• 한국환경농학회지
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• 제15권4호
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• pp.506-519
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• 1996

The water quality in the rural areas is degrading due to a variety of causes such as the increase of the urban sewage and industrial wastes, the disposal of solid wastes, the growth of livestock waste, the growth of leisure facilities, the establishment of agricultural industry estates and etc. The water pollutants are scarce while the effluent is increasing from wide scattered sources. The technology specifically designed for the rural wastes water treatment plant needs to be implemented with improvement of agricultural water quality. 1. An integrated management measures against water pollution sources. The prevention of water pollution is the best measures in the environmental pollution. Hence, the most effective measures needs to be against the sources. Small-scale water treatment plants needs to be constructed in each village in the rural areas. As for the industrial effluent, the effluent discharge needs to be strictly monitored. Government subsidy for the establishment of treatment plant for livestock wastes is necessary. 2. The establishment of national-wide network for agricultural water quality. The network for agricultural water quality have been operated to conserve the agricultural water quality, and to develop management policies by the assessment of water pollution in the rural areas. The results of agricultural water quality network indicates that the water quality is degrading not only around urban areas but also in the distant rural areas, and the water quality at the pumping stations and weirs is worse than that of reservoirs. 3. The legal, systematic, and technical approaches for the agricultural water quality management. The actions currently implemented for the improvement of agricultural water quality involve temporary measures such as the improvement of irrigation facilities. These contingency measures are not effective in the long-term, and sometimes bring secondary pollution. Therefore, integrated measures covering the whole water environment such as the flow, quality, river morphology, aquatic ecosystem, and the surrounding environment, need be invented and implemented. Besides, the legal, systematic, and technical frameworks for the management are not fully established so far. The technology for the treatment of rural water pollution should be refined afterwards, and the research for the development of rural waste water treatment plant should be carried out.

• 한국환경복원기술학회지
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• 제15권5호
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• pp.103-114
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• 2012

The purpose of this research is classifying stream into different types depending on various factor from the perspective of stream corridor restoration and using it as basic data, which are used to consider efficient management and planning for the healthy stream according to the characteristic by types. In this study, 130 points of location of the Nakdong river basin which consist of various geographic factors have been chosen and hierarchical cluster analysis has been carried out in these points by using biological and physiochemical factors whose health can be considered to be predicted and evaluated. As a result of cluster analysis, there were three divided types. Type A whose biology and water quality are considered the best was the highest in forest area percentage so that it was classified into natural stream. Type B was classified into a rural region stream with a mixture of urban and agricultural region. Type C, with the most damaged water quality and biology health had the most urban region surface area and was named as urban region stream. Moreover, an overall restoration strategy according to characteristic by stream types was set. By the results of correlation analysis on factors, water quality showed a high correlation with biological properties and was affected by surrounding land usage. In evaluation of streams, it proves the need to consider not only other habitat's geographical and biological factors but also the water quality and land usage factors. There needs to be further research on stream ecosystem functionality factors and structural aspects by using a more objective and total evaluation result in selecting additional index and various other specific classification methods by stream types and its restoration strategies.

• 환경생물
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• 제35권2호
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• pp.143-151
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• 2017

본 연구는 부산시의 대표적인 도시하천인 온천천에서 가뭄 및 집중호우 등 환경적 교란이 수질 및 부착규조류 군집에 미치는 영향을 파악하기 위하여 2013년~2014년 2년간 연구를 수행하였다. 긴 갈수기였던 2013년 4분기~2014년 1분기와 2014년 3분기에 강한 집중 호우 사이에 급격한 하천 수질 변화를 보였다. 부착규조류는 비교적 짧은 유하거리에 비해 도심화 정도에 따라 상류에서 하류까지 뚜렷하게 군집 구조 변화를 보였으나 긴 가뭄기간 동안 감소된 유량은 종조성에 영향을 주어 Cocconeis placentula var. lineata에서 Gomphonema clevei이 우점종으로 바뀌고 Gomphonema 속 등 주요 분포 종으로 조사되었다. 갈수기 이후 강한 강우로 부착규조류의 종조성보다 생물량이 급격하게 감소되었고 이는 국지적 기후 변화로 수생태계 구조와 기능에 많은 영향이 생김을 알 수 있었다. 따라서, 기후 변화에 의한 도시기후의 이상현상과 도시하천의 수질 및 부착규조류의 분포 특성 연구는 도시하천 생태계 특성과 변화 연구에 있어서 기초 자료로 활용될 수 있을 것으로 기대하며 국지적인 환경변화에 대응하는 도시하천의 유지관리 방안을 찾는 데 도움이 될 것으로 판단된다.

