• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.313-314
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• 2017

본 논문에서는 부천시 핵심 국가기반시설로서 부천시민의 삶의 질에 가장 큰 영향을 끼치는 요인인 수돗물 공급서비스의 위험요인를 파악하고 이를 해소하는 방안을 마련하며, 국제 및 국내적으로 테러의 위험이 높아가고 있는 가운데 재난대비역량을 강화하여 시민이 수돗물을 안심하고 이용할 수 있도록 수돗물 공급역량 강화 방안을 마련하였다. 본 논문에서는 팔당댐 수원지에서 부천시 정수장까지 원수 공급 과정부터 정수장내 취수/정수/배수과정을 거쳐 소비자에게 공급하는 전과정에서 위험요인과 개선방안을 도출하였으며 향후계획 수립 방향을 제시하였다.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.247-250
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• 1998

This study was carried out to investigate the effects of changes of ionic strength according to growth stage on growth and flowering of Dendranthema grandiflorum (Ramat.) Kitamura 'Seiun' grown hydroponically in perlite. The stage I, II, and III covered early vegetative growth (27-40 days after planting), latter vegetative growth (41-54 days), and reproductive growth (55-80 days), respectively. The 2 strength (1S and 2S) of nutrient solution were treated in stage I, whereas 3 strengths (1S, 1-2S, and 2S) were treated in stage II. Then, total 9 treatments in stage III were designated by 3 treatments (tap water, 1S, and 2S) for each 3 strengths in stage II. Each nutrient solution was applied 8 times per day. At vegetative growth stage (54 days after planting), stem length was highest when irrigated 8 times a day with 1S nutrient solution. Both photosynthesis and transpiration rate were higher in 1S than those in other treatments (1-2S, 2S), whereas leaf chlorophyll content was highest in 2S treatment. Ion content of plant treated with 2S was higher than other treatments. Growth (plant height, leaf area, stem length), fresh weight, and dry weight of each plant organ after flower bud formation were better in tap water treatment (1-1-0) than other 1S treatments (1-1-1, 1-1-2). Regarding the number of days to flowering, tap water treatment was the most effective. Thus, after flower bud formation supplying tap water or lower concentration of nutrient solution than those used during the vegetative growth stage was economical in saving chemical fertilizers, shortening the number of days to flowering, reducing salt accumulation in media, saving efforts of leaching, and reducing ground water contamination.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.463-470
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• 1998

To improve muscle quality and prolong freshness of sashimi, the effects of freezing-thawing condition on physicochemical and rheological properties of plaice muscle were investigated. Muscle tested were frozen with quick freezing (liquid nitrogen gas) or slow freezing ($-15^{\circ}C$ air). Transition time of zone of ice crystal formation was within 10 minute for quick freezing and 110 minute for slow freezing. Time required for thawing to $0^{\circ}C$ in muscle temperature by various thawing methods was shortest with $25^{\circ}C$ tap water, followed by $15^{\circ}C$ tap water, $10^{\circ}C$ tap water, $25^{\circ}C$ air, $5^{\circ}C$ tap water and $0^{\circ}C$ cold water. Breaking strength of muscle was higher in quickly frozen sample than in slowly frozen sample. According to sashimi term, changes in breaking strength of muscle did not show any difference in quickly frozen sample, while showed significant difference in slowly frozen sample. The remaining content of ATP was not effected by freezing speed, and ATP content was apt to higher in quickly thawed sample than in slowly thawed sample. IMP was the majority of ATP and it's related compounds of sample after freezing and thawing. Collagen matrix was weakened markedly in slowly frozen sample than in quickly frozen sample.

