• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.233-242
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• 2020

As studies and developments of nano-material increase, the release of the nano-sized material to water environment increase. Especially, silver nanoparticles have been found as dissolved and particulate state since nano-silver particle have been intensively used in industrial and our living environment due to the anti-bacterial effect of the nano-particles. The silver nano-particles and silver ion gives adverse effect on ecology and US-EPA set a secondary drinking water standards as 0.1 mg/L. Current study focused on the analysis of silver in groundwater, small scale water supply systems in Gyeongbook area. The results have been compared with the secondary drinking water standards and discussed at the point of characteristics of the local area and purpose of use of the water sample. Among the total of 298 samples, 2 samples exceed the secondary drinking water standards of EPA, 0.64% rate. Community drinking water and simplified water service showed relatively high detection rate and groundwater gave relatively higher concentration of silver indicating anthropogenic source and natural source could contribute simultaneously on groundwater.

• Environmental and Resource Economics Review
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• v.10 no.3
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• pp.433-459
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• 2001

The water quality of Paldang reservoir now grades the third class water based on COD criterion, meaning that it is no longer suitable for drinking. This study attempted to estimate the economic value of water quality improvement in Paldang reservoir using CVM. The survey used payment card format to measure the willingness to pay of the questionnaire respondents for the improvement of water quality and also factors that affect the WTP. The survey showed that men rather than women, those had higher income and paid more water supply charges, those who lived in the area for a shorter period of time, those who do not use city water for drinking, had willingness to pay more. The WTP was estimated 4,952 to 5,497 won on a monthly average. The economic value of the improvement of the water quality of Paldang reservoir was estimated between 344.2~382.1 billion won on an annual basis.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1997-1998
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• 2006

In this paper, we propose a remote control system which is used by internet network system in the small water booster supply. So far, TMTC(Tele Metering Tele Control) has been used to control and monitor small water booster pump. But it is possible and easy to control and observe local booster panel with the rapid development of internet, This new system is to provide operators and managers with sufficient information and control in order to implement the operation in an efficient and economical way. This system consists of three parts that are controller, netpump server and netview client. Controller has a dual architecture. The motive for installing controller is the continuous production and supply of drinking water.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.5
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• pp.312-320
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• 2013

Particulates in drinking water distribution system (DWDS) are mostly influenced by internal corrosion of metal pipes and sediment in pipelines due to the solution of this effect is limited. The particle size, component and properties of compounds for particulates in distributed water are different and the difference of these characteristics will be occurred by the kind of facilities, pipe condition, external factors and supply system etc. In this study, conducting the investigation of water quality in DWDS researches with particulates in the water. Monitoring sites were each water supply reservoir and the end of water supply area in DWDS. To collect particulate material at each sampling site, $47{\phi}$ glass microfiber filter type GF/C was performed using a filtration. Substances that the effect of the turbidity in the water according to particulate suspended solids and inorganic materials is due to the increasing particulates in the end of DWDS were increased. The result of compounds analysis by using X-ray diffraction (XRD) were Goethite (${\alpha}$-FeOOH), Magnetite ($Fe_3O_4$) in the end of DWDS and Quartz ($SiO_2$), Yeelimite ($Ca_4Al_6O_{12}SO_4$) at the effluent of waterworks and reservoirs. There were differences the compounds and sediments in the releasing or remaining water distribution facilities.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.11-21
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• 2022

The COVID-19 started to spread at early 2020 in South Korea and has been threatening our life in many aspects. Countermeasures such as social distancing to prevent COVID-19 spread have brought many changes in our society an human life. In this study, as a part of the COVID-19 pandemic management, drinking water usage change is analyzed to evaluate potential risks on water supply service. We collected hourly water use data of residential area in S city, which is a mid-size city in South Korea, before and after the COVID-19 pandemic. The collected data were analyzed to reveal the changes in total water consumption, water usage weight, and hourly water-demand pattern caused by the COVID-19 pandemic. The case study revealed the noticeable changes in water consumption caused by the COVID-19 pandemic and required more secured and adaptive operation of drinking water system under the pandemic situation caused by infectious disease.

