• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.362-372
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• 2010

Although different disposal routes of waste-activated sludge are possible, anaerobic digestion plays an important role for its abilities to further transform organic matter into methane. The potential of using methane as energy source has long been widely recognised and the present paper extensively reviews the principles of anaerobic digestion, the process parameters and hydrolysis. Hydrolysis is recognised as rate-limiting step in the complex digestion process. To accelerate the digestion and enhance the production of biogas, various pre-treatments can be used to improve the rate-limiting hydrolysis. These treatments include mechanical, thermal, chemical and biological interventions to the feedstock. All pre-treatments result in a lysis or disintegration of sludge cells, thus releasing and solubilizing intracellular material into the water phase and transforming refractory organic material into biodegradable species. The reader will finally be guided to extensive discussion for anaerobic digestion processes.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.124-129
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• 1999

지난 몇 십년간 생물계 폐기물 호기성 처리의 경제적이고 실용적인 공법으로 가축분뇨처리에 적용되어온 유기성 폐자원의 호기성 분해공정은 축산환경 보전, 지력증강 자원의 고갈 및 지구온난화문제 등에 의해서 더욱 주목받아 오고 있다. 특히, 기존의 호기성 고형폐기물 처리시설에서 저투입, 고효율의 처리시설을 개발하여 보다 많은 숙성퇴비를 얻을 수 있는 통기퇴적식 퇴비화 시설은 강제통풍 통기방식으로 호기성 미생물의 분해시간을 단축하고 암모니아가스 휘산을 저감하는 등의 탁월한 처리효율을 나타내었다(Brinton et al., 1995). (중략)

• KSBB Journal
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• v.19 no.4
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• pp.245-249
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• 2004

A combined method of autolysis and enzymatic hydrolysis of baker's yeast was developed for the production of yeast extract, which is widely used as a natural food ingredient. From statistical analysis, NaCl and ethanol addition were found to be significantly effective factors in autolysis of yeast. The optimum dosages of salt and ethanol were 3% and 1%, respectively. Heat treatment and the use of cell lytic enzyme were not significantly effecting on the autolysis. Yeast hydrolysate was prepared by autolysis, followed by enzymatic hydrolysis using proteases, nuclease and deaminase. Additionally, the hydrolysate was processed by downstream process including Maillard reaction and debittering. The total dry matter yield and total nitrogen yield for the process were 76% and 59%, respectively. Compared to a process using brewer's yeast, when baker's yeast was used as a raw material, a higher recovery yield was obtained.

• Journal of Hydrogen and New Energy
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• v.34 no.6
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• pp.594-600
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• 2023

In this study, a process model and optimization design direction for a hydrogen production plant through ammonia decomposition are presented. If the reactor decomposition rate is designed to approach 100%, the amount of catalyst increases and the devices that make up the entire system also have a large design capacity. However, if the characteristics of the hydrogen regeneration process are reflected in the design of the reactor, it becomes possible to satisfy the total flow rate of fuel gas with the discharged tail gas flow rate. Analyzing the plant process simulation results, it was confirmed that when an appropriate decomposition rate is maintained in the reactor, the phenomenon of excess or shortage of fuel gas disappears. In addition, it became possible to reduce the amount of catalyst required and design the optimized capacity of the relevant processes.

• Journal of Digital Convergence
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• v.14 no.1
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• pp.253-262
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• 2016

Yeonsan Ogae has been known as supporting health and high efficacy of treatment. In recent days, as the efficacy of functional peptides has known, the optimization of oligo peptides production and its characteristics from Ogae viscera has been performed. Response surface method was used to perform the optimizaion of enzyme hydrolysis. The range of processes was temperature (40, 50 and $60^{\circ}C$), pH(6.0, 7.0 and 8.0), and enzyme(1, 2 and 3%). The degree of hydrolysis, amono acids, molecular weight of products were analyzed. The optimum process of enzyme hydrolysis were determined as temperature $58^{\circ}C$, pH 7.5, and enzyme concetration 3%. At optimum conditions, the degree of hydrolysis after 2 h reaction was 75-80%. The total amino acids of amino acid and were 386.15 mg/100 g and 155.26 mg/100 g, respectively. The molecular weight of products by using Maldi-TOF was ranged from 300 to 1,000 Da.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.29-32
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• 2006

