• Korean journal of applied entomology
• /
• v.46 no.3
• /
• pp.363-373
• /
• 2007

To evaluate environment of farm lands using indicator insects and evaluation indices, the insect abundance of which is one of the major criteria for the evaluation of agricultural environment of farm land in urban areas and industrial complex, three sites (Ansan, Daesan, Suncheon) were designated and monitored from 2004 to 2006. The flora of agricultural land was more than urban areas and industrial complex of that in three sites. Soil, water and air pollution of urban areas and industrial complex were more serious than those of agricultural land in three sites. Overall population of insects were high from June to August in the surveyed three sites. Collected insects in agricultural land were 12 order, 106 family and 166 species, those in urban areas were 11 order, 102 family and 148 species, and in industrial complex were 11 order, 100 family and 152 species. Species and population belonging to Coleoptera was dominant in the surveyed sites. The insect diversity indices of farm land were 2.36 in agricultural land, 1.92 urban areas and industrial complex. And agricultural environment of agricultural land was good, urban areas was common and industrial complex was poor. Based on the major criteria of evaluation items, the criteria were selected as diversity index over 2.1, insect indicator Pheropsophus javanus in agricultural land, diversity index 1.5-2.0, insect indicator Nephotettix cincticeps in urban areas, diversity index below 1.5, insect indicator Pagria signata in industrial complex.

• Korean Journal of Ecology and Environment
• /
• v.37 no.3 s.108
• /
• pp.344-354
• /
• 2004

A pilot study was performed from September 2000 to April 2004 to examine the feasibility of the wetland-pond system for the agricultural reuse of reclaimed water. The wetland system was a subsurface flow type, with a hydraulic residence time of 3.5 days, and the subsequent pond was 8 $m^3$ in volume (2 m ${\times}$ 2 m ${\times}$ 2 m) and operated with intermittent-discharge and continuous flow types. The wetland system was effective in treating the sewage; median removal efficiencies of $BOD_5$ and TSS were above 70.0%, with mean effluent concentrations of 27.1 and 16.8 mg $L^{-1}$, respectively, for these constituents. However, they did often exceed the effluent water quality standards of 20 mg $L^{-1}$. Removal of T-N and T-P was relatively less effective and mean effluent concentrations were approximately 103.2 and 7.2 mg $L^{-1}$, respectively. The wetland system demonstrated high removal rate (92 ${\sim}$ 90%) of microorganisms, but effluent concentrations were in the range of 300 ${\sim}$ 16,000 MPN 100 $mL^{-1}$ which is still high for agricultural reuse. The subsequent pond system provided further treatment of the wetland effluent, and especially additional microorganisms removal in addition to wetland-pond system could reduce the mean concentration to 1,000 MPN 100 $mL^{-1}$ from about $10^5$ MPN 100 $mL^{-1}$ of wetland influent. Other parameters in the pond system showed seasonal variation, and the upper layer of the pond water column became remarkably clear immediately after ice melt. Overall, the wetland system was found to be adequate for treating sewage with stable removal efficiency, and the subsequent pond was effective for further polishing. This study concerned agricultural reuse of reclaimed water using natural systems. Considering stable performance and effective removal of bacterial indicators as well as other water quality parameters, low maintenance, and cost-effectiveness, wetland- pond system was thought to be an effective and feasible alternative for agricultural reuse of reclaimed water in rural area.

• Korean Journal of Head & Neck Oncology
• /
• v.28 no.2
• /
• pp.149-152
• /
• 2012

Paraganglioma of the thyroid is a neuroendocrine tumor originating from the neural crest. To our knowledge, only 32 cases of thyroid paraganglioma(TP) have been reported to date. TP is difficult to distinguish from medullary thyroid cancer(MTC), hence correct diagnosis is seldom obtained preoperatively. Although immunohistochemistry is helpful for confirmation of TP, these markers are not specific for differential diagnosis between TP and MTC. Therefore, an index of suspicion is important when encountered with MTC with unusual features, or given pathology with neuroendocrine features and unusual immunohistochemical findings. The authors report a case of TP misdiagnosed as MTC at preoperative work-up and intraoperative frozen section analysis, with a review of the literature. The case depicts various immunohistochemical characteristics of the tumor.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.493-497
• /
• 2005

