• 한국환경보건학회지
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• 제21권1호
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• pp.7-20
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• 1995

The aims of this study are to enhance the students' knowledge of the drinking water and its reliability by investigating drinking water situation on the drinking water. The results are as following 1. Status and drinking behavior about school drinking water (1) 97.82% of the schools are using the tap water as the resource of drinking water. (2) 46 schools are in possession of water tank and 18 schools of them are using the water tank as the resource of drinking water. The clearing and sanitization of the tank are carried out once in a year with hypochloronatrium by the low-level officials. (3) 51.28% of the schools are providing the students with drinking water and 75% of them with boiled water. The drinking water supply managers are low-level officials, nurse teachers, and dietitian. 2. Analysis of the drinking water quality (1) Most of the drinking water provided by the school are tap water 35.8%, barely tea 5.85%, filtered water 6.3%, ground water 1.1% and all turned out to be suitable for drinking. (2) The drinking water carried from home turned out to be unsuitable for drinking except pH criterion, especially the test of APC(Aerobic Plate Count) and Coliform group showed worse degree. These results were caused by the hygiene problem and maltreatment in water container.

• 한국물환경학회지
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• 제24권6호
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• pp.651-658
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• 2008

Estuary barrier is a hydraulic structure constructed to supply safely water as protecting chlorine penetration of sea water. However, the barrier brings about a problem which decreases original functions of estuary because hydraulic ecology was disrupted as obstructing natural water exchange between fresh water and sea water. It is important to supply Enough fresh water in the estuary ecosystem. But it is possible to reduce the problems brought from barrier throughout efficient water gate operation of estuary barrier. It was shown in this study that the environmental effect of estuary in Nakdong river was investigated according to the control of water level. Also, the basic information about the effective water gate operation was provided. The analysis results showed that the release rate of estuary was increased about 20% as changing the operational water levels. This helps supplying fresh water durably to the mixing zone. Also, CE-QUAL-W2 model was utilized to assess water quality. The values of BOD and COD were not changed in estuary area. From the result, it was analyzed the effect of water quality according to the water gate operation was not indicated.

• 한국물환경학회지
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• 제24권4호
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• pp.415-422
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• 2008

Drinking water treatment is enhanced by coagulant dosages and chlorine injection because of pH increase in raw water in droughty seasons such as spring and fall. But water quality deterioration is occurred by increase in residual aluminium and disinfection by-products. Coagulation process can be used to control natural organic matter (NOM) during water treatment. The effect of coagulation process appeared to depend on the pH of water rather than coagulant dosages. In this study, for water treatment in high pH season $H_2SO_4$ was applied for pH adjustment at full scale. Before and after pH adjustment by $H_2SO_4$ injection, water quality of drinking water was evaluate. In the result of investigation of total organic carbon (TOC) removal in high pH season, TOC was removed approximately 30~40%, which showed decrease in water treatment efficiency. Also, it is increased both particle numbers and residual Al concentration in the water. After $H_2SO_4$ injection for adjustment to pH<7.5 in settled water, treated water turbidity decreased in 0.047 NTU from 0.059 NTU, and particle numbers of filtered water decreased in 20/mL from 90/mL. On the other side, TOC removal efficiency increased in approximately 10% after adjustment of pH. In the result of decrease in pH in raw water through more coagulants and prechlorine without $H_2SO_4$ injection, trihalomethanes (THMs) concentration increased in $16{\mu}g/L$ from $8{\mu}g/L$.

• 한국물환경학회지
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• 제23권2호
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• pp.228-235
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• 2007

For efficient turbid water withdrawal in the Imha reservoir, a selective withdrawal facility was recently installed and operated during summer season of year 2006. In this research, CE-QUAL-W2 model was utilized to assess the efficiency of the selective withdrawal facility, in comparison with the original surface withdrawal, on turbid water management. Model calibration was carried out using data observed at four automatic monitoring stations in the reservoir. It was found that the model appropriately simulated, with the RMSE less than 5.2 NTU, the observed vertical and horizontal distributions of water temperature and turbidity as well as the location of maximum turbid water at each monitoring station. The analysis results showed that selective withdrawal is more effective in removing high turbid water than surface withdrawal as selective withdrawal contributed to reducing $35Mm^3$ of high turbidity water (> 100 NTU) in the reservoir by increasing outflows of high turbid water. Therefore, effective management of turbid water in the reservoir can be achieved by changing locations of intake depending on turbid water distribution conditions. The results of this study will provide some basic information for establishing better operation strategies to cope with turbid water problems.

