• 제목/요약/키워드: Environmental water

검색결과 19,112건 처리시간 0.043초

Hydrogen Bonding in Aromatic Alcohol-Water Clusters: A Brief Review

  • Ahn, Doo-Sik;Jeon, In-Sun;Jang, Sang-Hee;Park, Sung-Woo;Lee, Sung-Yul;Cheong, Won-Jo
    • Bulletin of the Korean Chemical Society
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    • 제24권6호
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    • pp.695-702
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    • 2003
  • Recent experimental and theoretical advances on the aromatic alcohol-water clusters are reviewed, focusing on the structure of the hydrogen bonding between the alcoholic OH group and the binding water molecules. The interplay of experimental observations and theoretical calculations for the elucidation of the structure is demonstrated for phenol-water, benzyl alcohol-water, substituted phenol-water, naphthol-water and tropolone -water clusters. Discussion is made on assigning the role (either proton-donating or -accepting) of the hydroxyl group by measuring the shifts of infrared frequency of the OH stretching mode in the cluster from that of bare aromatic alcohol for the experimental determination of the cluster structure.

Rubbish, Stink, and Death: The Historical Evolution, Present State, and Future Direction of Water-Quality Management and Modeling

  • Chapra, Steven C.
    • Environmental Engineering Research
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    • 제16권3호
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    • pp.113-119
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    • 2011
  • This study traces the origin, evolution, and current state-of-the-art of engineering-oriented water-quality management and modeling. Three attributes of polluted water underlie human concerns for water quality: rubbish (aesthetic impairment), stink (ecosystem impairment), and death (public health impairment). The historical roots of both modern environmental engineering and water-quality modeling are traced to the late nineteenth and early twentieth centuries when European and American engineers worked to control and manage urban wastewater. The subsequent evolution of water-quality modeling can be divided into four stages related to dissolved oxygen (1925-1960), computerization (1960-1970), eutrophication (1970-1977) and toxic substances (1977-1990). Current efforts to integrate these stages into unified holistic frameworks are described. The role of water-quality management and modeling for developing economies is outlined.

Treatment of surface water using cold plasma for domestic water supply

  • Nguyen, Dung Van;Ho, Phong Quoc;Pham, Toan Van;Nguyen, Tuyen Van;Kim, Lavane
    • Environmental Engineering Research
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    • 제24권3호
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    • pp.412-417
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    • 2019
  • This paper presents the results of using cold plasma to treat surface water for domestic use purpose. Experimental results showed that cold plasma was an effective method for destroying bacteria in water. After treatment with cold plasma, concentration of coliform and Escherichia coli dramatically reduced. Besides, cold plasma significantly removed water odor, increased dissolved oxygen and decreased the concentration of chemical oxygen demand. However, cold plasma significantly raised the concentration of nitrite and nitrate. Other disadvantages of treating with cold plasma were conductivity increase and pH reduction. Pretreatment steps of coagulation, flocculation, sedimentation and sand filtration followed by disinfection with cold plasma exhibited a high efficiency in surface water treatment. All parameters of surface water after treatment by using the prototype satisfied with the allowance standard of domestic water quality.

경안천의 오염현황 (Status of Water Pollution of Gyeongan River, Korea)

  • 이동석;박갑성
    • 한국물환경학회지
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    • 제20권6호
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    • pp.698-702
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    • 2004
  • At five stations in Gyeongan River, a tributary of Lake Paldang, physicochemical and biological environmental factors of water, particulate matters, and sediments were investigated biweekly from April 11 to December 22 in 2001. The studied area was characterized as a stream-lake system. The system is primarily referred to a place where the environmental factors had considerably changed depending on the amount of precipitation. As a result, the river turned out to be strongly eutrophicated. Also, some characteristics of the water and the particulate matters at midstream such as average concentrations of conductivity, nutrients, and chlorophyll $\alpha$ were higher than the characteristics of up and down-stream. However, the concentrations of organic matters and ratio of clay and silt of the midstream were determined to be higher than up and down-stream sediments. As the result of the factor analysis, 4 major different patterns for environmental factors are found from samples of water, particulate matters, and sediments.

Establishment of Alarm Criteria for Automatic Water Quality Monitoring System in Korea

  • Lim, Byung-Jin;Hong, Eun-Young;Kim, Hyun-Ook;Jeong, Eun-Sook;Heo, Woo-Myung;Kim, Yoon-Hee
    • 생태와환경
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    • 제41권4호
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    • pp.423-430
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    • 2008
  • As of September 2008,45 Automatic Water Quality Monitoring Systems (AWQMS) have been installed at different sites on the 4 rivers to detect early the presence of pollutants in water and to issue an alarm. We count the number of issuing alarms by AWQMS, however, we will find the alarm has hardly been issued. The reasons for the scarcity of alarm issue are extensively being examined. The National Institute of Environmental Research attributes wrong alarm criteria for each AWQMS station to one the reasons. In this study, a suggestion has been made to modify the current alarm criteria to correspond with characteristics of river water quality. The current system with only two criteria (low and high) should be replaced as four-criteria systems (low, medium, high, and severe) based on cases of other advanced countries and stream conditions of Korea. The highest value of data collected for 5 years was suggested as the alarm criteria for each parameter. Meanwhile the alarm criteria for VOCs, phenol and heavy metals were established as same as drinking water quality criteria.