엄청난 자원의 매장고, 국가간의 대규모 교역을 가능케 한 항로, 어족자원의 공급원등으로서 인류의 생존과 번영에 일익을 담당하고 있는 바다는 인간의 증가하는 에너지 수요를 지속적으로 감당할 수 있는 무공해에너지의 보고로도 다가오고 있다. 그러나, 에너지 밀도가 타 에너지에 비하여 상대적으로 낮아 큰 규모의 에너지추출장치가 필요하다는 단점에도 불구하고, 대부분의 바다에서 하루에 두 번 씩 발생하는 조석현상을 이용하는 조력발전은 조석의 반복적이고 주기적인 특성 , 태양계가 존속하는 한 영구히 발생한다는 영속성, 현대과학과 관련기술의 진보 등으로 전 세계적으로 그 개발에 인류의 관심이 높아져 있다. 현재 조력발전소가 건설 중인 시화호는 포화상태에 있는 수도권에 공업용지를 공급하고 우량농지 조성으로 경쟁력 있는 농업을 육성하기 위하여 담수호로 조성되었으나,하수처리장 등 기초환경시설이 미비한 상태에서 인근지역으로부터 오염물질이 유입되어 수질이 악화되자 정부는 수질개선을 위하여 시화호를 해수호로 용도를 변경하였다. 본 논문에서는 조수간만의 차를 이용하여 무공해 전력을 생산하는 조력발전의 원리 및 최적발전량 산정기법과 높은 조수간만의 차로 조력개발적지로 유망한 서해안에 건설하게 될 시화호 조력발전소의 사업 및 기후변화협약 이행 시 기대효과 등에 대하여 논하고자 한다.

• Journal of Korean Society of Water and Wastewater
• /
• v.31 no.1
• /
• pp.93-101
• /
• 2017

In this study, we investigated the correlation between the number of cyanobacterial species and the water quality factors after installation of Nakdong river weirs. Factor analyses of water quality factors were also performed. The results of correlations showed that there was no significant water quality with the cyanobacterial concentration but the correlation coefficient of nutrients increased from the upstream to the downstream. There was a significant correlation between W T and pH as important water quality factors for the growth of cyanobacteria. In the downstream region of Nakdong river, algae were more frequently detected than in the upstream region, and the blooms of algae species seem to be influenced by the higher pH and the influx of the phosphorus from the upstream tributaries. Nutrient concentration was higher in the downstream region than in the upstream region due to the effects of tributaries Geumho river and Nam river in Nakdong river. As a result of the factor analyses, nitrogen species were the principal factors in the upper region, and phorsphorus species were the principal factors in the downstream region.

• Journal of Wetlands Research
• /
• v.13 no.3
• /
• pp.489-497
• /
• 2011

In this study the main purpose is to reduce non-point source pollution and improve water quality of Hoeya reservoir using constructed wetlands. As part of the efforts to improve water quality of the reservoir, cattail and reed-wetland cells were constructed in front of the reservoir to remove nitrogen(N) and phosphorus(P). Also, effects of hydraulic and seasonal variation on removal efficiencies of N and P were investigated. Total P and N removal efficiencies of the wetland system were approximately 20.7% and 42.7%, respectively. Removal efficiencies of N and P during the growth season (july to august) and blooming season of cattail and reed (september to october) were higher than other seasons. These results suggest that wetland system could be an effective alternative for control of non-point source pollutnat such as N and P of reservoir.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.1658-1662
• /
• 2009

최근 들어 기후 변화로 인한 이상 강우 현상과 기록적인 집중 강우로 탁수 발생의 빈도와 강도가 증가하고, 탁수의 장기간 하류 방류로 인해 경제적인 피해가 발생할 뿐만 아니라 환경적으로도 중요한 문제로 대두되고 있다. 저수지로 유입된 탁수의 시공간적 분포 예측 결과의 신뢰도는 탁수 밀도류 해석의 정확도에 가장 큰 영향을 받으므로 유입 하천수의 밀도 거동에 대한 정확한 해석이 필요하다. 따라서 탁수의 거동해석은 수리 및 수질의 연동 모의(Coupled modeling)가 필수적이다. 본 연구의 목적은 수리 및 수질의 연동 해석이 가능한 2차원 횡 방향 평균 모형(CE-QUAL-W2)을 소양호에 구축하고, 기록적인 강우 사상을 보인 2006년 수문조건에서의 모형의 적용성과 한계점을 평가하는데 있다. 구축한 소양호 탁수 예측 모델을 2006년 탁수사상에 적용한 결과, 홍수 사상으로 이중 첨두 유량이 발생한 후 저수지 내에서 중층 밀도류와 바닥밀도류의 두 가지 밀도류 형태가 혼재하여 진행되는 현상이 적절히 모의되었다. 하지만, 저수지내에서 측정한 탁수 수괴(plume)의 시공간적 수직분포(profiles)는 모의결과와 다소 편차를 보였으며, 특히 저수지 바닥 인근에서 모델은 실측값을 과대평가 하였다. 오차의 원인은 모델 입력 자료의 불확실성과 수치모델의 불확실성으로 판단된다. 따라서 향후 탁수 거동 모델링과정의 불확실성을 최소화하고 모의결과의 신뢰도를 개선하기 위해서 극한탁수 사상에서 발생하는 수리학적 현상과 SS 입자 동력학에 대한 이론적 연구와 입력 자료의 정확한 산정을 위한 현장 실험이 필요하다.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.11 no.1
• /
• pp.5-8
• /
• 1978

