1
|
Yang Z, Wu W, Zhao Q, Angelidaki I, Arhin SG, Hua D, Zhao Y, Sun H, Liu G, Wang W. Enhanced direct gaseous CO 2 fixation into higher bio-succinic acid production and selectivity. J Environ Sci (China) 2024; 143:164-175. [PMID: 38644014 DOI: 10.1016/j.jes.2023.05.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 05/24/2023] [Accepted: 05/24/2023] [Indexed: 04/23/2024]
Abstract
Utilizing CO2 for bio-succinic acid production is an attractive approach to achieve carbon capture and recycling (CCR) with simultaneous production of a useful platform chemical. Actinobacillus succinogenes and Basfia succiniciproducens were selected and investigated as microbial catalysts. Firstly, the type and concentration of inorganic carbon concentration and glucose concentration were evaluated. 6 g C/L MgCO3 and 24 g C/L glucose were found to be the optimal basic operational conditions, with succinic acid production and carbon yield of over 30 g/L and over 40%, respectively. Then, for maximum gaseous CO2 fixation, carbonate was replaced with CO2 at different ratios. The "less carbonate more CO2" condition of the inorganic carbon source was set as carbonate: CO2 = 1:9 (based on the mass of carbon). This condition presented the highest availability of CO2 by well-balanced chemical reaction equilibrium and phase equilibrium, showing the best performance with regarding CO2 fixation (about 15 mg C/(L·hr)), with suppressed lactic acid accumulation. According to key enzymes analysis, the ratio of phosphoenolpyruvate carboxykinase to lactic dehydrogenase was enhanced at high ratios of gaseous CO2, which could promote glucose conversion through the succinic acid path. To further increase gaseous CO2 fixation and succinic acid production and selectivity, stepwise CO2 addition was evaluated. 50%-65% increase in inorganic carbon utilization was obtained coupled with 20%-30% increase in succinic acid selectivity. This was due to the promotion of the succinic acid branch of the glucose metabolism, while suppressing the pyruvate branch, along with the inhibition on the conversion from glucose to lactic acid.
Collapse
Affiliation(s)
- Ziyi Yang
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Wanling Wu
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Qing Zhao
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Irini Angelidaki
- Department of Chemical and Biochemical Environmental Engineering, Technical University of Denmark, DK-2800, Kgs Lyngby, Denmark
| | - Samuel Gyebi Arhin
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Dongliang Hua
- Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Biomass Gasification Technology, Jinan 250014, China
| | - Yuxiao Zhao
- Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Biomass Gasification Technology, Jinan 250014, China
| | - Hangyu Sun
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Guangqing Liu
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China
| | - Wen Wang
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
| |
Collapse
|
2
|
Arhin SG, Cesaro A, Di Capua F, Esposito G. Acidogenic fermentation of food waste to generate electron acceptors and donors towards medium-chain carboxylic acids production. J Environ Manage 2023; 348:119379. [PMID: 37898048 DOI: 10.1016/j.jenvman.2023.119379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/06/2023] [Accepted: 10/14/2023] [Indexed: 10/30/2023]
Abstract
This study investigated the optimum pH, temperature, and food-to-microorganisms (F/M) ratio for regulating the formation of electron acceptors and donors during acidogenic fermentation to facilitate medium-chain carboxylic acids (MCCAs) production from food waste. Mesophilic fermentation at pH 6 was optimal for producing mixed volatile fatty acids (719 ± 94 mg COD/g VS) as electron acceptors. Under mesophilic conditions, the F/M ratio (g VS/g VS) could be increased to 6 to generate 22 ± 2 g COD/L of electron acceptors alongside 2 ± 0 g COD/L of caproic acid. Thermophilic fermentation at pH 6 was the best condition for producing lactic acid as an electron donor. However, operating at F/M ratios above 3 g VS/g VS under thermophilic settings significantly reduced lactic acid yield. A preliminary techno-economic evaluation revealed that converting lactic acid and butyric acid generated during acidogenic fermentation to caproic acid was the most profitable food waste valorization scenario and could generate 442-468 €/t VS/y. The results presented in this study provide insights into how to tailor acidogenic fermentation reactions to desired intermediates and will help maximize MCCAs synthesis.
