• 분석과학
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• 제28권1호
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• pp.58-64
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• 2015

이 연구에서는 농촌지역 마을상수 중에 함유된 trihalomethanes (THMs)의 농도 분포 및 발생 특성을 파악하였다. 농촌지역의 마을상수 시료는 2010년과 2011년 여름에 강원도 춘천시의 40가정에서 두 차례에 걸쳐 채취하였고, 도시상수 시료는 2011년의 같은 기간에 비교 목적으로 20곳의 수도꼭지에서 채취하였다. 현장에서 수온, pH 및 잔류염소(총 및 유리) 농도를 측정하였고, 물 시료는 실험실에서 용존 유기탄소(DOC)와 THMs 농도에 대해 분석하였다. 마을상수 중 DOC의 평균 농도는 원수로 사용된 지하수와 지표수 간에 거의 차이를 보이지 않았다(1.81 vs. 1.91 mg/L). 그러나 마을상수의 지하수에서($9.77{\mu}g/L$)의 총 THMs(TTHMs)의 평균 농도는 지표수보다($2.85{\mu}g/L$) 훨씬 더 높았고, 도시상수 중 TTHMs의 평균 농도($10.8{\mu}g/L$)와 유사하였다. 도시상수와는 다르게, 마을상수(특히 지하수)는 dibromochloromethane (DBCM)과 같은 더 많이 브롬화된 THMs을 함유하였는데, 이는 마을상수의 원수 중에 bromide ion(Br-)이 비교적 높은 수준으로 존재함을 암시하였다. 이 연구를 통해 마을상수는 도시상수와는 다른 THMs 생성 특성을 나타내는 것을 알 수 있었는데, 이것은 아마도 원수의 수질 특성의 차이에서 비롯되는 것으로 생각된다.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 Proceedings of KSEH.Minamata Forum
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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.

• 상하수도학회지
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• 제20권6호
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• pp.849-855
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• 2006

Taste and odor (T&O) problems in drinking water supplies caused by eutrophication have become increasingly important because aesthetic qualities are the primary measures by which consumers estimate the quality of their drinking water. In order to overcome T&O problem, it is necessary to early detection method for T&O compounds before these compounds enter to water treatment plant. In this background, a early waming device for T&O compounds was developed and its performance tested under different operating condition. According to the experimental results on the adsorption efficiency of T&O compounds, when the raw water flowrate was 5 mL/min, the optimum stripping time and air flowrate were 5 hrs and 0.5 L/min, respectively. Comparison of activated carbon showed that foreign activated carbon was better than domestic activated carbon in terms of adsorption efficiency.

• 한국물환경학회지
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• 제33권3호
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• pp.359-369
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• 2017

Water distribution systems supply drinking water to consumers' taps. Internal corrosion of metallic pipe used in drinking water distribution systems has reduced water quality and led to increased levels of toxic heavy metals such as lead, copper and nickel. These problems have been experienced to varying degrees by water utilities in many countries. North America has successfully managed and controlled pipe corrosion and corrosive water in water distribution system based on various policies, regulations and rules. Practical and engineering guidelines for evaluation of pipe corrosion and determination of treatment options are also provided to assist drinking water supplies. In addition, the corrosion mechanism in water distribution systems, such as the complex effects of physical and chemical parameters on the corrosion pipes has been improved to accurately predict corrosion rates of metallic pipes in actual water distribution systems. This paper reviews various regulations, policy statement, and treatment produces on controlling corrosion in drinking water distribution systems in US and Canada and then offers suggestion for management of corrosive water and pipe corrosion in drinking water distribution system in Korea.

• Parasites, Hosts and Diseases
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• 제49권1호
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• pp.9-15
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• 2011

To understand the distribution of Giardia cysts in drinking water supplies in Seoul, Korea, we collected water samples quarterly at 6 intakes in the Han River, its largest stream and 6 conventional water treatment plants (WTPs) serving drinking water, from 2000 to 2009. Giardia cysts in each of 10 L water were confirmed in 35.0% of intake water samples and the arithmetic mean was 1.65 cysts/10 L (range 0-35 cysts/10 L). The lowest cyst density was observed at Paldang and Kangbuk intakes, and the pollution level was higher at 4 intakes downstream. It seemed that these 4 intakes were under influence of Wangsuk stream at the end of which cysts were found in all samples with the mean of 140 cysts/10 L. The annual mean number of cysts was 0.21-4.21 cysts/10 L, and the cyst level at the second half of the 10 years was about 1/5 of that at first half on average. The cysts were more frequently found in winter, and their mean density was 3.74 cysts/10 L in winter and 0.80-1.08 cysts/10 L in other seasons. All finished water samples collected at 6 WTPs were negative for Giardia in each of 100 L sample for 10 years and cyst removal by physical process was average 2.9-log. It was concluded that conventional water treatment at 6 WTPs of Seoul appears to remove the cysts effectively under the present level of their source water. Domestic wastewater from the urban region could be an important source of Giardia pollution in the river.

