• Journal of Ecology and Environment
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• 제29권1호
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• pp.41-47
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• 2006

We investigated the enect of $O_3$ on the photosynthetic characteristics of tree of heaven (Ailanthus altissima) that is naturalized plant and used as restoration plant for contaminated area. Two-year-old seedlings were planted to pots and transferred into closed $O_3$ chamber. Photosynthetic pigments contents and photosynthetic characteristics were measured every three weeks under 100 pub $O_3$ fumigation. There was no visible foliar injury by $O_3$ exposure and contents of photosynthetic pigments did not show significant differences between control and $O_3$-treated seedlings. Also there were no significant differences in stomatal conductance, and water use efficiency. But photosynthetic rate and apparent quantum yield (AQY) of $O_3$ treated seedlings were reduced after nine weeks of ozone fumigation. In addition, the reduction of carboxylation efficiency and photorespiration were observed in the leave of $O_3$ treated seedlings after six weeks. In accordance with our result, carbon fixation system of A. altissima was most sensitive to $O_3$ stress to evaluate physiological damage induced by $O_3$.

• 상하수도학회지
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• 제23권5호
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• pp.655-667
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• 2009

An experimental study is performed on reducing the pollutants supplied by storm water through enhancing efficiency of SS from the detention storage tank where CSOs are kept temporarily before discharge to the receiving water system. SS removal efficiency is investigated in accordance with various conditions of the detention pond-such as its length, the existence of training wall, and the use of gravel filling. The removal efficiency is strongly affected by the detention pond's length until the critical falling distance of the suspended solids is reached. For cases where the tank has a length longer than this critical condition, the removal rate shows less sensitivity. To enhance the SS removal efficiency of tanks of shorter than the critical length, we studied alternative types of tank in which inside training walls are installed. The results showed improvement of 14 to 37% in removal efficiency in 2hours detention(2 training walls). The important factor in achieving a high SS removal rate is ensuring the critical length of the detention pond, but for the cases where the basin length cannot be guaranteed, baffles or a gravel filling scheme may be introduced to attain considerable efficiency. The results of studying and comparing different storage tank conditions show that, in terms of elimination efficiency, a storage tank with gravel filling and training walls > a storage tank with gravel filling > a storage tank with training walls > an empty tank. The experimental results should contribute to development of related further research, by empirically verifying the already assumed importance of critical falling distance, training walls, and gravel filling schemes.

• 한국막학회:학술대회논문집
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• 한국막학회 2001년도 국제 Workshop:상수원의 현황과 분리막 상수처리(Water Resource and Menbrane Water Treatment)
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• pp.133-154
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• 2001

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.2169-2175
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• 2009

This research aims to evaluate the concept of eco-efficient water infrastructure and provides a list of case studies in order to help understand the applicability of eco-efficient water infrastructure to Asia and the Pacific. A set of indicators have been explored to assess eco-efficiency in water infrastructure for the region on a micro and macro scale. The core idea of eco-efficiency, 'more value with less impact (on the environment)', has proven to be applicable in management of water infrastructure. The fundamental elements in eco-efficient water infrastructure should encompass physical infrastructure and non-physical infrastructure, which is more needed particularly in Asian countries. The case studies have demonstrated the applicability of the concept of eco-efficient water infrastructure. The Republic of Korea has provided the case of the eco-friendly approaches to enhance dam management and its innovative solutions how to use water more efficiently through state-of-art technologies. The experiences of Singapore are some of the best evidence to establish eco-efficient water infrastructure, for instance, the NEWater project via application of cutting edge technologies (recycled water) and institutional reform in water tariff systems to conserve water as well as enhance water quality. A list of indicators to assess eco-efficiency in water infrastructure have been discussed, and the research presents a myriad of project cases which are good to represent eco-efficiency in water infrastructure, including multipurpose small dams, customized flood defense systems, eco-efficient ground water use, and eco-efficient desalination plants. The study has presented numerous indicators in five different categories: 1) the status of water availability and infrastructure; 2) production and consumption patterns of freshwater; 3) agricultural products and sources of environmental loads; 4) damages from water-caused natural disaster; and 5) urban water supply and sanitation. There are challenges as well as benefits in such indicators, since the indicators should be applied very carefully in accordance with specific socio-economic, political and policy contexts in different countries in Asia and the Pacific Region. The key to success of establishment of eco-efficient water infrastructure in Asia primarily depends on the extent to which each country is committed to balancing its development of physical as well as non-physical water infrastructure. Particularly, it is imperative for Asian countries to transform its policy focus from physical infrastructure to non-physical infrastructure. Such shift will help lead to implementation of sustainable in Asian countries.

