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Anaerobic Digestion of the Residue (Combination of Wastewater and Solid Waste) from a New Olive-Oil Manufacturing Process Based on an Olive Cold-Pressing System: Kinetic Approach and Process Performance. Processes (Basel) 2022. [DOI: 10.3390/pr10122552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
This research evaluates the anaerobic digestion (AD) process of the residue generated in a new olive-oil manufacturing process for cold-pressed olive, a residue consisting of a mixture of the wastewater and solid waste obtained from this process. Additionally, in order to assess the possible influence of the level of ripening of the olives on the performance of anaerobic processing, olives of the Picual variety were collected at two stages, i.e., green olives and olives in veraison. The AD processes of the residues obtained from the cold-pressing process and the process without pressure (control) were comparatively assessed by means of biochemical methane potential (BMP) assays conducted at mesophilic temperature (35 ± 1 °C). Maximum values for methane yield (390 ± 1 NL CH4/kg VSadded) and biodegradability (84.5%) were obtained from the cold-pressed green olive residues. For the rest of the wastes studied, biodegradability also reached high values, ranging from 79.1 to 79.6%. The logistic model adequately fit the experimental data and allowed for the assessment of the anaerobic biodegradation of these wastes and for obtaining the kinetic parameters for each case studied. The theoretical values for ultimate methane production predicted from this model showed less than a 1% deviation from the experimental values. A decrease was detected for both types of olives tested in the rate of maximum methane production, Rm, during the cold-pressing process, from 44.3 ± 0.1 to 30.1 ± 1.3 L CH4/(kg VS·d) (green olives) and from 43.9 ± 1.5 to 38.7 ± 1.6 L CH4/(kg VS·d) (olives in veraison). Finally, the highest energy output result was detected in the waste from cold-pressed green olives (15.7 kJ/g VSremoved), which coincided with its high methane yield.
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Hydrogen and Methane Production from Anaerobic Co-Digestion of Sorghum and Cow Manure: Effect of pH and Hydraulic Retention Time. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8070304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The need for alternative energy sources is constantly growing worldwide, while the focus has shifted to the valorization of biomass. The aim of the present study was to determine the optimal pH and hydraulic retention time (HRT) values for treating a mixture of sorghum biomass solution with liquid cow manure (in a ratio 95:5 v/v) through anaerobic digestion, in a two-stage system. Batch tests were initially carried out for the investigation of the pH effect on bio-hydrogen and volatile fatty acids (VFA) production. The highest hydrogen yield of 0.92 mol H2/mol carbohydratesconsumed was obtained at pH 5.0, whereas the maximum degradation of carbohydrates and VFA productivity was observed at pH 6.0. Further investigation of the effect of HRT on hydrogen and methane production was carried out. The maximum yield of 1.68 mol H2/mol carbohydratesconsumed was observed at an HRT of 5 d, with H2 productivity of 0.13 L/LR·d. On the other hand, the highest CH4 production rate of 0.44 L/LR·d was achieved at an HRT of 25 d, with a methane yield of 295.3 mL/g VSadded, whereas at a reduced HRT of 20 d the process exhibited inhibition and/or overload, as indicated by an accumulation of VFAs and decline in CH4 productivity.
