• 한국안전학회지
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• 제24권4호
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• pp.34-39
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• 2009

The adsorption characteristics of amatanth by granular activated carbon were experimently investigated in the batch adsorber and the packed column. The adsorptivity of activated carbon for amaranth were largely improved by pH control, and 94 percent of initial concentration(100mg/L) could be removed at pH 9. It was estabilished that the adsorption equilibrium of amaranth on granular activated carbon was sucessfully fitted by Freundlich isotherm equation in the concentration range from 1mg/L to 100mg/L. The characteristics of breakthrough curve of activated carbon packed column, which depend on the design variables such as initial concentration, bed height, and flow rate, were studied.

• 한국식품영양학회지
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• 제6권4호
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• pp.268-275
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• 1993

The whole cells of Actinoplanes missouriensis KCTC 1780 which produce glucose isomerase was immobillized by flocculation method for the effective production of high fructose syrup using packed-bed bioreactor system. Among the flocculation methods used In this study, the glucose Isomerase activity of flocculated cells using 5% polyethylenimmine and 0.2% glutaraldehyde was the highest as 46.3 unit, and the flocculant was 10.3g(wet weight) per 100m1 of broth, and the residual activity was 92.5%. In the batch operation of glucose isomerization using the flocculated cells, the optimum pH, temperature and isomerization ratio were 7.0, 75$^{\circ}C$ and 31%, respectively. The optimum concentration of Mg2+ which was activator on the glucose isomerization of flocculated cells was 0.1M, and glucose isomerase activity was increased by about 40% compared to none of Mg2+. In the packed-bed bioreactor system with 1.2 hour of residence time at 7$0^{\circ}C$, the reaction stability maintained until 96 hour without toss of activity, and the equilibrium was kept up to 120 hours of the operation.

• Journal of Microbiology and Biotechnology
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• 제2권2호
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• pp.98-101
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• 1992

Continuous production of fructo-oligosaccharides employing a packed bed reactor charged with immobilized cells of Aureobasidium pullulans was investigated. The optimum conditions for reactor operation were a feed concentration of 860 g/l; a feed rate, expressed as superficial space velocity of $0.2\;h^{-1}$, and a temperature of $50^\circ{C}$. Under these optimum conditions, the productivity of the reactor was $180\;g/l\cdot{h}$. Initial activity was maintained for more than 100 days. The reactor was successfully scaled up to a production scale of 1000l.

• 대한설비공학회지:설비저널
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• 제7권1호
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• pp.13-19
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• 1978

An experiment has been performed of find a temperature distribution of the circulating fluid in a packed bed thermal storage system when the inlet fluid temperature is constant. The thermal storage system is a specific-heat type in which the circulating fluid, hot air, exchanges heat directly with the heat storage materials, glass balls, in a heat storage bin. An empirical equation which includes two dimensionless variables $t^*\;and\;T_f^*$, is obtained. Also, heat storage efficiency and heat storage capacity are calculated from this equation, The heat transfer coefficient calculated by the suggested equation was compared with the value determined by the existing empirical equation.

• 대한토목학회논문집
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• 제32권1B호
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• pp.85-91
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• 2012

영가철을 이용한 투수성 반응벽체는 지하수를 처리하는 원위치정화기술로 국내외적으로 연구가 활발히 진행되고 있다. 본 연구는 기존 영가철을 이용한 투수성 반응벽에 직류전원을 공급하여 효율이 향상된 TCE 처리기술 개발을 목적으로 하였다. 주문진규사로만 충진한 컨트롤컬럼, 영가철과 주문진규사로 충진한 영가철컬럼(영가철:주문진규사 = 1:2(v/v)) 그리고 영가철 컬럼에 직류전원을 공급한 복극전기분해컬럼, 이 세 컬럼의 운전을 통해 TCE 분해효율을 비교하였다. 실험 결과, 영가철를 충진하고 직류전원을 공급한 복극전기분해컬럼이 영가철만을 사용한 컬럼에 비해 높은 TCE의 환원효율을 나타내었다. 이는 영가철 입자가 미세전극으로 작용하여 전자의 이동을 촉진시킨 것에 기인한 것으로 보인다. 따라서 영가철이 반응매질로서의 역할만 할 때보다 반응매질의 역할과 동시에 전극으로서 작용했을 때, TCE 분해효율이 더 높게 나타났음을 알 수 있었다.

• Environmental Engineering Research
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• 제10권4호
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• pp.191-198
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• 2005

A novel technology for the removal of nitrogen from wastewater, an autotrophic denitrification process with sulfur particles, has been developed. A respirometer was employed to monitor the nitrogen gas produced in the reactor, while 4',6-diamidino-2-phenylindole staining was employed to investigate the biomass distribution in terms of cell number according to the reactor height. From the respirometric monitoring, the denitrification reaction was defined as a first order reaction. The reactor was divided into 7 sections and biomass was analyzed in each section where cell number was ranged from $4.8\;{\times}\;10^6\;to\;8.7\;{\times}\;10^7$ cells/g dry weight of sulfur. Cells placed mostly in the lower layer ( < 10 cm of height). A function for biomass distribution was obtained with non-linear regression. Then a mathematical model has been developed by combining a plug-flow model with the biomass distribution function. The model could make a vertical profile of the up-flow packed-bed reactor resulting in a reasonable comparison with measured nitrate concentration with 5% of error range.

