혐기성 수소발효를 결합한 생물학적 2단공정의 유기성폐자원 처리 및 바이오에너지 생산

이채영,유규선,한선기 한국수소및신에너지학회 2015 한국수소 및 신에너지학회논문집 Vol.26 No.3

This study was performed to investigate the application of dark H2 fermentation to two-stage bioprocesses for organic waste treatment and energy production. We reviewed information about the two-stage bioprocesses combining dark H2 fermentation with CH4 fermentation, photo H2 fermentation, microbial fuel cells (MFCs), or microbial electrolysis cells (MECs) by using academic information databases and university libraries. Dark fermentative bacteria use organic waste as the sole source of electrons and energy, converting it into H2. The reactions related to dark H2 fermentation are rapid and do not require sunlight, making them useful for treating organic waste. However, the degradation is not complete and organic acids remain. Thus, dark H2 fermentation should be combined with a post-treatment process, such as CH4 fermentation, photo H2 fermentation, MFCs, or MECs. So far, dark H2 fermentation followed by CH4 fermentation is a promising two-stage bioprocess among them. However, if the problems of manufacturing expenses, operational cost, scale-up, and practical applications will be solved, the two-stage bioprocesses combining dark H2 fermentation with photo H2 fermentation, MFCs, or MECs have also infinite potential in organic waste treatment and energy production. This paper demonstrated the feasibility of two-stage bioprocesses combining dark H2 fermentation as a novel system for organic waste treatment and energy production.

Effects of pH and Carbon Sources on Biohydrogen Production by Co-Culture of Clostridium butyricum and Rhodobacter sphaeroides

( Jung Yeol Lee ),( Xue Jiao Chen ),( Eun Jung Lee ),( Kyung Sok Min ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.3

To improve the hydrogen yield from biological fermentation of organic wastewater, a co-culture system of dark- and photo-fermentation bacteria was investigated. In a pureculture system of the dark-fermentation bacterium Clostridium butyricum, a pH of 6.25 was found to be optimal, resulting in a hydrogen production rate of 18.7 ml-H2/l/h. On the other hand, the photosynthetic bacterium Rhodobacter sphaeroides could produce the most hydrogen at 1.81mol-H2/mol-glucose at pH 7.0. The maximum specific growth rate of R. sphaeroides was determined to be 2.93 h-1 when acetic acid was used as the carbon source, a result that was significantly higher than that obtained using either glucose or a mixture of volatile fatty acids (VFAs). Acetic acid best supported R. sphaeroides cell growth but not hydrogen production. In the co-culture system with glucose, hydrogen could be steadily produced without any lag phase. There were distinguishable inflection points in a plot of accumulated hydrogen over time, resulting from the dynamic production or consumption of VFAs by the interaction between the dark- and photofermentation bacteria. Lastly, the hydrogen production rate of a repeated fed-batch run was 15.9 ml-H2/l/h, which was achievable in a sustainable manner.

Sodium (Na⁺) concentration effects on metabolic pathway and estimation of ATP use in dark fermentation hydrogen production through stoichiometric analysis

Lee, M.J.,Kim, T.H.,Min, B.,Hwang, S.J. Academic Press 2012 Journal of environmental management Vol.108 No.-

Batch experiments were conducted to investigate the effects of Na<SUP>+</SUP> concentration on hydrogen production with dark fermentation. The Na<SUP>+</SUP> concentration was varied from 0 to 8 g/L in the mixed culture using an anaerobic sludge treated by acid. The maximum hydrogen production was achieved with 1 g-Na<SUP>+</SUP>/L, whereas the hydrogen production was decreased over 2 g-Na<SUP>+</SUP>/L due to the inhibitory of Na<SUP>+</SUP>. The mechanisms of Na<SUP>+</SUP> inhibition to the hydrogen production are studied using pure culture of Clostridium butyricum by calculating the energy balance. At a high sodium concentration, C. butyricum used a greater proportion of the ATP generated via fermentation for cell maintenance rather than for cell synthesis. Additionally, higher Na<SUP>+</SUP> concentrations shifted the fermentation process toward the acetate synthesis pathway instead of the butyrate pathway, and the value of Y<SUB>X/ATP</SUB> decreased. With high Na<SUP>+</SUP> concentrations, a greater ratio of hydrogen was produced via the oxidation of NADH. Excess hydrogen production decreased as the Na<SUP>+</SUP> concentration increased.

