• 대한환경공학회지
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• 제28권7호
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• pp.776-781
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• 2006

제초제, 로켓 추진제 등에 주로 사용되는 과염소산(perchlorate, $ClO_4^-$)은 갑상선의 요오드 섭취를 방해하여 갑상선 암을 유발할 수 있으며 임산부가 섭취 시 태아의 뇌 발달을 저해하는 등 인체 독성을 나타내는 것으로 알려져 있다. 최근 미국을 중심으로 perchlorate 관련 연구가 활발하게 진행되고 있으며 2006년 US. EPA에서 먹는물에서의 perchlorate 가이드라인을 설정하였다. 그러나 아직 국내에서는 perchlorate에 관한 독성 및 환경 내 오염 정도 등에 관해 구체적으로 조사된 바가 없다. 따라서 본 연구에서 국내 수 환경에서의 Perchlorate 오염 정도 파악을 위해 영남권 지역 주민들의 주 상수원수로 사용되고 있는 낙동강 수계와 낙동강 권역에 위치한 도시들의 수돗물을 대상으로 perchlorate를 분석하였다. 분석 결과 낙동강 수계 중에서는 $ND{\sim}278.4$ ${\mu}g/L$의 범위로 perchlorate가 검출되었으며 구미공단천(2차)에서 가장 높게 나타났으며 하류로 내려올수록 perchlorate 농도가 감소하였다. 수돗물의 경우 대상 도시에 따라 다소 편차를 나타냈으며 농도 범위는 $ND{\sim}34.1$ ${\mu}g/L$이었다. 조사 대상 지역 중 대구 달서 감삼동에서 가장 높게 검출되었고 부산에서는 비슷한 농도($9{\sim}11$ ${\mu}g/L$)로 대부분의 구에서 검출되었다. 본 조사결과는 낙동강 수계에 perchlorate 오염원이 있으며 낙동강을 상수원수로 사용하는 지역은 수돗물에서 perchlorate 관리대책이 필요함을 의미한다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.145-149
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• 2006

The effect of alkaline environmental condition on durability of GFRP composites according to additives has been investigated. Additives used were polyvinyl alcohol (PVA), kaolin and alumina powder. Weight gains increased with immersion time in all GFRP composites at $80^{\circ}C$. But weight gain of specimen added PVA did not differ through the whole immersion time in both tap water and alkaline solution at 20 and $80^{\circ}C$. Tensile strength decreased with immersion time in all environment conditions. Tensile strength of GFRP composites regardless of additives decreased rapidly up to 5 days of immersion and then decreased slowly up to 30 days in alkaline solution environment at $80^{\circ}C$. The weight gains were not much difference in both tap water and alkaline solution at $20^{\circ}C$. But the ones of GFRP composites added PVA was smaller than the composites without additive in all aqueous at $20^{\circ}C$. Test strength of GFRP composites added polyvinyl alcohol has improved through the whole immersion time in both tap water and alkaline solution environment at $20^{\circ}C$.

• 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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• 제22권6호
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• pp.1107-1108
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• 2006

As expanding municipal and industrial areas since started the economic development plan in earnest in 1970's, the water resource, mainly river surface water has been seriously polluted. Nevertheless, being upgraded in their treatment technologies for the drinking water, the safety has been issued one of crucially social problem in Korea. The water authorities has tried to improve the quality such as amending the drinking water quality standard to be monitored; hazardous chemicals and microorganis have been added and now 55 items, before 47 items, since in 2002. The Water Authorities of Seoul, the capital city of Korea, planned to assess the safty of drinking water quality after amended the standard. This study was conducted to assess the risk due to polluted chemicals including 21 heavy metals, VOCs, pesticides, PAHs, DBPs and organic chemicals among the regulated items. The risk assessment were undertaken hazard identification, exposure assessment, dose-response assessment and risk characterization. For the exposoure assessment, tap water, bottled water and purified water were sampled and analyzed in February, 2004. Risk characterization of detected chemicals was categorized into carcinogenecity and noncarcinogenecity, and estimated the excess of carcinogens and compapared with the reference dose (RfD) of noncarcinogenns. The excess risk of carcinogens from samples were considered comparatively in the acceptable levels; $10^{-6}$ for cancer risk and hazard quotient (HQ) 1.0 for noncancer risk. The deteced levels were estimated in $10^{-5}{\sim}10^{-6}$ of cancer risk and below 1.0 of HQ of noncancer risk. While three kinds of water were determined within the acceptal levels, DBPs were detected in tap water and purified were and some undesireable chemicals such as more fluoride detected rather than the quality stanadard. For the drinking water safety, it shoud be continuously monitored, assessed and managed as well risk communiction between the authoritis and public.

• 한국수자원학회논문집
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• 제45권1호
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• pp.29-37
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• 2012

본 연구에서는 울산지역의 수돗물 수질 개선에 대한 응답자들의 지불의사액을 도출하였다. 이를 위해 조건부 가치측정법(CVM)을 활용하되, CVM 연구에서 지켜야하는 다양한 지침을 엄격하게 준수하여 가구조사를 시행하고 1.5경계 양분선택형 스파이크 모형을 적용하여 분석하였다. 울산광역시 400개 가구를 대상으로 가구조사를시행하였고 일대일 개별면접을 통해 수돗물 수질개선 프로그램에 대한 지불의사금액을 질문하였다. 응답자 중 71.5%가 지불할 의사가 없다고 응답한 것을 고려할 때 스파이크 모형의 적용은 적절하였으며, 분석결과 가구당 월 평균 1,611원의 지불의사액을 가지고 있는 것으로 나타났다. 이러한 지불의사는 교육 및 소득과 같은 가구 특성변수에 유의하게 영향을 받았다. 이 값을 울산광역시 전체로 확장하면 2011년 6월 기준으로 연간 약 83억 원에 해당하였다. 본 연구의 결과는 수돗물 수질개선이 경제적으로 타당성을 가지는지에 대한 판단을 할 때 편익정보로서 중요한 역할을 할 것으로 기대된다.

