• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.51-52
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• 2003

질소제거의 경우 포기 60min인 경우 90% 이상의 제거율을 보였으나, 인 제거를 위해 굴곡점 시간 이후 30분 이상의 비포기 상태를 유지하였을 때 낮은 제거율이 나타났다.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.8
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• pp.523-527
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• 2012

This study was performed to determine optimum conditions of semi-continuous cultivation of chlorella sp. FC-21 cultivated under red light emitting diode (LED). Semi-continuous cultivation was conducted using red LED because red LED was found to be the best light source for chlorella sp. FC-21. During cultivation, phosphate and nitrogen were quickly diminished where cell concentration of chlorella was inversely proportional to the concentrations of phosphate and nitrogen in culture solution. To increase the period of dilution of culture solution, additional amounts of phosphate and nitrogen were inserted in the culture solution to increase the concentrations of phosphate and nitrogen. The cell concentrations of chlorella increased in the modified culture, but cell diameter was diminished as the dilution of culture was periodically conducted. When considered the cell concentration and cell diameter during the cultivation, amount of biomass produced was maintained constant.

• Elastomers and Composites
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• v.39 no.2
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• pp.105-120
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• 2004

The flame retarded NBR foams were prepared with metal hydroxides and various phosphorus/nitrogen-contain ing flame retardants. The dependency of the phosphorus content on thermal properties, flame retardancy, smoke density, and foaming properties were investigated in the foams. Foaming properties and morphology of the flame retarded NBR foams with P/N flame retardants( ${\le}10 phr$) were similar to those of the foams without P/N ones but containing metal hydroxides The flame retardancy of the foams was improved with increasing the phosphorus content and char formation under combustion atmosphere. The cone-calorimeter test and LOI index were also coincided with the TGA analysis quite well. The heat release rate (HRR), total heat release (THR), and effective heat of combustion (EHC) were decreased, whereas the carbon monoxide yield was increased with increase of the phosphorus content of P/N flame retardant. The smoke density values were closely related with CO yield values obtained by the cone-calorimeter test due to the high and hard char formation.

• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.76-82
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• 1998

The feasibility of algae as means of removing nitrogen and phosphorus from secondary treated swine wastewater was studied. Among the tested 7 species of Chlorella vulgaris (UTEX 265), Chlorella sp. GE 21, Botryococcus braunii (UTEX 572), Botryococcus sp. GE 24, Scenedesmus quadricauda, Phormidium sp. GE 2, and Spirulina maxima (UTEX 2342), C. vulgaris was selected for its fast growth and abilities to remove nitrogen and phosphorus and to produce algal biomass from swine wastewater. C. vulgaris grew well at 35$^{\circ}C$, and the optimum initial pH for growth was 8.0. In the effect of light intensity, the growth of C. vulgaris was limited under a light intensity of less than 40 ${\mu}$E/$m^2$/s. The secondary treated swine wastewater contained 58.7 mg/l of total nitrogen and 14.7 mg/l of total phosphorus, and was diluted to 75, 50, and 25% with groundwater to be treated. Nitrogen and phosphorus were removed by C. vulgaris in all diluted swine wastewaters among which the most effective removal was in 75% swine wastewater (swine wastewater:groundwater=3:1). There was a tendency of linear increase in nitrogen and phosphorus removal time with increasing concentration of swine wastewater. Under the optimized culture condition, total nitrogen and total phosphorus were effectively removed to 95.3% and 96.0%, respectively, in 25% swine wastewater after 4-day incubation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.1
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• pp.81-88
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• 1983

