Co-digestion of untreated macro and microalgal biomass for biohydrogen production: Impact of inoculum augmentation and microbial insights

Sivagurunathan, Periyasamy,Kumar, Gopalakrishnan,Kobayashi, Takuro,Xu, Kaiqin,Kim, Sang-Hyoun,Nguyen, Dinh Duc,Chang, Soon Woong Elsevier 2018 International journal of hydrogen energy Vol.43 No.25

<P><B>Abstract</B></P> <P>This study assessed the co-digestion of macro and microalgal biomass towards the improvement of hydrogen production. The red macroalgal biomass (<I>Gelidium amansii</I>) and green mixed microalgal biomass was mixed in a ratio of 8:2, with an initial substrate concentration of 10 g/L, and various amount of inoculum addition range from 3 to 15% (v/v) was evaluated to assess the feasible substrate to inoculum ratio for the effective co-digestion of the algal biomass. The results showed that the co-digestion with 6% inoculum addition provided the peak hydrogen yield of 45 mL/g dry biomass added with a high hydrogen content of 24% in the gas phase. The other tested conditions showed moderate hydrogen content in the range of 17–22%, respectively. These results suggest that anaerobic co-digestion of macro and microalgal biomass, with appropriate initial biomass loading (6%) is essential for enhanced hydrogen production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Inoculum augmentation improves the co-digestion performances. </LI> <LI> Maximum hydrogen yield of 45 mL H<SUB>2</SUB>/g TS was achieved. </LI> <LI> Peak COD removal efficiency of 28.5% achieved at 6% inoculum loading rate. </LI> <LI> <I>Eubacteria</I> and <I>Clostridium</I> were the dominant microflora. </LI> </UL> </P>

Improvement of hydrogen fermentation of galactose by combined inoculation strategy

Sivagurunathan, P.,Anburajan, P.,Kumar, G.,Arivalagan, P.,Bakonyi, P.,Kim, S.H. Society for Bioscience and Bioengineering, Japan ; 2017 Journal of bioscience and bioengineering Vol.123 No.3

<P>This study evaluated the feasibility of anaerobic hydrogen fermentation of galactose, a red algal biomass sugar, using individual and combined mixed culture inocula. Heat-treated (90 degrees C, 30 min) samples of granular sludge (GS) and suspended digester sludge (SDS) were used as inoculum sources. The type of mixed culture inoculum played an important role in hydrogen production from galactose. Between two inocula, granular sludge showed higher hydrogen production rate (HPR) and hydrogen yield (HY) of 2.2 L H2/L-d and 1.09 mol H2/mol galactoseadded, respectively. Combined inoculation (GS + SDS) led to an elevated HPR and HY of 3.1 L H2/L-d and 1.28 mol H2/mol galactoseadded, respectively. Acetic and butyric acids are the major organic acids during fermentation. Quantitative polymerase chain reaction (qPCR) revealed that the mixed culture generated using the combined inoculation contained a higher cluster I Clostridium abundance than the culture produced using the single inoculum. (C) 2016, The Society for Biotechnology, Japan. All rights reserved.</P>

Biohydrogen fermentation of galactose at various substrate concentrations in an immobilized system and its microbial correspondence

Sivagurunathan, Periyasamy,Pugazhendhi, Arivalagan,Kumar, Gopalakrishnan,Park, Jong-Hun,Kim, Sang-Hyoun Elsevier 2018 Journal of bioscience and bioengineering Vol.125 No.5

<P>The effects of substrate concentration on fermentative hydrogen production from galactose at a fixed hydraulic retention time of 12 h were investigated in an immobilized continuously stirred tank reactor. Peak hydrogen production rate and hydrogen yield of 9.57 L/L-d and 1.10 mol/mol galactose<SUB>added</SUB>, respectively, were obtained at a feed substrate concentration of 30 g/L and an organic loading rate of 60 L/L-d. Quantitative polymerase chain reaction analysis showed that the variations in the performance resulted primarily from metabolic alterations within the metabolism of the established microbial community rather than modifications in the population. The results obtained showed that optimal substrate concentration is essential for the efficient, continuous production of hydrogen from galactose.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Substrate concentration influenced the biohydrogen performance. </LI> <LI> Feed galactose of 30 g/L provided the peak H<SUB>2</SUB> production of 9.5 L/L-d. </LI> <LI> Substrate overloading caused metabolic shift of <I>Clostridium</I> to lactate production. </LI> </UL> </P>

Effect of hydraulic retention time (HRT) on biohydrogen production from galactose in an up-flow anaerobic sludge blanket reactor

Sivagurunathan, P.,Anburajan, P.,Kumar, G.,Kim, S.H. Pergamon Press 2016 International journal of hydrogen energy Vol.41 No.46