• 상하수도학회지
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• 제32권3호
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• pp.235-242
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• 2018

Corrosion inhibitors including calcium hydroxide have been used to prevent corrosion in the pipes for tap water supply. The corrosion index (i.e., Langelier Index) differs by area and water quality. The corrosion indices of the areas studied differed by more than 2.0. The 'homogenized' calcium hydroxide was added to the treated water at the K water treatment plant, in order to increase the value of the corrosion index and the concentration of calcium. As the result, the concentration of calcium was increased while the turbidity and pH changed little. The corrosion rate of the tap water with the 'homogenized' calcium hydroxide could be slowed down pretty much. The results suggested that the technology of 'homogenization' of calcium hydroxide can applied to tap water and desalinated water to prevent corrosion in water pipes even in corrosive pipes.

• 한국환경보건학회지
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• 제43권2호
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• pp.143-156
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• 2017

The purpose of this study was to investigate water quality through a field survey at six floor fountain sites. The floor fountain facilities were designed and operated in such a way that tap water was stored in a water tank and recycled repeatedly. The water tank was cleaned once or twice per week in the summer. The number of facility users was low during the day due to sweltering heat, but up to 40 people, mainly children, were using them around 8 pm. Since the operation time was as short as 30 minutes, it is considered necessary to extend it for at least one hour for the number of users. As a result of the water quality test of the reservoir tank prior to operation after cleaning, it was measured to be within drinking water quality standards at the six facilities. As a result of the water quality test after use, ammonia nitrogen was measured to be 1.45 mg/L at Site IV. This exceeded the drinking water quality standard of 0.5 mg/L. In the case of turbidity, two cases exceed at 7.38 and 4.52 NTU when applying 4 NTU as the water quality standard for waterscape facilities. Twenty-eight cases exceed the standard of drinking water quality. The result of microbiological tests, at five sites excepting Site I, where disinfectant was injected, was that the maximum total colony count was 180,000 CFU/mL, total coliforms was 2,100,000 CFU/100 mL, fecal coliforms was 4,600 CFU/100 mL, Escherichia coli was 170 MPN/100 mL and Enterococcus was 100 CFU/100 mL. This exceeded the water quality standards of drinking water. Children are very likely to inhale because the water spews from below and falls from above, so it is necessary to apply water quality standards for ammonia nitrogen, turbidity and microbes. Current floor fountain facilities are highly susceptible to disease caused by microbial contamination because of water cycling and reuse, so it is necessary to change the water every day, clean the water tank, and perform chlorination. Therefore, it is necessary to inject calcium hypochlorite according to the free chlorine water quality standard of swimming pools with a different water tank capacity. In addition, facilities should be improved to prevent the reuse of water by installing the water tank at a separate location.

• Asian Journal of Business Environment
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• 제10권4호
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• pp.29-34
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• 2020

Purpose: Town of Woldia, a semi-arid region in the Northern Wollo region of Ethiopia, faces water supply shortage in general, though the town possesses a running stream of clean water throughout the year. This study is aimed at analyzing the possibility of using rainwater for water scarcity and non-potable water needs of the Woldia University. A careful study and analysis have been made to assess the feasibility of using rainwater in place of the tap water supply. Research design and methodology: This study was done inside the main campus of Woldia University located in Woldia town. The runoff water from the roof of buildings was studied, by the time of rainfall in the town. Also, the budget needed for implementing a rainwater harvesting system was calculated. Results: The findings of the study clearly indicates that the requirements of the water to use for flushing, cleaning, and washing toilets in the administrative buildings and classrooms can be satisfied by using rainwater as an alternative to tap water. Conclusion: Based on the results the study finds it is benefitable for the Woldia University to install the rainwater harvesting system at the earliest to solve the water problems prevailing in the current situation.

• 생명과학회지
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• 제13권2호
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• pp.197-205
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• 2003

미국 EPA (Environment Protection Agency)와 환경부에서 규정하고 있는 표준검출법인 총세포배양법 (Total Culturable Virus Assay : TCVA)을 이용하여 부산시 상수원수 및 정수장을 대상으로 2001년 7월에서 2002년 11월까지 바이러스 검사를 실시하였다. 검사결과 21개의 상수원수 시료 중 13개 시료에서 CPE (cytopathic effect)가 확인되어 61.9%의 양성률을 보였으며, 정수 및 수도꼭지수에서는 모두 검출되지 않았다. 또한, 검출된 바이러스를 계절별로 보면 주로 여름철과 초겨울에 분포하는 특성을 보였다. 검출된 바이러스는 TCVA-MPN 방법에 의해 1.92-9.70 MPN/100 L의 범위로 전량 되었으며, 면역형광법 (Immunofluorescent assay)에 의해 human poliovirus type 1과 enterovirus종으로 동정되었다.

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 1995년도 특강 및 학술논문발표요지
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• pp.75-78
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• 1995

양액재배시 배양액의 pH는 중요한 재배인자이며, 이는 용수의 성질에 따라 큰 영향을 받는다. 용수로는 지하수를 많이 사용하나, 수돗물을 사용하는 경우도 흔히 있다. 수돗물은 pH가 7.5 정도로, pH가 낮은 용수를 사용할 경우와 같은 조성의 배양액을 조제하면 배양액의 pH가 높아 생육에 나쁜 영향을 끼친다. 따라서, 용수의 성질에 따라 배양액의 조성을 달리하여 pH를 적정수준으로 유지하는 것이 중요하다. (중략)