• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.61-65
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• 2003

Bottom ash among the coal ash is not used because of its poor properties. But encouraging the use of bottom ash as a construction material is a sensible method of utilization as it avoids the problems and costs associated with disposal and provides an alternative aggregate source. This study was aimed at using bottom ash as an alternative fine aggregate source to provide a solution to disposal and insufficient fine aggregate for the production of concrete. So properties of domestic bottom ash were estimated due to the difference of each domestic bottom ash. And compressive strength and durability were estimated as basic data to use bottom ash in building industries. As a result of the experiment, the very porous surface and angular shape of the bottom ash particles necessitate a higher apparent water-cement ratio. And due to the higher water requirement, the compressive strength and durability of mortar is lower than those of the control samples. But when 25 percent of the total dry weight of the natural fine aggregate was replaced by bottom ash, the engineering characteristics were similar.

• Journal of Environmental Impact Assessment
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• v.14 no.5
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• pp.337-346
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• 2005

Pollution load allocation can likely be much controversial, which is essential to formulate the total water pollution load management plan. Existing rules(or guidances) in Korea, can provide no specific criteria for load allocation. Therefore, this paper studied(comprehensively) possible standards how or why to choose any particular allocation method, which was applied in the Gwangju City's load allocation for the satisfaction of set water quality goal. This load allocation is basically focused on the load reduction of domestic wastewater rather than industrial wastewater, because the land-use is strictly regulated and larger sources of pollution are few in the Gwangju City. This paper recommends the city to increase the capacity of sewage treatment plants, promote sewerage maintenance, and set higher effluent standards.

• Journal of Korean Society on Water Environment
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• v.29 no.2
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• pp.276-287
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• 2013

Domestic sewage contains increasingly more pharmaceuticals and personal care products (PPCPs), due to rising use of medicines, health supplement food and daily necessities. And various types of industrial wastewater from pollution sources in treatment areas could flow into the public sewerage treatment plants (PSTPs) in metropolitan areas. The conventional PSTPs are designed to treat suspended solids, biodegradable organics, nitrogen and phosphorous from residential and industrial areas and public facilities. However, toxic, conventional, and non-coventional pollutants from non-domestic sources that discharge into sewer system as well as domestic source with various chemicals could not be treated in the conventional PSTPs and discharged untreated to public basin. In this paper we aim to consider the establishment system of effluent standard of PSTPs in comparison with water quality standard of water environment and wastewater discharge regulation. And also we suggest the necessity of regulations on the pretreatment of industrial wastewater as part of efforts to improve water quality in sewerage systems and to protect public basin.

• Journal of Korean Society on Water Environment
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• v.32 no.6
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• pp.570-581
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• 2016

A watershed model was constructed using the Hydrological Simulation Program Fortran to predict the water quality, especially chlorophyll-a concentraion, at major tributaries of the Nakdong River basin, Korea. The BOD export loads for each land use in HSPF model were estimated at $1.47{\sim}8.64kg/km^2/day$; these values were similar to the domestic monitoring export loads. The T-N and T-P export loads were estimated at $0.618{\sim}3.942kg/km^2/day$ and $0.047{\sim}0.246kg/km^2/day$, slightly less than the domestic monitoring data but within the range of foreign literature values. The model was calibrated at major tributaries for a three-year period (2008 to 2010). The deviation values ranged from -31.5~1.6% of chlorophyll-a, -24.0~2.2% of T-N, and -5.7~34.8% of T-P. The root mean square error (RMSE) ranged from 4.3~44.4 ug/L for chlorophyll-a, -0.6~1.5 mg/L for T-N, and 0.04~0.18 mg/L for T-P, which indicates good calibration results. The operational water quality forecasting results for chlorophyll-a presented in this study were in good agreement with measured data and had an accuracy similar with model calibration results.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.903-916
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• 2023

This study aims to establish basic data for efficient management of rural water by analyzing regional irrigation facilities and benefitted areas in the statistical yearbook of land and water development for agriculture at the watershed level. For 511 domestic rural water use areas, water storage facilities (reservoirs, pumping & drainage stations, intake weirs, infiltration galleries, and tube wells) are spatially distributed, and the benefitted areas provided at the city/county level are divided by water use area to provide agricultural water supply facilities. The characteristics of rural water district areas such as benefitted area, were analyzed by basin. The average area of Korea's 511 rural water districts is 19,638 ha. The average benefitted area by rural water district is 1,270 ha, with the Geum River basin at 2,220 ha and the Yeongsan River basin at 1,868 ha, which is larger than the overall average. The Han River basin at 807 ha, the Nakdong River basin at 1,121 ha, and the Seomjing River basin at 938 ha are smaller than the overall average. The results of this basic analysis are expected to be used to set the direction of various supply and demand management projects that take into account the rational and scientific use and distribution of rural water and the characteristics of water use areas by presenting a quantitative definition of Korea's agricultural water districts.