• 농촌계획
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• 제28권3호
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• pp.49-59
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• 2022

Recently, Korea aimed to increase water use efficiency by implementing integrated management according to the water management unification policy. Considering the enormous use of water resources in the agricultural sector, it is necessary to efficiently conserve water in terms of demand management by intensifying the stakeholders' involvement and awareness campaigns. The existing agricultural water management system in Korea is based on a top-down approach by which the government agencies directly plan budgets and policies to be enforced on and implemented by farmers, with little to no involvement of farmers in the decision-making process. However, this process has hindered the desired water resources management and the water conservation goal at the field level. Moreover, the limited research on water governance operations focusing on agricultural water creates a knowledge gap, particularly in Korea. Thus, it is necessary to investigate water governance cases with successful implementations in agricultural and rural areas to identify the factors applicable to domestic governance in Korea. In addition, a more systematic governance model should be established by identifying the subjectivity of the stakeholders' involvement in agricultural water governance. Therefore, this study proposed a new bottom-up model for agricultural water governance, which aims to raise the problem of autonomous water governance while promoting stakeholders' voluntary participation in agricultural water management and reflecting farmers' involvement in the decision-making process. Moreover, if agricultural water governance is expanded nationwide by reflecting agricultural and water resource policies in the future, it is believed that positive effects can be achieved in increasing utilization efficiency and securing sustantiality through agricultural water saving.

• 상하수도학회지
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• 제32권6호
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• pp.507-515
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• 2018

The results of the survey on water utilization status, the wasted water factor, the awareness, and the education and promotional activities of water saving in Daejeon City are as follows: The percentage of using tap valve with a closure was 66% when showering. 74% of water was used with closing the tap valve when washing faces with no water needed, it was still considered that there existed a wasting water. The most wasting reasons of water were found to be shower, bath, and laundry in order. In the awareness of practicing tap water saving, 9.1% of respondents acted actively, 53.4% of them were trying to practice it, and more than 63% had a positive awareness. In the contents of practicing saving water, locking water when soaping while showering, non-laundry of small quantity, and using cups when brushing teeth were top priorities. About 50% of the reasons for saving water was to practice purely saving water, when saving for economic help was excluded. The level of water saving awareness was not high when considering that the ratio of usage without water saving equipment and installation, and using method was relatively high when moving in. In order to make usage of water saving equipment more common, it was deemed necessary to provide information on the purchase of water saving equipment and to promote and educate the efficiency of saving of related products. More than about 90% of the respondents responded that water saving education or promotional activities had an effect of improving water saving awareness. The most effective method of education and promotional activities was found to be 40.4% by mass media activities, and 21.7% by promotions through mobile devices.

• 한국물환경학회지
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• 제26권2호
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• pp.243-251
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• 2010

Evapotranspiration and rainfall-runoff are the major components of hydrological cycle and thereby the changes of them can directly affect the wetness/dryness or runoff characteristics of basins. In this study the wetness/dryness in Geum river basin are classified by dint of cumulative probability density function of monthly moisture index and the long term changes of them are analyzed based on climatic water balance concept. The drought events in Geum river basin are selected through evaluation of monthly moisture index and the various hydrological properties of them are investigated in detail. Also the trends of time-series of climatic water balance components are examined by Seasonal Kendall test and the variability of hydrological cycle in Geum river basin during the recent decade is inquired. It is judged that the results of this study can be contributed to establishment of the counter plan against the future drought events as the fundamental information.

• KIEAE Journal
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• 제10권6호
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• pp.67-72
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• 2010

This study was conducted to examine the change of heating environment with the creation of an indoor water space. Living environments and comfort of dwellers can be improved by utilizing the physical properties of water effectively. This study focuses on the basic examination of the effect of water space and the environmental effects of water space by experiment. Two identical models were fabricated to compare the changes in indoor temperature and humidity with and without a water space. With the water space, temperature was reduced by an average of $0.55^{\circ}C$ a day and moisture content increased by an average of 4%. As a result, it was possible to obtain quantitative data on water space's temperature reduction and humidity control capacities. This study is expected to provide basic information for further studies on the effect of water spaces in various buildings.

• 대한기계학회논문집B
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• 제28권11호
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• pp.1322-1331
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• 2004

This paper presents studies on the design of water hydraulic system and components to replace oil with tap-water as the pressure transmission medium in hydraulic systems. In order to improve the performance of water hydraulic system, the thermal and hydraulic properties of tap-water are first investigated. Based on these characteristics, the design parameters, such as the clearances of the moving parts, the cross-sectional area of pipes and relative roughness, are proposed so that the performance of water hydraulic system is the same as that of oil. In addition, the operating ranges, which show the possibility of using water hydraulic system, are examined.

• 한국물환경학회지
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• 제37권5호
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• pp.398-404
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• 2021

The use of water purifiers has been increasing every year due to increased drinking water safety concerns raised by the water pollution accidents occasionally reported. Currently, more than 10 million water purifiers have been distributed in Korea, and the estimation of the purifier sales reaches two million units per year. As a result, the number of used water purifier filters that must be replaced on a regular basis has gradually increased. However, regardless of the considerations for the capacity of used filters remaining, water purifier filters were replaced and collected at regular intervals. The high cost of disposal of the used filters by landfill or incineration were required. Thus, in this study, the current status and trends of recycling technologies for used water purifier filters were reviewed. It is noted that there was insufficient statistical data to understand the current status of the difference between the number of used water filters discarded and the number of those recycled. Most studies on the recycling of old water purifier filters have concentrated on pretreatment and cleaning methods for sediment filters and membrane filters, with the goal of extending the lifespan of used filters. Further, the study suggested future study directions on the recycling of used water purifier filters, which could be useful information on establishing environmental policy to promote the recycling of used filters.