• Parasites, Hosts and Diseases
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• 제43권2호
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• pp.47-50
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• 2005

A survey was carried out from August to December 2004 in Pusan, Korea to document the presence of free-living amoeba (FLA), including the genus Acanthamoeba, in both contact lens storage cases and domestic tap water. Acanthamoeba was isolated from $5(4.2\%)$ in 120 contact lens storage cases. Four house tap water samples from residents, whose contact lens storage cases had been contaminated by Acanthamoeba, were also found to be contaminated with Acanthamoeba. Therefore, the contamination rate of FLA and Acanthamoeba in domestic tap water was investigated in order to examine the role of domestic tap water in Acanthamoeba contamination of contact lens storage cases. FLA and Acanthamoeba were identified in $97(46.8\%)\;and\;16(7.7\%)$ of the 207 domestic tap water samples, respectively. There were no significant differences between the contamination rates of FLA in tap water according to the filtration plant of origin. No FLA was detected in the tap water directly supplied by the water purification plants. Water storage tanks appear to promote FLA colonization, including Acanthamoeba, in domestic tap water. This increases the risk of Acanthamoeba contamination in contact lens storage cases as well as increasing the risk of Acanthamoeba keratitis.

• 상하수도학회지
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• 제29권4호
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• pp.511-517
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• 2015

Korea's modern waterworks began with construction of DDukdo water treatment plant in 1908 and has been growing rapidly along with the country's economic development. As a result, water supply rates have reached 98.5% based on 2013. Despite multilateral efforts for high-quality water supply, such as introduction of advanced water treatment process, expansion of waterworks infrastructure and so on, distrust for drinking tap water has been continuing and domestic consumption rate of tap water is in around 5% level and extremely poor comparing to advanced countries such as the United States(56%), Japan(52%), etc. Recently, the water management has been facing the new phase due to water environmental degradation caused by climate change, aging facilities, etc. Therefore, K-water has converted water management paradigm from the "clean and safe water" to the "healthy water" and been pushing the Smart Water City(SWC) Pilot Project in order to develop and spread new water supply models for consumers to believe and drink tap water through systematic water quality and quantity management combining ICT in the whole water supply process. The SWC pilot projects in Pa-ju city and Go-ryeong county were an opportunity to check the likelihood of the "smart water management" as the answer to future water management. It is needed to examine the necessity of smart water management introduction and nationwide SWC expansion in order to improve water welfare for people and resolve domestic & foreign water problems.

• Parasites, Hosts and Diseases
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• 제47권4호
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• pp.337-344
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• 2009

In a previous study, we reported our discovery of Acanthamoeba contamination in domestic tap water; in that study, we determined that some Acanthamoeba strains harbor endosymbiotic bacteria, via our molecular characterization by mitochondrial DNA restriction fragment length polymorphism (Mt DNA RFLP). Five (29.4%) among 17 Acanthamoeba isolates contained endosymbionts in their cytoplasm, as demonstrated via orcein staining. In order to estimate their pathogenicity, we conducted a genetic characterization of the endosymbionts in Acanthamoeba isolated from domestic tap water via 16S rDNA sequencing. The endosymbionts of Acanthamoeba sp. KA/WP3 and KA/WP4 evidenced the highest level of similarity, at 97% of the recently published 16S rDNA sequence of the bacterium, Candidatus Amoebophilus asiaticus. The endosymbionts of Acanthamoeba sp. KA/WP8 and KA/WP12 shared a 97% sequence similarity with each other, and were also highly similar to Candidatus Odyssella thessalonicensis, a member of the $\alpha$-proteobacteria. The endosymbiont of Acanthamoeba sp. KA/WP9 exhibits a high degree of similarity (85-95%) with genus Methylophilus, which is not yet known to harbor any endosymbionts. This is the first report, to the best of our knowledge, to show that Methylophilus spp. can live in the cytoplasm of Acanthamoeba.

• 한국환경보건학회지
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• 제39권1호
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• pp.32-42
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• 2013

Objectives: Cryptosporidium, a protozoan parasite, has been recognized as a frequent cause of waterborne disease due to its extremely strong resistance against chlorine disinfection. Although there has as yet been no report of a Cryptosporidium outbreak through drinking water in Korea, it is important to estimate the health risk of Cryptosporidium in water supply systems because of the various infection cases in human and domestic animals and frequent detection reports on their oocysts in water environments. Methods: This study evaluated the annual infection risk of Cryptosporidium in tap water using the quantitative microbial risk assessment technique. Exposure assessment was performed upon the results of a national survey on Cryptosporidium on the water sources of 97 large-scale water purification plants in Korea, water treatment efficacy, and daily unboiled tap water consumption. The estimates of the US Environmental Protection Agency on the mean likelihood of infection from ingesting one oocyst were applied for effect assessment. Results: Using probabilistic methods, mean annual infection risk of Cryptosporidiosis by the intake of tap water was estimated to fall within the range of $2.3{\times}10^{-4}$ to $1.0{\times}10^{-3}$ (median $5.7{\times}10^{-4}$). The risk in using river sources was predicted to be four times higher than with lake sources. With 0.5-log higher removal efficacy, the risk was estimated to be $1.8{\times}10^{-4}$, and could then be lowered by one-third. Conclusions: These estimations can be compared with acceptable risk and then used to determine the adequacy and priority of various drinking water quality strategies such as the establishment of new treatment technology.

