• 한국환경보건학회지
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• 제23권3호
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• pp.40-49
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• 1997

In Korea, naked barley and tapioca are main raw materials for the production of fermentation ethyl alcohol, and one million drums bf 95% fermentation ethyl alcohol is produced per year by use of them. Stillage of alcoholic fermentation is mostly digested by methane fermentation process, and methane gas occured if methane fermentation process is recovered and mixed with fuel to decrease 25-30% for total fuel used in factories. In the anaerobic digestion process of naked barley stillage, supplement of nutrients is necessary to slove the problems caused by inhibitory materials contained if stillage and deficiency of nutrients. Therefore, the objective of this study was to examine why the anaerobic digesters using the naked barley distillery wastewater have shown the poor digestability frequently and how to control it. As the poor digestion was supposed to be occurred by the lack of iron as trace nutrient, the experiments were carried out to find out the optimum dosage and the way of addition of iron and to assess the quantitative evaluation of the type of iron in digesters. Initially, bottle test as batch digesters and lab-scaled continuous flow digesters were used in order to determine the digestion characteristics with tapioca and naked barley distillery wastewater. According to the results of batch tests, the poor digestion was caused by volatile fatty acids and could be improved by adding of calcium. The activity of the methanogenic bacteria were increased remarkably when the iron was added to the digester in the form of mixture with substrates.

• 한국환경과학회지
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• 제22권9호
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• pp.1161-1170
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• 2013

The efficiency of coal-based activated carbon in removing methylene blue (MB) and phenol from aqueous solution was investigated in batch experiments. The batch adsorption kinetics were described by applying pseudo-first-order, pseudo-second-order, and first order reversible reaction. The results showed that the adsorption of MB and phenol occurs complexed process including external mass transfer and intraparticle diffusion. The maximum adsorption capacity obtained from Langmuir isotherm was 461.0 mg/g for MB and 194.6 mg/g for phenol, respectively. The values of activation parameters such as free energy (${\Delta}G^0$), enthalpy (${\Delta}H^0$), and entropy (${\Delta}S^0$) were also determined as -19.0~-14.9 kJ/mol, 25.4 kJ/mol, and 135.2 J/mol K for MB and 51.8~54.1 kJ/mol, -29.0 kJ/mol, and -76.4 kJ/mol K for phenol, respectively. The MB adsorption was found to be endothermic and spontaneous process. However, the CV adsorption was found to be exothermic and non-spontaneous process.

• Journal of Microbiology and Biotechnology
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• 제22권7호
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• pp.967-974
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• 2012

Cultivation of Spirulina platensis using ammonium salts or wastewater containing ammonium as alternative nitrogen sources is considered as a commercial way to reduce the production cost. In this research, by analyzing the relationship between biomass production and ammonium-N consumption in the fed-batch culture of Spirulina platensis using ammonium bicarbonate as a nitrogen nutrient source, an online adaptive control strategy based on optical density (OD) measurements for controlling ammonium feeding was presented. The ammonium concentration was successfully controlled between the cell growth inhibitory and limiting concentrations using this OD-based feedback feeding method. As a result, the maximum biomass concentration (2.98 g/l), productivity (0.237 g/l d), nitrogen-to-cell conversion factor (7.32 gX/gN), and contents of protein (64.1%) and chlorophyll (13.4mg/g) obtained by using the OD-based feedback feeding method were higher than those using the constant and variable feeding methods. The OD-based feedback feeding method could be recognized as an applicable way to control ammonium feeding and a benefit for Spirulina platensis cultivations.

• 한국식품과학회지
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• 제11권2호
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• pp.112-117
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• 1979

해바라기유의 재래식 탈납공정 경제성을 높이기 위해서 여러가지 유화제(0.2% sodium bexametaphosphate, 0.05% sodium lauryl sulfate, 0.001% dioctyl sodium sulfosuccinate)를 이용한 새로운 탈납공정을 개발하였다. 해바라기 원유를 회분식 (batch process)과 연속식(continuous process)으로 유화제 수용액과 유화시킨후 원심분리기로 분리시켰을 때 재래식 탈납공정에 비견할 만한 탈납을 할 수있음을 알았다. 탈납 공정에서 위에 설명한 탈납정도(degree of dewaxing)외에 또 하나의 중요인자는 수율(dewaxirg loss)인바 회분식 공정의 경우에는 재래식 탈납공정의 수율과 같았으나 연속식 공정의 경우에는 개량할 여지가 있음을 알았다. 실험결과에 의하면 회분식 공정의 경우 탈납전 원유에 함유된 납(wax)의 다과에 관계없이 수율은 $0.62{\sim}0.82%$로 재래식 공정과 같았으나 연속식 공정인 경우에는 탈납전 원유에 함유된 납의 양이 적은 경우와 많은 경우 각각 2.28%와 5.68%로 현격한 차이를 보였다. 또한 연속식 공정의 경우 원유와 유화제를 유화시키는 방법에 따라 수율에 많은 영향이 미치는 것으로 밝혀졌으며 contactor와 static mixer를 썼을때 각각 5.2%와 2.8%이었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.97.1-97
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• 2001

One of the main problems to constitute control method on biologically oriented wastewater purification processes, e.g. activated sludge process, sequential batch reactor, rotating bio-disk contactor, etc. is that it is hard to control the target component directly. For instance, while biochemical oxygen demand, suspended solids, and chemical oxygen demand are the key components to check the process performance, one may not control them directly since they are the results of microbial activities related to numerous physiochemical factors. Therefore controllers for bioprocess should be designed to make favorable condition for microorganisms´ living, e.g. dissolved oxygen level favorable, mixed liquor suspended solids concentration suitable ...

