• Journal of environmental and Sanitary engineering
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• v.10 no.1
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• pp.106-125
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• 1995

Recently, in accordance with elevation of life style and economics, the public demand became increasingly concerned about drinking water quality. Without an adequate supply of safe water, healthy and comfortable life could not exist. Therefore, the purpose of this study is to provide the guidelines and the basic informations to enable supply of clean, tasty and healthy drinking water acceptable for various demands. We analyzed the quality of tap water, mineral water, purified tap water using home tap water purifier. And we researched on the sense of the public complaint over the tap water. We proposed several items relating to the comfortableness of water quality and the target value. Also we presented a case of water supply system for purity and the points at problem The items and target value are as follows 1. turbidity : not more than 1 degree 2. dry residue : $30~200{\;}mg/{\ell}$ 3. hardness : $10~100mg/{\ell}$ 4. free carbon dioxide : not more than $20mg/{\ell}$ 5. $KMnO_{4}$ consumption not more than $3mg/{\ell}$ 6. odor threshold not abnormal 7. residual chlorine : not more than $0.4mg/{\ell}$ 8. water temperature' not more than $20^{\circ}C$ 9. manganese : not more than $0.01mg/{\ell}$ 10. iron : not more than $0.02mg/{\ell}$ 11. aluminum : not more than $0.1mg/{\ell}$

• Journal of Hydrogen and New Energy
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• v.33 no.6
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• pp.623-635
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• 2022

As global warming accelerates, clean hydrogen production becomes more important to mitigate it. However, importing hydrogen is necessary for countries that have high energy demands but insufficient resources to produce clean hydrogen. In line with the trend, this study investigated both the economic and environmental viability of an overseas hydrogen supply chain between Australia and the Republic of Korea. Several possible methods of water electrolysis and hydrogen carriers are compared and effect of renewable electricity price on the cost of hydrogen production is evaluated.

• Journal of Hydrogen and New Energy
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• v.31 no.6
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• pp.596-604
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• 2020

Solid oxide electrolysis cell (SOEC) attracts much attention because of its high energy efficiency among many water-electrolysis technologies. SOEC operates at temperatures above 700℃, so that the water required for water-electrolysis must be supplied in the form of steam. When the steam to be supplied to the SOEC is generated by the SOEC system itself, an enormous amount of latent heat is required to vaporize the water, so additional energy must be supplied to the SOEC system. On the other hand, if the steam can be supplied from the outside, a small amount of energy is required to raise the temperature of the low temperature steam, so that the SOEC system can be operated without additional energy supply from outside, which enables efficient water-electrolysis. In this study, we figure out the size of heat exchanger for various steam temperature and effectiveness of heat exchanger, and propose the energy efficiency of the system.

• Environmental Engineering Research
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• v.20 no.3
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• pp.230-236
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• 2015

26 multi-regional water treatment plants (WTPs) were investigated, to determine the characteristics of manganese (Mn) concentration and removal in Korea. Mn concentrations of raw water in most WTPs were higher than the drinking water standard (i.e., 0.05 mg/L); thus, proper removal of Mn at the WTPs is needed. Mn concentration was generally higher in lakes than rivers due to seasonal lake turnovers. The Mn concentrations of treated water at 26 WTPs in 2012 were less than 0.05 mg/L, due to strict law enforcement and water treatment processes optimization. However, before 2010, those concentrations were more than 0.05 mg/L, which could have led to an accumulation of Mn oxides in the distribution system. This could be one of the main reasons for black water occurrence. Therefore, regular monitoring of Mn concentration in the distribution system, flushing, and proper Mn removal at WTPs are needed, to supply clean and palatable tap water.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.515-520
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• 2005

The objective of the study is to assess the water quality improvement resulted from the rearrangement of the irrigation water supply systems at Mankyeong River and Ansung Chun basin. There is a mixed type of watershed composed of urban and rural areas in the region. From the water quality analysis, showed high T-N, T-P concentration in Ansung chun and Mankyeong river caused by paddies separated widely around Ansung chun and Mankyeong river and by runoff of the pollution from the Ansung and Jeonju city. but the upstream of the river showed clean water quality, so if we use the upstream water as river maintenance water for water quality improvement, it is expected to be positive effect for rural environmental aspect.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.4
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• pp.511-517
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• 2015

