• 생물환경조절학회지
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• 제20권3호
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• pp.189-196
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• 2011

Ebb and flow 시스템을 사용한 분화 칼랑코에 재배에서 광도와 양액 농도가 생육, 양분 흡수율 및 배지 내 무기 이온의 집적에 미치는 영향을 구명하기 위하여 본 연구를 수행하였다. 연구 목적을 달성하기 위하여 광도 3수준(PPF 4.26, 5.51, $9.75mol{\cdot}m^{-2}{\cdot}d^{-1}$)과 양액 농도 3수준(EC 1.2, 1.8, $2.4dS{\cdot}m^{-1}$)을 조합하여 요인실험으로 수행하였다. 분화 재배한 칼랑코에의 생육은 광도와 양액 농도에 뚜렷하게 영향을 받았으며, 광도가 높아질수록 생육이 양호하였다. 각 광도 내에서는 양액의 EC를 $1.8\sim2.4dS{\cdot}m^{-1}$의 범위로 조절할 경우 칼랑코에 지상부 생육이 비교적 양호하였지만, EC를 $2.4dS{\cdot}m^{-1}$로 조절한 처리의 생체중, 건물중 및 엽면적이 가장 크게 나타났다. 광도와 양액 농도는 ebb and flow 시스템의 양액 탱크로부터 양분 및 수분 흡수량과 배지 내 무기 이온의 집적에 유의하게 영향을 미쳤지만, 식물체의 무기물 함량에는 뚜렷한 영향을 미치지 않았다. 광도는 양액의 EC에 비해 이온의 흡수율에 미치는 영향이 상대적으로 적었으며, 양액 EC가 높을 수록 $NO_3^-$, P, K, Mg 이온의 흡수율은 높았다. 이상의 연구결과를 고려할 때 ebb and flow 저면 관수 시스템에서 배지 내 무기 이온 집적에 영향을 주는 주 요인은 양액 농도임을 확인하였으며, 광도와 양액의 EC를 이용하여 배지 내 무기 이온의 집적량을 예측하기 위한 회귀식을 제시하였다.

• The Korean Journal of Ecology
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• 제18권2호
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• pp.243-253
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• 1995

Seral changes in environmental factors and recovery of soil fertility during abandoned field succession after shifting cultivation were investigated in eastern Kangwon-Do, Korea. Relative light intensity of herb and shrub layer decreased gradually until 50 years and increased slightly thereafter. Amount of litter and nutrients derived from it were depicted as a parabola form showing the gradual increment during the first 50 years and slight decrease thereafter. Organic matter, pH value, total-N and Mg of soil were plotted as an early depletion-mid pinnacle form showing the extrems depletion during the first 10 years, abrupt increase in about 20 or 50 years and gradual decrease thereafter. Ca, Al, Mn and Na of soil were depicted as a pinnacle form showing the peak in about 20 or 50 years. Thickness and field capacity of soil increased gradually, but K and total-P did not show any tendency as succession proceeded. The soil fertility, overall capacity of soil nutrients and water for plant growth, was plotted as the early depletion-mid pinnacle form.

• 한국환경과학회지
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• 제6권6호
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• pp.697-709
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• 1997

Sequencing Batch Reactor(SBR) experiments for organics and nutrients removal have been conducted to find an optimum anaerobic/anoxic/aerobic cycling time and evaluate the applicability of oxidation-reduction potential(ORP) as a process control parameter. In this study, a 61 bench-scale plant was used and fed with night-soil wastewater in K city which contained TCODcr : 10, 680 mg/l, TBm : 6, 893 mg/l, $NH_4^+-N$ : 1, 609 mg/l, $PO_4^{3-}-P$ : 602 mg/l on average. The cycling time In SBRs was adjusted at 12 hours and 24 hours, and then certainly included anaerobic, aerobic and inoxic conditions. Also, for each cycling time, we performed 3 series of experiment simultaneously which was set up 10 days, 20 days and 30 days as SRT From the experimental results, the optimum cycling time for biological nutrient removal with nlght-soil wastewater was respctively 3hrs, 5hrs, 3hrs(anaerobic-aerobic-anoxic), Nitrogen removal efficiency was 77.9%, 77.9%, 81.7% for each SRT, respectively. When external carbon source was fed in the anoxic phase, ORP-bending point indicating nitrate break point appeared clearly and nitrogen removal efficiency increased as 96.5%, 97.1%, 98.9%. Phosphate removal efficiency was 59.8%, 64.571, 68.6% for each SRT. Also, we finded the applicability of ORP as a process control parameter in SBRs.

