To enhance hydrogen production efficiency and energy recovery,a sequential dark fermentation and microbial electrochemical cell(MEC)process was evaluated for hydrogen production from food waste.The hydrogen production...To enhance hydrogen production efficiency and energy recovery,a sequential dark fermentation and microbial electrochemical cell(MEC)process was evaluated for hydrogen production from food waste.The hydrogen production,electrochemical performance and microbial community dynamics were investigated during startup of the MEC that was inoculated with different sludges.Results suggest that biogas production rates and hydrogen proportions were 0.83 L/L d and 92.58%,respectively,using anaerobic digested sludge,which is higher than that of the anaerobic granular sludge(0.55 L/L d and 86.21%).The microbial community were predominated by bacterial genus Acetobacterium,Geobacter,Desulfovibrio,and archaeal genus Methanobrevibacter in electrode biofilms and the community structure was relatively stable both in anode and cathode.The sequential system obtained a 53.8% energy recovery rate and enhanced soluble chemical oxygen demand(sCOD)removal rate of 44.3%.This research demonstrated an important approach to utilize dark fermentation effluent to maximize the conversion of fermentation byproducts into hydrogen.展开更多
The successful operation of any type of hydrogen-producing bioreactor depends on the performance of the microorganisms present in the system. Both substrate and partial gas pressures are crucial factors affecting dark...The successful operation of any type of hydrogen-producing bioreactor depends on the performance of the microorganisms present in the system. Both substrate and partial gas pressures are crucial factors affecting dark fermentation metabolic pathways. The main objective of this study was to evaluate the impact of both factors on hydrogen production using anaerobic granular sludge as inoculum and, secondly, to study the metabolic shifts of an anaerobic community subjected to low partial gas pressures. With this goal in mind, seven different wastewater （four synthetic media, two industrial waste- water, and one domestic effluent） and the effect of applying vacuum on the systems were analyzed. The application of vacuum promoted an increase in the diversity of hydrogen-producing bacteria, such as Clostridium, and promoted the dominance of acetoclasticover hydrogenotrophic methanogens. The application of different media promoted a wide variety of metabolic pathways. Nevertheless, reduction of the hydrogen partial pressure by application of vacuum lead to further oxidation of reaction intermediates irrespective of the medium used, which resulted in higher hydrogen and methane production, and improved the COD removal. Interestingly, vacuum greatly promoted biogenic hydrogen production from a real wastewater, which opens possibilities for future application of dark fermentation systems to enhance biohydrogen yields.展开更多
The study has assessed the denitrification performance of fermented and dark-fermented biosolids as external carbon sources using lab-scaled Sequencing Batch Reactors （SBRs）. This was done by adding fermented and da...The study has assessed the denitrification performance of fermented and dark-fermented biosolids as external carbon sources using lab-scaled Sequencing Batch Reactors （SBRs）. This was done by adding fermented and dark-fermented biosolids into anoxic zones of two SBRs, and then assessing the change of effluent characteristics comparing to before adding and to a third controlled reactor. The results showed that by adding 150-170 mg rbCOD/L of either of the selected fermented biosolids, almost complete denitrification could be reached for tested SBRs （reduced from initial -20 mg NO3/L to 〈 1 mg NO3/L）. Finally, the experiment also found that the impact of NI-I4 components of fermented and dark-fermented biosolids onto the final effluent were much lesser than expected, where only less than 2.5 mg NH4/L were detected in the effluent, much lower than the added 5.0-5.7 mg/L.展开更多