NaCl 농도가 암발효에 의한 수소생성 및 미생물 군집형성에 미치는 영향

장산,이윤희,김태형,황선진 한국폐기물자원순환학회 2013 한국폐기물자원순환학회지 Vol.30 No.1

The effects of NaCl concentration on bio-hydrogen production and microbial community by dark-fermentation were evaluated. The examined NaCl concentration was varied from 0 to 5%. When NaCl concentration ranged from 0 to 3%, the hydrogen production was insignificantly affected. 4% or more NaCl concentration decreased accumulated hydrogen production and the lag time was longer. In addition, the metabolite pathway of the bacteria were shifted from butyrate to acetate by microbial community changes with high concentration of NaCl. FISH analysis was achieved to analyze the microbial community after the dark-fermentation performance. Hydrogen producing bacteria, Clostridium sp. Cluster I and Cluster XI, was dominated with 0 ~ 3% of NaCl, while Eubacteria, general bacteria, was dominated with 4 ~ 5% of NaCl. Therefore, the growth and hydrogen production of the hydrogen producing bacteria were inhibited with over 4% of NaCl.

Feasibility of biohydrogen production from Gelidium amansii

Park, J.H.,Yoon, J.J.,Park, H.D.,Kim, Y.J.,Lim, D.J.,Kim, S.H. Pergamon Press ; Elsevier Science Ltd 2011 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.36 No.21

The feasibility of hydrogen production from red algae was investigated. Galactose, the main sugar monomer of red algae, was readily converted to hydrogen by dark fermentation. The maximum hydrogen production rate and yield of galactose were 2.46 L H<SUB>2</SUB>/g VSS/d and 2.03 mol H<SUB>2</SUB>/mol galactose<SUB>added</SUB>, respectively, which were higher than those for glucose (0.914 L H<SUB>2</SUB>/g VSS/d and 1.48 mol H<SUB>2</SUB>/mol galactose<SUB>added</SUB>). The distribution of soluble byproducts showed that H<SUB>2</SUB> production was the main pathway of galactose uptake. 5-HMF, the main byproduct of acid hydrolysis of red algae causes noncompetitive inhibition of H<SUB>2</SUB> fermentation. 1.37 g/L of 5-HMF decreased hydrogen production rate by 50% compared to the control. When red algae was hydrolyzed at 150 <SUP>o</SUP>C for 15 min and detoxified by activated carbon, 53.5 mL of H<SUB>2</SUB> was produced from 1 g of dry algae with a hydrogen production rate of 0.518 L H<SUB>2</SUB>/g VSS/d. Red algae, cultivable on vast tracts of sea by sunlight without any nitrogen-based fertilizer, could be a suitable substrate for biohydrogen production.

Effect of severity on dilute acid pretreatment of lignocellulosic biomass and the following hydrogen fermentation

Gonzales, R.R.,Sivagurunathan, P.,Kim, S.H. Pergamon Press 2016 International journal of hydrogen energy Vol.41 No.46

<P>This study aimed to investigate the relationship of the severity of dilute acid pretreatment and the following dark hydrogen fermentation performance. Empty palm fruit bunch, rice husk, and pine tree wood were hydrolyzed in 5% (v/v) H2SO4 at 10% (w/v) solid/liquid ratio and 121 degrees C for 30, 60, and 90 min, and then used as the substrate of batch hydrogen fermentation. The maximum sugar yield was achieved at pretreatment with 60 min reaction time; however, it did not guarantee the maximum H-2 production. Hydrolyzate obtained from pretreatment where the combined severity factor was at or over 2.01 showed severe 5-hydroxymethylfurfural production and consequent decrease of H-2 production rate. Peak H-2 production rates of 2640, 3340, and 2565 mL H-2 L-1 day(-1) were achieved at the following severity factors: 1.95, 1.86, and 1.83, for empty palm fruit bunch, rice husk, and pine tree wood, respectively. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.</P>