Korea's modern waterworks began with construction of DDukdo water treatment plant in 1908 and has been growing rapidly along with the country's economic development. As a result, water supply rates have reached 98.5% based on 2013. Despite multilateral efforts for high-quality water supply, such as introduction of advanced water treatment process, expansion of waterworks infrastructure and so on, distrust for drinking tap water has been continuing and domestic consumption rate of tap water is in around 5% level and extremely poor comparing to advanced countries such as the United States(56%), Japan(52%), etc. Recently, the water management has been facing the new phase due to water environmental degradation caused by climate change, aging facilities, etc. Therefore, K-water has converted water management paradigm from the "clean and safe water" to the "healthy water" and been pushing the Smart Water City(SWC) Pilot Project in order to develop and spread new water supply models for consumers to believe and drink tap water through systematic water quality and quantity management combining ICT in the whole water supply process. The SWC pilot projects in Pa-ju city and Go-ryeong county were an opportunity to check the likelihood of the "smart water management" as the answer to future water management. It is needed to examine the necessity of smart water management introduction and nationwide SWC expansion in order to improve water welfare for people and resolve domestic & foreign water problems.

• Asian Journal of Business Environment
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• v.10 no.4
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• pp.29-34
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• 2020

Purpose: Town of Woldia, a semi-arid region in the Northern Wollo region of Ethiopia, faces water supply shortage in general, though the town possesses a running stream of clean water throughout the year. This study is aimed at analyzing the possibility of using rainwater for water scarcity and non-potable water needs of the Woldia University. A careful study and analysis have been made to assess the feasibility of using rainwater in place of the tap water supply. Research design and methodology: This study was done inside the main campus of Woldia University located in Woldia town. The runoff water from the roof of buildings was studied, by the time of rainfall in the town. Also, the budget needed for implementing a rainwater harvesting system was calculated. Results: The findings of the study clearly indicates that the requirements of the water to use for flushing, cleaning, and washing toilets in the administrative buildings and classrooms can be satisfied by using rainwater as an alternative to tap water. Conclusion: Based on the results the study finds it is benefitable for the Woldia University to install the rainwater harvesting system at the earliest to solve the water problems prevailing in the current situation.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.5
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• pp.533-543
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• 2016

Supplying clean and safe water to people is facing both quantitative and qualitative challenges. Due to climate change, access to freshwater becomes increasingly difficult, while pollution from various sources decreases the public trust in water quality. Managed aquifer recharge (MAR) which stores and uses surface water in aquifer is receiving attention as a new technology to secure freshwater. Recently, there is a global expansion in the attempt to combine general purification plants and hazard analysis and critical control point (HACCP) which manages all the process from raw material to consumer for food safety. This research is about an attempt to apply HACCP to the drinking water supply process using MAR to secure both quantity and quality of drinking water. The study site is a MAR plant being constructed in the downstream area of the Nakdong River Basin, South Korea. The incorporation of HACCP with MAR-based water supply system is expected to enhance the safety and reliability of drinking water.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1207-1213
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• 2007

This paper has researched water supply facilities management using real-time water utility monitoring system based on USN(Ubiquitous Sensor Network) which is consisted of wireless sensors transferring waterworks facilities md treatment information about a valve-room and flowmeter-room of water supply installation. In the manholes, it was installed with flowmeter, pressure sensors, vibration sensors, Co-sensors, and hydro-thermograph sensors. These measurement values which are received by PDA are used for facilities operation on the spot safely and conveniently. It has also provided safe installation management via CDMA(Code Division Multiple Access) network which transfers data to remote servers to monitoring at a distance place. With safety management system of water supply facilities on USN technology convenience and safety is increased in real situation, and it is expected that we can supply clean water to people as much safer and more effective water supply installation management.

• Journal of Korean Public Health Nursing
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• v.10 no.1
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• pp.31-38
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• 1996

Disinfection is a very important process in water plant on account of our surface water usage. Particularly. the rainfall of Korea is concentrated in summer time. it is almost carried away to ocean before our utilization as water resource. To overcome the unbalance of water resource, artificial dams and reservoirs are constructed. According to such storage of water to aggravate water pollution and make the increase of water cleaning chemicals. Chlorine, as a main traditional chemical for water treatment. is focused on account of THMS formation in recent days. In this paper. the data of a water plant located in Seoul is adopted as the foundation of water quality analysis and introduce the substitute chemicals to supplement the harmful formation. additionally. Conclusions are summarized as follows: 1. The water quality of water resource is the worst in summer time and the supply of cleaning chemical is inevitably increased on account of general bacteria increase. 2. Chlorine, as a main chemical for water cleaning, formed the cancer-causing organic THMS with water molecules. 3. One of substitute chemical. chlorine dioxids suppress the formation of THMS comparing with the case of chlorine only. Therefore. the continuous research of substitute chemicals should be activated. 4. As the supply of disinfected clean water concerned with the citizen sanitary, the cultivation of professionals and academic conference must be needed on the basis of nation