• 해양환경안전학회지
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• 제3권1호
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• pp.99-109
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• 1997

The in situ observations and the seawater analyses were conducted in July and August, 1996 for the purpose of describing the characteristics of organic pollution, dissolved oxygen distributions, and the evaluation of water quality in Mokpo harbour. The vertical density distribution of water column was found to be in stable structure with higher water temperature and lower salinity on surface layer at ebb tide in summer. In July, dissolved oxygen was shown to be oversaturated on surface and bottom layers, while in August, which was shown to be oversaturated on surface layer, and to be unsaturated on bottom layer as 68∼93% of saturation percentage. Dissolved oxygen of bottom layer in August was evaluated to be under the regular grades, based on Korean standards of seawater quality. In view of COD, the seawater quality of Mokpo harbour in summer was evaluated to be deteriorated due to organic wastes and graded to be the third class, and TSS of Mokpo harbour in summer was graded to be the second class, based on Korean standards of seawater quality. In particular, COD of surface layer in August was found to be under the regular grades. It is, therefore, necessary to take measures for the control of pollution loads and the proper management of seawater quality in Mokpo harbour. The distribution patterns of DO, COD, VSS and Chlorophyll-a on surface layer along the downstream center line from inner harbour to harbour entrance were similar to one another at ebb tide in August.

• 한국수자원학회논문집
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• 제43권7호
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• pp.625-633
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• 2010

수자원개발의 한계와 수질의 오염으로 인해 제한된 수자원을 효율적으로 이용하고 수질을 보전하기 위한 통합수자원관리가 절실히 요구되는 상황이다. 최근 이를 위해 수자원을 통합적으로 평가하여 계획의 수립을 지원할 수 있는 통합수자원평가계획모형(K-WEAP)을 개발하였다. 본 연구에서는 3가지 부문에서 K-WEAP의 적용성을 평가하였다. 첫째는 수자원장기종합계획에 적용한 K-WEAP의 물 수급 전망 과정과 분석결과를 통하여 수자원 계획의 도구로서 K-WEAP의 유용성을 제시하였다. 둘째는 K-WEAP에서 제공하는 지표수-지하수 연계모의를 통해 보다 합리적이고 지속가능한 지하수이용 계획을 제시하였다. 마지막으로, K-WEAP의 수질모의 신뢰성을 평가하기 위하여 석화천을 대상으로 QUAL2E 모형의 결과와 비교하여 수량-수질 통합관리평가의 기능을 확인하였다.

• 한국농공학회논문집
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• 제56권6호
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• pp.85-91
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• 2014

In this study, the water quality purification of new medias which were NPS media, hyugato, mineral stone, charcoal for applying soil media of Integrated Management Practices (IMPs) of Low Impact Development (LID) were evaluated. The influent concentrations of COD, T-N, and T-P were 117.8 mg/L, 17.1 mg/L, and 2.062 mg/L, respectively. The infiltration capacities of NPS media, hyugoto, mineral stone, charcoal, and gravel were $7.1{\times}10m/s$, $7.3{\times}10^{-5}m/s$, $7.9{\times}10^{-5}m/s$, $6.0{\times}10^{-5}m/s$, respectively. All media meet criteria of infiltration capacity as surface soil layer at IMPs which is over $1.0{\times}10^{-5}m/s$. Maximum removal rates of COD, T-N, and T-P occurred at Charcoal with 98 % of COD removal rate, NPS with 78 % of T-N removal rate, and hyugato with 75 % fo T-P removal rate, respectively. For more high removal efficiency of all water quality item, the mixed media which is 4.5(NPS media): 1(charcoal) : 4.5 (hyugato) as volume ratio was evaluated. The infiltration capacity of mixed media was $7.9{\times}10^{-5}m/s$ and met the criteria of infiltration as surface soil layer. The water quality removal efficiencies of mixed media were very high with showing 70 % for COD, 85 % for T-N, and 71 % for T-P. The mixed media could purify the water quality of surface runoff and was recommended to used at the LID site of ground water quality problem.

• 한국물환경학회지
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• 제22권3호
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• pp.456-461
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• 2006

The facility of constructed wet land combined with filter media was examined in order to improve the water quality of a polluted stream, which has been performed as a part of national projects. Throughout 2 years of operation for a stream, it can provide the design and operating parameters for the purpose of future construction. The influent flow rate was about 50% against the design capacity. The removal efficiencies of BOD, $COD_{Mn}$, SS, T-N and T-P were 62.9%, 47.1%, 74.8%, 22.4% and 33.5%, respectively. In order to keep this facility stable, the removal of surface filter media and supplement should be periodically conducted. In addition, the proper selection of sites is recommended not to be flooded.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.412-416
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• 2001

Among water quality models, WASP5 was applied to Boryeong freshwater lake, as a part of Water Quality Management System. The WASP modeling system is a generalized modeling framework for contaminant fate and transport in surface waters. The simulated result was compaired with actual measurement. So, before and after making freshwater lake were compaired. After this research, the lake may have eutrophication and water quality would be worse after making the lake as freshwater lake. Therefore, to make the freshwater lake better, more appropriate plan is necessary.

