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Oduor WW, Wandera SM, Murunga SI, Raude JM. Enhancement of anaerobic digestion by co-digesting food waste and water hyacinth in improving treatment of organic waste and bio-methane recovery. Heliyon 2022; 8:e10580. [PMID: 36148270 PMCID: PMC9485044 DOI: 10.1016/j.heliyon.2022.e10580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/09/2022] [Accepted: 09/05/2022] [Indexed: 11/29/2022] Open
Abstract
In Kenya, 57% of the municipal solid waste generated is Food waste (FW) which has high organic content. However, the treatment and bioconversion of FW to biogas have always been challenging due to its rapid biodegradation, resulting from rapid hydrolysis and accumulation of volatile fatty acids and lowering pH in the bioreactor. In this study, the anaerobic digestibility of FW as a mono substrate was compared to co-digestion of FW with water hyacinth (WH) for improved biogas production and organic matter removal efficiency in a laboratory batch reactor. Different mix proportions of FW and WH were co-digested under mesophilic conditions (37 °C) at a dilution of 6% (w/v) Total Solids (TS) content. The TS of the substrates (Food waste and Water Hyacinth) were pre-processed to have a concentration of TS at 6% (60 g/L) to operate a wet AD which requires the substrate to be less than 15% TS. The proportions of WH: FW (v/v) were 100:0, 85:15, 70:30, 55:45, 30:70, 15:85, and 0:100. In the batch rectors the anaerobic co-digestion was conducted with Substrate to Inoculum (S/I) ratio of 1:1. FW is generally considered to have high volatile solids which hydrolyze rapidly lowering pH arising from excess production of Hydrogen which in presence of CO2 and acetogenic bacteria leads to more production of acetate, formate and other long chain fatty acids which inhibits methanogenesis as a result of rapid acidification. The rapid acidification of the bioreactors that are used to treat FW results in the inhibition of the methanogenesis process. The co-digestion of the substrates could have improved the process parameters by reducing acidity caused by the high C/N ratio, reducing the inhibitory range, and increasing the buffer capacity which enhanced the bio-methane potential and the microbial activity. The batch experiments were set in triplicate for both cases of FW, WH, mixtures, and Inoculum. The results showed that the average gas yields after 81 days for the various mix proportions were 256.27and 357.69 ml/g-VS for mono-digestion of WH and FW respectively. For the mixtures of WH: FW the average reported biogas production were 305.01, 280.27, 548.91,616.01 and 270.87 ml/g-VS for mixtures of 15:85, 30:70, 55:45,70:30 and 85:15 respectively. The modified Gompertz model showed that the digesters with WH and FW alone had lag times of 2.599 and 1.052 days respectively. The mix substrates of WH: FW 85:15, 70:30, 55:45, 30:70 and 15:85 shown lag times of 2.456, 3.777, 2.574, 1.956 and 1.75 days respectively. A mix (WH: FW) of 70:30 had the highest maximum specific biogas production Rmax and the maximum biogas production potential of 18.19 mlCH4/gVS per day and 607.7mlCH4/gVS respectively. The R2 and RSME values ranged from 0.9867 to 0.9963 and 2.663 to 9.359 respectively in all the digesters. The study shows that the co-digestion of WH and FW in the mix ratio of 70:30 improved the volume of biogas produced and organic matter removal efficiency reached 79%.