화학적 산화처리와 bioremedation 기법을 개별적 또는 복합적으로 동시에 적용함으로써 한 개별 기법의 단점을 보완하고 현장적용성을 증대시킬 수 있는 통합기법을 개발하고자 하였다. 펜톤유사 반응을 통해 고농도의 유류를 산화분해 시킨 후 미생물 처리를 통해 잔류 유류 오염물질을 제거하고자 하였다. 유류 오염토양의 화학 생물학적 통합처리 공정의 현장 적용성 및 토양 미생물에 미치는 영향을 검증하기 위해 처리과정 전 후의 미생물 군집구조를 분석하였다. 또한 토양 내 유류 분해균을 분리하기 위해 탄소원으로 경유와 벙커C를 이용하여 농화배양을 수행하였다. 경유 분해균 10여종, 벙커 C 분해균 6종을 분리하여 분해능 및 동정을 시도하였다. 또한 유류 분해미생물의 consortia를 분자생물학적 기법으로 분석을 시도하였다.

• Journal of the Korea Safety Management & Science
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• v.12 no.3
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• pp.135-143
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• 2010

본 연구에서는 대기오염물질인 유해 황산화물 가스를 이산화티탄 촉매 반응기와 연면 방전 반응기를 조합한 반응기에서 플라즈마 방전반응에 의하여 주파수 변화, 체류시간, 전극의 굵기, 첨가 모의가스 등의 공정 변수를 변화 시켜 분해제거 실험을 하였다. 실험 결과 황산화물의 분해제거 실험에서 주파수 10kHz에서 소비전력 19W에서 분해제거율은 99%이었으며 이산화티탄 촉매반응기를 부착한 경우가 없는 경우보다 5%이상 증가효과가 이었다. 첨가가스로 메탄을 첨가한 경우 분해제거율이 증가하였고, 산소농도가 높아질수록 증가하였다 또한 이산화 탄소를 첨가한 경우 분해율은 감소하였다.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.121-129
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• 2004

Anaerobic digestion is the most common process for sewage sludge stabilization and has benefits of VS reduction and biogas production. Many pretreatment methods have been studied to improve hydrolysis rate because the rate of sewage sludge degradation is slow in anaerobic digestion. This study mainly focused upon the effects on disintegration of sewage sludge by ultrasonic pretreatment according to the variation of acoustic density and duration of sonication time. In this study, acoustic density has been changed as follows : 33W/L, 70W/L, 88W/L, 139W/L in case of 40 kHz with the test time changes of 10min, 20min, 25min, 30min and 40min. In the comparison of $SCOD_{Cr}/TCOD_{Cr}$ variation for excess sludge and mixed sludge disintegration, the rates of $SCOD_{Cr}/TCOD_{Cr}$ have been increased in the condition of denser acoustic density and longer sonication time with acoustic frequency of 40kHz. The pH of the excess sewage sludge and mixed sewage sludge has been decreased in the condition of denser acoustic density and longer sonication time with acoustic frequency of 40kHz.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.4
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• pp.308-323
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• 2009

This review paper serves to describe the composition and activity of biological activated carbon (BAC) biofilm which is considered as a progressive process for water treatment. As well as several physical-chemical, biochemical and microbiological analysis methods for characterizing the composition and activity of BAC biofilm, the ability of the biofilm to remove and biodegrade organic matters and pollutants related to other water treatment processes such as pre-ozonation will be reviewed. In this paper, conversion of GAC into BAC, removal mechanism of pollutants, characteristics and affecting factors of BAC biofilm, and modeling of BAC are described in detail. In addition, strategies to control the growth of the BAC biofilm, such as varying the nutrient loading rate, altering the frequency of BAC filter backwashing and applying oxidative disinfection, will be dwelled on related to their respective process control challenges.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.86-92
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• 2017

A process, which converts carbon dioxide contained in the flue gas of coal-fired power plants to sodium bicarbonate, was studied experimentally and numerically. In this process, the carbon dioxide reacts with sodium hydroxide which is produced through saline water electrolysis. A bench scale reactor system was prepared for experiments of this process and numerical process modeling was performed for the bench scale reactor system. Comparing the process modeling results with the experimental data, responsibility of the process modeling was confirmed. Using this model, commercial scale process was simulated. Mass and energy balance of this process were calculated. Temperature profile in the reactor and carbon dioxide removal rate were obtained.