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Aravani VP, Tsigkou K, Papadakis VG, Kornaros M. Biochemical Μethane potential of most promising agricultural residues in Northern and Southern Greece. CHEMOSPHERE 2022; 296:133985. [PMID: 35176306 DOI: 10.1016/j.chemosphere.2022.133985] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 01/30/2022] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
Greece produces significant amounts of residual biomass due to its intense agricultural and agro-industrial sector. The anaerobic digestion process has been frequently considered as the best environmental and economic solution for energy recovery from different biodegradable waste such as agricultural waste, livestock manure, agro-industrial waste, as well as for their co-digestion. The aim of this study was the assessment of biochemical methane potential (BMP) of biomass feedstocks representative of Northern and Southern Greece, which are available during the fall/winter and spring/summer seasons, through the implementation of BMP assays. The raw residues evaluated in the current work included: (a) crop residues (corn silage and unsuitable for human consumption watermelon), (b) agro-industrial residues (malt, tomato processing residues, orange peels and olive pomace) and (c) livestock (cattle) manure. Tests of both single substrates and various mixtures were conducted for the evaluation of their methane yields. The results of the mono-substrates are in accordance with other studies in the literature, with watermelon presenting the highest methane potential (421.0 ± 3.4 ml CH4/g VSadded). After the evaluation of the mixtures and mono-substrates results, the most promising mixtures seemed to be the following: a) for Northern Greece, 10% corn silage-80% cattle manure-10% malt, b) for Southern Greece spring/summer season, 10% corn silage-14% cattle manure-66% watermelon-10% tomato processing residues, and c) for Southern Greece fall/winter season, 10% corn silage-57% cattle manure-23% orange peels-10% olive pomace.
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Affiliation(s)
- Vasiliki P Aravani
- Department of Environmental Engineering, University of Patras, 2 Seferi Str, 30100, Agrinio, Greece
| | - Konstantina Tsigkou
- Department of Chemical Engineering, University of Patras, 1 Karatheodori Str, University Campus-Rio, 26504, Patras, Greece
| | - Vagelis G Papadakis
- Department of Environmental Engineering, University of Patras, 2 Seferi Str, 30100, Agrinio, Greece
| | - Michael Kornaros
- Department of Chemical Engineering, University of Patras, 1 Karatheodori Str, University Campus-Rio, 26504, Patras, Greece.
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Thermophilic Dark Fermentation of Olive Mill Wastewater in Batch Reactors: Effect of pH and Organic Loading. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12062881] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In recent decades, olive oil consumption has almost tripled worldwide. Olive oil production is linked with the production of enormous amounts of olive mill wastewater, the main by-product derived from three-phase olive mills. Due to the environmental risks of olive mill wastewater disposal, the management and valorization of the specific waste stream is of great importance. This work focuses on the thermophilic dark fermentation of olive mill wastewater in batch reactors, targeting pH optimization and the organic loading effect. A series of experiments were performed, during which the organic load of the substrate remained at 40 g/L after dilution with tap water, and the pH was tested in the range of 4.5 to 7.5. The maximum yield in terms of produced hydrogen was obtained at pH 6.0, and the yields were 0.7 mol H2/mol glucose or 0.5 L H2/Lreactor. At the same conditions, a reduction of 62% of the waste’s phenols was achieved. However, concerning the effect of organic loading at the optimized pH value (6.0), a further increase in the organic load minimized the hydrogen production, and the overall process was strongly inhibited.
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Zhang L, Guo B, Mou A, Li R, Liu Y. Blackwater biomethane recovery using a thermophilic upflow anaerobic sludge blanket reactor: Impacts of effluent recirculation on reactor performance. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 274:111157. [PMID: 32805474 DOI: 10.1016/j.jenvman.2020.111157] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 07/03/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
Thermophilic anaerobic digestion is a promising process for high-solid blackwater (BW) treatment due to improved hydrolysis rates, high methanogenesis efficiency, and pathogen removal, when compared with mesophilic treatment. In the present work, the effects of effluent recirculation (i.e., mixing) on thermophilic blackwater treatment were studied. A laboratory-scale thermophilic upflow anaerobic sludge blanket reactor was operated with and without effluent recirculation. The methanogenesis efficiency of the BW treatment increased from 45.0 ± 2.9% when effluent recirculation was applied to 56.7 ± 5.5% without effluent recirculation. Without effluent recirculation, the COD accumulation in the bioreactor was reduced from 17.2 to 3.8% and the effluent volatile fatty acids (VFA) concentration was reduced from 0.64 ± 0.18 to 0.15 ± 0.10 g/L. Further, both acetoclastic and hydrogenotrophic methanogenic activity increased from 101.3 ± 10.8 and 93.9 ± 6.1 to 120.4 ± 9.4 and 118.2 ± 13.2 mg CH4-COD/(gVSS⋅d), respectively, after effluent recirculation was discontinued. The predominant methanogens changed from Methanothermobacter (67%) with effluent recirculation to Methanosarcina (62%) without effluent recirculation. As compared to the effluent recirculation conditions, the enhanced biomethane recovery and treatment performance without effluent recirculation can be attributed to the close proximity of bacteria and archaea groups and the reduced VFA accumulation. Predicted functional gene comparison showed higher prevalence of function for intermediate metabolite transportation (transporters, ATP-binding cassette (ABC) transporters, and two-component system) after discontinuing effluent circulation, which contributed to improved syntrophic propionate oxidation and syntrophic acetate oxidization and enhanced hydrogenotrophic methanogenesis.