The hydrogen-producing consortium conveying the lactate-fermentation pathway was enriched and used as a coinoculum with the non-enriched hydrogen-producing consortium for biohydrogen production in the presence of lact...The hydrogen-producing consortium conveying the lactate-fermentation pathway was enriched and used as a coinoculum with the non-enriched hydrogen-producing consortium for biohydrogen production in the presence of lactic acid bacteria(LAB).The co-inoculum treatment achieved superior hydrogen production performance compared to that of the non-enriched consortium treatment.The effects of enriched consortium concentration,initial pH,and glucose concentration were evaluated,and hydrogen production potential(HP)of 1,605±161 mL-H_(2)/L and a maximum hydrogen production rate(HPR)of 87.17±15.85 mL-H_(2)/L.h were achieved under optimal conditions.Biohydrogen production from food waste using the co-inoculum was 1,137 mL-H_(2)/L from non-autoclaved food waste,corresponding to 56.85 mL-H_(2)/g-VS_(added).Metabolite product and microbial community analyses during food waste fermentation indicated positive cross-feeding activity of hydrogen producers,LAB,and acetogenic bacteria.This study provides valuable information on the use of an efficient,enriched hydrogen-producing consortium to improve biohydrogen production from LAB-contaminated feedstock.展开更多
The impact of antibiotics on the environmental protection and sludge treatment fields has been widely studied.The recovery of hydrogen from waste activated sludge(WAS)has become an issue of great interest.Nevertheless...The impact of antibiotics on the environmental protection and sludge treatment fields has been widely studied.The recovery of hydrogen from waste activated sludge(WAS)has become an issue of great interest.Nevertheless,few studies have focused on the impact of antibiotics present in WAS on hydrogen production during dark anaerobic fermentation.To explore the mechanisms,sulfamethoxazole(SMX)was chosen as a representative antibiotic to evaluate how SMX influenced hydrogen production during dark anaerobic fermentation of WAS.The results demonstrated SMX promoted hydrogen production.With increasing additions of SMX from 0 to 500 mg/kg TSS,the cumulative hydrogen production elevated from 8.07±0.37 to 11.89±0.19 mL/g VSS.A modified Gompertz model further verified that both the maximum potential of hydrogen production(Pm)and the maximum rate of hydrogen production(R_(m))were promoted.SMX did not affected sludge solubilization,but promoted hydrolysis and acidification processes to produce more hydrogen.Moreover,the methanogenesis process was inhibited so that hydrogen consumption was reduced.Microbial community analysis further demonstrated that the introduction of SMX improved the abundance of hydrolysis bacteria and hydrogen-volatile fatty acids(VFAs)producers.SMX synergistically influenced hydrolysis,acidification and acetogenesis to facilitate the hydrogen production.展开更多
A major limitation associated with fermenta- tive hydrogen production is the low substrate conversion efficiency. This limitation can be overcome by integrating the process with a microbial fuel cell （MFC） which con...A major limitation associated with fermenta- tive hydrogen production is the low substrate conversion efficiency. This limitation can be overcome by integrating the process with a microbial fuel cell （MFC） which converts the residual energy of the substrate to electricity. Studies were carried out to check the feasibility of this integration. Biohydrogen was produced from the fermen- tation of cane molasses in both batch and continuous modes. A maximum yield of about 8.23 mol Hz/kg CODremoved was observed in the batch process compared to 11.6 mol Hz/kg CODremoved in the continuous process. The spent fermentation media was then used as a substrate in an MFC for electricity generation. The MFC parameters such as the initial anolyte pH, the substrate concentration and the effect ofpre-treatment were studied and optimized to maximize coulombic efficiency. Reductions in COD and total carbohydrates were about 85% and 88% respectively. A power output of 3.02 W/m3 was obtained with an anolyte pH of 7.5 using alkali pre-treated spent media. The results show that integrating a MFC with dark fermentation is a promising way to utilize the substrate energy.展开更多