<P>This study investigated the hydrogen fermentation from galactose in up-flow anaerobic sludge blanket (UASB) reactor under mesophilic temperature of 37 degrees C. The maximum hydrogen production rate (HPR) and hydrogen yield (HY) of 56.8 L/L/d and 2.25 mol/mol galactose added were achieved at a hydraulic retention time (HRT) of 2 h. Further shortening the HRT to 1.5 h, led to the significant drop in the HPR and HY with a value of 48.3 L/L/d and 1.44 mol/mol galactose added, respectively. During the reactor operation, neither external pH adjustment nor recirculation was required, while the pH was maintained in the range of 5.5-6.2 by the carbonate buffer in the nutrient medium. Acetate and butyrate were the major soluble metabolic products (SMPs) formed during the hydrogen fermentation with fewer amounts of lactate and propionate during the peak hydrogen production performances. The results showed that controlling appropriate HRT is prerequisite for the enhancement of hydrogen production performances. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.</P>

Effects of anti-foaming agents on biohydrogen production

Sivagurunathan, Periyasamy,Anburajan, Parthiban,Kumar, Gopalakrishnan,Bakonyi, Pé,ter,Nemestó,thy, Ná,ndor,Bé,lafi-Bakó,, Katalin,Kim, Sang-Hyoun Elsevier 2016 Bioresource technology Vol.213 No.-

<P><B>Abstract</B></P> <P>The effects of antifoaming agents on fermentative hydrogen production using galactose in batch and continuous operations were investigated. Batch hydrogen production assays with LS-303 (dimethylpolysiloxane), LG-109 (polyalkylene), LG-126 (polyoxyethylenealkylene), and LG-299 (polyether) showed that the doses and types of antifoaming agents played a significant role in hydrogen production. During batch tests, LS-303 at 100μL/L resulted in the maximum hydrogen production rate (HPR) and hydrogen yield (HY) of 2.5L/L-d and 1.08mol H<SUB>2</SUB>/mol galactose<SUB>added</SUB>, respectively. The following continuously stirred tank reactor operated at 12h HRT with LS-303 at 100μL/L showed a stable HPR and HY of 4.9L/L-d and 1.17mol H<SUB>2</SUB>/mol galactose<SUB>added</SUB>, respectively, which were higher than those found for the control reactor. Microbial community analysis supported the alterations in H<SUB>2</SUB> generation under different operating conditions and the stimulatory impact of certain antifoaming chemicals on H<SUB>2</SUB> production was demonstrated.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Antifoaming agents types and dosages influence the hydrogen productivity. </LI> <LI> LS-303 and other agents at 100μL/L showed stimulatory effects on H<SUB>2</SUB> production. </LI> <LI> Increased cluster I <I>Clostridium</I> content at the low dosage attributed high H<SUB>2</SUB> yield. </LI> </UL> </P>

Feasibility of enriched mixed cultures obtained by repeated batch transfer in continuous hydrogen fermentation

Sivagurunathan, Periyasamy,Kumar, Gopalakrishnan,Park, Jeong-Hoon,Park, Jong-Hun,Park, Hee-Deung,Yoon, Jeong-Jun,Kim, Sang-Hyoun Pergamon Press 2016 International journal of hydrogen energy Vol.41 No.7

<P><B>Abstract</B></P> <P>This research investigated the suitability of enriched mixed cultures (EMC) for anaerobic hydrogen fermentation in continuous operation. EMC was prepared after four successive transfers in PYG (peptone, yeast extract and galactose) medium in batch cultivation. The peak hydrogen production rate (HPR) and hydrogen yield (HY) of 770 ± 10 mL H<SUB>2</SUB>/L-d and 1.05 ± 0.06 mol H<SUB>2</SUB>/mol galactose<SUB>added</SUB>, were attained respectively. There forward a continuously stirred tank reactor (CSTR) has been operated with the substrate concentration of 15 g/L at a hydraulic retention time (HRT) of 12 h for more than 15 days by using EMC. The performance showed that HPR and HY were fluctuated significantly during the operation and the average values were 1710 ± 250 mL H<SUB>2</SUB>/L-d and 0.82 ± 0.12 mol H<SUB>2</SUB>/mol galactose<SUB>added</SUB>, respectively. The soluble metabolic products analysis revealed that butyrate, lactate and acetate were the dominant metabolic products with less quantity of propionic and formic acids. The microbial community structure has been determined by next generation DNA sequencing technique and revealed <I>Clostridium</I> sp. was the dominant microbial consortium during repeated batch transfer, whereas <I>Sporolactobacillus</I> sp. was the major population in continuous operation. This study demonstrates that operational mode (batch and continuous) significantly influence the microbial diversity and hydrogen production, and EMC obtained by repeated process may not be suitable for continuous hydrogen fermentation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Repeated batch transfer provided H<SUB>2</SUB> producing enriched mixed cultures (EMC). </LI> <LI> <I>Clostridium</I> sp. was the dominant microbial population in EMC. </LI> <LI> <I>Sporolactobacillus</I> sp. was the major population during continuous H<SUB>2</SUB> production. </LI> </UL> </P>