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Affiliation(s)
- William W Oduor
- Department of Civil, Construction and Environmental Engineering, Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000-00200, Nairobi, Kenya.,Department of Water and Waste Water Engineering Kenya Water Institute, P. O. Box 60013-00200, Nairobi, Kenya
| | - Simon M Wandera
- Department of Civil, Construction and Environmental Engineering, Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000-00200, Nairobi, Kenya
| | - Sylvia I Murunga
- Department of Agricultural and Biosystems Engineering, Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000-00200, Nairobi, Kenya
| | - James M Raude
- Soil, Water and Environmental Engineering Department (SWEED), Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000-00200, Nairobi, Kenya
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Sani K, Jariyaboon R, O-Thong S, Cheirsilp B, Kaparaju P, Wang Y, Kongjan P. Performance of pilot scale two-stage anaerobic co-digestion of waste activated sludge and greasy sludge under uncontrolled mesophilic temperature. WATER RESEARCH 2022; 221:118736. [PMID: 35714466 DOI: 10.1016/j.watres.2022.118736] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 05/04/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
Waste-activated sludge (WAS) and greasy sludge (GS) discharged from the canned tuna industry are considerably characterized as harsh organic wastes to be individually treated by using traditional anaerobic digestion. This study was attempted to anaerobically co-digest WAS and GS in continuous pilot scale two-stage process, comprising the first 50 L continuous stir tank reactor (CSTR1) and the second 250 L continuous stir tank reactor (CSTR2). The two-stage co-digesting operation of dewatered WAS:GS ratio of 0.4:1 (g-VS) at ambient temperature with the organic loading rate (OLR) of 12.6 ± 0.75 g-VS/L·d and 2.26 ± 0.13 g-VS/L·d, corresponding to 3-day and 17-day hydraulic retention time (HRT) for the first and second stage, respectively generated highest methane production rate of 957 ± 86 mL-CH4/L·d, corresponding to methane yield of 423.4 ± 36 mL-CH4/g-VS. Organic removal efficiency obtained was around 67.5% on COD basis. The microbial diversity was depended on the process's activity. Bacteria were mostly detected in the CSTR1, dominating with the phylum Firmicutes and Proteobacteria, whereas genus Methanosaeta archaea were found dominantly in the CSTR2. The economic analysis of process shows payback period (PBP), internal rate of return (IRR), and net present value (NPV) of 3 years, 30%, and 250,177 USD, respectively. This study demonstrated the potential approach to applying the two-stage anaerobic co-digestion process to stabilize both WAS and GS along with generating valuable bioenergy carriers.
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Affiliation(s)
- Khaliyah Sani
- Energy Technology Program, Faculty of Engineering, Prince of Songkla University, Hat-Yai, Songkhla 90110, Thailand; Bio-Mass Conversion to Energy and Chemicals (Bio-MEC) Research Unit, Prince of Songkla University, Pattani 94000, Thailand
| | - Rattana Jariyaboon
- Bio-Mass Conversion to Energy and Chemicals (Bio-MEC) Research Unit, Prince of Songkla University, Pattani 94000, Thailand; Department of Science, Faculty of Science and Technology, Prince of Songkla University, Meung, Pattani 94000, Thailand
| | - Sompong O-Thong
- International College, Thaksin University, Songkhla 90000, Thailand
| | - Benjamas Cheirsilp
- Biotechnology for Bioresource Utilization Laboratory, Department of Industrial Biotechnology, Faculty of Agro-Industry, Prince of Songkla University, Hat-Yai, Songkhla 90112, Thailand
| | - Prasad Kaparaju
- School of Engineering and Built Environment, Griffith University, Nathan 4111, Australia
| | - Yi Wang
- Key Laboratory of New Materials and Facilities for Rural Renewable Energy, MOA of China, Henan Agricultural University, Zhengzhou 450002, China
| | - Prawit Kongjan
- Bio-Mass Conversion to Energy and Chemicals (Bio-MEC) Research Unit, Prince of Songkla University, Pattani 94000, Thailand; Department of Science, Faculty of Science and Technology, Prince of Songkla University, Meung, Pattani 94000, Thailand.