• 상하수도학회지
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• 제21권6호
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• pp.727-735
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• 2007

The use of water by cities is increasing owing to industrialization, the concentration of population, and the enhancement of the standard of living. Accordingly, the amount of waste water is also increasing, and the degree of pollution of the water system is rising. In order to solve this problem, it is necessary to remove organisms and suspended particles as well as the products of eutrophication such as nitrates and phosphates. This study developed a high-end treatment engineering solution with maximum efficiency and lower costs by researching and developing a advanced treatment engineering solution with the use of Biosorption. As a result, the study conducted a test with a $50m^3/day$ Pilot Scale Plant by developing treatment engineering so that only the secondary treatment satisfies the standard of water quality and which provided optimal treatment efficiency along with convenient maintenance and management. The removal of organisms, which has to be pursued first for realizing nitrification during the test period, was made in such a way that there would be no oxidation by microorganisms in the reactor while preparing oxygen as an inhibitor for the growth of microorganism in the course of moving toward the primary settling pond. The study introduced microorganisms in the endogeneous respiration stage to perform adhesion, absorption, and filtering by bringing them into contact with the inflowing water with the use of a sludge returning from the secondary settling pond. Also a test was conducted to determine how effective the microorganisms are as an inner source of carbon. The HRT(Hydraulic Retention Time) in the nitrification tank (aerobic tank) could be reduced to two hours or below, and the stable treatment efficiency of the process using the organisms absorbed in the NAR reactor as a source of carbon could be proven. Also, given that the anaerobic condition of the pre-treatment tank becomes basic in the area of phosphate discharge, it was found that there was excellent efficiency for the removal of phosphate when the pre-treatment tank induced the discharge of phosphate and the polishing reactor induced the uptake of phosphate. The removal efficiency was shown to be about 94.4% for $BOD_5$. 90.7% for $COD_{Cr}$ 84.3% for $COD_{Mn}$, 96.0% for SS, 77.3% for TN, and 96.0% for TP.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.510-515
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• 2007

A Study on Typical Rates of Water-use for School Facilities has been carried out in this work. Water supply system is given much weight in school facilities. Therefore, it set up a basis efficiency using of water sources to calculate typical rates of water use. The results are summarized as follows ; 1) On the whole, typical rates of water-use was founded out 15 L / stu. d in pirmary school, 10 L / stu. d in middle school and 30L / stu. d in high school smaller than the existing it. It was rate of water-use change as season and Max. Rates of water-use was July. 2) I deem that school hours are 5 hour's in primary school, 7 hour's in middle school and 8 hour's in high school. It the concept of 1 hour that is lesson time 40 minutes and resting time 10 minutes in primary school, lesson time 45 minutes and resting time 10 minutes in middle school and lesson time 50 minutes and resting time 10 minutes in high school. 3) It is desired that we calculate the volume of pump and water tank throughout this concept and the size of water tank should be 1.5 times with taking pick load into consideration by this study on typical rate of water-use. 4) The amount of using water increases in gradually and I consider the life cycle of facilities is more than 10 years. As a result, I can forecast that the size will be insufficiency but I deem that if we devise a plan about parallel pumping on water tank space, we can cope with it. Also, it is expected that we can cut back the transport energy by controlling pump volume.