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Affiliation(s)
- Lei Zhang
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Canada
| | - Bing Guo
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Canada
| | - Anqi Mou
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Canada
| | - Ran Li
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Canada; College of Petroleum Engineering, Xi'an Shiyou University, Xi'an, 710065, Shaanxi Province, China
| | - Yang Liu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Canada.
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Ali SS, Mustafa AM, Kornaros M, Manni A, Sun J, Khalil MA. Construction of novel microbial consortia CS-5 and BC-4 valued for the degradation of catalpa sawdust and chlorophenols simultaneously with enhancing methane production. BIORESOURCE TECHNOLOGY 2020; 301:122720. [PMID: 31945685 DOI: 10.1016/j.biortech.2019.122720] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 12/26/2019] [Accepted: 12/30/2019] [Indexed: 06/10/2023]
Abstract
This study might be the first to explore the novel constructed microbial consortia CS-5 and BC-4 for enhancing methane (CH4) production during anaerobic digestion (AD) with simultaneous degradation of catalpa sawdust and chlorophenols (CPs). Significant reduction in cellulose, hemicellulose and lignin contents was achieved after the biodegradation of catalpa sawdust for 15 days by CS-5 and BC-4, with a total weight loss of 69.2 and 56.3%, respectively. The synergistic microbial consortia enhanced cumulative biogas and CH4 yields by 76.3 and 64.3%, respectively higher than the corresponding control at the end of AD. More than 90% of CH4 was produced within 18 days of AD as a result of microbial pretreatment of catalpa sawdust. These consortia resulted in remarkably higher energy conversion efficiency of 44.3% (218.1 LN CH4/kg TS) over the control. CS-5 and BC-4 removed more than 69 and 77% of the total amount of CPs tested after 15 days.
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Affiliation(s)
- Sameh S Ali
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China; Botany Department, Faculty of Science, Tanta University, Tanta 31527, Egypt
| | - Ahmed M Mustafa
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China; Department of Agricultural Engineering, Faculty of Agriculture, Suez Canal University, Ismailia 41522, Egypt
| | - Michael Kornaros
- Laboratory of Biochemical Engineering & Environmental Technology (LBEET), Department of Chemical Engineering, University of Patras, 1 Karatheodori Str., University Campus, 26504 Patras, Greece
| | - Alessandro Manni
- Department of Industrial Engineering, University of Rome Tor Vergata, Italy
| | - Jianzhong Sun
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
| | - Maha A Khalil
- Botany Department, Faculty of Science, Tanta University, Tanta 31527, Egypt; Biology Department, Faculty of Science, Taif University, Saudi Arabia
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Sakarika M, Stavropoulos K, Kopsahelis A, Koutra E, Zafiri C, Kornaros M. Two-stage anaerobic digestion harnesses more energy from the co-digestion of end-of-life dairy products with agro-industrial waste compared to the single-stage process. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2019.107404] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Mitrogiannis D, Psychoyou M, Kornaros ME, Tsigkou K, Brulé M, Koukouzas N, Alexopoulos D, Palles D, Kamitsos E, Oikonomou G, Papoutsa A, Xydous S, Baziotis I. Calcium-modified clinoptilolite as a recovery medium of phosphate and potassium from anaerobically digested olive mill wastewater. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:2977-2991. [PMID: 31838691 DOI: 10.1007/s11356-019-07212-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 11/29/2019] [Indexed: 06/10/2023]
