• Journal of Environmental Science International
• /
• v.16 no.2
• /
• pp.227-232
• /
• 2007

Water pollution in enclosed water bodies such as lake and river has become a serious problem over the world. Domestic wastewater is responsible for more than 60 % pollution load in public water area in Korea. Effluent of the treated domestic wastewater at low removal level is abundantly fed rivers and lakes and thus be an serious cause of lake pollution. Therefore, effective implement of domestic wastewater treatment in basin of lake and river must be prepared. The septic tank is one of the effective domestic wastewater treatment equipment and used in individual treatment for a unit of household, The purpose of septic tank as biological treatment system is simultaneously to remove BOD, T-N, T-P and reduce turbidity from influent. Accordingly, the appropriate control of functional microorganisms is important subject for the establishment of stability and economy of the biological treatment method. Especially, microanimals as a high-ranked microorganisms of food-chain are important, because microanimals control the other microorganisms especially various bacteria and effect on function of treatment. Therefore, it is necessary that functional predator like rotifers are attached in wastewater treatment process. In this study, the methods for attachment high density the rotifer to and improvement of transparency in the effluence by a dense rotifer was examined using laboratory scale biological treatment reactor simulated septic tank and real one.

• The Korean Journal of Food And Nutrition
• /
• v.21 no.4
• /
• pp.592-598
• /
• 2008

Deep sea water is found more than 200 m under the surface. As no sunlight reaches, no photosynthesis takes place, and it has very little organic matter or bacteria. In addition, deep sea water maintains a consistently low temperature throughout the year, and it does not mix with the water found closer to the surface, which means that its cleanliness is preserved. It is a long-term mature sea water resource that is rich in minerals. This paper examined the physical characteristics and the uses of deep sea water, a subject that has been attracting a great deal of public attention recently, together with the current status of domestic research into it and the direction of research in the USA and Japan, focusing on the existing literature. The aim of this paper was to provide are source to researchers in the field. Since the 1970s, scientists around the world have recognized the importance of deep sea water, and have been conducting research into it. In the USA, deep sea water has been researched with the view of its application to cooling, alternative energy, farming, and the development of new materials. In Japan, about 10 local self-governing bodies are currently promoting research and business relating to deep sea water, which has resulted in a number of products that have been released to the market. In Korea, the ministry of land transport and marine affairs has been studying deep sea water since 2000, and full-scale national R&D projects have been performed by 24 organizations, including KORDI, through industrial/academic cooperation. Large companies are participating in deep sea water research projects in several ways. A study of data foundusing NDSL relating to domestic studies of deep sea water found 50 theses, 177 domestic patents, 6 analyses, 2 reports, and 2 etc. in other areas.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.144-144
• /
• 2021

The rapid urbanization in many Asian countries has taken millions of people from the rural countryside to concentrated megacities, which eventually putting pressure on the existing water resources. The over-growing population and increasing living standard of people in the urban region of developed as well as developing countries such as Korea, China, Japan and India have witnessed a drastic change in terms of domestic water demand for the past few decades. In this study, we used the concept of potential surface water availability in the form of surface runoff for future vulnerability assessment. We focused on 42 megacities having population more than 5 million as per the United Nations (UN) census data 2020. The study shows that 30 out of 42 cities having more than 180L/p/d demand for domestic use based on various references. We have predicted the domestic water demand for all the cities on the basis of current per capita demand up to 2035 using UN projected population data. We found that the projected water demand in megacities such as Seoul, Busan, Shanghai, Ghuanzou are increasing because of high population as well as GDP growth rate. On the contrary, megacities of Japan considered in our stud shows less water demand in future due to decreasing trend of population. As per the past records provided by the local municipalities/authorities, we projected different scenarios based on the future supply for various megacities such as Chennai, Delhi, Karachi, Mumbai, Shanghai, Wuhan, etc. We found that the supply to demand ratio of these cities would be below 75% for future period and if such trend continues then the inhabitants will face serious water stress conditions. Outcomes of this study would help the local policy makers to adopt sustainable initiatives on urban water governance to avoid the severe water stress conditions in the vulnerable megacities.

