those of DDE in soils was highest in Gaduck Island(331.9 ng/g in average). However, the levels of each compound detected from soils in the respective remaining places were relatively low. The similar tendency as in the soils was observed in the mice, indicating that the concentration of pollutants in the mice could denote the status of pollution in the terrestrial environment. The composition of PCB congeners in the mice, however, was different from that of soils, but similar to those of other mammals. Moreover, the residual levels of PCBs and DDE in pregnant females from which fetuses were removed were lower than those of males and non-pregnant females. It suggests that these compounds accumulated in pregnant females might have been transferred to the fetuses through placenta as in other mammals. Judging from the above facts, it is suggested that the striped field mouse can be an useful biological index to evaluate the contamination in mammals inhabiting terrestrial environment.
The preventive effects of sodium molybdate on the acute toxicity of lead were studied by investigating tissue accumulation of lead, changes of nerve conduction velocity and concentrations of metabolites related to function of sciatic nerve in rats treated with lead, sodium molybdate and both, respectively. In lead-intoxicated rat, the conduction velocity, myo-inositol concentration and Na+/K+ ATPase activity of sciatic nerve were decreased by about 33 %, 48 % and 58 %, respectively.
However, sodium molybdate treatment significantly normalized the conduction velocity, Na+/K+ ATPase activity and myo-inositol concentration of sciatic nerve in lead-intoxicated rat. Also, sodium molybdate treatment decreased the contents of lead in blood and sciatic nerve through promotion of urinary excretion of lead. But sodium molybdate treatment did not affect the glucose concentration in sciatic nerve.
These results suggest that sodium molybdate prevented peripheral neuropathy not only by reducing lead contents in sciatic nerve and blood, but also by enhancing Na+/K+ ATPase activity in sciatic nerve.
The relationship between the distribution of sea surface temperature(SST) and dinoflagellate(Cochlodinium polykrikoides) bloom areas were studied.
The SST data were derived from the infrared channels of AVHRR(Advanced Very High Resolution Radiometer) sensor on NOAA(National Oceanic and Atmospheric Administration) 12 and 14 satellites during 1995-1998.
The initial water temperature at C. polykrikoides bloom was about 21℃ at the coastal areas of the South Sea and along the shore of the East Sea of Korea during the summer season of 1995. The northern limit of red tides was coincident with that of 21℃ isothermal line in the East Sea.
The red tides that initially bloomed at the coast of Pohang on September 21, 1995 moved to the coast of Uljin on September 26, 1995. The skipped appearance of the red tides in the areas between Pohang and Uljin was due to the East Korean Warm Current, which was moving offshore from Pohang to approach to Uljin.
The cold water which was formed by tidal front in the western coast of the South Sea and by upwelling water from deep layer in the southeastern coast of the Korean peninsula played a role in blocking the spreading of red tides during summer season in 1997 and 1998.
In conclusion, the distribution of red tides appeared to be dependent on the initial water temperature at red tides bloom.
The SST at the red tides varied from 21℃ to 25℃ ; 21℃, 23℃, 24℃ and 24-25℃ in 1995, 1996, 1997 and 1998, respectively.
충남 서천군 춘장대에서 채취한 갯벌을 통수칼럼에넣고 오염물질 정화능력을 평가 해 보았다. 각 칼럼에 사용된 시료수는 하수를 G2여과지(6㎛)로 여과한 여액(R1), 생하수를 GF/C여과지(1.2㎛)로 여과 후 하수중의 미생물에 의한 영향을 제거하기 위하여 고압멸균기(autoclaver)로 120℃에서 15분간 멸균한 하수( R2), 여과·멸균된 하수를 membrane filter로 여과한 해수와 1:1(하수:해수)로 혼합한 시료수(R3) 그리고 R3에서 사용된 하수와 해수를 이용해 그 비를 1:2로 혼합한 시료수(R4)를 이용하였다. 4종류로 조제된 시험수를 이용한 통수실험 결과를 요약하면 다음과 같다.
통수실험에 의해 제거된 COD 양은 시료수에 하수의 함유량이 증가할수록 증가하였다.
암모니아질소의 경우 각 칼럼에서 580분 실험한 후 총 누적 제거양은 R1 90.1㎎, R2 81.0㎎, R3 27.6㎎, R4 4.1㎎이었다. R1과 R2에서 총 누적 제거 양이 해수가 1:1로 함유된 R3보다는 약 3배 높았고, 생하수와 해수가 1:2로 함유된 R4보다는 약 20배 높아 시료수에 하수의 함량이 높을수록 COD와 마찬가지로 암모니아질소가 잘 제거되는 것으로 판단되었다. 총인의 경우 각 칼럼에서 580분 실험한 수 제거된 총 누적 양은 R1 3.4㎎, R2 4.2㎎, R3 5.6㎎, R4 2.0㎎이었다.
평균 유입수 농도와 평균 유출수 농도로 구한 Pb의 평균 제거율은 R3와 R4에서 94.6%와 94.9%로 R1과 R2에서의 66.5%와 77.0%보다 약간 높았고, Cd의 평균 제거율도 R3와 R4에서 93.1%와 88.5%로 R1과 R2에서의 61.2%와 82.7%보다 약간 높았다. 이상과 같이 칼럼실험에서 중금속은 해수가 첨가된 시료에서 제거율이 높았다. 하지만 초기 20분간 흡착된 중금속의 양은 580분 동안 흡착된 총 양의 3∼4%로 유사한 값을 나타내었다.