The valorization of sewage sludge and food waste to produce energy and fertilizers is a well-stablished strategy within the circular economy.Despite the success of numerous laboratory-scale experiments in converting w...The valorization of sewage sludge and food waste to produce energy and fertilizers is a well-stablished strategy within the circular economy.Despite the success of numerous laboratory-scale experiments in converting waste into high-value products such as volatile fatty acids(VFAs),large-scale implementation remains limited due to various technical and environmental challenges.Here,we evaluate the environmental performance of a hypothetical large-scale VFAs biorefinery located in Galicia,Spain,which integrates fermentation and purification processes to obtain commercial-grade VFAs based on primary data from pilot plant operations.We identify potential environmental hotspots,assess the influence of different feedstocks,and perform sensitivity analyses on critical factors like transportation distances and pH control methods,using life cycle assessment.Our findings reveal that,on a per-product basis,food waste provides superior environmental performance compared to sewage sludge,which,conversely,performs better when assessed per mass of waste valorized.This suggests that higher process productivity from more suitable wastes leads to lower environmental impacts but must be balanced against increased energy and chemical consumption,as food waste processing requires more electricity for pretreatment and solid-liquid separation.Further analysis reveals that the main operational impacts are chemical-related,primarily due to the use of NaOH for pH adjustment.Additionally,facility location is critical,potentially accounting for up to 99%of operational impacts due to transportation.Overall,our analysis demonstrates that the proposed VFAs biorefinery has a carbon footprint comparable to other bio-based technologies.However,enhancements in VFAs purification processes are necessary to fully replace petrochemical production.These findings highlight the potential of waste valorization into VFAs as a sustainable alternative,emphasizing the importance of process optimization and strategic facility placement.展开更多
Sustainable hydrogen production is central to achieving global decarbonization and water stewardship goals.This review is the first to present an integrated techno-economic and environmental feasibility assessment of ...Sustainable hydrogen production is central to achieving global decarbonization and water stewardship goals.This review is the first to present an integrated techno-economic and environmental feasibility assessment of producing hydrogen from industrial wastewater in Bangladesh,directly linking high-strength effluent management with clean energy generation.Industrial wastewater,often untreated and rich in biodegradable organics,presents an underexploited feedstock that can simultaneously mitigate pollution,reduce freshwater consumption,and generate clean energy.However,such integrated analyses remain scarce,particularly in developing economies where industrial effluent discharge is a major sustainability challenge.This review assesses the feasibility of hydrogen generation from industrial effluents via dark fermentation(DF)and proton exchange membrane electrolysis(PEME),supported by advanced pretreatment strategies.DF achieves yields up to~3.5 L H_(2)L^(-1)effluent(~3 mol mol^(-1)glucose)with strong cost advantages for high-COD(>1.5 g L^(-1))streams,while PEME offers>75%electrical efficiency and offsets 9-12 L kg^(-1)H_(2)in freshwater demand when treated wastewater is used.Pretreatment methods physical,chemical,biological,and nanomaterial-ekgsnabled remove>90%of inhibitory contaminants,enhancing system longevity.A Bangladesh case study illustrates the technology,cost,water-energy nexus,identifying DF as optimal for high-strength effluents and PEME as viable where low-cost renewable electricity and grid-service flexibility are prioritized.Addressing research gaps in pilot-scale validation,impurity-tolerant materials,and enabling policy frameworks can position wastewater valorization as a dual-benefit solution for SDGs 6 and 7,advancing both clean water and clean energy transitions.展开更多
Hydrogen production from food waste,cattle manure,potato pulp and pig manure was optimized through using mixture design in this study.The synergic and antagonistic effects of the four substrates on hydrogen yield,subs...Hydrogen production from food waste,cattle manure,potato pulp and pig manure was optimized through using mixture design in this study.The synergic and antagonistic effects of the four substrates on hydrogen yield,substrate conversion efficiency and pH were evaluated.The results showed that the optimal proportion of food waste,cattle manure,potato pulp and pig manure were 61.6%,38.4%,0,and 0,respectively.Under the optimal condition,hydrogen yield of 21.0 mL/g VS with VS reduction of 29.4%and pH of 5 could be obtained.The interaction between food waste and cattle manure had strongest synergistic effects.Hydrogen was mainly produced by acetic-butyric metabolic pathway,and ammonification of protein played an important role in the maintenance of pH.展开更多