• 한국농공학회논문집
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• 제66권2호
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• pp.25-34
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• 2024

The long-term monitoring of the Soyang Lake's water quality, covering 25% of the North Han River watershed, is crucial for effective management of both lake water quality and pollution sources in the broader region. This study utilized continuous monitoring data from the front of the Soyang Dam spanning 2003 to 2022, aiming to analyze trends and provide foundational insights for water quality management. Results revealed a slightly poor grade (IV) for total nitrogen (T-N) in both surface and mid-depth layers, indicating a need for concentrated T-N management. Trend analyses using the Mann-Kendall test and Sen's Slope depicted a decreasing trend in total phosphorus (T-P) for both layers, attributed to non-point source pollution reduction projects initiated after the Soyang Lake's designation as a pollution control area in 2007. The LOWESS analysis showed a T-P increase until 2006, followed by a decrease, influenced by the impact of Typhoon Ewiniar in that year. This 20-year overview establishes a comprehensive understanding of the Soyang Lake's water quality and trends, allowing for a seasonal and periodical analysis of water quality changes. The findings underscore the importance of continued monitoring and management strategies to address evolving water quality issues in the Soyang Lake over time.

• 품질경영학회지
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• 제47권3호
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• pp.425-435
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• 2019

Purpose: The purpose of this study was to resolve the Naval ship's Local Operation Panel(LOP) malfunction problems which caused by overheating in summer season and dispatching to equatorial regions. Methods: Instead of using dual type heat insulation materials(consist with ceramic wool and glass wool), aerogel heat insulation materials were used for decreasing heat emissions from gas-turbine heat waste steam pipes passing water-jet- room. Experiment and Computational analysis of heat flow were conducted to analyze the internal room temperature changes. Results: The results of this study are as follows; The aerogel heat insulation materials suppress heat emission more efficiently than dual type insulation materials. The cold surface temperature of insulation was far more decreased and internal room, LOP surface temperature also showed significant results too. Conclusion: The substituted heat insulation materials appeared remarkable performance in decreasing room temperature that it could be used for suppressing the LOP overheatings and malfunctions.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.599-602
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• 2003

The objective of this study is to analyze the function of the paddy-field in purifying water quality. This study was carried out is based on the data in the six case studies. To improve purification function of paddy field, the following farming management is required. 1) A guideline to control the inlet and outlet of the paddy plot is need to minimize drainage water by means of a reasonable irrigation management. 2) A guideline for fertilizer application in consideration of loading nutrients dissolved in irrigation water. 3) The reuse system of agricultural drainage water is required to minimize impacts on water quality of surface water(reservoir and river).

• 대한안전경영과학회지
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• 제5권1호
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• pp.115-128
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• 2003

To comparison the surface treatment methods of stone board materials, the results of Dorry's abrasive test were 23.4 for water-jet system and 18.9 for flame-burner system. Therefore abrasive hardness, the stone board materials by the water-jet system was greater than one by flame-jet system. As a result of Shore's hardness test, the stone board materials by water-jet system was twice greater than one by flame-jet system. Authors carried out microscopic observation to survey a defection of the composition minerals for two methods, but all of the both methods have not founded a defection. Therefore, the stone board materials by water-jet system was greater durability than one by flame-jet for the surface treatment methods.

• 대한안전경영과학회지
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• 제4권3호
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• pp.177-187
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• 2002

The contamination problem is getting worse now a day because of the industrial activities. Recently it has been announced that there's environmental hormone in river and lake which produces clean water, also there's too many of algae reproduces under the water and some virus in the drinking water. The quality of water is very important. pure and clean water is not only a precondition for human being to live but a basic factor to improve the quality of life. so a water purification system must be developed. This study is about the surface washing treatment technique. We tried to use a rotary nozzle to get a tush degree of efficiency, for it was not enough with present way of washing. The nozzle is run by water pressure. The results of the experiment are as follows. We got a clean and equal surface after washing. After washing, the water's maximum consistency was 330NTU and it shows that this way is better than before one with 215NTU. Clean level of the filter was 6$^{\circ}$and it's 2.8 times higher than 17$^{\circ}$with the old way. We can see the results that the new way of washing is more effective than old way based on this study.