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Co-production of Biohydrogen and Biomethane from Chicken Manure and Food Waste in a Two-Stage Anaerobic Fermentation Process. Appl Biochem Biotechnol 2022; 194:3706-3720. [PMID: 35499692 DOI: 10.1007/s12010-022-03945-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Batch experiments were performed to evaluate the biohydrogen and biomethane production by co-digestion of chicken manure and food waste in a two-stage mesophilic fermentation process. Results showed that no hydrogen was produced in the first stage of sole chicken manure fermentation, while methane yield was 247.3 mL·g-1-VS. By comparison, the co-digestion process with food waste proportions of 50-85% obtained hydrogen yields of 15.5-57.5 mL·g-1-VS, and the methane yields and maximum specific methane production rates were also improved by 7.0-16.7% and 80%, respectively. Moreover, the highest hydrogen and methane yields were achieved during sole food waste fermentation process. The acetate was the main volatile fatty acid (VFA) produced during sole chicken manure fermentation process in the first stage. Statistical analysis revealed that hydrogen production from co-digestion process and sole food waste fermentation process followed the n-butyrate-type pathway. Meanwhile, it should be noticed that the co-fermentation of chicken manure and food waste had antagonistic effects on the hydrogen fermentation, implying that there might be some inhibition factors existing in chicken manure or produced during the co-fermentation process. At the beginning of methane fermentation, the VFA profiles were similar to those at the end of hydrogen fermentation, and the main VFA compositions changed to acetate and propionate in the latter period of methane production. The volatile solid removal efficiencies were also promoted in co-digestion process compared with sole chicken manure digestion, which were increased by 9.7-14.4% with food waste proportions of 50-80%.
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Hosseini Koupaie E, Bazyar Lakeh AA, Azizi A, Hafez H, Elbeshbishy E. Integrated two-phase acidogenic-methanogenic treatment of municipal sludge with thermal hydrolysis. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 144:173-181. [PMID: 35367705 DOI: 10.1016/j.wasman.2022.03.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/04/2022] [Accepted: 03/21/2022] [Indexed: 06/14/2023]
Abstract
The purpose of this research was to investigate the impact of two process configurations integrating two-phase anaerobic digestion (AD) of municipal sludge with thermal hydrolysis (TH). The TH was positioned either before or after the acidogenic fermentation phase. The fermentation process was carried out under the semi-continuous flow regime with a retention time of three days. The TH was done at a temperature of 170 °C and for 30 min. Among all the tested scenarios, the TH of sludge followed by the acidogenic fermentation resulted in the highest COD solubilization ratio (39.5%) and volatile fatty acids production (6,420 ± 400 mg/L), which was 630% and 500% more than that of the raw sludge, respectively. The sequential TH/fermentation process achieved 40% higher ultimate methane yield (240 mL/g COD) than the non-pretreated (raw) sludge. Positioning TH after the fermentation process reduced the ultimate methane yield to 231 240 mL/g COD, although it was still 32% higher than that of the raw sludge. The analysis of methane production rate and biodegradation kinetics data suggested the formation of refractory intermediates during the thermal process of sludge, which reduced the overall performance rate during the first week of the AD process. It was also revealed that acidogenic fermentation of thermally-processed sludge could diminish the adverse effect of the recalcitrant compounds formed during the thermal hydrolysis on the subsequent AD process.
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Affiliation(s)
- E Hosseini Koupaie
- Department of Chemical Engineering, Queen's University, Kingston, ON, Canada.