This experiment was conducted to study about influenced inorganic element contents of flag leaf and chaff with different nitrogen and silicate application in Jinan (sea level 303m). The recommended rate of fertilizer application above N 15kg/10a was poor for dry production increment in cold in July elevation and was demanded increment of silicate. In the elevation of cold in July high rates of nitrogen application produced more incomplete grain and a reduced cold tolerance. These effects were due to over-content of soluble nitrogen within flag leaf and disturbance of uptaking potassium and silicate. On the other hand, the application of silicate could increase yield by promoting resistance to cold- damage. The application of increasing level of nitrogen resulted in increasing the contents of total nitrogen and phosphate in both sterile and fertile glumes. The contents of potassium and calcium were the highest at the level of nitrogen 10 - 15kg/10a, but magnessium was rather high at low nitrogen levels. It is interesting that at any level of nitrogen, over 6% higher silicate contents were noted in the fertile chaff than in the sterile chaff. Application of increasing level of silicate fertilizer decreased total nitrogen contents, but increased the contents of phosphate, potassium. and silicate in the chaff. Increasing rate of silicate content by increasing silicate addition was remarkably higher in the fertile chaff than in the sterile chaff.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.192-192
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• 2012

플라즈마 CVD와 아크방전법을 혼합한 하이브리드 공정을 통하여 알곤과 메탄 그리고 질소를 인입하여 Cr을 타겟으로한 아크방전과 기판에 전극을 인가하는 방식의 플라즈마 CVD공정을 복합화하여 금속이 함유된 Cr-C:H 박막을 합성하고, 공정에 질소를 인입하여 박막에 질소를 도핑하여 부내식성과 전기적 전도성에 관한 고찰을 하였다. 내부식성은 동전위분극시험에서 $1{\mu}A/cm^2$을 보였고, 전기저항은 $1m{\Omega}-cm$ 이하로 측정되어 내식성과 전기전도성을 동시에 갖는 박막을 합성할 수 있었다. 내식성과 전기전도성에 대한 원인규명을 위하여 박막의 구조분석을 XPS, XRD, Raman 분석을 통하여 실시하였다. 흑연화 탄소(Graphitic carbon)와 금속콤포짓(Metal composite)은 내식성에 영향을 주었으며, 전도성물질의 percolation효과와 질소와 탄소의 단일 결합과정에서 생성되는 잉여전자에 의한 단일 결합(C-N) 분율이 전기전도성에 영향을 주었다.

• Journal of the Korean Chemical Society
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• v.65 no.4
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• pp.249-253
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• 2021

Litter and manure were obtained at a cow house of a livestock farm in Andondg city. We examined the change of formation of nitrogen and phosphorous from these samples and tried to suggest a more useful and realistic way for removing them. Constituent and its content of sample were identified by XRF. NO₂^-, NO₃^-, and PO₄^3- ions and NH₄⁺, T-P and T-N released from sample were analyzed using ion chromatograph and UV/Vis spectrometry, respectively. As the results of this study, the ammonia nitrogen in the early stage of cow excretion is a need to make an ammonia gas state that can be immediately volatile by increasing the pH. Nitrogen and phosphorous, the main source of nutrition in green algal bloom can be removed by transforming insoluble salts such as calcium phosphate (CaHPO₄·3H₂O) and struvite (NH₄MgPO₄·6H₂O), respectively, with addition of Ca and Mg after stimulating fermentation of manure.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2007.05a
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• pp.375-379
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• 2007