Variations of Disinfection By-products in a Chlorinated Drinking Water Distribution System

  • Lee, Soo-Hyung;Park, Jeong-Kun;Lee, Hyung-Jun;Kim, He-Kap
    • 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.

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정수처리 공정 단계별 스테인리스관과 동관에 형성된 생물막 비교 (Comparison of Biofilm Formed on Stainless Steel and Copper Pipe Through the Each Process of Water Treatment Plant)

  • 김근수;민병대;박수정;오정환;조익환;장석재;김지혜;박상민;박주현;정현미;안태영;정원화
    • 미생물학회지
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    • 제49권4호
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    • pp.313-320
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    • 2013
  • 정수처리 시설에서 급 배수관으로 많이 사용되는 스테인리스관과 동관에 형성되는 생물막의 특성에 대해 16주 동안 조사하였다. 생물막 반응기는 실제 배급수관의 구조와 유사하게 설계하였으며, 정수처리장으로 유입되는 상수원수와 약품혼화 응집수, 침전수, 여과수, 처리수를 사용하였다. 평균 종속영양세균수는 $1.6{\times}10^4CFU/ml$, $5.8{\times}10^3CFU/ml$, $1.8{\times}10^3CFU/ml$, $1.3{\times}10^2CFU/ml$, 1 CFU/ml로 각 처리 과정을 거치면서 감소하였다. 스테인리스관과 동관에 형성된 생물막 세균수는 원수, 응집수, 침전수에서 2주만에 $2.9{\times}10^3CFU/cm^2$ 이상으로 증가하였고, 동관보다 스테인리스관에서 생물막 세균수가 높게 검출되었다. 여과수(평균 잔류염소 0.44 mg/L)에서는 두 관 재질에 따른 생물막 세균수의 명확한 차이는 없었으며, 5주 이후부터 두 관재질 모두 $18CFU/cm^2$ 이하의 생물막 세균이 검출되었다. 정수(평균 잔류염소 0.88 mg/L)에서는 두 관 재질 모두 생물막 세균이 검출되지 않았다. DGGE 분석결과, 원수, 응집수, 침전수에서 스테인리스관은 Sphingomonadaceae가 우점이였고, 동관에서는 Bradyrhizobiaceae와 함께 Sphingomonadaceae도 우점이였다. 여과수의경우, 5주차 이후 스테인리스관과 동관에 형성된 생물막에서 Propionibacterium sp., Sphingomonas sp., Escherichia sp. 등과 유사한 16S rRNA 유전자 서열을 가지는 밴드들이 검출되었다. 종 풍부도 및 다양성은 동관에 비해 스테인리스관이 더 높게 나타났다.

수질모형을 이용한 수질오염사고의 모의분석 (Simulation of Water Pollution Accident with Water Quality Model)

  • 최현구;박준형;한건연
    • 환경영향평가
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    • 제23권3호
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    • pp.177-186
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    • 2014
  • Depending on the change of lifestyle and the improvement of people's living standards and rapid industrialization, urbanization of recent, demand for water is increasing rapidly. So emissions of domestic wastewater and various industrial waste water has increased, and water quality is worsening day by day. Therefore, in order to provide a measure against the occurrence of water pollution accident, this study was tried to simulate water pollution accident. This study simulated 2008 Gimcheon phenol accident using 1,2-D model, and analyze scenario for prevent of water pollution accident. Consequently the developed 1-D model presents high reappearance when compared with 2-D model, and has been able to obtain results in a short simulation run time. This study will contribute to the water pollution incident response prediction system and water quality analysis in the future.

물 부족 문제와 관련된 환경교육 발전 방향에 대한 연구 (A Study on the Direction of Middle School Environmental Education Related to Water Shortage Problem)

  • 곽태성;이두곤
    • 한국환경교육학회지:환경교육
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    • 제20권3호
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    • pp.113-124
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    • 2007
  • The purpose of this study is to investigate the direction of how to educate water shortage problem to middle school students. In the reality that many people of the world have been painful of the water shortage problem, Korea is classified as 'water shortage country'. Here, we investigated the awareness of middle school students about the contents related to the water shortage problem by surveying with the questionnaires developed in this study. And we analyzed how water shortage problem appeared in the environmental textbook of middle school. Based on these, we examined the direction of environmental education in middle school on the theme of the water shortage problem. The results of the survey showed that students revealed difference of knowledge and experience, and also revealed difference of knowledge and feeling related to the water shortage problem. The students had the knowledge about water shortage problem but they did not have experience in their real lives. Also, the results of the survey showed that students had attitude of waste in water use, even though they had awareness and knowledge about the importance of water resources. And the students did not have enough knowledge related to the water shortage problem. From the analysis of the textbooks, We found that the contents were not composed to enhance deep understanding of the students about the water shortage problem. Based on the analysis of the results, the directions of middle school environmental education in Korea about water shortage problem were extracted in this research.

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