• 대한방사선기술학회지:방사선기술과학
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• 제44권6호
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• pp.671-677
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• 2021

Interest in the everyday hazards of radon has recently increased as such, this study attempted to examine the dangers of radon in spilled groundwater by comparing the radon concentrations of the drained groundwater and tap water used in recirculating systems in Incheon Subway restrooms. At five stations of Incheon Subway Line 1 and three stations of Line 2, drained groundwater is recirculated and used in restrooms for toilet flushing. Stations restroom tap water for hand washing that used as a control and the measured values of each were compared. With the cooperation of Incheon Transportation Corporation, samples of spilled groundwater and tap water were collected sealed to prevent contact with the air, and a DURRIDGE RAD7 was used as the experimental equipment. The collected samples were subjected to radial equilibration for approximately 3.5 h, at which the radon concentration reached its maximum, and then calculated as 10 measurements using the RAD7 underwater radon measurement mode. In all eight stations, the radon concentration in tap water was lower than the recommended amount. However, in an average of 7 out of the eight stations, the radon concentration in the effluent groundwater was 100 times higher than that in tap water. Since high radon concentrations in groundwater runoff can be harmful to humans, and there is no accurate standard for radon concentrations in domestic water, it is necessary to continuously monitor radon in water and prepare a guidance of recommended values.

• 생태와환경
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• 제45권3호
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• pp.271-277
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• 2012

본 연구에서는 D. magna의 배양배지로서의 국내 자연수의 적절성을 평가하기 위하여, Elendt M4 배지에서 생산된 태어난 지 24시간 미만 된 어린 D. magna를 Elendt M4 배지, 탈염소 수도수 및 먹는 샘물에 21일 동안 노출시켜 생존율 및 번식능력을 평가하였다. 대조배지인 Elendt M4 배지와 먹는 샘물에서 배양한 D. magna는 어미의 생존율, 첫 배를 생산하는 시기, 생존한 어미 당 생산된 총 어린 물벼룩 평균수, 생존한 어미 당 생산된 죽은 어린 물벼룩 평균수는 2회의 번식시험 모두에서 Jonczyk과 Gilron (2005) 및 OECD No. 211, Daphnia magna Reproduction Test 지침서(OECD, 2008)의 기준을 벗어나지 않았다. 그러나 탈염소 수도수에서 배양을 한 경우에는 2번의 번식시험 모두 어미의 사망률이 20% 이상으로, 배양 13일, 15일, 18일에 사망된 개체가 관찰되었다. D. magna는 경도가 80 mg $CaCO_3\;L^{-1}$ 이상인 물에서 사용을 추천하고 있으나, 본 연구에서 사용된 탈염소 수도수의 경도는 50~53 mg $CaCO_3\;L^{-1}$ 이었다. 탈염소 수도수에서 나타난 지연된 사망률은 배양배지의 급격한 경도 차이에 의한 영향으로 판단된다. 그러므로 국내의 자연수(지하수, 표면수, 탈염소 수도수 등)를 사용하여 D. magna를 배양할 경우, 배양배지의 경도를 100 mg $CaCO_3\;L^{-1}$ 이상 강화시켜 사용하는 것이 필요하다. 그리고 궁극적으로는 국내에 서식하는 토착 물벼룩류를 대상으로 국내 수 환경에 적합한 시험생물을 개발하는 국가적인 연구가 필요하다고 사료된다.