To investigate the influence of illumination on the fermentative hydrogen production system, the hydro- gen production efficiencies of two kinds of anaerobic activated sludge （floc and granule） from an anaerobic baf...To investigate the influence of illumination on the fermentative hydrogen production system, the hydro- gen production efficiencies of two kinds of anaerobic activated sludge （floc and granule） from an anaerobic baffled reactor were detected under visible light, dark and light-dark, respectively. The 10 mL floc sludge or granular sludge was respectively inoculated to 100 mL diluted molasses （chemical oxygen demand of 8000 mg.L^-1） in a 250 mL serum bottle, and cultured for 24 h at 37℃ under different illumination conditions. The results showed that the floc was more sensitive to illumination than the granule. A hydrogen yield of 19.8 mL was obtained in the dark with a specific hydrogen production rate of 3.52mol.kgLMLVSS.d^-1 （floc）, which was the highest among the three illumination conditions. Under dark condition, the hydrogen yield of floc sludge reached the highest with the specific hydrogen production rate of 3.52mol.kg^-1MLVSS.d^-1, and under light-dark, light, the specific hydrogen production rate was 3.11 and 2.21mol.kg^-1 MLVSS.d-1, respectively. The results demonstrated that the illumination may affect the dehydrogenase activity of sludge as well as the activity of hydrogen-producing acetogens and then impact hydrogen production capacity.展开更多
Energy shortages have hindered global economic development.By utilizing waste as a substrate for microbial fermentation,hydrogen production can transform waste into a valuable resource,significantly reducing the cost ...Energy shortages have hindered global economic development.By utilizing waste as a substrate for microbial fermentation,hydrogen production can transform waste into a valuable resource,significantly reducing the cost of hydrogen production and addressing a significant hurdle in achieving large-scale production of microbial hydrogen.This approach has significant potential for future hydrogen-production applications.Two-stage indirect photohydrolysis has recently emerged as a promising and efficient method for hydrogen production using cyanobacteria and green algae.However,this method cannot be directly applied to organic wastewater for hydrogen production.In contrast,dark fermentation by bacteria,particularly ethanol-type fermentation,is highly efficient for producing hydrogen.Therefore,the combination of the indirect photohydrolysis of algae and dark fermentation by bacteria is expected to significantly enhance the hydrogen-production capacity of organic wastewater,laying the groundwork for future large-scale microbial hydrogen production.This study reviews the main types and technical principles of microbial hydrogen production from waste,available waste types,research progress in the microbial hydrogen-production process,strategies to improve the hydrogen-production rate,and challenges faced during industrialization.Future research directions for microbial-waste hydrogen production are also proposed.The aim of this study is to provide a valuable reference for large-scale biological hydrogen-production research.展开更多
基金supported by the National Natural Science Foundation of China(grant numbers 21406213 and 51408572).
文摘To enhance hydrogen production efficiency and energy recovery,a sequential dark fermentation and microbial electrochemical cell(MEC)process was evaluated for hydrogen production from food waste.The hydrogen production,electrochemical performance and microbial community dynamics were investigated during startup of the MEC that was inoculated with different sludges.Results suggest that biogas production rates and hydrogen proportions were 0.83 L/L d and 92.58%,respectively,using anaerobic digested sludge,which is higher than that of the anaerobic granular sludge(0.55 L/L d and 86.21%).The microbial community were predominated by bacterial genus Acetobacterium,Geobacter,Desulfovibrio,and archaeal genus Methanobrevibacter in electrode biofilms and the community structure was relatively stable both in anode and cathode.The sequential system obtained a 53.8% energy recovery rate and enhanced soluble chemical oxygen demand(sCOD)removal rate of 44.3%.This research demonstrated an important approach to utilize dark fermentation effluent to maximize the conversion of fermentation byproducts into hydrogen.
