• Journal of environmental and Sanitary engineering
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• v.11 no.2
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• pp.1-7
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• 1996

The behavior of total organic carbon (TOC) and phosphate were observed for 15 days with immobilized activated sludge using polyacrylamide (PAA) by sequencing batch reactor (SBR). In the preparation of immobilized sludge by PAA, it was found that suitable acrylamide concentration for actual wastewater treatment was to be 15% through the batch test. When SBR system was operated in the repeated aerobic and anaerobic conditions, TOC removal efficiency was 92%. The uptake rate of phosphate was increased from 1.78 mg-P/g cell/hr on the 5th day of acclimation to 2.5 mg-P/g cell/hr on the 15th day of acclimation. And the total phosphorus content in PAA bead was increased from 40 mg-P/g cell on the 1st day of operation to 55 mg-P/g cell on the 15th day of operation. From this study, lowering the volume of aeration tank was possible when PAA bead was used in wastewater treatment and long operation was also possible without the settler.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.05a
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• pp.96-98
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• 2006

축산폐수는 축사가 대부분 상수원보다 상류지역에 산재하고 있어 이를 효과적으로 관리하기 어려우나, 연속 회분식 반응기(Sequencing Batch Reactor, SBR)는 장치가 간단하고 경제성이 우수하여 축산폐수처리에서 효율적으로 적용될 수 있다. 본 연구에서는 DO(Dissolved Oxygen)과 ORP(Oxidation-Reduction Potential)을 이용하여 지식기반 고장진단 시스템을 제안하였다. 실시간으로 얻어진 ORP, DO값들을 전처리하여, [ORP], [DO]외에 [ORP DO]합성data와 ORP, DO의 특징백터의 합에서 얻어진 fusion data의 총 4개의 data set을 이용하여 각각에 대한 진단과 분류성능을 검토하였다. 이 값을 이용하여 FCM (fuzzy C-mean) 클러스터링 한 후, K-PCA과 LDA로 차원축소시켜 특징백터를 추출하였다. 그리고 Hamming distance로 test data와 특징백터의 거리를 계산하여 각 class를 F1에서 F8까지 분류하였다. 그 결과 데이터를 그대로 이용하는 것 보다 차분데이터형태로 이용하는 것이 우수했으며 그 중 fusion 데이터의 결과가 다른 것들보다 향상된 결과를 보였다. 그리고 K-PCA와 LDA를 결합한 결과가 다른 방법에 비해 우수한 결과를 보였으며 fusion method를 이용한 최고인식율은 98.02%를 나타내었다.

• Journal of Energy Engineering
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• v.8 no.1
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• pp.189-201
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• 1999

범용 열가소성 플라스틱(polyethylene(PE), polypropylene(PP), polystyrene(PS), polyethylene-terephthalate(PET), acrylonitrile-butandiene-styrene(ABS))과 폐윤활유의 동시처리 열분해반응 실험을 수행하였다. 반응실험은 40$m\ell$ 용량의 회분식 미분반응기(microreactor)를 이용한 실험과 1리터 용량의 autoclave를 이용한 실험의 두 가지로 구분하여 행하였다. 전자의 경우는 통계적 실험적계획법(statistical experimental design)의 하나인 회전계획실험(rotatable design experiments)으로서 오각형 실험계획(pentagonal experimental design)에 의거한 반응변수 실험을 수행한 후 반응표면(response surface)을 회기분석법에 의하여 분석함으로써 최대의 오일 수율을 얻을 수 있는 최적 반응조건을 추적, 결정하였다. Autoclave 반응실험의 기본적인 목적은 실제 연속공정에 있어서 열분해 반응기 거동을 모사하기 위한 전초단계로서 충분한 시료의 확보를 통하여 이 때 생성된 연로유의 체계적인 분석(비등점분포특성, 진공증류, 기체분석, 원소분석, 발열량, 비중 등)을 행함으로써 연료유 수율 및 품질을 모사하고자 하였다. 미분반응기 실험에 있어서 주 범용열가소성수지인 PE, PP 그리고 PS는 각각의 최적반응조건하에서 거의 100%에 가깝게 오일로 전환되었지만 응축수지인 PET와 그래프트공중합수지인 ABS의 오일수율은 각기 78% 및 90%로서 상대적으로 낮게 나타났다. Autoclave를 이용한 실험의 경우 혼합플라스틱을 폐유에 대하여 40wt% 혼합하여 열분해하였을 때, 80wt% 오일, 15wt% 코우크, 그리고 나머지 5wt%는 탄화수소기체(C1-C6)로 전환되었다. 진공증류(252$^{\circ}C$,2 torr) 결과, 기/액-분리도는 3으로서 이는 생성오일의 75wt%가 경질연료유(가솔린, 등유, 경유)로 회수 가능하였다.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.349-354
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• 2009

In this study, a bubbling fluidized-bed reactor was used to study $CO_2$ capture from flue gas using a potassium-based dry sorbent. A dry sorbent, manufactured by the Korea Electric Power Research Institute, consists of 35% of $K_2CO_3$ for $CO_2$ absorption and 65% of supporters for mechanical strength. $H_2O$, a reactant of the carbonation reaction, was supplied in the reactor as a form of saturated water vapor at a given temperature. The experiment of the regeneration reaction was performed by raising up to a given temperature using $N_2$ as a fluidization gas. It was indicated that sorption capacity and regenerability of dry sorbents showed high-efficiency at $1.97\;mol\;H_2O/mol\;CO_2$ and $400^{\circ}C$, respectively. The regenerated sorbent samples were analyzed by TGA to confirm the extent of the reaction. When the regeneration temperature was $150^{\circ}C$, the regenerability of dry sorbents was about 60%, which was capable of applying those sorbents to a two-interconnected fluidized-bed reactor system with continuous solid circulation. The results obtained in this study can be used as basic data for designing and operating a large scale $CO_2$ capture process with two fluidized-bed reactors.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.2
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• pp.127-133
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• 1999