Optimization of batch dilute-acid hydrolysis for biohydrogen production from red algal biomass

Park, J.H.,Cheon, H.C.,Yoon, J.J.,Park, H.D.,Kim, S.H. Pergamon Press ; Elsevier Science Ltd 2013 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.38 No.14

Marine algae are promising alternative sources for bioenergy including hydrogen. Their polymeric structure, however, requires a pretreatment such as dilute-acid hydrolysis prior to fermentation. This study aimed to optimize the control variables of batch dilute-acid hydrolysis for dark hydrogen fermentation of algal biomass. The powder of Gelidium amansii was hydrolyzed at temperatures of 120-180 <SUP>o</SUP>C, solid/liquid (S/L) ratios of 5-15% (w/v), and H<SUB>2</SUB>SO<SUB>4</SUB> concentrations of 0.5-1.5% (w/w), and then fed to batch hydrogen fermentation. Among the three control variables, hydrolysis temperature was the most significant for hydrogen production as well as for hydrolysis efficiency. The maximum hydrogen production performance of 0.51 L H<SUB>2</SUB>/L/hr and 37.0 mL H<SUB>2</SUB>/g dry biomass was found at 161-164 <SUP>o</SUP>C hydrolysis temperature, 12.7-14.1% S/L ratio, and 0.50% H<SUB>2</SUB>SO<SUB>4</SUB>. The optimized dilute-acid hydrolysis would enhance the feasibility of the red algal biomass as a suitable substrate for hydrogen fermentation.

Continuous biohydrogen production from starch wastewater via sequential dark-photo fermentation with emphasize on maghemite nanoparticles

Mahmoud Nasr,Ahmed Tawfik,Masaaki Suzuki,Sheena Kumari,Faizal Bux 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

Hydrogen production from starch wastewater via sequential dark-photo fermentation process wasinvestigated. Two anaerobic baffled reactors (ABRs) were operated in parallel at an OLR of 8.11 0.97 g-COD/L/d, and a HRT of 15 h. ABR-1 and ABR-2 was inoculated with pre-treated sludge and sludgeimmobilized on maghemite nanoparticles, respectively. Better hydrogen yield of 104.75 12.39 mL-H2/g-COD-removed was achieved in ABR-2 as compared to 66.22 4.88 mL-H2/g-COD-removed in ABR-1. Theeffluent of ABR-2 was used for further hydrogen production by photo fermentation in ABR-3. An overallhydrogen yield of 166.83 27.79 mL-H2/g-COD-removed was achieved at a total HRT of 30 h. 16S rRNAphylogeny showed that Clostridium and Rhodopseudomonas palustris species were dominant in ABR-1, ABR-2and ABR-3, respectively.

Optimization of substrate concentration of dilute acid hydrolyzate of lignocellulosic biomass in batch hydrogen production

Gonzales, R.R.,Sivagurunathan, P.,Parthiban, A.,Kim, S.H. Elsevier Applied Science 2016 INTERNATIONAL BIODETERIORATION AND BIODEGRADATION Vol.113 No.-

Lignocellulosic biomass is a promising alternative source for biohydrogen production. Its recalcitrant structure requires physicochemical pretreatment methods, such as dilute acid pretreatment, to utilize the carbohydrates in the biomass for fermentation. This study was aimed to investigate the optimum substrate concentration of dilute acid lignocellulosic hydrolyzate for dark hydrogen fermentation processes. Empty palm fruit bunch, rice husk, and pine tree wood were used as the substrates. The lignocellulosic biomass samples were hydrolyzed and fed to batch hydrogen fermentation after adjustment of substrate concentration of the hydrolyzate solutions to 5, 10, 15, and 20 g/L. The maximum hydrogen production rates were 1510 +/- 96 mL H<SUB>2</SUB> L<SUP>-1</SUP> day<SUP>-1</SUP>, 1860 +/- 245 mL H<SUB>2</SUB> L<SUP>-1</SUP> day<SUP>-1</SUP>, and 1629 +/- 170 mL H<SUB>2</SUB> L<SUP>-1</SUP> day<SUP>-1</SUP> at 10 g L<SUP>-1</SUP> substrate concentration of empty palm fruit bunch, rice husk, and pine tree wood, respectively. These correspond to hydrogen yields of 0.96 +/- 0.04 mol H<SUB>2</SUB> mol<SUP>-1</SUP> sugar, 1.25 +/- 0.15 mL H<SUB>2</SUB> mol<SUP>-1</SUP> sugar, and 0.99 +/- 0.05 mL H<SUB>2</SUB> mol<SUP>-1</SUP> sugar, respectively. The results indicate that dilute acid pretreated lignocellulosic biomass would be a suitable substrate for fermentative hydrogen production.