• Journal of Korean society of Dental Hygiene
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• v.10 no.3
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• pp.483-493
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• 2010

Objectives : The purpose of this study was to obtain the information for the improvement of the support in oder to expand the adjusted water fluoridation program to Myeong-dong water treatment plant in Gimhae city, Korea. Methods : Questionnaires were distributed to the parents of elementary schoolchildren and their responses were collected. All collected data were analyzed using the SPSS program. Results : The percentage of respondents using the tap water was 47.0% for drinking and 54.4% for cooking, respectively. The percentage of respondents using the water purified the tap water with the home water purifier was 45.1% for drinking and 36.2% for cooking, respectively. Respondents who knew the adjusted water fluoridation program was 48.3%. Respondents who knew the implementation of the adjusted water fluoridation program at the moment in Gimhae was 27.0%. 90.2% of residents agreed on the expansion of the adjusted water fluoridation program to Myeong-dong water treatment plant, Significant variables in the approval rates of the adjusted water fluoridation program were age, residence period, occupation, recognition of the program. Conclusions : It is desirable to expand the adjusted water fluoridation program to Myeong-dong water treatment plant in Gimhae as the percentage of respondents who agreed on the introduction of the program was high.

• Environmental Analysis Health and Toxicology
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• v.12 no.3_4
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• pp.23-29
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• 1997

The main reason of applying chlorination is to sterilize microbes existing in the drinking water treatment. But chlorination could lead to the formation of disinfection by-products (DBPs) by the reaction of free chlorine with humic substance in the water. Especially the DBPs including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and haloketones (HKs) exist in the tap water. The US environmental protection agency (US EPA) defines that trihalomethanes, dichloroacetic acid, trichloroacetic acid, and dichloroacetonitrile among DBPs are probable/possible human carcinogens. US EPA suggests maximum contaminant levels (MCLs) for THMs (80$\mu$g/L) and HAAs (60$\mu$g/L) in drinking water. In Korea, THMs in drinking water has been surveyed but DBPs in general has not been studied in drinking water practically. Therefore only THMs have been regulating as criteria compounds since 1990 but neither HAAs nor HANs. Researches on HAAs are yet to be found. HAA formation potentials(HAAFPs) have not been practiced. HAAs depends on the characteristics of water sources by chlorination. In this study, HAAFPs from three distinct sources were investigated by laboratory chlorination experiments. This study was performed to measure the level of HAAs in drinking water in Seoul area. At April 1996, after collecting the raw waters from the three sites with the different properties, the water samples were chlorinated at various conditions(pH 5.5, pH 7.0 and without pH adjustment) in the state of raw water to have 0. 5mg/L of residual chlorine concentration. And the raw water, treated water, and tap water of water treatment were collected to measure the HAAs concentration. The quantitative analysis of HAAs was conducted by US EPA methods.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.12a
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• pp.103-114
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• 2005

Chlorine disinfection has been used in drinking water supply to disinfect the water-borne microbial disease which may cause to serious human disease. As Chlorination is still the least costly, relatively easy to use, chlorination is the primary means to disinfect portable water supplies and control bacterial growth in the distribution system. However, chlorine also reacts with natural organic matter (NOM), which presents in nearly all water sources, and then produces disinfection by-product (DBps), which may have adverse health effects. Although the existent DBPs have been reported in drinking water supplies, it is not feasible to predict the levels of the various DBPs due to the complex chemistry reaction involved. The objectives of this study were to investigate seasonal variation of DBPs formation and difference of DBPs concentration in the plant to tap water. The average concentration of THMs was 20.04 ${\mu}g/{\ell}$, HAAs 8-15 ${\mu}g/{\ell}$, HANs 2-4.5 ${\mu}g/{\ell}$ respectively. Distant variation of DBPs formation is that THMs concentration increase by 17% at 2 km point from the plant and by 28% at 7 km and HAAs, HANs also increase each by 16%, 32%, at 2 km from the plant and 35%, 56%, at 7 km. DBPs increase in water supply pipe continually. The seasonal occurrence of DBPs is that in May and August DBPs concentration is very high then in March, in May DBPs concentration is highest. The temperature is main factor of DBPs formation, precursor also. Precursor which was accumulated for winter flowed into the raw water by flooding in spring and summer and produced DBPs. Therefore for the supply of secure drinking water, it is required to protect precursor of flowing into raw water and to add to BCAA and DBAA to drinking water standards.

