• 한국전기화학회:학술대회논문집
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• 2005.07a
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• pp.177-186
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• 2005

미래의 친환경 에너지인 수소에너지 생산을 위해서 생물학적인 수소생산방법에 관한 관심이 증폭되고 있다. 생물학적인 수소생산 방법에는 여러 가지가 있으나 그중 유기물을 혐기발효하여 수소를 생산하는 방법에 관한 연구가 수행되었다. 본 연구에서 혐기성 미생물인 Enterobacter asburiae SNU-1이 쓰레기 매립지 토양에서 분리되어 수소생산 조건의 최적화 실험을 수행하였다. 본 실험에 이용된 미생물의 경우는 기존에 연구 된 적이 없는 새로운 종으로써 다른 미생물과는 다른 특징을 나타내며 수소생산 능력도 뛰어난 것을 알 수 있었다. 미생물을 이용한 수소생산에 영향을 미치는 인자로는 pH, initial glucose concentration 등이 있으며 각각의 조건에서 수소생산량을 비교하였다. 실험 결과 strain SNU-1의 최적 pH는 7이었으며 최적 initial glucose concentration은 25 g/1이다 이와 같은 최적 조건에서 strain SNU-1은 6.87 mmol/l/hr의 productivity를 나타내었다. 또한 다른 미생물과 달리 미생물이 더 이상 자라지 않는 정지기에서 더 많은 수소생산량을 나타내는 특이한 거동을 보이는 것이 관찰되었다.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.1
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• pp.131-138
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• 2006

In this study, the optimum condition of pH was investigated on the hydrogen gas production under anaerobic fermentation process. The results of the experiment showed that the optimum condition was observed at pH 6, resulting in 1175.87 mL/L of hydrogen gas production rate and 22.51% theoretical hydrogen conversion ratio. Hydrogen gas production rate and theoretical hydrogen conversion ratio were 901.77 mL/L and 17.48 % respectively at pH 5. At pH 7 and 8, the production rate of hydrogen gas was little low as 82.15 mL/L. Among the organic acids from the sucrose fermentation, propionate was observed as the dominant acid at pH 7 and 8 but butyrate was the dominant at pH 5 and 6.

• KSBB Journal
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• v.20 no.6
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• pp.393-400
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• 2005

Hydrogen($H_2$) as a clean, and renewable energy carrier will be served an important role in the future energy economy. Several biological $H_2$ production processes are known and currently under development, ranging from direct bio-photolysis of water by green algae, indirect bio-photolysis by cyanobacteria including the separated two stage photolysis using the combination of green algae and photosynthetic microorganisms or green algae alone, dark anaerobic fermentation by fermentative bacteria, photo-fermentation by purple bacteria, and water gas shift reaction by photosynthetic or fermentative bacteria. In this paper, biological $H_2$ production processes, that are being explored in fundamental and applied research, are reviewed.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.83-88
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• 2012

The algal bloom, resulting from eutrophication, has caused serious water quality problems in river and lake. Therefore, it has to be removed by any means including physicochemical or biological treatment for preserving water quality. This study was conducted to investigate the microalgae removal and energy production using combined electro-flotation and anaerobic hydrogen fermentation processes. The result showed that algae removal efficiency based on chlorophyll a removal increased with the current. At a current of 0.6A, the maximum microalgae removal efficiency of 95.9% was achieved. The treatability of anaerobic hydrogen fermentation was investigated to recover energy from microalgae removed by electro-flotation. The ultimate hydrogen yields of algae before and after ultrasonic pretreatment were 17.3 and 61.1 ml $H_2/g$ dcw(dry cell weight), respectively. The ultrasonic pretreatment of algae led to 3.4-fold higher $H_2$ production due to the increase of hydrolysis rate.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.3
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• pp.73-78
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• 2011

The pH is one of the most important factors affecting metabolism pathway and activity of hydrogen producing bacteria. The effect of operational pH on anaerobic hydrogen fermentation of food waste was evaluated at mesophilic condition. In this batch experiment, the initial pH was 8.0 and the operational pH was controlled at 4.7~7.0 by the addition of 5N KOH solutions. At the operational pH of 4.7, the lag phase and the maximum hydrogen production were 47.9h and 534.4 mL, respectively. The lag phase and the maximum hydrogen production were decreased as the operational pH increased. At the operational pH of 7.0, the lag phase and the maximum hydrogen production were 4.2 h and 213.8 mL, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.2
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• pp.97-103
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• 2017