• Journal of Korean Society of Water and Wastewater
• /
• v.12 no.3
• /
• pp.41-47
• /
• 1998

Doam Lake is located around the pasture area and Yongpyung Resort. Because of the waste load of domestic animals, nutrient concentration of the stream is high. In this study, waste load of Doam Lake watershed is calculated, and QUAL2E model is applied to the upper part of the Songcheon to calculate the input boundary concentration of Doam Lake. And WASP5 model is applied for the water quality modeling of Doam lake. The results indicate that advanced treatment of domestic animal wastes is necessary for the lake water quality management.

• Journal of the Korean Society of Industry Convergence
• /
• v.6 no.3
• /
• pp.231-238
• /
• 2003

An experimental study was performed to improve a domestic hot water boiler with a coil type heat exchanger. By using Korean Standard B 8107, B 8021 and B 6205, the boiler efficiency for heating, bathing and combution are calculated. Finally, the efficiency of the boiler are compared with those of the commercial production. On the whole, the performance of the hot water generator is higher than that of the other generator.

• Proceedings of KOSOMES biannual meeting
• /
• 2005.11a
• /
• pp.171-184
• /
• 2005

As recently, ' International convention for the control and management of ship's ballast water and sediments ' was adopted, it is necessary to accept the international convention in Korea. The systems of foreign countries for ship's ballast water control and management were investigated, and domestic environment-related laws were reviewed and compared regarding the discharge of industrial wastewater and ship's ballast water. Alternative measures of domestic legislation were suggested for acceptance of the international convention.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.11 no.2 s.23
• /
• pp.83-96
• /
• 2005

As recently, 'International convention for the control and management of ship's ballast water and sediments' was adopted, it is necessary to accept the international convention in Korea The movements of foreign countries for ship's ballast water control and management were investigated, and domestic environment-related laws were reviewed and compared regarding the discharge of industrial wastewater and ship's ballast water. Alternative measures of domestic legislation were suggested for acceptance of the international convention.

• Transactions of the Korean hydrogen and new energy society
• /
• v.22 no.4
• /
• pp.559-567
• /
• 2011

This paper deals with an economic evaluation of domestic low-temperature water electrolysis hydrogen production. We evaluate the economic feasibility of on-site hydrogen fueling stations with the hydrogen production capacity of 30 $Nm^3/hr$ by the alkaline and the polymer electrolyte membrane water electrolysis. The hydrogen production prices of the alkaline water electrolysis, the polymer electrolyte membrane water electrolysis, and the steam methane reforming hydrogen fueling stations with the hydrogen production capacity of 30 $Nm^3/hr$ were estimated as 18,403 $won/kgH_2$, 22,945 $won/kgH_2$, 21,412 $won/kgH_2$, respectively. Domestic alkaline water electrolysis hydrogen production is evaluated as economical for small on-site hydrogen fueling stations, and we need to further study the economic evaluation of low-temperature water electrolysis hydrogen production for medium and large scale on-site hydrogen fueling stations.

• 한국연소학회:학술대회논문집
• /
• 2000.05a
• /
• pp.93-104
• /
• 2000

Rivers of our country are in the serious state of water pollution because of sewages, factory wastes, domestic animal excreta, and so forth. The development of waste water treatment technology applied in a small-scaled farm is urgent because the government regulation becomes strict. In the present study, four types of solid fuels are made by blending domestic animal excreta, rice hulls and briquets, and its combustion characteristics is investigated by analyzing burning pictures. Domestic animal excreta sampled from a farm in Kimhae was dried with sunlight. From experimental results, it is shown that combustion characteristics of solid fuels becomes better by blending rice hulls which have superior ignitability. Since solid fuel made by blending domestic animal excreta with rice hulls can bum continuously, it can be appropriate for the heating fuels.

• Water for future
• /
• v.29 no.4
• /
• pp.223-231
• /
• 1996

For the most efficient operation of water mains, 124 head losses in domestic water supply steel mains were measured to provide the values of friction coefficient and the variable affecting the deterioration rate of Hazen Williams' and Darcy-Weisbach's friction coefficient. The experimental results show that pipe age is governing the friction coefficient of large mains (Diameter > 1100 mm). On the other hands, pipe age and pipe diameter are affecting the variation of carrying capacity for small mains (Diameter < 1100 mm). The friction coefficient of water mains in foreign countries is higher than that in Korea by about 5 to 10 in Hazen Williams' C value. The growing rate of roughness height of domestic water main is about 0.41 mm/year which is higher than the average of United States of America. So further study is required to find out what causes the serious deterioration rate.