• 한국토양비료학회지
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• 제44권4호
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• pp.600-614
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• 2011

Classical methods which used for removal of heavy metals from contaminated water are adsorption, precipitation, coagulation, ion exchange resin, evaporation, and membrane processes. Microbial biosorption can be used for the removal of contaminated waters with pollutants such as heavy metals and dyes which are not easily biodegradable. Microbial biosorbents are inexpensive, eco friendly and more effective for the removal of toxic metals from aqueous solution. In this review, the bacterial and fungal abilities for heavy metals ions removal are emphasized. Environmental factors which affect biosorption process are also discussed. A detailed description for the most common isotherm and kinetic models are presented. This article reviews the achievements and the current status of bacterial and fungal biosorption technology for heavy metals removal and provides insights for further researches.

• 대한토목학회논문집
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• 제29권2B호
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• pp.193-205
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• 2009

태풍은 열대태평양 지역에서 발생하여 북상하면서 우리나라에 영향을 끼치게 되며, 태풍이 우리나라를 지나면서 강풍과 호우를 통하여 자연재해를 유발시키게 된다. 따라서 본 연구에서는 태풍으로 인해 발생하는 호우 사상을 여러 통계적 기법을 통해 정량적으로 평가하였다. 첫 번째로 빈도해석을 통해 확률강우량과 태풍 확률강우량을 산정하여 비교하였다. 두 번째로 미공병단에서 개발한 EST 기법을 통해 태풍의 극치강우량을 평가하여 EST 확률강우량을 산정하였다. 마지막으로 비매개변수적 모의발생기법과 지역가중다항식을 결합하여 태풍에 의한 NL 확률강우량을 추정하였다. 분석결과에서 대상지점 중에서 강릉과 목포는 태풍의 영향을 다른 지점에 비해 많이 받으며, 서울과 인천은 태풍에 의한 호우의 영향이 미비한 것으로 나타났다. 또한, EST 확률강우량과 NL 확률강우량은 관측 자료를 이용하여 장기간의 모의를 통하여 quantile을 산정하므로 주요 수공구조물과 태풍의 영향이 큰 지역에서는 이를 검토할 필요성이 있으며, 태풍특성인자의 모의를 통하여 강우량을 평가하므로 지구온난화 등에 따른 기후변화의 영향에 대한 연구에 활용 할 수 있다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1992년도 수공학연구발표회논문집
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• pp.325-328
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• 1992

The purpose of this research is to develop the technique of heavy metal removal from wastewater. The research is divided into two parts, one part uses complex precipitation and the other uses adsorption. In the first part of the study, humic acid is used as the complex agent, humic acid is a polyelectrolyte with a high complexation affinity. Lead, copper, zinc and cadmium were studied for their complex precipitation efficiencies. In the batch studies, humic acid was effective in removing 100% of the lead and 48.2% of the copper respectively from wastewater without anytreatment. The efficiency of cadmium and zinc, however, was very low. In the second part of the study, wastewater is introduced at the top of a silicagel adsorption column and then bottom effluent concentration is analyzed. The results of the analysis are used to draw a breakthrough curve.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.379-381
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• 2003

Metal sorption onto the ICS (Iron oxide coated sand) was studied in batch experiments. Heavy metal cations such as Cd, Pb, and Cu, and a metal anion, As, which sporadically exist in mine sites, were tested for the sorptive removal by ICS. In low pH conditions As showed the highest removal efficiency compared to the other metal cations. And the sorption removal of As was apparently pH-independent reaction. However, removal of metal cations increased with pH and above pH 7 most metal cations showed very low soluble concentrations after treatment. Such a high removal ratio of metal cations above the neutral pH appeared predominantly due to precipitation.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.163-163
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• 2023