文摘The successful operation of any type of hydrogen-producing bioreactor depends on the performance of the microorganisms present in the system. Both substrate and partial gas pressures are crucial factors affecting dark fermentation metabolic pathways. The main objective of this study was to evaluate the impact of both factors on hydrogen production using anaerobic granular sludge as inoculum and, secondly, to study the metabolic shifts of an anaerobic community subjected to low partial gas pressures. With this goal in mind, seven different wastewater （four synthetic media, two industrial waste- water, and one domestic effluent） and the effect of applying vacuum on the systems were analyzed. The application of vacuum promoted an increase in the diversity of hydrogen-producing bacteria, such as Clostridium, and promoted the dominance of acetoclasticover hydrogenotrophic methanogens. The application of different media promoted a wide variety of metabolic pathways. Nevertheless, reduction of the hydrogen partial pressure by application of vacuum lead to further oxidation of reaction intermediates irrespective of the medium used, which resulted in higher hydrogen and methane production, and improved the COD removal. Interestingly, vacuum greatly promoted biogenic hydrogen production from a real wastewater, which opens possibilities for future application of dark fermentation systems to enhance biohydrogen yields.
文摘The study has assessed the denitrification performance of fermented and dark-fermented biosolids as external carbon sources using lab-scaled Sequencing Batch Reactors （SBRs）. This was done by adding fermented and dark-fermented biosolids into anoxic zones of two SBRs, and then assessing the change of effluent characteristics comparing to before adding and to a third controlled reactor. The results showed that by adding 150-170 mg rbCOD/L of either of the selected fermented biosolids, almost complete denitrification could be reached for tested SBRs （reduced from initial -20 mg NO3/L to 〈 1 mg NO3/L）. Finally, the experiment also found that the impact of NI-I4 components of fermented and dark-fermented biosolids onto the final effluent were much lesser than expected, where only less than 2.5 mg NH4/L were detected in the effluent, much lower than the added 5.0-5.7 mg/L.
基金funded by the Fundamental Fund of Khon Kaen University from the National Science,Research and Innovation Fund(NSRF)the Research Group for Development of Microbial Hydrogen Production Process from Biomass,Khon Kaen University,Thailand.
文摘The hydrogen-producing consortium conveying the lactate-fermentation pathway was enriched and used as a coinoculum with the non-enriched hydrogen-producing consortium for biohydrogen production in the presence of lactic acid bacteria(LAB).The co-inoculum treatment achieved superior hydrogen production performance compared to that of the non-enriched consortium treatment.The effects of enriched consortium concentration,initial pH,and glucose concentration were evaluated,and hydrogen production potential(HP)of 1,605±161 mL-H_(2)/L and a maximum hydrogen production rate(HPR)of 87.17±15.85 mL-H_(2)/L.h were achieved under optimal conditions.Biohydrogen production from food waste using the co-inoculum was 1,137 mL-H_(2)/L from non-autoclaved food waste,corresponding to 56.85 mL-H_(2)/g-VS_(added).Metabolite product and microbial community analyses during food waste fermentation indicated positive cross-feeding activity of hydrogen producers,LAB,and acetogenic bacteria.This study provides valuable information on the use of an efficient,enriched hydrogen-producing consortium to improve biohydrogen production from LAB-contaminated feedstock.
基金supported by the National Key R&D Program of China(No.2018YFE0106400)。
文摘The impact of antibiotics on the environmental protection and sludge treatment fields has been widely studied.The recovery of hydrogen from waste activated sludge(WAS)has become an issue of great interest.Nevertheless,few studies have focused on the impact of antibiotics present in WAS on hydrogen production during dark anaerobic fermentation.To explore the mechanisms,sulfamethoxazole(SMX)was chosen as a representative antibiotic to evaluate how SMX influenced hydrogen production during dark anaerobic fermentation of WAS.The results demonstrated SMX promoted hydrogen production.With increasing additions of SMX from 0 to 500 mg/kg TSS,the cumulative hydrogen production elevated from 8.07±0.37 to 11.89±0.19 mL/g VSS.A modified Gompertz model further verified that both the maximum potential of hydrogen production(Pm)and the maximum rate of hydrogen production(R_(m))were promoted.SMX did not affected sludge solubilization,but promoted hydrolysis and acidification processes to produce more hydrogen.Moreover,the methanogenesis process was inhibited so that hydrogen consumption was reduced.Microbial community analysis further demonstrated that the introduction of SMX improved the abundance of hydrolysis bacteria and hydrogen-volatile fatty acids(VFAs)producers.SMX synergistically influenced hydrolysis,acidification and acetogenesis to facilitate the hydrogen production.