Collapse
Affiliation(s)
- Samuel Gyebi Arhin
- Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125, Naples, Italy.
| | - Alessandra Cesaro
- Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125, Naples, Italy
| | - Francesco Di Capua
- School of Engineering, University of Basilicata, via dell'Ateneo Lucano 10, 85100, Potenza, Italy
| | - Giovanni Esposito
- Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125, Naples, Italy
| |
Collapse
|
3
|
Arhin SG, Cesaro A, Di Capua F, Esposito G. Recent progress and challenges in biotechnological valorization of lignocellulosic materials: Towards sustainable biofuels and platform chemicals synthesis. Sci Total Environ 2023; 857:159333. [PMID: 36220479 DOI: 10.1016/j.scitotenv.2022.159333] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Lignocellulosic materials (LCM) have garnered attention as feedstocks for second-generation biofuels and platform chemicals. With an estimated annual production of nearly 200 billion tons, LCM represent an abundant source of clean, renewable, and sustainable carbon that can be funneled to numerous biofuels and platform chemicals by sustainable microbial bioprocessing. However, the low bioavailability of LCM due to the recalcitrant nature of plant cell components, the complexity and compositional heterogeneity of LCM monomers, and the limited metabolic flexibility of wild-type product-forming microorganisms to simultaneously utilize various LCM monomers are major roadblocks. Several innovative strategies have been proposed recently to counter these issues and expedite the widespread commercialization of biorefineries using LCM as feedstocks. Herein, we critically summarize the recent advances in the biological valorization of LCM to value-added products. The review focuses on the progress achieved in the development of strategies that boost efficiency indicators such as yield and selectivity, minimize carbon losses via integrated biorefinery concepts, facilitate carbon co-metabolism and carbon-flux redirection towards targeted products using recently engineered microorganisms, and address specific product-related challenges, to provide perspectives on future research needs and developments. The strategies and views presented here could guide future studies in developing feasible and economically sustainable LCM-based biorefineries as a crucial node in achieving carbon neutrality.
Collapse
Affiliation(s)
- Samuel Gyebi Arhin
- Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125 Naples, Italy.
| | - Alessandra Cesaro
- Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125 Naples, Italy
| | - Francesco Di Capua
- School of Engineering, University of Basilicata, via dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - Giovanni Esposito
- Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125 Naples, Italy
| |
Collapse
|
4
|
Yang Z, Wu S, Sun H, Arhin SG, Papadakis VG, Goula MA, Liu G, Zhang Y, Zhou L, Wang W. Efficient degradation of organic compounds in landfill leachate via developing bio-electro-Fenton process. J Environ Manage 2022; 319:115719. [PMID: 35849928 DOI: 10.1016/j.jenvman.2022.115719] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/02/2022] [Accepted: 07/09/2022] [Indexed: 06/15/2023]
Abstract
Efficient and harmless disposal of landfill leachate has attracted increasing attention. In this study, the bio-electro-Fenton method was investigated and developed to degrade the organic compounds in landfill leachate by hydroxyl radical oxidation. The optimal operational parameters (i.e., pH and external voltage) of the bio-electro-Fenton system were detected. Under the conditions of pH 2, 0.6 V, the highest total chemical oxygen demand (COD) decrement efficiency was obtained (about 70%), with apparent removal constant at 6 h (kapp-6h) of about 0.12 h-1. Subsequently, to further increase the degradation efficiency, functionalized carbon black and functionalized carbon nanotube (FCNT) were prepared as catalysts for the cathode electrode modification. With 0.4 mg/cm2 FCNT coated on the cathode electrode, 91.3% of the organic compounds were degraded, remaining only 84 mg/L COD (kapp-6h = 0.24 h-1). In all the reactors, the COD was mainly decreased in 0-6 h, contributing to over 68% of the total degradation efficiency. In the bio-electro-Fenton system, the bio-anode electrode could enhance H2O2 production and the conversion between Fe2+ and Fe3+ by strengthening electrons generation and transportation via the oxidation of organics by biofilms (dominant with Geobacter) covered on the carbon brush.
Collapse
Affiliation(s)
- Ziyi Yang
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Shimin Wu
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Hangyu Sun
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Samuel Gyebi Arhin
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Vagelis G Papadakis
- Department of Environmental Engineering, University of Patras, Seferi 2, 30100, Agrinio, Greece
| | - Maria A Goula
- Laboratory of Alternative Fuels and Environmental Catalysis, Department of Chemical Engineering, University of Western Macedonia, GR-50100, Greece
| | - Guangqing Liu
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yi Zhang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Ling Zhou
- Modern Agricultural Engineering Key Laboratory at Universities of Education Department of Xinjiang Uygur Autonomous Region, Tarim University, Alar, Xinjiang Uygur Autonomous Region, 843300, China.