• 상하수도학회지
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• 제10권4호
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• pp.73-84
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• 1996

Fluoride was first introduced into the drinking water of residents of Grand Rapids, Michigan in 1945 for the prevention of dental caries. Ever since, growing numbers of communities favor fluoridation. Now, over 7000 communities in the United States are adding F(0.7~1.2ppm) to their drinking water. The most effective to prevent tooth decay is putting lower concentrated fluoride(F, 0.7~1.2ppm) into drinking water. However, exact fluoride injection amount have not been decided, because the research of the fluoride injection effect was insufficient. Therefore, after separating fluoridation and non-fluoridation into public water supplies, we investigated concentration of fluoride, alkalinity, Al, Ca, Mg, evaporation residuals in APT, domestic, commercial area. Then, we decided allowable concentration of fluoride, injection point of fluoride in water supply system, cost effectiveness.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.263-272
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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. it 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 reacts with natural organic matter(NOM), that presents in nearly all water sources, and then produces disinfection by-products(DBPs), that 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. 1. The objectives of this study is to investigate seasonal variation difference concentration of DBPs 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. 2. Distant variation of DBPs furmation by the distance is that THMs concentration increased by 17% at 2km point from the plant and by 28% at 7km 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, 3. The seasonal occurrence of BBPs is that in May and August DBPs concentration is very higher than in march, in May DBPs concentration is highest. The temperature is main factor of DBPs formation, precursor also. 4. Precursor which was accumulated for winter flowed into the raw water by flooding in spring and summer and produced DBPs. 5. 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 Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권2호
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• pp.71-78
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• 2000

The chlorination of municipal drinking water supplies leads to the formation of so-called disinfection by-products(DBPs), many of which have been reported to cause harmful health effects based on animal studies. This study was conducted: 1) to observe seasonal changes in the major DBPs at four sampling sites on a drinking water distribution system located in Chunchon, Kangwon Do; and 2) to examine the effects of major water quality parameters on the formation of DBPs. During the field sampling, the water temperature, pH, and total and free chlorine residuals were all measured. The water samples were then analyzed for total organic carbon(TOC) and eight disinfection by-products in the laboratory. Chloroform, dichloroacetic acid, and trichloroacetic acid were the major constituents of the measured DBPs. The concentrations of the total DBPs were highest in fall, particularly in October, and lowest in summer. The concentrations of the total DBPs increased with increasing TOC concentrations. Multiple regression analyses showed that the concentrations of chloroform, bromodichloromethane, and chloral hydrate were linearly correlated with the pH. Other water parameters were not included in the regression equations. Accordingly, these results suggest that TOC and pH are both important factors in the formation of DBPs.

• 기술사
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• 제42권3호
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• pp.47-53
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• 2009

Riverbed filtration(RBF) system is used to develop ground water and infiltrated water supplies from permeable sand and gravel deposits. RBF plants are constructed with a reinforced concrete caisson that serves as a wet well pumping station. The lateral well screens are projected horizontally into waterbearing deposits from inside the caisson. Riverbed filtration(RBF) is a low-cost and efficient alternative water treatment for drinking-water applications.

• Parasites, Hosts and Diseases
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• 제48권3호
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• pp.219-224
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• 2010

This study has been conducted to estimate the occurrence of Cryptosporidium oocysts in water supplies in the Metropolitan area of Seoul, South Korea, for 10 years from 2000 to 2009. Water samples were collected quarterly at 6 intakes in the Han River and its largest stream and 6 conventional Water Treatment Plants (WTPs) serving drinking water for 10 million people of Seoul. Cryptosporidium oocysts were found in 22.5% of intake water samples and arithmetic mean was 0.65 oocysts/10 L (range 0-22 oocysts/10 L). Although the annual mean of oocyst number was as low as 0.04-1.90 oocysts/10 L, 3 peaks in 2004 and 2007 were observed and the pollution level was a little higher in winter. The lowest density was observed at Paldang intake and the pollution level increased at Kuui and Jayang intakes. At the end of the largest stream, oocysts were found in 70% of collected samples (mean 5.71 oocysts/10 L) and it seemed that its joining the Han River resulted in the increase at Kuui intake and downstream. Oocyst removal by physical process exceeded 2.0-2.3 log and then all finished water samples collected at 6 WTPs were negative for Cryptosporidium in each 100 L sample for 10 years. These results suggested that domestic wastewater from the urban region could be a source of Cryptosporidium pollution and separating sewage systems adjacent to the intakes could be meaningful for some intakes having weakness related to parasitological water quality.