• Journal of Environmental Science International
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• v.19 no.1
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• pp.9-16
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• 2010

This pilot study evaluated fueling feasibility of sewage sludge, which contains a large amount of water content, by applying melting of thermoplastic polyethylene (PE). This study has identified a simultaneous achievement of drying and heating value improvement of the sewage sludge. The sewage sludge collected from a sewage sludge treatment plant during a winter period had a water content of 83.7 wt%, a combustible volatile content of 12.5 wt%, and an ash content of 3.8 wt%. The higher heating value (HHV) of the dried sewage sludge, before impregnation or coating of PE, was 4,600 kcal/kg. The collected sewage sludge was immersed into the melted PE solution, which had a HHV of 11,070 kcal/kg, and kept immersing with increasing reaction time. As the reaction (immersing or coating or impregnation) time increased, the water content of the sludge decreased. However, the HHV of the sludge increased with increasing the reaction time. The HHVs of the sewage sludge immersed or dipped into the melted PE solution for 15 min ranged from 6,780 to 8,170 kcal/kg with water content less than 7 wt%. This result indicates the melted PE solution can be utilized as an improvement technology for dryness and heating value of the sewage sludge with high water content. The sewage sludge impregnated or coated with melted PE can be utilized as potential fuel or energy resources.

• Journal of Environmental Science International
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• v.18 no.2
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• pp.187-195
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• 2009

This study was investigated to control the corrosion and scale at the cooling water system in steel works. Laboratory and field tests were performed for the indirect cooling water system of plate mill. Throughout the experiment, various factors such as leakage of pipes, heating rate and capacity, and the reaction between existing and substitute inhibitors were carefully monitored. The results showed that the harmful effect of high temperature could be minimized, and satisfactory corrosion/scale controls were effectively achieved using inhibitor, even at the increased temperature of $80^{\circ}C$. The batch and field tests in the gas scrubbing cooling water system of blast furnace and cooling water system of corex plant indicated that the new inhibitor was more effective for the prevention of corrosion and scale than the existing one.

• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.241-244
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• 2004

Radiation treatment with gamma-rays and electron-beams was used to remove polyvinyl alcohol(PVA), one of the main components of dyeing wastewater. PVA was effectively decomposed by radiation treatment, thus the removal was near 100 % at an initial PVA concentration of 44 mg/L. However, total organic carbon(TOC) removal was less than 5 % due to lower transformation of PVA to $CO_2$. This directly indicates the radiation treatment alone is not appropriate for the complete decomposition of PVA. In this sense, the improvement of biodegradability($BOD_5/COD$) of PVA by radiation treatment was studied. Both gamma-ray and electron-beam treatments significantly increased the biodegradability of PVA by transforming non-biodegradable PVA to biodegradable by-products. This suggests radiation treatment, especially electron-beam treatment that showed better improvement of biodegradability, can be used as a pre-treatment of biological degradation process of PVA.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2004.05a
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• pp.45-45
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• 2004

• Journal of Korea Water Resources Association
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• v.45 no.9
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• pp.929-941
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• 2012

In recent years, interest in river environment such as riparian landscape, water quality and ecological conservation has been growing with increasing recreation on agricultural river watershed. That caused the increase of necessity of water resources development, one of solutions for the diversification of agricultural water demand and shortages. In this respects, heightening irrigation dam, as a part of the 4-major river restoration project, is necessary to secure not only additional agricultural water but also instream flow for water quality improvement. However, operation plan of irrigation dam still not be clear. In this study, additional storage which secured through heightening irrigation dam was estimated using SWAT model. And instream flow effects on water quality of downstream were evaluated. The findings show that the additional water supply will contribute positively to water quantity and quality of downstream. The results show a 2~10% water quality improvement effect on nutrients, as well as an 1~8% water quantity increasing effect. In particular, additional storage can be effectively supplied from February to April by the reservoir operation. However, maintaining better water quality in irrigation reservoirs is important because the water quality of irrigation reservoirs can be negatively impacts the water quality in downstream of reservoirs.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.5
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• pp.1-17
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• 2013

We researched the fauna restoration of 5 urban streams in Ulsan established as ecological streams by improving water quality and river environment. The fauna inhabitation were compared according to the conditions of geometrical feature such as river width, low-water channel width, ect and water quality, water volumn, inland and forceland. The Mugeo cheon has clearly shown the fauna restoration effects resulting from supplying sustainable maintenance water and wastewater treatments. In the Yaksa cheon, on the other hand, the restoration effects were low due to the inflow of wastewater and sledges in some part of stream ever though the improvement of water quality. The Yeocheon cheon was found to have disadvantage on the ecological inhabitations due to supplying the maintenance water with highly concentrated salinity. The fauna restoration effect of the Meongjeong cheon was low due to the inflow of wastewater to the down stream. Therefore by supplying the maintenance water and improving the connection to the Taehwa river at the estuary, better restoration effects could be observed. In the Cheokgwa cheon, which is almost a natural river, the ecological integrity of the fauna population has been maintained quite well. It was concluded that the project to transform urban streams into ecological streams should focus on not only keeping water volume and quality but also maintaining favorable conditions for the migration and settlement of animal species close to the natural state.

• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.397-408
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• 2013

The purpose of this study is to analyze water cycle area ratio and spatial evaluation of water cycle in urban area of Changwon-si, Gyeongsangnam-do. Water cycle area ratio are analyzed by using spatial data of land-cover and land-use, and Hot spot analysis of GIS program was used for spatial evaluation of water cycle. The results are as below. Firstly, the high water cycle area ratio areas were forests, parks, and rivers, but urban areas covered asphalt and concrete were low under 40%. Public institutions and co-residential of urban areas were higher than others because of high area ratio of pervious land-cover. Spatial evaluation of water cycle was analyzed to vulnerable areas there are dense residential and commercial area. These areas are really occurring frequently flooding and immersion, therefore, is required water management facilities and improvement of land-cover from impervious to pervious. In the future, it will require additionally analysis of water cycle area ratio supplemented data of water management facility and ground water.

• Journal of Environmental Science International
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• v.33 no.1
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• pp.9-16
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• 2024

This study analyzed a survey of residents' awareness of rivers and water spaces that reflected residents' awareness in order to establish a basic park green space plan. Through this, the perception and requirements of rivers and water spaces were analyzed and important information was provided for urban planning and environmental management. As a result of analyzing residents' neutral satisfaction with rivers and their opinions on the frequency of use, role, and purpose, it was confirmed that rivers are recognized as an important part of urban life and contain the potential for development for a better urban environment. . However, considering the dissatisfied response and the relatively low frequency of use, we came to the conclusion that better urban planning and management is needed to meet the needs of residents by improving the river environment and providing various facilities. Based on this, city managers should focus on river management and improvement by actively collecting residents' opinions. Through analysis of the causes of dissatisfied responses, measures such as improving the environment around rivers and waste management should be prepared, and a broad strategy for environmental conservation and utilization should be established by reflecting the diverse expectations and demands of residents. These ongoing efforts are expected to have a positive impact on the sustainability of the city and improvement of residents' quality of life. Additionally, the results of this study will be able to contribute to establishing policies for urban planning and environmental improvement through similar research and analysis in other regions.

• Hwankyungkyoyuk
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• v.13 no.2
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• pp.74-90
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• 2000

The environmental quality in Korea was significantly deteriorated though the past economic development period. Even though the government has spent huge sum of resources on the policies and projects to improve the environmental quality, it is much removed from what the people hope for. To solve the environmental problems effectively, pollutants generated at source should be kept as minimum as possible, and possible, and pollutants from source be controlled before leaving the sources, and most of all, environmental strategies and systems be established and enforced properly. So, it is not too much to say that nation's environmental quality is entirely dependent on the education and training of the environmental managers such as environmental employees for air, water, and noise discharge facilities, technicians at environmental plants, and environmental officers of central and local governments. Regimes for the improvement of the education and training for environmental managers are suggested into four categories-educational institute, circular of the study, training contents and trainees. Referring to the improvement of integrated institute, and to improvement on educational institute, it is necessary to investigate the feasibility of integrated institute, and to recommend the inclusion of the local colleges and universities, and environmental societies. For the improvement on training courses, it is necessary that the non-obligatory course be expanded, and the courses be developed in such a way to meet the needs from the field. As for the improvement on training contents. It is suggested that the practical training on size be strengthened, and also full time environmental specialist and integrated committee be required to develop the effective circular and selection of proper lectures. Finally, environmental education for high ranked officers of autonomies, and international courses for developing countries are suggested.

• Journal of Environmental Impact Assessment
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• v.12 no.5
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• pp.359-367
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• 2003

The total pollution load management system of watershed has been implemented upon Special Law pertaining to the Han River Watershed Water Quality Improvement and Residents Support, Special Law pertaining to the Nakdong River Watershed Water Management and Residents Support, Special Law pertaining to the Youngsan River Watershed Water Management and Residents Support, and Special Law pertaining to the Seomjin River Watershed Water Management and Residents Support in Korea since 2002. But many other similar systems with total pollution load management system of watershed are being operated separately or independently, even though its purpose is nearly same with those of the total maximum pollutants load management in Law on Water Quality Environmental Protection, environmental impact assessment(EIA) in Law of Impact Assessment on Environment, Transportation and Disaster and Pre-environmental assessment of Environmental Policy Act. Therefore the contents of total pollution load management system of watershed and many other related systems could be overlapped and at some times have inconsistency among them. This study suggests first the integrated operation of total pollution load management system of watershed, EIA, pre-environmental assessment, urban planning, and sewage planning and secondly EIA system development by integration of EIA and pre-environmental assessment and strategic environmental assessment(SEA).