• 한국산업정보학회논문지
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• 제22권4호
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• pp.11-18
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• 2017

본 논문은 소비자에게 공급되는 수돗물의 공급시설(Water Supply Network)에 IoT 기술을 활용하여 소비자의 물 사용량을 원격으로 검침하고, 공급시설의 누수를 줄여서 원가를 절감하는 스마트 물관리(Smart Water Management) 기술의 적용효과를 검증하였다. SWM 실증모형은 수돗물 공급시설에 원격 누수감지센서, 스마트 미터링(Smart Metering), 초소형 멀티센서를 설치하고, 원격에서 운영현황을 실시간으로 감시하고 소비자에게 수돗물 사용량과 수질을 스마트폰 앱으로 제공하였다. 이때, 소비자가 수돗물 사용량 정보를 이용하여 수돗물을 아껴 쓰는지, 수돗물 수질정보를 이용하여 직접 음용하는지를 조사하였다. 특히, 본 연구에서는 SWM을 실증 적용함으로써 공급시설의 유수율 향상, 수돗물 음용률 향상, 소비자 민원 감소, 운영비용 절감, 수돗물 사용량 절감이 달성되는지를 검증하는데 목적이 있다. 또한 수돗물 공급시설의 IoT 센서, 운영자 모니터링 시스템, 이상발생시 탐사복구 솔루션이 융합된 하나의 SWM 모델을 수립하였으며, 관련 기술 개발을 통해 국내 물산업을 육성하고, SWM을 선진수준으로 확산하였다는데 의의가 있다고 하겠다.

• 생태와환경
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• 제54권3호
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• pp.240-246
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• 2021

깔따구(Diptera: Chironomidae)는 저서성 대형무척추동물로 환경 및 수질 변화에 민감한 영향을 받는 중요한 환경지표생물이다. 이러한 깔따구 유충이 정수장에서 본 연구에서는 제주 정수처리장에서 발견된 깔따구 유충의 종을 분류하기 위해 형태 사진 및 COI (cytochrome c oxidase subunit I) Primer로 증폭시킨 DNA의 염기서열을 계통수 분석을 통해 분석을 실시하였다. 정수장 내 수도꼭지와 소화관 등에서 채집된 17개체는 둥근깃깔따구(O. tamarutilus) 14개체, 타마긴털깔따구(P. tammaater) 3개체 총 2종으로 확인되었다. 각 깔따구 종의 형태적 특징은 두부, 하순기절, 대악, 안테나, 발톱의 형태적 특징의 분류기로 종 동정하였다. NCBI Genbank에 등록된 깔따구 19종 COI 염기서열을 기반으로 본 연구에서 조사된 17개체의 계통진화적 분석 결과 채집된 깔따구 COI 염기서열이 둥근깃깔따구(O. tamarutilus)와 타마긴털깔따구(P. tammaater) 2종으로 각각 계통군(clade)를 이루는 것이 확인되었다. 이러한 결과는 정수장 환경별 발견되는 깔따구 유충의 다양성의 확인과 형태적-유전적 종 동정 분류정보를 바탕으로 수환경 관리 및 평가를 위한 기반 정보로 활용될 것이다.

• 환경위생공학
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• 제5권1호
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• pp.65-72
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• 1990

To study on the water quality of domestic purifier, twenty four samples of clean water by purifier and the raw water(tap water) were tested for biological and physico-chemical examination and were checked for style of purification and the period elapsed after changing of purification medium. The results were as follows; Biological and physico-chemical findings of raw water were not exceeded standard values. Average number of general bacteria,2.coli and pH in clean water were significantly higher than that of raw water(respectively, p<0.01), but mean contents of turbidity, chloride, nitrate and iron in clean water were significantly lower than that of raw water(respectively, p<0.01). In general count of bacteria and E.coli, a half of the clean water of ceramic filter and roverse osmosis style were exceeded standard values for drinking water. All of the pH of the ion exchange style clean water were exceeded standard values. But other findings were within standard values. In average bacterial counts and physico-chemical findings of clean water by purification style of purifier, clean water of ion exchange style purifier were lowest number of general bacteria and not detected in 2. coli. But other items were highest. The longer period elapsed after changing of purification medium were the higher contents of biological and physico-chemical findings of clean water.

• 한국물환경학회지
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• 제28권4호
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• pp.615-623
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• 2012

In this study, we evaluate the corrosion indexes (CI) such as Langelier Index (LI), Larson ratio (LR), Ryznar saturation index (RSI), Aggressiveness index (AI) of water quality for raw water, treated water and water in distribution reservoir at major eight drinking water treatment plants (DWTPs) in Korea. By analyzing secondary contamination of tap water, the variation of secondary contaminants was investigated with regard to pipe materials, aging and corrosion index (CI). In addition, we suggested an appropriate CI applicable water quality and the management plan for CI monitoriing. All CI showed corrosive water quality, and they did not change significantly in the distribution network. However, Copper (Cu), iron (Fe) and zinc (Zn) concentrations as secondary contaminants increased through the distribution network. Among CI, LI was most sensitive to changes in raw water quality and drinking water treatment. Also, it has high correlations with other indexes such as RSI, AI. Therefore, LI is considered as an appropriate CI to the domestic water quality. Based on these result, we propose LI as a drinking water quality standard to control the pipe corrosion from DWTPs.