Spring, ground and thermal waters in the vicinity of Mt. Geumjeong and Mt. Baekyang area have been sampled and analyzed for major and minor elements. According to the Piper diagram, spring water belongs to Ca-HCO3 and Na-HCO3 types, groundwater to Ca-HCO3 type, and thermal water to Na-Cl type. Based on the phase stability diagrams of [Ca2+]/[H+]2, [Mg2+]/[H+]2, [K+]/[H+], and [Na+]/[H+] vs. [H4SiO4], spring water, groundwater and thermal water are mostly in equilibrium with kaolinite. The result of factor analysis shows three factors (factor 1, 2 and factor 3) for the spring water, the groundwater and the thermal water which are represented by the influence of the dissolution of feldspar, calcite, anthropogenic sources (domestic and industrial wastes) and salt water.
Twenty-two water samples(fifteen groundwater and seven geothermal water samples) were collected to elucidate chemical characteristics of the ground and geothermal waters in the Haeundae hot-spring area and its vicinity. Major and minor elements were analyzed for ground and geothermal water samples. The concentrations of K-, Na-, Ca2+, SO42-, Cl-, F+ and SiO2 were higher in the geothermal water samples than the groundwater samples except HCO3 and Mg2+ ions. Based on the contents of Fe, Zn, Cu, Al, Mn and Pb, some of the ground and geothermal water samples are contaminated by anthropogenic sources. The ground waters shown on the Piper diagram belong to Ca-HCO3 type, while the geothermal waters Na-Cl type. The graphs of Cl- versus Na+, Ca2+ Mg2+, K-, SO42- and HCO3- indicate that the groundwater is related partly with mineral-water reaction and partly with anthropogenic contamination, while the geothermal water is related with saline water. On the phase stability diagram, groundwater and thermal water mostly fall in the field of stability of kaolinite. This indicates that the ground and geothermal waters proceed with forming kaolinite. Factor and correlation analyses were carried out to simplify the physicochemical data into grouping some factors and to find interaction between them. Based on the Na-K, Na-K-Ca and Na-K-Ca-Mg geothermometers and silica geothermometers, the geothermal reservoir is estimated to have equilibrium temperature between 125℃ and 160℃.
The purpose of this study is to investigate the physicochemical characteristics of salinization of groundwater at the estern area of Cheju island. For this purpose, the major ions of groundwater. spring water are analyzed. The concentration of Cl- and Na-+K- contained in the groundwater at near the coastline are higher than those at inland area away from the coastline. The water quality components of groundwater observed at this area can be classified into 4 types such as Na-Cl, HCO3, Na-Cl-HCO3 and Ca-HCO3. The concentration ratio of SO4- to Cl- is 0.1354(R2=0.972) at this area. This value is very similar with Dittomer's ratio of 0.13. For Na-, K-, and Mg2+ versus Cl-, their ratios also show a significant relationship between sea water and groundwater in this area. From the chloride-bicarbonate ratio, it can be estimated that the intrusion distance of seawater from coastline to inland area is 2.8km at Onpyung-Nansan, Sangdo and Pyungdae areas, and 5.4㎞ at Kosung-Susan area.
The mixing ratio between seawater and fresh water by the intrusion of seawater is decreased with the distance toward inland from coastline. This ratio(fresh water : seawater) is 80:20 in spring water adjacent the coastlines, Onpyung area and 99.8:0.2 in the well at No.3 of Susan located at inland away from the coastline. The concentration of Na- observed at field is 25∼45% lower than that theoretically calculated by this mixing ratio. Based on the data of EC, the equipotential line of 500μmhos/㎝ is located at 4∼5㎞ point at Kosung-Susan area and 2.5㎞ point at the other area. The equation of correlation between Cl- concentration and EC values is Cl-=0.1927EC-16.683 for the area lower than 500μmhos/㎝ and Cl-=0.2773EC for the area beyond 500 μmhos/㎝.
A kinetic study for nitrate removal by anion exchange resin was performed using continuous column reactors. Kinetic approach from the packed bed showed the reaction rate constant k1 was 0.07∼0.17 ℓ/㎎·hr and maximum exchange quantity q0 was 27.75∼31.81 ㎎/g. The results from the continuous column well agreed with that from the batch reactor. An economic analysis of the water treatment plant by anion exchange resin with a regenerating system was performed to design plant and process. Based on the treatment of 20 ㎎/ℓ nitrate-contained wastewater of 10,000 gallons per day to 2 ㎎/ℓ , total capital cost and total annual cost are estimated to be 836 million wons and 211 million wons, respectively.
In order to understand the impact for decomposition of blue-green algae Microcystis on water quality, the algae were cultivated with collection of natural population during approximately one month, when water-bloom of Microcystis dominated at August 31, 1999 in the lower part of the Okchon Stream. The enrichment of inorganic N·P nutrients didn't in algal assay and the effect of Microcystis on water quality was assessed from the variation of nutrients by algal senescence. Microcystis population seemed to play a temporary role of sink for nutrients in the water body. Initial algal density of Microcystis was 2.3×106 cells/ml. When Microcystis population died out under light condition, algal N·P nutrients between 9∼12 days affected to increase of biomass after reuse by other algal growth as soon as release to the ambient water. However, cellular nutrients under dark condition were almost moved into the water during algal cultivation. NH4, NO3 and SRP concentration were highly increased with 160, 17 and 79 folds, respectively relatve to the early. As a result, the senescence of Microcystis population seemed to be an important biological factor in which cause more eutrophy and increase of explosive algal development by a lot of nutrients transfer to water body. There are significantly observed an effort of reduce for production of inner organic matters such a phytoplankton as well as load pollutants from watershed in side of the water quality management of reservoir.