• 한국환경과학회지
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• 제13권12호
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• pp.1041-1048
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• 2004

In this study the results of optimal water supply analysis by operating constraints of reservoirs during drought period are as follows. During drought period, water supply reliability is possible about $97\~61{\%}$ by CASE 1-CASE 5. Water supply reliability is possible about $97.3{\%}$ in case of the Andong dam and $87.7{\%}$ in case of the Imha dam by CASE 3. Also, under the constraints of CASE 4, water supply reliability is possible about $87.5{\%}$ in case of the Andong dam and $73.3{\%}$ in case of the Imha dam. The reason what low of available water supply ratio is decreased inflow of Imha dam. When compare standard deviation of average storage with standard deviation of storage, stable storage can be secured during successive drought period. And it also can minimize shortage of water during drought. therefore, it is impossible that reservoir supply sufficient water but change of operating condition is better than pervious on that followed by full reservoir level. It is need that the study for optimal water supply during drought period has to be continued.

• 한국환경과학회지
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• 제15권11호
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• pp.1077-1086
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• 2006

This study aims at analyzing relationships between land use and habitat types of winter wildbirds to provide basic understanding of ecosystem for preservation and restoration of urban ecosystem in the future. The research area is Hanam City. Researches on land use types showed Hanam City had 79.1% of greenspace and openspace, but intensive urban development has been taking place in greenspace that is adjacent to urban districts. This has brought the problems of lack of greenspace in urban districts and damages to cultivated areas and grassland. A total of 61 and 8,642 populations of winter wildbird species were observed in research areas. Paradoxornis webbiann(16.91), Passer montanus(11.93), Pica pica(6.88) were dominant species. When they were divided according to habitat types, 20 species of interior species, 8 species of interior-edge generalist species, 12 species of edge species and 3 species of urban species were observed. When which land use type was mostly served as wildbirds habitats was examined, urban species(3 species and 290 populations) was a dominant species in urban districts while in greenspace and openspaece, water species(19species and 3,075 populations) including winter migratory birds was. Among greenspace and openspaece, edge species was dominant in forest while urban species was a dominant species in cultivated areas. This shows there is a need to improve diversity of wildbirds through restoration of cultivated areas in the central part of Hanam City.

• 한국물환경학회지
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• 제22권2호
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• pp.314-320
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• 2006

Diffuse pollution from an urban area contributes to the significant pollution loading to a receiving water body. In this paper, rainfall runoffs from an urban basin with combined sewer systems located in the city of Daejeon were monitored to measure the rainfall runoff discharge rates and pollutant concentrations. Strong first flush effects were observed for all monitored rainfall runoffs. The first flush effects were closely related to rainfall intensity, while suspended solids were closely related to pollutant constituents. The observed averaged Event Mean Concentrations (EMCs) of Combined Sewer Overflows (CSOs) were 536.1 mg SS/L, 467.7 mg CODcr/L, 142.7 mg BOD/L, 16.5 mg TN/L, and 13.5 mg TP/L. Storage volumes for containing the first flush to improve water quality of the receiving stream can be estimated based on suspended solid concentration. In this study, retainment of the first flush equivalent to 5mm of precipitation could reduce diffuse pollution loading induced by CSOs to a receiving water body by up to 80% of suspended solid loading.