| | - A A Bazyar Lakeh
- Department of Civil Engineering, Ryerson University, Toronto, ON, Canada
| | - A Azizi
- Department of Civil Engineering, Queen's University, Kingston, ON, Canada
| | - H Hafez
- Greenfield Global, Chatham, ON, Canada
| | - E Elbeshbishy
- Department of Civil Engineering, Ryerson University, Toronto, ON, Canada
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Hou T, Zhao J, Lei Z, Shimizu K, Zhang Z. Supplementation of KOH to improve salt tolerance of methanogenesis in the two-stage anaerobic digestion of food waste using pre-acclimated anaerobically digested sludge by air-nanobubble water. BIORESOURCE TECHNOLOGY 2022; 346:126360. [PMID: 34801723 DOI: 10.1016/j.biortech.2021.126360] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/12/2021] [Accepted: 11/12/2021] [Indexed: 06/13/2023]
Abstract
Air-nanobubble water (NBW) was applied to pre-acclimate anaerobically digested sludge that was then used as the inoculum in the two-stage anaerobic digestion (AD) of high saline (20 g NaCl/L) food waste (FW) to optimize NBW application in the AD of high saline FW. K+ was simultaneously supplemented during the methanogenic stage to resist the inhibition of salt on methanogens. Results showed that after the second pre-acclimation cycle, the inoculum activity was increased 27% in the Air-NBW supplemented reactor in comparison to the deionized water (DW) supplemented one. In the first-stage AD, H2 yield was enhanced by 46% in the Air-NBW pre-acclimated sludge reactor compared with the DW pre-acclimated sludge reactor. Besides, supplementation of KOH in the methanogenic stage could enhance methane production by 17-25% in the DW reactors at initial pH 7.5, 8.0, and 9.0 when compared to the control reactor (using NaOH adjusted initial pH to 7.5), respectively.
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Affiliation(s)
- Tingting Hou
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Jiamin Zhao
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Zhongfang Lei
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Kazuya Shimizu
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Zhenya Zhang
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
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Anaerobic Digestion of Agri-Food Wastes for Generating Biofuels. Indian J Microbiol 2021; 61:427-440. [PMID: 34744198 DOI: 10.1007/s12088-021-00977-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 08/25/2021] [Indexed: 12/24/2022] Open
Abstract
Presently, fossil fuels are extensively employed as major sources of energy, and their uses are considered unsustainable due to emissions of obnoxious gases on the burning of fossil fuels, which can lead to severe environmental complications, including human health. To tackle these issues, various processes are developing to waste as a feed to generate eco-friendly fuels. The biological production of fuels is considered to be more beneficial than physicochemical methods due to their environmentally friendly nature, high rate of conversion at ambient physiological conditions, and less energy-intensive. Among various biofuels, hydrogen (H2) is considered as a wonderful due to high calorific value and generate water molecule as end product on the burning. The H2 production from biowaste is demonstrated, and agri-food waste can be potentially used as a feedstock due to their high biodegradability over lignocellulosic-based biomass. Still, the H2 production is uneconomical from biowaste in fuel competing market because of low yields and increased capital and operational expenses. Anaerobic digestion is widely used for waste management and the generation of value-added products. This article is highlighting the valorization of agri-food waste to biofuels in single (H2) and two-stage bioprocesses of H2 and CH4 production.
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Hou T, Zhao J, Lei Z, Shimizu K, Zhang Z. Enhanced energy recovery via separate hydrogen and methane production from two-stage anaerobic digestion of food waste with nanobubble water supplementation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143234. [PMID: 33162132 DOI: 10.1016/j.scitotenv.2020.143234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/21/2020] [Accepted: 09/29/2020] [Indexed: 06/11/2023]
Abstract
This study investigated the enhancement effect of N2- and Air-nanobubble water (NBW) supplementation on two-stage anaerobic digestion (AD) of food waste (FW) for separate production of hydrogen and methane. In the first stage for hydrogen production, the highest cumulative H2 yield (27.31 ± 1.21 mL/g-VSadded) was obtained from FW + Air-NBW, increasing by 38% compared to the control (FW + deionized water (DW)). In the second stage for methane production, the cumulative CH4 yield followed a descending order of FW + Air-NBW (373.63 ± 3.58 mL/g-VSadded) > FW + N2-NBW (347.63 ± 7.05 mL/g-VSadded) > FW + DW (300.93 ± 3.24 mL/g-VSadded, control), increasing by 24% in FW + Air-NBW and 16% in FW + N2-NBW compared to the control, respectively. Further investigations indicate that different gas-NBW may positively impact the different stages of AD process. Addition of N2-NBW only enhanced the hydrolysis/acidification of FW with no significant effect on methanogenesis. By comparison, addition of Air-NBW promoted both hydrolysis/acidification stage and methanogenesis stage, reflecting by the enhanced activities of four extracellular hydrolases at the end of hydrolysis/acidification and coenzyme F420 at the end of methanogenesis, respectively. Results from this work suggest the potential application of Air-NBW in the two-stage AD for efficient renewable energy recovery from FW.