• Environmental Analysis Health and Toxicology
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• v.10 no.1_2
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• pp.37-46
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• 1995

The purpose of this research is to estimate a safe environmental level of human exposure to thresholding-acting toxicants in drinking water and recommend the acceptable levels and management plans for maintaining good quality of drinking water' and protecting health hazard. This research has been funded as a national project for three years from 1992 to 1995. This study(the second year, 1993-1994) was conducted to monitor 39 species of noncarcinogenic chemicals such as volatile organic compounds(VOCs), polynuclear aromatic hydrocarbens(PAHs), pesticides and heavy metals of drinking water at some area in six cities of Korea, and evaluate health risk due to these chemicals through four main steps (hazard identification, exposure assessment, dose-response assessment and risk characterization) of risk assessment in drinking water. In hazard identification, 39 species of non-carcinogenic chemicals were identified by the US EPA classification system. In the step of exposure assessment, sampling of tap water from the public water supply system had been conducted from 1993 to 1994, and 39 chemicals were analyzed. Inclose-response assessment for non-carcinogens, reference doses(RfD) and lifetime health advisories(HAs) of lifetime acceptable levels were calculated. In risk characterization of detected chemicals, the hazard quotients of noncarcinogens were less than one except those of manganese and iron in D city.

• Journal of Korean Medical Science
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• v.33 no.46
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• pp.288.1-288.12
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• 2018

Background: Diarrheal and intestinal infectious disease caused by inadequate drinking water, sanitation, and hygiene (WASH) is not only a great concern in developing countries but also a problem in low-income populations and rural areas in developed countries. In this study, we assessed the exposure to inadequate WASH in Korea and estimated the burden of disease attributable to inadequate WASH. Methods: We used observational data on water supply, drinking water, sewage treatment rate, and hand washing to assess inadequate WASH conditions in Korea, and estimated the level of exposure in the entire population. The disease burden was estimated by applying the cause of death data from death registry and the morbidity data from the national health insurance to the population attributable fraction (PAF) for the disease caused by inappropriate WASH. Results: In 2013, 1.4% of the population were exposed to inadequate drinking water, and 1.0% were living in areas where sewerage was not connected. The frequency of handwashing with soap after contact with excreta was 23.5%. The PAF due to inadequate WASH as a cluster of risk factors was 0.353 (95% confidence interval [CI], 0.275-0.417), among which over 90% were attributable to hand hygiene factors that were significantly worse than those in American and European high-income countries. Conclusion: The level of hand hygiene in Korea has yet to be improved to the extent that it shows a significant difference compared to other high-income countries. Therefore, improving the current situation in Korea requires a continuous hand washing campaign and a program aimed at all people. In addition, continuous policy intervention for improvement of sewage treatment facilities in rural areas is required, and water quality control monitoring should be continuously carried out.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.41-46
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• 2001

Trihalomethane(THMs) levels in drinking tap water, indoor swimming pool water and industrial effluent in Kunsan area were surveyed in this study. During experimental period, the monthly averages of THMs in drinking tap water from Keumkang wide-area supply ranged from 15$\mu\textrm{g}$/ι/to 50 $\mu\textrm{g}$ showing the highest level in summer. 3 indoor swimming pools showed the monthly average levels of THMs formation ranging from 8$\mu\textrm{g}$/ι/to 20$\mu\textrm{g}$/ι and the pool under public management seemed to maintain its water quality more stable than those under private management THMs concentrations in the effluents. discharged from 10 manufacturing companies, ranged from N.D. to 95$\mu\textrm{g}$/ι and it was estimated that the overall THMs level discharged front those manufacturing companies is not high, reflecting the traces recorded for most effluents. The composition ratios of individual THMs for industrial effluents showed a difference from those for drinking water and swimming pool water, along with their wide variations according to the company and relatively high composition ratios of Br substituents.

• Journal of the Korean housing association
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• v.19 no.1
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• pp.79-88
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• 2008

Hot water is used by having a wash, dishes, taking tub and drinking water in residential buildings, and the use objective is to raise comfort of human body sense, washing and sterilization effect and so on. Cold & hot water supply system is understanded simpler than HVAC systems relatively, so it is true that pace of performance improvement is slower than other systems for plan and technical development. In this study, the performance evaluations are conducted under the condition of composition ratio by 1:1 for cold & hot water supply manifold system using functionally complex valves such as constant flow regulating valve and 3-way mixing valve in the area of $105.6m^2$ apartment which consist of the largest part of the whole apartment. Also, flow rate related to simultaneous use of faucets and change of hot water temperature are compared with the existing method.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.3
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• pp.143-148
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• 2006

There are need to manage the water quality to supply an safety to consumer through pipe and reservoir the drinking water that produced in a clean water reservoir. However, a management of water quality and monitoring in reservoir have never been performed. Recently, the government has enforced standards of water quality. However, we have a inferior technology of water quality as compared with one in USA, Japan, Germany, etc. In case of water quality inspection and analysis equipments, sensor technology is very important to improve the water quality inspection and to develop the analysis equipments. In this paper, we analyze a law and a regulation for management of drinking water quality, and propose the measurement standards of drinking water quality in pH, conductivity, residual chloride, turbidity and water temperature. Then, we analyze electrode sensors that interference within pH, conductivity, residual chloride in interference experiment.