• Environmental and Resource Economics Review
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• v.3 no.2
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• pp.337-358
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• 1994

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.74-81
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• 2009

In this research, we investigated the actual conditions of water purification systems at ten elementary schools located in Gunsan, Korea from July to December, 2007. The results were as follows; The population densities of heterotrophic bacteria in water purifiers ranged from 0 to $1.2{\pm}0.2{\times}10^4$ CFU/ml and those of tap water were in the range from 0 to $1.9{\pm}0.3{\times}10^4$ CFU/ml during investigation periods. Ninety percentage of purified water samples in July and September, 87.2% in October and November, and 93.7% in December turned out not to be suitable for drinking. The seasonal variation of the population densities of heterotrophic bacteria from purified waters was not notable. The total coliform, Salmonella and Shigella were not detected in purified water and tap water during investigation periods. Forty-five species of bacteria were isolated from water purifiers. The identified bacterial genera were Sphingomonas, Methylobacterium, Caulobacter, Novosphingobium, Bosea, Brevundimonas, Aminobacter, Ralstonia, Mitsuaria, Variovorax, Acidovorax, Massilia, Pseudomonas, Acinetobacter, Aeromonas, Bacillus, Staphylococcus, Brevibacillus, Microbacterium, Lapillicoccus, Micrococcus, Arthrobacter, Janibacter, Flavobacterium, Chryseobacterium, and Hymenobacter: Among the isolates, opportunistic pathogens such as Pseudomonas fluorescens, Staphylococcus epidermidis, Flavobacterium johnsoniae, and Acinetobacter johnsonii were also found.

• Korean Journal of Microbiology
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• v.1 no.1
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• pp.48-50
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• 1963

The authors have investigated about the microbial contamination of goods which is a criterion of hygienic control. Conducting on investigation, a special attention has been paid on the rate of microbial contamination in the goods, especially in manufacturing process of the softdrink. The authors also made an experiment on total microbes which is the criterion of contamination in each step of the process and in raw materials together with materials to be used for subdividing. Results obtained were as follows : 1) The orgin of microbial contamination was found in bottle cap and in tap water, that is, there appeared 9 colony per ml in bottle cap and 31-74 colony per ml in tap water, respectively. 2) It was found that microbial contamination are 4 colony per ml in average through year. However, it appeared 1 colony per ml in winter and 8 colony per ml in summer. 3) Coliform groups are not detected in goods through a year. 4) There was no variation in number of total microbes after ion exchange resin passage in purification process of tap water. 5) The number of microbes in goods are decreased when the raw materials are treated in high temperature short time (HTST) sterilization.

• Journal of Veterinary Clinics
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• v.18 no.2
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• pp.116-123
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• 2001

This study was undertaken to find out the effect of Korean safflower seed powder on histopathological changes of cadmium toxicity in mice. Fifty BALB/c mice were divided into a control group(A) and four experimental groups(B, C, D, E) : group A received tap water and basal diet, group B received tap water and diet supplemented with 3% Korean safflower seed powder alone, group C received basal diet and 300 $\mu\textrm{g}$/g of cadmium, group D and E received basal diet supplemented with 3% and 10% Korean safflower seed powder and 300$\mu\textrm{g}$/g of cadmium respectively. Cadmium dissolved in tap water was used, and the Korean safflower seed powder were mixed with feed. All mice were dissected on the 56th day. Histopathological changes in liver, kidney, lung, cortical osseous tissue of femoral shaft, bone trabecular of femur, and epiphyseal cartilage plate of femur were observed. Group B showed no significant changes compared with the control group. But group C showed the unclearness of specific cells in liver, the loss of architecture and focal necrosis of hepatocyte, the glomerular swelling, degeneration and necrosis of convoluted tubules, desquamation and vacuolization of the greater part of the renal tubular epithelium, the marked congestion and thickness of the wall of alveolus in lung, slightly thinning of the cortical osseous tissue in femoral shaft, reduction of cancellous bone volume and marked narrowness of bone trabecular, marked thinning of epiphyseal cartilage plate and irregular arrangement of columnar structure of cartilage cells. On the other hand, Korean safflower seed powder-treated group showed a little convalescent changes and maintained their normal architectures in liner, kidney, lung, cortical osseous tissue of femoral shaft, bone trabecular of femur and epiphyseal cartilage plate of femur.