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Affiliation(s)
- Tingting Hou
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Jiamin Zhao
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Zhongfang Lei
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
| | - Kazuya Shimizu
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Zhenya Zhang
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
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Chen H, Huang R, Wu J, Zhang W, Han Y, Xiao B, Wang D, Zhou Y, Liu B, Yu G. Biohythane production and microbial characteristics of two alternating mesophilic and thermophilic two-stage anaerobic co-digesters fed with rice straw and pig manure. BIORESOURCE TECHNOLOGY 2021; 320:124303. [PMID: 33126132 DOI: 10.1016/j.biortech.2020.124303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 06/11/2023]
Abstract
To investigate biohythane production and microbial behavior during temperature-phased (TP) anaerobic co-digestion (AcD) of rice straw (RS) and pig manure (PM), a mesophilic-thermophilic (M1-T1) AcD system and a thermophilic-mesophilic (T2-M2) AcD system were continuously operated for 95 days in parallel. The maximal ratio (8.44%v/v) of produced hydrogen to methane demonstrated the feasibility of biohythane production by co-digestion of RS and PM. T2-M2 exhibited higher hydrogen (16.68 ± 1.88 mL/gVS) and methane (197.73 ± 11.77 mL/gVS) yields than M1-T1 (3.08 ± 0.39 and 109.03 ± 4.97 mL/gVS, respectively). Methanobrevibacter (75.62%, a hydrogenotrophic methanogen) dominated in the M1 reactor, resulting in low hydrogen production. Hydrogen-producing bacteria (Thermoanaerobacterium 32.06% and Clostridium_sensu_stricto_1 27.33%) dominated in T2, but the abundance of hydrolytic bacteria was low, indicating that hydrolysis could be a rate-limiting step. The thermophilic acid-producing phase provided effective selective pressure for hydrogen-consuming microbes, and the high diversity of microbes in M2 implied a more efficient pathway of methane production.
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Affiliation(s)
- Hong Chen
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha 410004, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Rong Huang
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha 410004, China
| | - Jun Wu
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha 410004, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Wenzhe Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yunping Han
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Benyi Xiao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Dongbo Wang
- Hunan University, College of Environmental Science & Engineering, Changsha 410082, China
| | - Yaoyu Zhou
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
| | - Bing Liu
- Resources and Environment Innovation Research Institute, School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250101, China
| | - Guanlong Yu
- Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha 410004, China
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Abstract
There is a growing need of substrate flexibility for biobased production of energy and value-added products that allows the application of variable biodegradable residues within a circular economy. It can be used to balance fluctuating energy provision of other renewable sources. Hydrolysis presents one of the biggest limitations during anaerobic digestion. Methods to improve it will result in broader process applicability and improved integration into regional material cycles. Recently, one focus of anaerobic digestion research has been directed to systems with a separate hydrolysis–acidogenesis stage as it might be promised to improve process performance. Conditions can be adjusted to each class of microorganisms individually without harming methanogenic microorganisms. Extensive research of separate biomass pretreatment via biological, chemical, physical or mixed methods has been conducted. Nevertheless, several methods lack economic efficiency, have a high environmental impact or focus on specific substrates. Pretreatment via a separate hydrolysis stage as cell-driven biotransformation in a suspension might be an alternative that enables high yields, flexible feeding and production, and a better process control. In this review, we summarize existing technologies for microbial hydrolytic biotransformation in a separate reactor stage and the impacts of substrate, operational parameters, combined methods and process design as well as remaining challenges.
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