• 한국환경과학회지
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• 제17권11호
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• pp.1265-1271
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• 2008

Aerated submerged bio-film (ASBF) pilot plant has been developed. The presented studies optimized an inexpensive method of enhanced wastewater treatment. The objectives of this research were to describe pilot scale experiments for efficient removal of dissolved organic and nitrogen compounds by using ASBF reactor in plug-flow reactor (PFR) and improve understanding of dissolved organic matter and nitrogen compounds removal rates with dynamic relationships between heterotrophs and autotrophs in the fixed-film reactor. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. This direct gas-phase contact should increase the oxygen transfer rate into the bio-film, as well as increase the micro-climate mixing of water, nutrients, and waste products into and out of the bio-film. This research also investigated the efficiency of dissolved organic matter and ammonia nitrogen removals in the ASBF. As it was anticipated, nitrification activity was highest during periods when the flow rate was lower, but it seemed to decline during times when the flow rate was highest. And ammonia nitrogen removal rates were more sensitive than dissolved organic matter removal rates when flow rates exceeded 2.2 L/min.

• 한국시스템다이내믹스연구
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• 제16권1호
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• pp.25-51
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• 2015

The purpose of this paper is to analyze nutrients dynamics depending on biomass of Menyanthes trifoliata L., the endangered species, in a small closed-type wetland. In order to understand dynamics between Menyanthes trifoliata L. and eutrophication, causal loops and stock-flow diagram were constructed. The result of the model simulation was matched well with monitoring data (Menyanthes trifoliata L. biomass, TN, TP, DO). The model was simulated with 3 scenarios. In case of scenario 1, the initial value of biomass was 0mg/L, and the eutrophic state period was 77 days. In case of scenario 2, the initial value of biomass was 35.8 mg/L, and the eutrophic state lasted for 13 days. In case of scenario 3, the initial value of biomass was 71.6 mg/L, and the eutrophic state was nonexistent. The scenario 3 was selected as planting plan of Menyanthes trifoliata L. Through this study, planting design with an endangered plant was developed to control eutrophication in small closed-type wetland.

• 한국유기농업학회지
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• 제19권4호
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• pp.589-602
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• 2011

In this study, experiments were conducted to determine the effect of different compost teas on plant growth reponses and yield of leaf lettuce. Compost tea is a liquid extract of compost obtained by mixing compost and water for a defined period of time. The pig manure and spent mushroom compost were made by steeping compost in water. Compost tea was aerated from 24 hours and molasses and kelp were added as supplements. The four types of compost were tested growth of lettuce. EC of animal manure compost tea was higher than that of spent mushroom compost tea. Mineral nutrients were significantly higher in animal manure compost tea compared with spent mushroom compost tea. Compost tea contains nutrient and a ranges of different organisms. The beneficial fungi and actinomycetes were prominent in a spent mushroom compost tea. Compost tea from animal manure had the higher numbers of total bacteria. The actinomycetes densities were high in spent mushroom compost tea. But actinomycetes were not founded in animal manure compost tea. The growth characteristics of lettuce in animal manure compost tea were higher than those of spent mushroom compost tea. And also SPAD value in leaf was high in plot treated with animal manure compost tea. The fresh yield of lettuce in animal compost tea was higher by 181% that of control plot. The effect of compost tea on growth of lettuce was largely attributable to mineral nutrient.

• KSBB Journal
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• 제18권3호
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• pp.234-238
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• 2003

생물막 공정은 소규모 오수처리공정에서 운전과 유지가 간단하기 때문에 활성 슬러지 공정보다 각광을 받고 있다. 담체로 폐토기와 폐비닐을 충진한 컬럼형 반응기로 실폐수인 식당 폐수의 오염물을 제거하는 실험을 수행하였다. 실험결과, 수력학적 체류시간 (HRT)이 18 hr일 때 COD 제거율은 93.7%로 칙대 COD 제거율을 보였다. 같은 조건에서 T-N과 T-P의 평균 제거율은 각각 82.3%, 25.9%를 나타내었다. 따라서 HRT를 18 hr 이상일 때 유기물과 질소의 제거 측면에서 비교적 만족할 만한 처리효율을 얻을 수 있었다.