• 한국환경과학회지
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• 제7권4호
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• pp.461-466
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• 1998

One hundred and thirty two ground water samples from the Usan area were divided into urban and non-urban groupings and were assessed between 1993 and 1996. The results of statistical analysis were as follows: There were significant differences between the two groupings in the average value of the following water quality parameters: total hardness, nitrate , pH, iron, ammonia and chloride ion in the order of Z-score . Because total hardness, nitrate, and pH were also significant in ANOVA test, these three parameters can be regarded as the most sensitive parameters of artirial pollutants. By the comprehensive com- parison of Ulsan water Quality to that of Kangwon-do, all of the major parameters(pH, KMnO4 consumption, sulfate, chloride and hardness except nitrated were confirmed as being significantly Increased levels.

• Membrane and Water Treatment
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• 제11권5호
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• pp.345-351
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• 2020

Eutrophication of surface waters is commonly caused by excessive inputs of nutrients such as nitrogen and phosphorus. Nakdong River basin was chosen as the study area to investigate the effect of point and non-point source pollution of nitrogen on eutrophication in water body. Non-point source inputs of nitrogen accounted for approximately 84% in the total nitrogen input of the upper Nakdong river watershed, which mainly consists of agricultural land and forests. However, point source inputs of nitrogen accounted for 58~85% in the total nitrogen input of the middle and lower watersheds, including urban area. Therefore, for watershed near urban area, control of point source inputs of nitrogen may be an optimal method to control eutrophication. In this respect, the enforcing reduction of nitrogen in the final effluent of wastewater treatment facilities is needed. On the other hand, to enact more stringent nitrogen regulations, the LOT (limit of technology) and environmental impact should be considered. In this study nitrogen data were analyzed to propose new nitrogen regulations.

• Membrane and Water Treatment
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• 제8권5호
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• pp.449-462
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• 2017

Direct treatment of municipal wastewater by forward osmosis (FO) process was evaluated in terms of water flux decline, reverse salt diffusion, pollutants rejection and concentration efficiency by using synthetic seawater as the draw solution. It was found that when operating in PRO mode (active layer facing the draw solution), although the FO membrane exhibited higher osmotic water flux, more severe flux decline and reverse salt diffusion was also observed due to the more severe fouling of pollutants in the membrane support layer and accompanied fouling enhanced concentration polarization. In addition, although the water flux decline was shown to be lower for the FO mode (active layer facing the feed solution), irreversible membrane fouling was identified in both PRO and FO modes as the water flux cannot be restored to the initial value by physical flushing, highlighting the necessity of chemical cleaning in long-term operation. During the 7 cycles of filtration conducted in the experiments, the FO membrane exhibited considerably high rejection for TOC, COD, TP and $NH_4{^+}-N$ present in the wastewater. By optimizing the volume ratio of seawater draw solution/wastewater feed solution, a concentration factor of 3.1 and 3.7 was obtained for the FO and PRO modes, respectively. The results demonstrated the validity of the FO process for direct treatment of municipal wastewater by using seawater as the draw solution, while facilitating the subsequent utilization of concentrated wastewater for bioenergy production, which may have special implications for the coastline areas.

• 한국환경성돌연변이발암원학회지
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• 제25권1호
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• pp.32-39
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• 2005

In order to identify potential biomarkers of environmental monitoring, we evaluated heat shock genes expressions as effects of various environmental pollutants (nonylphenol, bisphenol-A, 17a­ethynyl estradiol, bis(2-ethylhexyl)phthalate, endosulfan, paraquat dichloride, chloropyriphos, fenitrothion, cadmium chloride, lead nitrate, potassium dichromate, benzo[a]pyrene and carbon tetrachloride) on larvae of aquatic midge Chironomus tentans (Diptera, Chironomidae). Heat shock protein 70 gene expression increased in most of chemicals treated larvae compared to control. The response was rapid and sensitive to low chemical concentrations but not stressor specific. In conjunction with stressor specific biomarkers, heat shock protein 70 gene expression in Chironomus might be developed for assessing exposure to environmental stressors in the fresh water ecosystem. Considering the potential of Chironomus larvae as biomonitoring species, heat shock gene expression has a considerable potential as a sensitive biomarker for environmental monitoring in Chironomus.