Numerical changes of coliform bacteria in a recirculating aquarium were measured as fouling indicator. The contamination of the filter bed was mainly due to the food given to fishes, the fecal materials and the additional supply of water polluted already. Abundance of the bacteria in the aquarium was controlled by the physiochemical factors of water quality. Of these factors, pH was the main factor. Under the water temperature $20^{\circ}C$, if pH was controlled at lower than $5\~6$, the bacteria did not flourish seriously. Under the water temperature over $30^{\circ}C$, the bacterial growth was markedly decreased regardless of the pH value, and the bacterial flora seemed to be active in growth under temperature condition lower than $30^{\circ}C$.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1998.11a
• /
• pp.114-118
• /
• 1998

농촌지역인 공주시 유구읍 명곡리 지역의 천부지하수와 먹는 샘물 공장의 취수정 심부 지하수을 대상으로 지화학적 특성을 밝히고, 물-암석 상호반응과 오염물질 유입에 대해서 토의하였다. 천부 지하수의 화학적 유형은 Ca-HCO$_3$형에서 Ca-Cl(SO$_4$)형으로 전반적으로 약산성화 되어있고, $K^{＋}$, Cl$^{-}$, NO$_3$$^{-}$오염이 상당히 진행되어 70 %이상이 음용수로 불가능한 상태이다. 군집방법에 의하면 신선한 물과 오염된 물사이에 뚜렷한 경향의 차이를 보인다. 천부지하수의 주요 오염원은 각가정에 있는 재래식 화장식, 생활하수, 가축의 축사, 비료등으로 보인다. 심부지하수는 알카리성의 Na-HCO$_3$형에서 Na(Ca)-HCO$_3$형의 화학적 유형이며, 2 TU 이하의 삼중수소 함량으로 1950년대 이전에 함양된 비교적 오랜 물-암석 상호반을 거친 물로 판단된다. 반면 천부형 지하수는 1950년대 이후에 충전된 상당히 젊은 연령의 지하수로 보인다. $^{18}$ O/$^{16}$ O, D/H 환경동위원소 조성값으로 볼 때 심부지하수의 함양지역은 고도의 효과를 보인다. 이 연구결과는 농촌지역의 지하수 수질 오염에 대한 하나의 사례연구로 향후 전국을 대상으로 한 농어촌지역의 지하수 오염연구에 기본방향을 제시하는데 의의 가 있을 것이다.

• Journal of Korean Society of Water and Wastewater
• /
• v.26 no.1
• /
• pp.131-139
• /
• 2012

Field experiment was performed from June 2010 to July 2011 to evaluate pollutants removal efficiency in the constructed wetland system for the treated wastewater and the river water. The wetland systems were constructed near Gyungan river. Two different systems with meandering shape were compared for seasonal base and operational period base. Several kinds of aquaculture are planted through the corridor of wetland system. Average removal rate of BOD, T-N and T-P for A system were 15.8%, 14.8% and 26.5%, respectively. Average removal rate of BOD, T-N and T-P for C system were 23.5%, 27.8% and 10.6%, respectively. The effluent from two wetland systems often exceeded effluent water quality standards for wastewater influent, however effluent water quality standards for river water. However, the wetland system can be useful to treat polluted river water and effluent from wastewater plant. Removal rate of pollutants in seasonal variation was the highest in summer for BOD and T-N, however the removal rates of T-P were higher in spring and autumn than in summer.