Abstract
Olive mill wastewater (OMW) is characterized as a high-strength effluent due to the high organic load, low biodegradability, and presence of phytotoxic compounds. Most of the OMW treatment methods proposed, including adsorption, focus mainly on the reduction of chemical oxygen demand and recovery of polyphenols. Adsorption studies aiming at nutrient removal from OMW are very limited. In the present work, Ca(OH)2-treated zeolite (CaT-Z) in a granular form was used for simultaneous recovery of phosphate (PO43-) and potassium (K+) ions from two samples of anaerobically digested OMW. Nutrient adsorption was investigated as a function of contact time, pH and dilution of OMW with deionized water. The lower removal efficiency of phosphorus (P) by CaT-Z was observed at higher dilution ratios consisted of 3.125-6.25% OMW-1 and 5% OMW-2. The maximum P removal was 73.9% in 25% OMW-1 and 85.9% in 10% OMW-2. Potassium removal, as the predominant cation of OMW samples, increased from 17.3 to 46.1% in OMW-1 and from 15.1 to 57.7% in OMW-2 with increasing dilution. The maximum experimental adsorption capacities were 15.8 mg K and 2.14 mg P per gram of CaT-Z. Five sequential treatments of 50% OMW-2 with fresh CaT-Z at each stage ensured a cumulative removal of 87.5% for P and 74.9% for K. Adsorption kinetics were faster for K than for P. The plant-available P was found to be the predominant fraction on the loaded CaT-Z. Electron Probe Micro-analysis confirmed the enhanced content of K and P on the loaded CaT-Z, whereas X-ray mapping revealed the co-distribution of Ca and P. This study demonstrates the potential usage of CaT-Z as an immobilization medium of P and K from anaerobically treated OMW.
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Affiliation(s)
- Dimitris Mitrogiannis
- Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75 Iera Odos, 11855, Athens, Greece.
| | - Maria Psychoyou
- Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75 Iera Odos, 11855, Athens, Greece
| | - Michael E Kornaros
- Laboratory of Biochemical Engineering & Environmental Technology, Department of Chemical Engineering, University of Patras, Rion, GR 26504, Patras, Greece
| | - Konstantina Tsigkou
- Laboratory of Biochemical Engineering & Environmental Technology, Department of Chemical Engineering, University of Patras, Rion, GR 26504, Patras, Greece
| | - Mathieu Brulé
- Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75 Iera Odos, 11855, Athens, Greece
| | - Nikolaos Koukouzas
- Centre for Research and Technology Hellas (CERTH), Chemical Process and Energy Resources Institute (CPERI), 52 Egialias str., Maroussi, 15125, Athens, Greece
| | - Dimitris Alexopoulos
- Centre for Research and Technology Hellas (CERTH), Chemical Process and Energy Resources Institute (CPERI), 52 Egialias str., Maroussi, 15125, Athens, Greece
| | - Dimitrios Palles
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635, Athens, Greece
| | - Efstratios Kamitsos
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635, Athens, Greece
| | - Georgios Oikonomou
- Institute of Geology and Mineral Exploration, Olympic Village Acharnae, 13677, Athens, Greece
| | - Angeliki Papoutsa
- Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75 Iera Odos, 11855, Athens, Greece
| | - Stamatis Xydous
- Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75 Iera Odos, 11855, Athens, Greece
| | - Ioannis Baziotis
- Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, 75 Iera Odos, 11855, Athens, Greece
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