Flooding has become an increasing event which is one of the major natural disasters responsible for direct economic damage in South Korea. Driven by climate change, precipitation extremes play significant role on the flood damage and its further increase is expected to exacerbate the socioeconomic impact in the country. However, the empirical evidence associating changes in precipitation extremes to the historical flood damage is limited. Thus, there is a need to assess the causal relationship between changes in precipitation extremes and flood damage, especially in agricultural region like Chungcheong region in South Korea. The spatial and temporal changes of precipitation extremes from 10 synoptic stations based on daily precipitation data were analyzed using the ClimPACT2 tool and Mann-Kendall test. The four precipitation extreme indices consisting of consecutive wet days (CWD), number of very heavy precipitation wet days (R30 mm), maximum 1-day precipitation amount (Rx1day), and simple daily precipitation intensity (SDII), which represent changes in intensity, frequency, and duration, respectively, and the time series data on flooded area and flood damage from 1985 to 2020 were used to investigate the causal relationship in the ARDL-ECM framework and pairwise Granger causality analysis. The trend results showed that majority of the precipitation indices indicated positive trends, however, CWD showed no significant changes. ARDL-ECM framework showed that there was a long-run relationship among the variables. Further analysis on the empirical results showed that flooded area and Rx1day have significant positive impacts on the flood damage in both short and long-runs while R30 mm only indicated significant positive impact in the short-run, both in the current period, which implies that an increase in flooded area, Rx1day, and R30 mm will cause an increase in the flood damage. The pairwise Granger analysis showed unidirectional causality from the flooded area, R30 mm, Rx1day, and SDII to flood damage. Thus, these precipitation indices could be useful as indicators of pluvial flood damage in Chungcheong region of South Korea.

• Water Engineering Research
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• 제3권1호
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• pp.1-8
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• 2002

Cloud seeding has not been used now to regulate water supplies in Korea and this results in losses to economy. The fastest experiments on precipitation enhancement in the world show that there are real possibilities to increase precipitation by 10-20%. Investigations of economic losses due to the lack of routine cloud seeding experiments in Korea have shown that they exceed about 100 million US dollars In 1999. Recommendations on cloud seeding activities including works on precipitation augmentation and prevention of heavy rains are presented. Spatial and temporal necessity to carry out this or that work is discussed.

• 토지주택연구
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• 제2권2호
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• pp.157-162
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• 2011

본 논문은 강원도 횡성지역에서 집중호우와 태풍 에위니아, 빌리스의 선행강우에 의해 2006년 7월 16일에 발생한 산사태 피해 발생 원인과 특성에 대하여 분석한 결과이다. 산사태 발생의 직접적인 원인은 7월 12일~13일의 선행강우로 지반의 포화도가 증가된 상태에서 7월 15일~16일의 집중호우로 인해 피해가 발생한 것으로 확인되었다. 자연 사면의 산사태 유형은 얕은 심도의 풍화잔류토층과 기반암의 경계면에서 활동이 진행되는 전이형 사면활동으로 확인되었다. 횡성지역에서 발생한 100개소에 대한 자료의 종합적인 분석 결과, 산사태 발생의 사면길이는 100m이하(87%), 사면 폭은 30m이하(74%), 평균사면경사는 $24^{\circ}$로 나타났다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1018-1019
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• 2005

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.123-123
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• 2020

The present study is aimed to correcting radar-based mean areal precipitation forecasts to improve urban flood predictions and uncertainty analysis of water levels contributed at each stage in the process. For this reason, a long short-term memory (LSTM) network is used to reproduce three-hour mean areal precipitation (MAP) forecasts from the quantitative precipitation forecasts (QPFs) of the McGill Algorithm for Precipitation nowcasting by Lagrangian Extrapolation (MAPLE). The Gangnam urban catchment located in Seoul, South Korea, was selected as a case study for the purpose. A database was established based on 24 heavy rainfall events, 22 grid points from the MAPLE system and the observed MAP values estimated from five ground rain gauges of KMA Automatic Weather System. The corrected MAP forecasts were input into the developed coupled 1D/2D model to predict water levels and relevant inundation areas. The results indicate the viability of the proposed framework for generating three-hour MAP forecasts and urban flooding predictions. For the analysis uncertainty contributions of the source related to the process, the Bayesian Markov Chain Monte Carlo (MCMC) using delayed rejection and adaptive metropolis algorithm is applied. For this purpose, the uncertainty contributions of the stages such as QPE input, QPF MAP source LSTM-corrected source, and MAP input and the coupled model is discussed.

• KSBB Journal
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• 제29권3호
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• pp.139-144
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• 2014

Microorganisms play a significant role in bioremediation of heavy metal contaminated seawater. In this study, we reported an effective removal of Cu and Zn in marine envionment by using Desulfovibrio desulfuricans (D. desulfuricans) which belong to sulfate reducing bacteria. D. desulfuricans showed stable growth characteristics in high salt concentration and had resistance to heavy metals. Cu and Zn was removed not only by physical adsorption on the surface of bacteria but also by precipitation reaction of microbial metabolism by D. desulfuricans in seawater. In case of different heavy metal concentration, Cu was effectively removed 85% at 25 ppm and 60% at 50 ppm and Zn was effectively removed 54% at 50 ppm and 46% at 200 ppm, respectively.