文摘A major limitation associated with fermenta- tive hydrogen production is the low substrate conversion efficiency. This limitation can be overcome by integrating the process with a microbial fuel cell （MFC） which converts the residual energy of the substrate to electricity. Studies were carried out to check the feasibility of this integration. Biohydrogen was produced from the fermen- tation of cane molasses in both batch and continuous modes. A maximum yield of about 8.23 mol Hz/kg CODremoved was observed in the batch process compared to 11.6 mol Hz/kg CODremoved in the continuous process. The spent fermentation media was then used as a substrate in an MFC for electricity generation. The MFC parameters such as the initial anolyte pH, the substrate concentration and the effect ofpre-treatment were studied and optimized to maximize coulombic efficiency. Reductions in COD and total carbohydrates were about 85% and 88% respectively. A power output of 3.02 W/m3 was obtained with an anolyte pH of 7.5 using alkali pre-treated spent media. The results show that integrating a MFC with dark fermentation is a promising way to utilize the substrate energy.
基金supported by the European Union NextGenerationEU/PRTR,and the project Biological Resources Certifications Schemes(BIORECER)funded by the European Executive Agency under call HORIZON CL6-2021-ZEROPOLLUTION-01(101060684)It was also carried out thanks to the INTERREG ECOVAL and CIGAT CIRCULAR projects,funded by Interreg Sudoe and the Xunta de Galicia and Viaqua,respectively.
文摘The valorization of sewage sludge and food waste to produce energy and fertilizers is a well-stablished strategy within the circular economy.Despite the success of numerous laboratory-scale experiments in converting waste into high-value products such as volatile fatty acids(VFAs),large-scale implementation remains limited due to various technical and environmental challenges.Here,we evaluate the environmental performance of a hypothetical large-scale VFAs biorefinery located in Galicia,Spain,which integrates fermentation and purification processes to obtain commercial-grade VFAs based on primary data from pilot plant operations.We identify potential environmental hotspots,assess the influence of different feedstocks,and perform sensitivity analyses on critical factors like transportation distances and pH control methods,using life cycle assessment.Our findings reveal that,on a per-product basis,food waste provides superior environmental performance compared to sewage sludge,which,conversely,performs better when assessed per mass of waste valorized.This suggests that higher process productivity from more suitable wastes leads to lower environmental impacts but must be balanced against increased energy and chemical consumption,as food waste processing requires more electricity for pretreatment and solid-liquid separation.Further analysis reveals that the main operational impacts are chemical-related,primarily due to the use of NaOH for pH adjustment.Additionally,facility location is critical,potentially accounting for up to 99%of operational impacts due to transportation.Overall,our analysis demonstrates that the proposed VFAs biorefinery has a carbon footprint comparable to other bio-based technologies.However,enhancements in VFAs purification processes are necessary to fully replace petrochemical production.These findings highlight the potential of waste valorization into VFAs as a sustainable alternative,emphasizing the importance of process optimization and strategic facility placement.
文摘Sustainable hydrogen production is central to achieving global decarbonization and water stewardship goals.This review is the first to present an integrated techno-economic and environmental feasibility assessment of producing hydrogen from industrial wastewater in Bangladesh,directly linking high-strength effluent management with clean energy generation.Industrial wastewater,often untreated and rich in biodegradable organics,presents an underexploited feedstock that can simultaneously mitigate pollution,reduce freshwater consumption,and generate clean energy.However,such integrated analyses remain scarce,particularly in developing economies where industrial effluent discharge is a major sustainability challenge.This review assesses the feasibility of hydrogen generation from industrial effluents via dark fermentation(DF)and proton exchange membrane electrolysis(PEME),supported by advanced pretreatment strategies.DF achieves yields up to~3.5 L H_(2)L^(-1)effluent(~3 mol mol^(-1)glucose)with strong cost advantages for high-COD(>1.5 g L^(-1))streams,while PEME offers>75%electrical efficiency and offsets 9-12 L kg^(-1)H_(2)in freshwater demand when treated wastewater is used.Pretreatment methods physical,chemical,biological,and nanomaterial-ekgsnabled remove>90%of inhibitory contaminants,enhancing system longevity.A Bangladesh case study illustrates the technology,cost,water-energy nexus,identifying DF as optimal for high-strength effluents and PEME as viable where low-cost renewable electricity and grid-service flexibility are prioritized.Addressing research gaps in pilot-scale validation,impurity-tolerant materials,and enabling policy frameworks can position wastewater valorization as a dual-benefit solution for SDGs 6 and 7,advancing both clean water and clean energy transitions.