혐기성 발효에 의한 다시마 추출물로부터 휘발성 유기산 제조

최재형(Jae Hyung Choi),송민경(Min Kyung Song),전병수(Byung Soo Chun),이철우(Chul Woo Lee),우희철(Hee Chul Woo) 한국청정기술학회 2013 청정기술 Vol.19 No.2

본 연구에서는 거대 갈조류 대표종인 다시마(Saccharina japonica)로부터 물리화학적 전처리 방법, 미생물 접종비율, 다시마 추출물의 농도 및 pH 조건에 따른 휘발성 유기산(volatile fatty acids, VFAs) 생산 가능성 확인과 생산 효율을 평가하고자 하였다. 물리화학적 전처리 방법에 따른 휘발성 유기산의 최대 농도는 황산, 아임계수, 지질 추출 후 아임계수 전처리 순으로 나타났다. 황산 전처리 방법에서 미생물 접종비율(유효용적(WV)/미생물 부피(M) = 10~30), pH (6.0~7.0) 및 다시마 추출물의 농도(18.0~72.0 g/L)의 혐기성 발효 조건에 따른 휘발성 유기산 생성 농도에 미치는 영향을 확인한 결과, 발효 온도 35℃, 미생물 접종비율 15, pH 7.0, 발효시간 372시간에서 다시마 추출물의 농도가 18.0, 36.0, 54.0, 72.0 g/L일 때, 휘발성 유기산의 최대 농도가 각각 9.8, 13.9, 18.6, 22.3 g/L로 확인되었다. 생산된 휘발성 유기산의 조성은 pH가 높을수록 아세트산과 프로피온산의 생산 비율이 높았으며, pH가 낮을수록 부티르산의 비율이 높게 확인되었다. 생산된 저농도의 휘발성 유기산은 농축 및 분리공정과 연계하여 향후 기초화학 원료와 바이오연료 등으로 사용될 수 있으므로, 기존 화석연료의 대체에너지 생산에 기여할 수 있을 것으로 기대된다. Volatile fatty acids (VFAs) production from marine brown algae, Saccharina japonica, was investigated in anaerobic dark fermentation. In order to evaluate the VFAs productivity, various experimental parameters (i.e., physicochemical pre-treatment, microorganism inoculation ratio, substrate concentration, and pH) were evaluated. According to the physicochemical pre-treatment methods, the maximum concentrations of VFAs were obtained in the order of sulfuric acid, subcritical water and subcritical water with lipid-extraction. Also, we investigated the operating parameters such as microorganism inoculation ratio (MV/M = 10 to 30), the substrate concentration (18.0 to 72.0 g/L) and pH (6.0 to 7.0) in sulfuric acid pre-treatment method. When the substrate concentrations were 18.0, 36.0, 54.0 and 72.0 g/L at 35 ℃, microorganism inoculation ratio 15, pH 7.0 for 372 hours, the maximum concentrations of VFAs were respectively 9.8, 13.9, 18.6 and 22.3 g/L. The change in VFAs concentrations was detected that acetic- and propionic acids increased according to increasing pH, while the butyric acid increased with decreasing pH. The VFAs obtained from concentration and separation process may be used as basic chemistry materials and bio-fuel, and they will expect to produce alternative energy of fossil fuel.