• 한국환경보건학회지
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• 제45권6호
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• pp.561-568
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• 2019

Objectives: The most commonly detected heavy metals in rocks and soils, including Pb, Cd, Cu, Fe, Mn and As, are representative pollutants discharged from abandoned mines and have been listed as potential sources of contamination in drinking water. This study focused on increasing the removal efficiency of heavy metals from drinking water resources by surface modification of natural adsorbents to reduce potential health risks. Methods: Iron oxide coating and graft polymerization with zeolites and talc was conducted for bipolar surface modification to increase the combining capacity of heavy metals for their removal from water. The removal efficiency of heavy metals was measured before and after the surface modification. Results: The removal efficiency of Pb, Cu, and Cd by surface modified zeolite showed 100, 92, and 61.5%, respectively, increases compared to 64, 64, and 38% for non-modified zeolite. This implies that bipolar surface modified natural adsorbents have a good potential use in heavy metal removal. The more interesting finding is the removal increase for As, which has both cation and anion characteristics showing 27% removal efficiency where as non-modified zeolite showed only 2% removal. Conclusions: Zeolite is one of the most widely used adsorptive materials in water treatment processes and bipolar surface modification of zeolite increases its applicability in the removal of heavy metals, especially As.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.198-198
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• 2017

Climate change causes unpredictable and erratic climatic patterns which affects crop production in agriculture and threatens public health. To cope with the challenges of climate change, sustainable and sound growth environment for crop production should be secured. Recent attention has been given to the development of smart irrigation system using sensors and wireless network as a solution to achieve water conservation as well as improvement in crop yield and quality with less water and labor. This study developed the smart irrigation technique for farmlands by monitoring the soil moisture contents and real-time climate condition for decision-making support. Central to this design is micro-controller which monitors the farm condition and controls the distribution of water on the farm. In addition, a series of laboratory studies were conducted to determine the optimal irrigation pattern, one time versus plug time. This smart technique allows farmers to reduce water use, improve the efficiency of irrigation systems, produce more yields and better quality of crops, reduce fertilizer and pesticide application, improve crop uniformity, and prevent soil erosion which eventually reduce the nonpoint source pollution discharge into aquatic-environment.

• 제어로봇시스템학회논문지
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• 제15권7호
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• pp.688-693
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• 2009

In terms of water meter reading, the majority of 16 million houses use mechanical water meter in korea. So, a member of the utility's staff needs to access periodically the water meter and the value of the metered volume. However, due to the use of mechanical water meter, many issues have been appeared as cost, time, errors, accessibility, and readability. To settle these issues, we developed the walk-by meter reading system of digital water meter and outside indicator based on ubiquitous. And we could get the characteristics and the economical efficiency for water meter reading system. Thus, this study shows that the system can be widely used to the block system and the meter reading system for stable water supply.

• 한국토양비료학회지
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• 제43권3호
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• pp.253-259
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• 2010

본 연구는 휴경논 벼 대체작물로서 보리, 밀, 조의 수분스트레스에 대한 생육특성을 비교하기 위하여 실시하였다. 라이시미터를 이용하여 지하수위를 0, 25, 50, 75, 100 cm의 5개 수위로 처리하여 지하수위에 따른 생체량과 증발산량 및 증산량을 조사하고 수분이용효율 특성과 작물별 적정 지하수위를 추정하였다. 보리, 밀, 조 모든 작물은 과습에 대한 내성이 약하였으며 작물별로는 보리 > 조 > 밀의 순이었다. 지상부 건물중 1 g을 생산하는데 소요된 증발산량으로 나타낸 증발산비율로 비교할 경우 보리는 166~605 mL, 밀은 136~481 mL, 조는 81~418 mL의 분포로서 보리 > 밀 > 조의 순이었고 100 cm 지하수위에서 0 cm 지하수위로, 즉 수분포화 조건으로 갈수록 증발산 비율은 증가되었다. 지하수위에 따른 지상부 건물중의 회귀식으로부터 최대 건물중을 나타내는 지하수위는 밀이 76 cm로 평가되었고 보리와 조의 경우는 지하수위가 낮아질수록 거의 직선적으로 증가되는 경향을 보이며 처리구 시험범위 밖인 100 cm 이하로 평가되었다. 작물 재배기간 동안 토양의 용적수분 함량은 작물에 의한 수분흡수량만큼 모세관을 통한 수분공급량이 부족하여 재배기간이 경과할수록 급격하게 감소되는 경향을 보였다.