基金National Natural Science Foundation of China(Grant No.51506027)”Young Talents”Project of Northeast Agricultural University(Grant No.16QC18).
文摘Hydrogen production from food waste,cattle manure,potato pulp and pig manure was optimized through using mixture design in this study.The synergic and antagonistic effects of the four substrates on hydrogen yield,substrate conversion efficiency and pH were evaluated.The results showed that the optimal proportion of food waste,cattle manure,potato pulp and pig manure were 61.6%,38.4%,0,and 0,respectively.Under the optimal condition,hydrogen yield of 21.0 mL/g VS with VS reduction of 29.4%and pH of 5 could be obtained.The interaction between food waste and cattle manure had strongest synergistic effects.Hydrogen was mainly produced by acetic-butyric metabolic pathway,and ammonification of protein played an important role in the maintenance of pH.
文摘To investigate the influence of illumination on the fermentative hydrogen production system, the hydro- gen production efficiencies of two kinds of anaerobic activated sludge （floc and granule） from an anaerobic baffled reactor were detected under visible light, dark and light-dark, respectively. The 10 mL floc sludge or granular sludge was respectively inoculated to 100 mL diluted molasses （chemical oxygen demand of 8000 mg.L^-1） in a 250 mL serum bottle, and cultured for 24 h at 37℃ under different illumination conditions. The results showed that the floc was more sensitive to illumination than the granule. A hydrogen yield of 19.8 mL was obtained in the dark with a specific hydrogen production rate of 3.52mol.kgLMLVSS.d^-1 （floc）, which was the highest among the three illumination conditions. Under dark condition, the hydrogen yield of floc sludge reached the highest with the specific hydrogen production rate of 3.52mol.kg^-1MLVSS.d^-1, and under light-dark, light, the specific hydrogen production rate was 3.11 and 2.21mol.kg^-1 MLVSS.d-1, respectively. The results demonstrated that the illumination may affect the dehydrogenase activity of sludge as well as the activity of hydrogen-producing acetogens and then impact hydrogen production capacity.
基金Supported by the Natural Science Basic Research Program of Shaanxi Province(S2021-JC-LHJJXMLH-QY-SM-0119).
文摘Energy shortages have hindered global economic development.By utilizing waste as a substrate for microbial fermentation,hydrogen production can transform waste into a valuable resource,significantly reducing the cost of hydrogen production and addressing a significant hurdle in achieving large-scale production of microbial hydrogen.This approach has significant potential for future hydrogen-production applications.Two-stage indirect photohydrolysis has recently emerged as a promising and efficient method for hydrogen production using cyanobacteria and green algae.However,this method cannot be directly applied to organic wastewater for hydrogen production.In contrast,dark fermentation by bacteria,particularly ethanol-type fermentation,is highly efficient for producing hydrogen.Therefore,the combination of the indirect photohydrolysis of algae and dark fermentation by bacteria is expected to significantly enhance the hydrogen-production capacity of organic wastewater,laying the groundwork for future large-scale microbial hydrogen production.This study reviews the main types and technical principles of microbial hydrogen production from waste,available waste types,research progress in the microbial hydrogen-production process,strategies to improve the hydrogen-production rate,and challenges faced during industrialization.Future research directions for microbial-waste hydrogen production are also proposed.The aim of this study is to provide a valuable reference for large-scale biological hydrogen-production research.