• Journal of Microbiology and Biotechnology
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• 제30권8호
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• pp.1227-1234
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• 2020

In this study, yeast cell immobilization was carried out in a packed bed reactor (PBR) to investigate the effects of the volumetric capacity of carriers as well as the different fermentation modes on fuel ethanol production. An optimal volumetric capacity of 10 g/l was found to obtain a high cell concentration. The productivity of immobilized cell fermentation was 16% higher than that of suspended-cell fermentation in batch and it reached a higher value of 4.28 g/l/h in repeated batches. Additionally, using this method, the ethanol yield (95.88%) was found to be higher than that of other tested methods due to low concentrations of residual sugars and free cells. Continuous ethanol production using four bioreactors showed a higher productivity (9.57 g/l/h) and yield (96.96%) with an ethanol concentration of 104.65 g/l obtained from 219.42 g/l of initial total sugar at a dilution rate of 0.092 h^-1. Furthermore, we reversed the substrate-feed flow directions in the in-series bioreactors to keep the cells at their highest activity and to extend the length of continuous fermentation. Our study demonstrates an effective method of ethanol production with a new immobilized approach, and that by switching the flow directions, traditional continuous fermentation can be greatly improved, which could have practical and broad implications in industrial applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.922-926
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• 2002

In this paper, in order to investigate the catalytic effect of the sludge exhausted from waterworks as heating temperature for NOx removal, we measure NO, $NO_2$ concentration as increasing temperature of sludge pellets and applying high voltage to sludge pellets in a quartz-glass reactor at the same time. NO initial concentration is 100ppm balanced with air gas in a mixing chamber. The gas flow is 5[l/min] and the heating temperature of sludge pellets in a quartz-glass reactor is adjusted from $200[^{\circ}C]$ $400[^{\circ}C]$ to investigate the effect of sludge pellets for removal NOx$(NO+NO_2)$ as increasing temperature. $BaTiO_3$ pellets is filled in a packed-bed reactor for corona discharge to measure how much NOx$(NO+NO_2)$ is removed after generating $NO_2$ from the packed-bed reactor. AC[60Hz] voltage is supplied to the reactor for discharge. In the result, $NO_2$ concentration is decreased by sludge pellets without heating temperature for sludge pellets in case of sludge pellets done heat treatment, however NO concentration is almost the same to be compared NO initial concentration. As increasing heating temperature for sludge pellets, $NO_2$ adsorbed on the sludge surface done heat treatment is converted to NO by the thermal energy, so NO concentration is extremely increased by reduction decomposition of $NO_2$. Finally, We think the sludge is possible to use for reduction catalysts, however we need to study more about the possibility and endurance of sludge as catalysts for NOx removal.

• 청정기술
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• 제13권1호
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• pp.16-21
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• 2007

본 실험은 질화세균을 고정화한 충전층 생물반응기에서 저농도 암모니아성 질소(total ammonia nitrogen, TAN)의 제거 시 수력학적 체류시간(hydraulic residence time, HRT), 유입수 암모니아성 질소농도 및 온도에 의한 영향을 평가하였다. 수력학적 체류시간이 감소함에 따라 암모니아성 질소의 제거속도는 증가하였고, 암모니아성 질소의 제거 시 최적 수력학적 체류시간은 0.2시간이었다. 수력학적 체류시간이 0.2시간에서 암모니아성 질소의 제거속도는 $226.1\;g/m^3{\cdot}day$, 제거효율은 88.8%을 나타내었다. 유입수 암모니아성 질소 농도가 증가함에 따라 암모니아성 질소의 제거속도는 증가하였다. 온도 $20{\sim}35^{\circ}C$에서 암모니아성 질소의 제거속도와 제거효율은 일정하게 유지했다.

• 한국식품과학회지
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• 제29권5호
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• pp.969-973
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• 1997

고정화 CGTase를 이용하여 당전이 스테비오사이드를 연속적으로 제조하기 위하여 몇가지 생물반응기의 적용가능성을 조사하였다. 연속형 반응기로는 packed-bed reactor(PBR)가 적합하였다. 이때 specific productivity는 0.4 g/hr-g immobilized enzyme으로 회분식반응기의 50% 정도이나 연속생산이 가능한 장점이 있었다. PBR의 운전조건이고 $10{\sim}60\;cm/hr$의 선속도 범위내에서 스테비오사이드 전환률 70% 이상을 보이는 기질의 유속은 공간속도로 $0.5{\sim}0.7\;hr^{-1}$이었다. 고정화 효소의 운전 안정성은 $47^{\circ}C$에서 30%의 기질로 2주 일간 연속 사용이 가능하고, 반응기의 control방법으로 반응기 상부에서 20%의 효소를 교체하면 20일 이상 전환률이 유지되었다.