• 상하수도학회지
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• 제25권5호
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• pp.783-790
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• 2011

The purpose of this study was to suggest the alternative measures to properly manage the water quality of Lake Euiam, Chuncheon. Current pollution level of Gongji stream (influent to Lake Euiam) and sources of contamination in Lake Euiam were investigated. Particle size, organic matter and nutrient contents, heavy metals were analyzed for sediment samples taken from lower region of Gongji stream. Average organic matter content of nine sediment samples was 5.7%, and for nitrogen and phosphorus it was 750 mg/kg and 977mg/kg, respectively. Heavy metals including aluminum, iron, manganese and zinc were measured, whereas Cd and As were not detected. Effluent from Chuncheon Wastewater Treatment Plant appeared to be one of the main cause of organic matter and nutrients level in Lake Euiam. Inhibition of primary production and consequent reduction of organic matter content within the Lake should be a key measure to protect the water quality of Lake Euiam. Preventive measures to reduce the level of nutrients in wastewater treatment effluent were found necessary.

• 한국환경과학회지
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• 제22권12호
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• pp.1643-1650
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• 2013

This study investigated water quality of effluents and stream from the sewage treatment plants located at Gumi Complex 4, Gumi, and Wonpyeong in Gumi. Downstream region was found to increase the concentration of nutrients for sewage treatment plant effluent. Both phosphorus and nitrogen were accounted most as soluble form. In particular, the high ratio of dissolved effluent of sewage treatment plants were investigated. In the streams, Phosphorus concentration was high during rainy season and nitrogen concentration was high in the dry season. Sewage treatment plant effluent was relatively less microbial activity and nutrient concentrations were higher in the winter. TN/TP ratio was the highest in the upstream region and the lowest in the sewage treatment plant effluent. The effect of the nutrient matter from a discharge of a sewage treatment plant on rivers varied depending on the size of the river and the treatment plant. However, the influence of the concentration was greater than that of flowrate. Sewage treatment plant effluent loads phosphorus, nitrogen accounted for 8% and 6% respectively at the point N3 of the Nakdong river.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2022년도 추계학술대회
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• pp.51-51
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• 2022

Water dropwort (Oenanthe stolonifera DC.) is a perennial herbaceous plant that grows wild throughout Korea. As of 2020, 24,819 tons (51.7% of open field, 48.3% of facility) are produced in 1,278 ha (59.9% of open field, 40.1% of facility) nationwide. Water dropwort, which is rich in nutrients such as vitamins and iron, is mainly cultivated by vegetative propagation method using local traditional species, however, seed propagation and breeding of cultivars are insufficient so far. Since securing, propagating and continuous characterization of various genetic resources are required to breed new cultivars, this study was conducted to compare the main characteristics of domestic genetic resources and to improve their utilization. Growth characteristics such as plant height, fresh weight, plant type, and flowering date were investigated for the 89 varieties of genetic resources owned by Jeollabuk-do Agricultural Research and Extension Services after vegetative propagation in the individual pots. Also, the morphological image information of leaves and flowers was constructed. Genetic resources were collected nationwide and originated in 30 regions including Hwaseong, Siheung and Jeju. Their plant types could be classified into straight, intermediate and creeping types according to their morphological characteristics, and at this time, the number of intermediate types accounted for the largest proportion. Flowering was carried out under high-temperature and long-day conditions in summer. According to the flowering date, they could be classified into early, middle and late flowering varieties, and at this time, the middle flowering varieties occupied the largest proportion. As a result of the investigation of vegetative growth characteristics, varieties with long plant height, heavy fresh weight and thick stem thickness were identified. Along with this result, it is thought that classification and selection of genetic resources for various purposes will be possible through additional investigations such as analysis of components and antioxidant activity. Moreover, it is judged that such results can be used as basic data for breeding new water dropwort cultivars in the future.