| | - Wen Wang
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
| |
Collapse
|
5
|
Yang Z, Sun H, Zhou L, Arhin SG, Papadakis VG, Goula MA, Liu G, Zhang Y, Wang W. Bioaugmentation with well-constructed consortia can effectively alleviate ammonia inhibition of practical manure anaerobic digestion. Water Res 2022; 215:118244. [PMID: 35259562 DOI: 10.1016/j.watres.2022.118244] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/11/2022] [Accepted: 03/01/2022] [Indexed: 06/14/2023]
Abstract
Bioaugmentation is an attractive method to improve methane production (MP) in the anaerobic digestion (AD) process. In this study, to tackle the ammonia inhibition problem, a long-term (operating over 6 months) acclimatized consortia and a well-constructed consortia were selected as the bioaugmentation consortia for sequencing batch AD reactors fed with dairy manure and pig manure under mesophilic condition. Similar responses, in terms of the reactor performance and microorganisms structure to the different consortia, were observed with both manure kinds indicating that the effectiveness of bioaugmentation was mainly decided by the composition of the added consortia, not the feedstock. 39 - 49% increment in MP was obtained in the reactors bioaugmented with well-constructed consortia, which was higher than the acclimatized consortia (about 25% increment in MP). Both acetogenesis and methanogenesis (advantageous) steps were stimulated with well-constructed consortia bioaugmentation. According to key functional enzyme analysis, the increment of glycine hydroxymethyltransferase and phosphoglycerate mutase might be the critical point in the bioaugmented AD system. Based on the higher functional contribution rate of the well-constructed consortia bioaugmentation reactors, Methanosarcina could have expressed more comprehensive functions or performed stronger activities in different functions than Methanosaeta.
Collapse
Affiliation(s)
- Ziyi Yang
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, 507 Zonghe Building, 15 North 3rd Ring East Road, Beijing 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Hangyu Sun
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, 507 Zonghe Building, 15 North 3rd Ring East Road, Beijing 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Ling Zhou
- Modern Agricultural Engineering Key Laboratory at Universities of Education Department of Xinjiang Uygur Autonomous Region, Tarim University, Xinjiang Uygur Autonomous Region, Alar 843300, China
| | - Samuel Gyebi Arhin
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, 507 Zonghe Building, 15 North 3rd Ring East Road, Beijing 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Vagelis G Papadakis
- Department of Environmental Engineering, University of Patras, Seferi 2, Agrinio 30100, Greece
| | - Maria A Goula
- Laboratory of Alternative Fuels and Environmental Catalysis, Department of Chemical Engineering, University of Western Macedonia, 50100, Greece
| | - Guangqing Liu
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, 507 Zonghe Building, 15 North 3rd Ring East Road, Beijing 100029, China
| | - Yi Zhang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Wen Wang
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, 507 Zonghe Building, 15 North 3rd Ring East Road, Beijing 100029, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
| |
Collapse
|
6
|
Liu C, Ji J, Wu W, Arhin SG, Papadakis VG, Goula MA, Zhang S, Zhang Y, Wang W. Heterogeneous Catalyst–Microbiome Hybrids for Efficient CO-Driven C6 Carboxylic Acid Synthesis via Metabolic Pathway Manipulation. ACS Catal 2022. [DOI: 10.1021/acscatal.2c00768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Chao Liu
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jiacheng Ji
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Wanling Wu
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China
| | - Samuel Gyebi Arhin
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China
| | - Vagelis G. Papadakis
- Department of Environmental Engineering, University of Patras, Agrinio 30100, Greece
| | - Maria A. Goula
- Laboratory of Alternative Fuels and Environmental Catalysis, Department of Chemical Engineering, University of Western Macedonia, Kozani 50100, Greece
| | - Sanpeng Zhang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Yi Zhang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Wen Wang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China
| |
Collapse
|
7
|
Sun H, Yang Z, Shi G, Arhin SG, Papadakis VG, Goula MA, Zhou L, Zhang Y, Liu G, Wang W. Methane production from acetate, formate and H 2/CO 2 under high ammonia level: Modified ADM1 simulation and microbial characterization. Sci Total Environ 2021; 783:147581. [PMID: 34088123 DOI: 10.1016/j.scitotenv.2021.147581] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/09/2021] [Accepted: 05/01/2021] [Indexed: 06/12/2023]
Abstract
This study evaluated the methanogenic performance of typical substrates (acetate, formate, H2/CO2, and glucose) under low and high ammonia levels and the Anaerobic Digestion Model No.1 (ADM1) was extended and modified for better simulation and understanding of the process. Formate-utilizing and hydrogen-utilizing methanogenesis showed stronger ammonia resistance than acetate-utilizing methanogenesis (13-23% vs. 34% decrease in methane production (MP)). Model extension, based on foundational experiments fed with three typical precursors (R2 > 0.92), was then validated with glucose degradation experiments, and satisfactory predictions of MP and total volatile fatty acids were obtained (R2 > 0.91). Based on the modified ADM1, the carbon fluxes of glucose degradation were determined, and formate-utilizing methanogenesis showed its importance with a 28-34% contribution of the total methanation, becoming the dominant pathway under high ammonia level. Formate-utilizing methanogenesis also had a thermodynamic advantage among the three pathways. 16S rRNA sequencing suggested a homology between the hydrogen-utilizing and formate-utilizing methanogens. Methanobacterium and Methanobrevibacter were found to be key methanogens, and their enrichment under high ammonia level confirmed the stronger ammonia tolerance of formate-utilizing and hydrogen-utilizing methanogenesis. The microbial characterization and modified ADM1 simulations supported each other.