Mesophilic biogenic H₂ production using galactose in a fixed bed reactor

Sivagurunathan, P.,Anburajan, P.,Park, J.H.,Kumar, G.,Park, H.D.,Kim, S.H. Pergamon Press 2017 International journal of hydrogen energy Vol.42 No.6

<P>This study investigated hydrogen fermentation from galactose in a fixed bed reactor (FBR) under a mesophilic temperature of 37 degrees C. The fixed bed reactor was packed with Lantec HD-Q-PAC material to support biomass growth and microbial assisted granule formation over the time course of the reactor operation. Hydraulic retention times (HRT) of 1.5-12 h over 79 days of bioreactor operation were assessed to determine the optimal hydrogen production efficiency of the system. The maximum hydrogen production rate and hydrogen yield of 65.5 L/L/d and 2.60 mol/mol hexoseadaed were achieved at a hydraulic retention time (HRT) of 2 h, which is higher than the reported maximum hydrogen production performance of reactors fed with galactose using other reactor configuration. The major volatile fatty acids formed were butyric and acetic acids. Microbial community analysis by quantitative real time polymerase chain reaction revealed that population changes greatly affected hydrogen production performance. The increase in the bacterial fraction of Lactobacillus spp. over 21.5% at a 1.5 h HRT led to increased lactic acid production up to 1865 mg/L, which deteriorated the reactor performances. Conversely, a bacterial fraction of Clostridium butyricum over 98% was observed when the H-2 production performance and organic acid distribution were recovered using a 2 h HRT. FBR would be a promising reactor configuration to achieve high hydrogen productivity while preventing the wash out of active biomass. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.</P>

Enhanced Fermentative Hydrogen Production from Galactose using Bioaugmentation Strategy

( Periyasamy Sivagurunathan ),( Anburajan Parthiban ),( Gopalakrishnan Kumar ),( Sang Hyoun Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 3RINCs초록집 Vol.2015 No.-

This study evaluated the feasibility of anaerobic hydrogen fermentation of galactose (red algal biomass sugar) using individual and bioaugmented mixed cultures. Heat-treated (80ºC 30 min) samples of granular sludge and digester sludge were used as inoculum source and their individual and bioaugmentive role on hydrogen production were examined in batch tests. Among the tested individual inoculum, granular sludge provided the maximum hydrogen production rate (HPR) and hydrogen yield (HY) of 2.8 L/L-d and 0.64 mol/mol galctoseadded. Bioaugmented (granular sludge+ digester sludge) mixed culture showed a peak HPR and HY of 3.2 L/L-d and 0.84 mol/mol galctose added, respectively. The results showed that there was a significant improvement in hydrogen production performances were observed when the individual hat-treated mixed cultures were added together. The hydrogen content was maintained over ~52% in both individual and bioaugmented cultures. The sugar consumption rate was more than 90% in all cases. The soluble metabolic products analysis revealed that butyrate and acetate was the major dominant metabolic products. This study proved that bioaugmentation could be a feasible strategy for improving hydrogen production from galactose and to solve the energy issue in the future.

Single component crystalline core/amorphous shell structured Nickel Cobaltite electrocatalyst for Oxygen Evolution Reaction

( Thangavel Sivagurunathan Amarnath ),김도형 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.1

Enhanced hydrogen fermentation by zero valent iron addition

Hwang, Yuhoon,Sivagurunathan, Periyasamy,Lee, Mo-Kwon,Yun, Yeo-Myeong,Song, Young-Chae,Kim, Dong-Hoon Elsevier 2019 International journal of hydrogen energy Vol.44 No.6

<P><B>Abstract</B></P> <P>In this study, zero valent iron (ZVI) was applied to enhance hydrogen fermentation (H<SUB>2</SUB>). Glucose was used as a substrate at various concentrations of 5–40 g COD/L, and ZVI concentration was adjusted at 0–10 g/L. Without ZVI addition, H<SUB>2</SUB> yield decreased as substrate concentration increased, due to organic acids accumulation as substrate concentration increased. At low substrate concentration of 5 g COD/L, there was a slight increase of H<SUB>2</SUB> yield from 1.4 to 1.5 mol H<SUB>2</SUB>/mol glucose added by ZVI addition. However, the increment was substantial at higher substrate range. For example, H<SUB>2</SUB> yield increased from 0.9 to 1.2–1.5 mol H<SUB>2</SUB>/mol hexoseadded by ZVI addition at 20 g COD/L. The results indicated that ZVI may create a more favorable environment for anaerobic microbial acidogenesis with providing buffering effect to prevent pH drop due to produced hydroxyl ions as it dissolved. These changes of environmental conditions also brought differences on organic acids profile and microbial community, and those may affect to overall H<SUB>2</SUB> fermentation performances.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Investigate the effect of ZVI on the dark fermentative hydrogen production. </LI> <LI> H<SUB>2</SUB> yield and production rate were increased up to 54% and 72%, respectively. </LI> <LI> pH decrease was well prevented by buffering effect of ZVI. </LI> <LI> Organic acid production was significantly enhanced with favorable composition. </LI> </UL> </P>