폐비닐 여재(Synthetic Waste Polyethylene Media)를 적용한 부착성장식 공정의 유기물 및 질소${\cdot}$인 제거특성에 관한 Pilot Plant 실험 결과 다음과 같은 결론을 얻을 수 있었다. 1) 제거효율은 $RUNI1{\sim}3$에서 $COD_{cr}$ 91.4, 92.4, 93.9%, T-N 56.9, 61.4, 65.1%, T-P는 모든 단계에서 약 45%이상 제거되어 부하변동시에 강한 대처능력을 나타내었다. 2) BOD용적부하 $0.18{\sim}0.40kg/m^3{\cdot}d$, COD용적부하 $0.28{\sim}0.53kg/m^3{\cdot}d$, ${NH_4}^{+}-N$용적부하 $0.12kg/m^3{\cdot}d$을 나타내었다. 3) 도시하수 처리를 위한 생물학적 질소 및 인 제거공법을 본 여재를 이용하여 공정설계시 고려할 사항들과 적절한 대처방법을 다음과 같이 제시할 수 있다. - 1차 침전지에서 유기질소 및 유기인 농도가 높다면 유기질소 및 인 부하량을 감소시키기 위하여 1차 침전지를 설치하되 질소 및 인제거에 유리한 $BOD_5/T-N$, $BOD_5/T-P$를 유지할 수 있도록 체류시간을 1시간미만으로 설계하는 것이 경제적이라고 판단된다. 만일 유기질소와 유기인의 함량이 낮다면 1차 침전지는 제외하는 것이 유리할 것이다. - 여재의 배치는 폭기조에서 용존산소의 균일분포와 슬러지의 적정탈리를 위해 여재를 상하로 배치하거나 또는 여재끼리 일정 간격을 두어 배치하는 것이 바람직하다. 농촌에서의 처분이 문제시 되고 있는 폐비닐을 적용한 본 연구에서의 수처리특성은 기존 하수처리공정에서의 제거효율에 상응하는 처리특성을 나타내었다. 또한 폐비닐 처분의 문제를 해결할 수 있을뿐만 아니라 하수처리시에도 부하변동 등에 강한 대처능력을 나타내어 기존의 하수처리공정에 대체가능성을 나타내었다.

• Journal of the Korean GEO-environmental Society
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• v.10 no.1
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• pp.43-48
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• 2009

This study was performed to investigate the characteristics of nutrient removal by Sequencing Batch Reactor (SBR) system, which could achieve high removal efficiencies of nitrogen and phosphorus and make it possible convenient management and operation. In this study, dissolved oxygen (DO), chemical oxygen demand (COD), nitrogen, and phosphorus in SBR system were examined by variation of anoxic-oxic phase repetition in order to optimize an operational method. The 1~4 times of anoxic-oxic phases (Run 1~4) were repeated during 1 cycle operation period. As the repetition frequency increased, it was more difficult to maintain DO condition enough for denitrification. The SBR system showed high COD removal efficiency more than 91% regardless of operational condition. About 68% of nitrogen removal rate was obtained in conditions of 2 or 3 times repetition of anoxic phases, in which NOx-N among discharged total nitrogen account for more than 99%. Approximately 40% of phosphorus was eliminated in the conditions of 1~3 times of anoxic phase repetition.

• Microbiology and Biotechnology Letters
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• v.33 no.2
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• pp.136-141
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• 2005

A bench-scale feasibility study was conducted with solid farming feed to evaluate a treatment process for microbiological removal of nitrogen (N) and phosphorus (P). Strains, Bacillus sp. CK-10 and Bacillus sp. CK-13, were originally isolated from water samples of shrimp farming pond. Simultaneous removal of N/P in marine media was monitored in the co-cultures, CK-10 and CK-13. As the results, $400\;{\mu}M\;NH^{+}_4$ and $400\;{\mu}M\;NO^{-}_2$ were eliminated within 12 hours and $NO^{-}_3$ within 36 hours, and $500\;{\mu}M\;PO^{-3}_4$ was completely disappeared within 36 hours from the media. Cultures of CK-10 and CK-13 were applied for removal of N/P leached from shrimp farming fred. HPAEC-PAD system was used to analyze sugars in farming feed, resulting in resolution of various sugars including glucose, galactose, galatosamine, mannose, and fucose. $0.2\%$ (w/v) Pulp densities of the farming feed contained approximately $33.3\;{\mu}M\;NH^{+}_4,\;12.9\;{\mu}M\;NO^{-}_2.\;81.5\;{\mu}M\;NO^{-}_3\;and\;248\;{\mu}M\;PO^{-3}_4$ which could dissolved within 72 hours of leaching in aqueous solution followed by bacterial removal. Complete bacterial removal of N/P was achieved within 84 hours at $0.2\%$ of the feed in co-cultures, whereas single cultures removed to incompletion of N/P during the incubation period. This work demonstrated that test cultures, CK-10 and CK-13 showed effective removal of N/P derived from shrimp farming feed.