Collapse
Affiliation(s)
- Hangyu Sun
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China
| | - Ziyi Yang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China
| | - Guangyao Shi
- School of Water Resources & Environment, China University of Geosciences, Beijing 100191, China
| | - Samuel Gyebi Arhin
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China
| | - Vagelis G Papadakis
- Department of Environmental Engineering, University of Patras, Seferi 2, 30100 Agrinio, Greece
| | - Maria A Goula
- Laboratory of Alternative Fuels and Environmental Catalysis, Department of Chemical Engineering, University of Western Macedonia, GR-50100, Greece
| | - Ling Zhou
- Modern Agricultural Engineering Key Laboratory at Universities of Education Department of Xinjiang Uygur Autonomous Region, Tarim University, Alar, Xinjiang Uygur Autonomous Region 843300, China
| | - Yi Zhang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Guangqing Liu
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China
| | - Wen Wang
- College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing 100029, China.
| |
Collapse
|
8
|
Zhao Q, Arhin SG, Yang Z, Liu H, Li Z, Anwar N, Papadakis VG, Liu G, Wang W. pH regulation of the first phase could enhance the energy recovery from two-phase anaerobic digestion of food waste. Water Environ Res 2021; 93:1370-1380. [PMID: 33528855 DOI: 10.1002/wer.1527] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/23/2021] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
The effect of pH regulation in phase I on hydrolysis and acidogenesis rate, metabolites production, microbial community, and the overall energy recovery efficiency during two-phase anaerobic digestion (AD) of food waste (FW) was investigated. pH strongly affected the acidogenesis rate and the yield of the fermentation products. The highest acidogenesis efficiency (60.4%) and total volatile fatty acids (VFA)/ethanol concentration (12.4 g/L) were obtained at pH 8 during phase I. Microbial community analysis revealed that Clostridium IV was enriched at pH 8, relating to the accumulation of butyrate. Also, Clostridium sensu stricto played a crucial role in hydrogen production and was abundant at pH 6, resulting in the highest hydrogen yield (212.2 ml/g VS). In phase II, the highest cumulative methane yield (412.6 ml/g VS) was obtained at pH 8. By considering the hydrogen and methane production stages, the highest energy yield (22.8 kJ/g VS, corresponding to a 76.4% recovery efficiency) was generated at pH 8, which indicates that pH 8 was optimal for energy recovery during two-phase AD of FW. Overall, the results demonstrated the possibility of increasing the energy recovery from FW by regulating the pH in the hydrolysis/acidogenesis phase based on the two-phase AD system. PRACTITIONER POINTS: pH 8 was suitable for hydrolysis, acidogenesis, and methanogenesis. High hydrogen yields were obtained at pH 5-8 (about 200 ml/d). Clostridium sensu stricto might have played a crucial role in hydrogen production. High methane production (about 400 ml/g VS) was obtained at pH 7-9. pH 8 was optimal for energy recovery from FW with an efficiency of 76.4% (22.8 kJ/g VS).
Collapse
Affiliation(s)
- Qing Zhao
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, China
| | - Samuel Gyebi Arhin
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, China
| | - Ziyi Yang
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, China
| | - Haopeng Liu
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, China
| | - Zongye Li
- Beijing No. 80 High School, Beijing, China
| | - Naveed Anwar
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, China
| | - Vagelis G Papadakis
- Department of Environmental Engineering, University of Patras, Agrinio, Greece
| | - Guangqing Liu
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, China
| | - Wen Wang
- Biomass Energy and Environmental Engineering Research Center, Beijing University of Chemical Technology, Beijing, China
| |
Collapse
|