• Transactions of the Korean hydrogen and new energy society
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• v.13 no.4
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• pp.330-338
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• 2002

A long-term energy system in the future is expected to be based on the ideal circulation system between water and hydrogen in the sense that the hydrogen prepared from water eventually returns to water again after its use. Currently, with respect to the hydrogen energy system, it is predicted that the turning-point at which the production cost of hydrogen will become to be lower than that of fossil fuels would be after 2010. However, fuel cell technology would be able to be practically used for the applications to the transportation vehicles and small-scale power sources from 2004, and therefore, an efficient construction of the infrastructure covering hydrogen production and supply systems would be required with short-/mid-term technologies for the $CO_2$ reduction associated with fossil fuel utilization. In this paper, the hydrogen quantity available in domestic market has been estimated focusing on the hydrogen by-produced from domestic industries, and also the infrastructure for hydrogen-driven vehicles like fuel cell cars has been reviewed.

• Environmental Engineering Research
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• v.20 no.4
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• pp.403-409
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• 2015

This study aims to investigate the use of a floating media filter (FMF) to eliminate waterborne microorganism in treated domestic wastewater for reuse in agriculture. A conventional sand filter (SF) was used concurrently to compare treated water quality. The total/fecal coliforms and somatic coliphage were employed as fecal indicators. The result showed that the FMF was fed with 3 times higher infiltration rate ($15m^3/m^2.h$) than that in the SF ($5m^3/m^2.h$), in which both filters gave similar coliform removal at 6 hours operation. The somatic coliphage elimination tended to increase with operational time for the FMF while that of the SF showed decreasing trend. When a 24 hour continuous operation was applied for the FMF, it showed better removal of somatic coliphage (78%), fecal coliforms (60%) and total coliforms (56%) than that of 6 hour operation. In conclusion, the FMF gave better performance than the SF did by producing a good quality of treated water for agriculture in terms of waterborne microorganisms including turbidity and suspended solids.

• Journal of Korea Water Resources Association
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• v.35 no.6
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• pp.703-714
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• 2002

During drought, there have been a number of conflicts because of the limited and insufficient water to allocate for the numerous water users. To solve the problems, the decision on the priority of water use should be made with social rationality A rational and systematic procedure needs to be implemented in order to decide the priority of water use. First, a criteria level is made of the main and detailed drought impacts which come from the economic, environmental, and social aspects. Four alternatives are then identified for priority of water use. Second, survey to the two group(professional, residents) has been done with using pair wise comparisons. Finally, the relative weights and the priority of alternatives are determined by means of the Analytic Hierarchy Process(AHP) which is one of the Multi-Attributed Decision Method(MADM). By using AHP, it has been concluded that the water allocation during drought should be accomplished in order of domestic, irrigation, industrial, and river maintenance water. If the AHP method were improved for inconsistency which may be generated with survey analysis, a number of applications will be used for the solutions of problem in water resources systems.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.882-889
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• 2012

This study has evaluated the trophic state in Daecheong Lake by Carlson (1977) method, Aizaki (1981) method, Yang and dickman (1993) method, and Korean trophic state index method. For estimating the trophic state index from each analysis method we use water quality factors such as COD, TN, TP, Chl-a, and SD provided by the water information system and the ministry of environment. The seasonal lake trophic state results denote the mesotrophic state lake from Carlson (1977) method, Aizaki (1981) method, and Korean trophic state index method and the high relation between Carlson (1977) method and Aizaki (1981) method with the coefficient of determination $R^2$ greater than 0.9 for all the seasons. Although Korean trophic index method has relatively weak relation to other methods with the coefficient of determination $R^2$ ranging from 0.419 to 0.701, we propose that Korean trophic index method is suitable for use in domestic lakes since Korean trophic index results show the similar periodicity and tendency with other method results. Hence, Korean trophic index method incorporating domestic lake characteristics is expected to can contribute to seasonal water quality management measures in lakes.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1348-1351
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• 2006

Recently human beings face serious water crisis, namely water management at the critical moment because of rapid increasing in population, subordinate part of a national budget, water pollution by domestic use and industrial use or waste, agricultural water use by intensive market farming, excessive development and extraction of water sources, and etc. We become to recognize that water and sanitation is the one of most important part which is threatening us with a drain on the water resources and death around the world and then are making opportunities of discussion for water policies and solutions of water problems through international network such as Global Water Partnership(GWP), World Water council(WWC). World Water Forum(WWF), as one of main water-related activities, aims at sharing knowledge and experience among various stakeholders for accomplishing a holistic water resources management by making common thoughts regarding the necessity of integration among different organizations related with water management, problems and issues. Also the unity of each local area for the holistic approach focuses on showing present local actions and actively supporting them, and suggesting new ideas. With Korea's participation in the 4th WWF this year, Korean government should have consistency in its establishment and implementation of sustainable water resources policies as a more active and future-oriented member of international water network. Finally it will be necessary that we will set up an organization and system which does publicity activities about results of various local actions of Korea around the world through next WWF in the future and contribute to solving global water problems.