In this study, variations of hydrogen production were investigated with food waste fermentation in the presence of heavy metals. Hydrogen production was 79.48 mL/g COD with fermentation of food waste. In the presence of 1 mg/L of zinc, the hydrogen production was decreased about 60%. When the copper is present, the production of hydrogen is severely inhibited, while the coexistence of copper with zinc relaxes the inhibition of copper and restores hydrogen production. Butyric acid or acetic acid was observed as the main species during hydrogen production. Klebsiella sp., Clostridium sp., and Dysgonomonas sp. were mainly appeared in the samples not containing heavy metals. However, Enterococcus sp. extremely influenced the hydrogen production activities of samples containing zinc or copper.

• Transactions of the Korean hydrogen and new energy society
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• v.13 no.1
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• pp.52-64
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• 2002

유기성 폐기물을 이용하여 생물학적 수소생산 통합화 시스템 연구를 수행하였다. 통합화 시스템은 유기성폐기물의 전처리, 2단계 혐기발효 및 광합성 배양으로 구성된 생물학적 수소생산 공정, 초임계수 가스화 공정, 생산된 가스의 저장, 분리 및 연료전지를 이용한 전력 생산으로 구성되었다. 실험에 사용된 유기성 폐자원은 식품공장 폐수, 과일폐기물, 하수슬러지이며, 전처리는 폐기물에 따라 열처리 및 물리적 처리를 하였으며, 전처리된 시료는 생물학적 수소생산 공정에 직접 적용되었다. Clostridium butyricum 및 메탄 생성조에서 발생하는 하수슬러지중의 미생물 복합체는 수소생산 혐기 발효공정에 사용되었으며, 광합성 수소생산 미생물인 홍색 비유황 세균은 광합성 배양에 사용되었다. 생물학적 공정에서 발생하는 미생물 슬러지는 초임계수 가스화 공정으로 수소를 발생하였으며, 슬러지 중의 COD를 저하시켰다. 생물학적 공정 및 초임계수 가스화 공정에서 발생하는 수소는 가스탱크에 가입상태로 저장한 후, 95%순도로 분리하였으며, 정제된 수소는 연료전지에 연결하여 전력 생산을 하였다.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.5
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• pp.440-446
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• 2017

This study was aimed at evaluating the effects of carbohydrate, protein and lipid content of substrate on hydrogen yields and microbial communities. The hydrogen yields were linearly correlated to carbohydrate content of substrates while others (content of proteins and lipids) did not make a significant contribution. The chemical composition of substrates produced effects on the final products of anaerobic hydrogen fermentation. Acetate and butyrate were the main fermentation products, with their concentration proving to correlate with carbohydrate and protein content of substrates. The result of microbial community analysis revealed that the relative abundances of Clostridium butyricum increased and Clostridium perfringens decreased as the carbohydrate content increased.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.5
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• pp.427-433
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• 2018

This study was performed to evaluate initial pH and substrate concentration on hydrogen fermentation of protein. The optimum initial pH and substrate concentration of hydrogen fermentation using protein was 8.0 and 1.0 g peptone/L, respectively. The maximum hydrogen yield at initial pH 8.0 and 1.0 g peptone/L was $19.2{\pm}0.8mL\;H_2/g$ peptone. As results of VFAs analysis, percentages of valerate was similar to hydrogen yield. Also, C. stickalandii, which was hydrogen and valerate producing bacteria, was dominated.

• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.926-931
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• 2011

Among various techniques for hydrogen production from organic wastewater, a dark fermentation is considered to be the most feasible process due to the rapid hydrogen production rate. However, the main drawback of it is the low hydrogen production yield due to intermediate products such as organic acids. To improve the hydrogen production yield, a co-culture system of dark and photo fermentation bacteria was applied to this research. The maximum specific growth rate of R. sphaeroides was determined to be $2.93h^{-1}$ when acetic acid was used as a carbon source. It was quite high compared to that of using a mixture of volatile fatty acids (VFAs). Acetic acid was the most attractive to the cell growth of R. sphaeroides, however, not less efficient in the hydrogen production. In the co-culture system with glucose, hydrogen could be steadily produced without any lag-phase. There were distinguishable inflection points in the accumulation of hydrogen production graph that resulted from the dynamic production of VFAs or consumption of it by the interaction between the dark and photo fermentation bacteria. Lastly, the hydrogen production rate of a repeated fed-batch run was $15.9mL-H_2/L/h$, which was achievable in the sustainable hydrogen production.