The purpose of this study was to determine the optimum hydrolysis conditions for the production of enzymatic hydrolysate from tuna boiled extract (TBE) using membrane (molecular weight cut off 10,000Da) reator. The tuna pyloric caeca crude enzyme (TPCCE) was identified as the most suitable enzymes for the hydrolysis of TBE. The optimum hydrolysis conditions of TBE in the batch reactor were $40^{\circ}C$, pH 9 and substrate to TPCCE ratio 50 (w/w). For 6hr under the above conditions, $70\%$ of the total amount of initial TBE was hydrolysed. The optimum hydrolysis conditions of TBE in the membrane reactor were $40^{\circ}C$, pH 9, enzyme 0,1 g/$\ell$, volume 1$\ell$ and substrate to enzyme ratio 100(w/w). The degree of hydrolysis of TBE was above $60\%$ for 3 hr. The TBE hydrolysate were prepared with $5\%$ TBE solution under the optimum hydrolytic conditions in the membrane reactor

• KSBB Journal
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• v.4 no.2
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• pp.74-77
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• 1989

To increase the volumetric productivity a contimuous cell-recycled system was implemented. Cell concentrations between 9.2 and 15.0 g/1 were obtatined in the continuous fermentor study. At a 4% xylose feed and a specific oxygen supply rate(SOSR) of 1.04 g O2.hr-g DCW the ethanol yield was 0.36% at dilution rate. This represented a 26-% increase over that of th batch fermentation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.3
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• pp.127-136
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• 1990

In this paper, the experimental study was carried out for the removal of olive oil in wastewater by the use of Biological Fluidized Bed(BFB) with the reticulated polypropylene sheets as media. The nonbiodegradable olive oil, one of the animal and vegitable oil, was used bacause of the relative simplicity of constitution. Biological degraciability and removal characteristics of emulsified olive oil were studied by batch and continuous experiments respectively. From the results of batch experiments, it was observed that the emulsified olive oli used in BFB reactor was absorbed by media and sludge in about 12 hours, and degradation of the absorbed olive oli was mostly completed for 24 hours. The functional relationship of Michaelis-Menten's Enzyme reaction equation exists between oil concentration and maximum specific rate of olive oil. From the continuous experiments for the removal of olive oil using BFB reactor, it was proved that the substrate removal rate coefficient $k=0.004d^{-1}$, which is the first order kinetics. It was apperared that oxygen utlization coefficients for synthesis(a') and endogeneous respiration(b') of microorganisms in the reactor are respectively 0.85mg $O_2/mg$ $COD_{cr}$ and 0.011mg $O_2/mg$ BVS. day.

• Journal of Environmental Science International
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• v.14 no.9
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• pp.861-871
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• 2005

This study was carried out to get more operational characteristics of Anoxic(anaerobic)-Oxic-Anoxic-Oxic $(AO)_2$ sequencing batch biofilm reactors (SBBRs) at the low TOC concentration, The operating time in anoxic (anaerobic) time to oxic time was I : I. Experiments were conducted to find the effects of the aeration time distribution on the organic matters and nutrients removal. Three lab-scale reactors were fed with synthetic wastewater based on glucose as carbon source. During studies, the operation mode was fixed. The first aeration time to the second aeration time in SBBR-I was 2 : 3, and those in SBBR-2 and SBBR-3 were I : 4 and 3 : 2, respectively. The organic removal efficiency didn't show large difference among three reactors of different aeration time distribution. However, from these study results, the optimum aeration time distribution in the first and the second aeration time for biological nutrient removal was shown as 3 : 2. The release of phosphorus was inhibited at the second non-aeration period because of the low TOC concentration and the nitrate produced by the nitrification at the first aeration period.

• KSBB Journal
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• v.17 no.2
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• pp.182-188
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• 2002

Enterococcus faecalis RKY1 cells were immobilized in an asymmetric hollow fiber bioreactor for application to the continuous production of succinic acid. The media was fed into shell-side of the module using a peristaltic pump, and the products were collected through lumen-side outlet. The number of hollow fibers within the module did not affect the bioreactor efficiency in the transverse operated hollow fiber bioreactor. The steady state at the outlet of hollow fiber bioreactor was reached after 24 hr cultivation at flow rate of 0.25 mL/mim, 12 hr at 0.5 L/min, and 9 hr at 1.0 mL/mm, respectively. The succinate and fumarate concentrations within the hollow fiber bioreactor, however, were as changeful as increasing the flow rate. During continuous operation with the flow rates between 0.5 and 2.0 mL, the productivity of succinate was 8.0-10.9 g/L $.$ hr at 30 g/L fumarate, 4.9-14.9 g/L hr at 50 g/L fumarate, and 7.2-17.1 g/L hr at 80 galL fumarate, respectively.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.105-108
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• 2000

Enhanced biological phosphorus removal (EBPR) is not always successfully achieved by anaerobic/aerobic operation. It has been reported that the EBPR deterioration was caused by the outgrowth of glycogen-accumulating organisms (GAO) over polyphosphate-accumulating organisms (PAO). It was found that pHcould be a tool which might induce the success of EBPR in a sequencing batch reactor (SBR) supplied with acetate. When the pH of anaerobic phase was controlled at 7.0, the operation resulted in failure of EBPR. However, when the pH of anaerobic phase increased up to 8.4, complete EBPR was achieved. We explained the mechanism of pH effect on the competition between GAO and PAO with experimental results and previously proposed biochemical models.