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2009년도 학술발표대회
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• pp.213-214
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• 2009

In order to promote an efficiency CPB process, we developed microwave system in CPB process. The whiteness and penetration ability of microwave-CPB pre-treated fabrics were superior to CPB only. This results indicates that microwave-CPB pre-treatment promotes CPB efficiency in agent usages and batching time.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권4호
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• pp.275-287
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• 2000

Fermentation strategies for recombinant protein production in Pichia pastoris have been investigated and are reviewed here. Characteristics of the expression system, such as phenotypes and carbon utilization, are summarized. Recently reported results such as growth model establishment, app58lication of a methanol sensor, optimization of substrate feeding strategy, DOstat controller design, mixed feed technology, and perfusion and continuous culture are discussed in detail.

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.52-59
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• 2004

Fructose와 galactose를 배지에 동시에 사용하였을 때 catabolite repression에 의한 PAFS생산성 저해 현상을 극복하기 위해서 본 연구에서는 두 가지 탄소원의 공급량과 유속을 달리하는 유가식 배양으로 PAFS 생산성을 향상시키고자 하였다. 또한 통계적으로 성공률이 매우 높다고 밝혀진 실험방법에 의해 모균주로부터 고생산변이주를 선별하여 생산성이 가장 우수한 것으로 판명된 AP-20 균주를 생물반응기를 이용한 회분식 배양 및 유가식 배양 실험에 이용하였다. 생물반응기에서의 유가식 배양이 회분식 배양에서보다 PAFS생산성이 약 4배 이상 향상되었음을 확인할 수 있었다. 또한 생산균주의 배양생리학적 특성으로서 Pseudomonas aeruginosa는 galactose를 이용해서 세포성장과 이차대사산물 생합성과 관련된 유전자의 발현을 하고 fructose를 이용하여 PAFS를 생합성하는 것으로 추론되며, 너무 느린 탄소원의 공급은 세포성장에 제한요소로 작용하여 이차대사산물의 생합성을 저해하는 것으로 판단되었다. 한편 유가식 배양일지라도 배양 조건에 따라 그 생산성이 뚜렷이 차이가 나는 것으로 관찰되었다 즉 galactos의 초기량이 20g/L이고 fructose 30g/L를 0.032 mL/min의 속도로 공급했을 경우의 PAFS생산량을 100%로 정의했을 때, 초기부터 40 g/L의 galactose가 존재하고 20 g/L의 fructose를 0.032 mL/min의 속도로 공급한 경우에 PAFS생산성이 약 580%향상된 것으로 나타났다.

• 한국컴퓨터정보학회논문지
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• 제6권1호
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• pp.95-102
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• 2001

오늘날 공급사슬경영(Supply Chain Management)은 우리나라뿐만 아니라 전 세계적으로 기업경영의 화두가 되고 있다. 이는 비용절감, 리드타임 단축, 서비스 수준 향상 등의 가치창출이 기업내부에서 뿐만 아니라 오히려 기업과 기업 간에서 더욱 큰 잠재력을 가지고 있음을 발견하게 되었기 때문이다. 본 연구에서는 공급사슬경영의 논리적인 Frame work을 입증하기 위하여 최적화시스템을 시뮬레이션 한다. 최적화생산시스템을 이용하는 시스템 하에서는 생산 시스템의 문제를 효과적인 흐름의 통제라는 관점에서 파악하며. 생산 현장에서 발생하는 많은 문제가 이들 흐름을 방해하는 요인에 의하여 발생하고 있다고 간주하기 때문이다 이와 같은 실험을 통하여 본 연구에서는 최적화생산시스템의 시뮬레이션 결과를 제시하고, 이로써 공급사슬경영의 유용성을 입증하는데 그 의의가 있다

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권5호
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• pp.1-7
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• 2016

The removal of non-aqueous phase liquids (NAPLs) from groundwater using pure water, via pump and treat, is quite ineffective due to their low solubility and hydrophobicity. Therefore, the objectives of pilot tests were to select potentially suitable surfactants that solubilize tetrachloroethylene (PCE) and trichloroethylene (TCE) present as contaminants and to evaluate the optimal range of process parameters that can increase the removal efficiency in surfactant-enhanced soil flushing (SESF). Used experimental method for surfactant selection was batch experiments. The surfactant solution parameters for SESF pilot tests were surfactant solution concentration, surfactant solution pH, and the flow rate of surfactant solution in the SESF pilot system. Based on the batch experiments for surfactant selection, DOSL (an anionic surfactant) was selected as a suitable surfactant that solubilizes PCE and TCE present as contaminants. The highest recovery (95%) of the contaminants was obtained using a DOSL surfactant in the batch experiments. The pilot test results revealed that the optimum conditions were achieved with a surfactant solution concentration of 4% (v/v), a surfactant solution pH of 7.5, and a flow rate of 30 L/min of surfactant solution (Lee and Woo, 2015). The maximum removal of contaminants (89%) was obtained when optimum conditions were simultaneously met in pilot-scale SESF operations. These results confirm the viability of SESF for treating PCE and TCE-contaminated groundwater.