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Oliveira JMS, Ottosen LDM, Kofoed MVW. Continuous biomethanation of flue gas-carbon dioxide using bio-integrated carbon capture and utilization. Bioresour Technol 2024; 399:130506. [PMID: 38423486 DOI: 10.1016/j.biortech.2024.130506] [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: 12/14/2023] [Revised: 02/26/2024] [Accepted: 02/26/2024] [Indexed: 03/02/2024]
Abstract
Biomethanation of carbon dioxide (CO2) from flue gas is a potential enabler of the green transition, particularly when integrated with the power-to-gas chain. However, challenges arise in achieving synthetic natural gas quality when utilizing CO2 from diluted carbon sources, and the high costs of CO2 separation using amine-based solutions make large-scale implementation unfeasible. We propose an innovative continuous biomethanation system that integrates carbon capture and CO2 stripping through microbial utilization, eliminating expenses with the stripper. Stable continuous biomethane production (83-92 % methane purity) was achieved from flue gas-CO2 using a biocompatible aqueous n-methyldiethanolamine (MDEA) solution (50 mmol/L) under mesophilic and hydrogen-limiting conditions. MDEA was found to be recalcitrant to biodegradation and could be reused after regeneration. Demonstrating the microbial ability to simultaneously strip and convert the captured CO2 and regenerate MDEA provides a new pathway for valorization of flue gas CO2.
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Affiliation(s)
- Jean M S Oliveira
- Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10C, DK-8000, Denmark
| | - Lars D M Ottosen
- Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10C, DK-8000, Denmark; The Novo Nordisk Foundation CO2 Research Center (CORC), Aarhus University, Gustav Wieds Vej 10C, DK-8000, Denmark
| | - Michael V W Kofoed
- Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10C, DK-8000, Denmark; The Novo Nordisk Foundation CO2 Research Center (CORC), Aarhus University, Gustav Wieds Vej 10C, DK-8000, Denmark.
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Yee MO, Ottosen LDM, Rotaru A. Electrical current disrupts the electron transfer in defined consortia. Microb Biotechnol 2024; 17:e14373. [PMID: 38070192 PMCID: PMC10832552 DOI: 10.1111/1751-7915.14373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 11/03/2023] [Accepted: 11/05/2023] [Indexed: 02/03/2024] Open
Abstract
Improving methane production through electrical current application to anaerobic digesters has garnered interest in optimizing such microbial electrochemical technologies, with claims suggesting direct interspecies electron transfer (DIET) at the cathode enhances methane yield. However, previous studies with mixed microbial communities only reported interspecies interactions based on species co-occurrence at the cathode, lacking insight into how a poised cathode influences well-defined DIET-based partnerships. To address this, we investigated the impact of continuous and discontinuous exposure to a poised cathode (-0.7 V vs. standard hydrogen electrode) on a defined consortium of Geobacter metallireducens and Methanosarcina barkeri, known for their DIET capabilities. The physiology of DIET consortia exposed to electrical current was compared to that of unexposed consortia. In current-exposed incubations, overall metabolic activity and cell numbers for both partners declined. The consortium, receiving electrons from the poised cathode, accumulated acetate and hydrogen, with only 32% of the recovered electrons allocated to methane production. Discontinuous exposure intensified these detrimental effects. Conversely, unexposed control reactors efficiently converted ethanol to methane, transiently accumulating acetate and recovering 88% of electrons in methane. Our results demonstrate the overall detrimental effect of electrochemical stimulation on a DIET consortium. Besides, the data indicate that the presence of an alternative electron donor (cathode) hinders efficient electron retrieval by the methanogen from Geobacter, and induces catabolic repression of oxidative metabolism in Geobacter. This study emphasizes understanding specific DIET-based interactions to enhance methane production during electrical stimulation, providing insights for optimizing tailored interspecies partnerships in microbial electrochemical technologies.
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Affiliation(s)
- Mon Oo Yee
- Nordcee, Department of BiologyUniversity of Southern DenmarkOdenseDenmark
- Nature EnergyOdenseDenmark
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Xiong X, Shang Y, Bai L, Luo S, Seviour TW, Guo Z, Ottosen LDM, Wei Z. Complete defluorination of perfluorooctanoic acid (PFOA) by ultrasonic pyrolysis towards zero fluoro-pollution. Water Res 2023; 235:119829. [PMID: 36958219 DOI: 10.1016/j.watres.2023.119829] [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: 11/02/2022] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
Advanced oxidation/reduction of PFAS is challenged and concerned by the formation of toxic, short-chain intermediates during water treatments. In this study, we investigated the complete defluorination of PFOA by ultrasound/persulfate (US/PS) with harmless end-products of CO2, H2O, and F‒ ions. We observed 100% defluorination after 4 h of US treatment alone with a power input of 900 W. PS addition, however, suppressed defluorination. We demonstrated by kinetics-fitted Langmuir-type adsorption modeling, the added PS increased competition with PFOA for adsorption sites on the bubble-water interface where radical oxidation and pyrolysis may occur. Providing sulfate (SO4•-) and hydroxyl (•OH) radicals by means other than US did not defluorinate PFOA, indicating that pyrolysis likely contributes to the high defluorination performance. Bond dissociation energies for CC and CF were independent of pressure but decreased at elevated temperatures within cavitation bubbles (i.e., 5000 K) favoring the pyrolysis reactions. Furthermore, bond length calculations indicated that PFOA cleavage only begins to occur at temperatures in excess of those generated at the bubble interface (i.e., >1500 K) at the femtosecond level. This suggests that PFOA vaporizes or injects by nanodrops upon attachment to the cavitation bubble, enters the bubble, and is then cleaved within the bubble by pyrolysis. Our research in low-frequency ultrasonic horn system challenges the previous founding that defluorination of PFOA initiates and occurs at the bubble-water interface. We describe here that supplementing US-based processes with complementary treatments may have undesired effects on the efficacy of US. The mechanistic insights will further promote the implementation of US technology for PFAS treatment in achieving the zero fluoro-pollution goal.
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Affiliation(s)
- Xingaoyuan Xiong
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark
| | - Yanan Shang
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark; Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, No. 27 Shanda South Road, Jinan 250100, China
| | - Lu Bai
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark
| | - Shuang Luo
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark; College of Environment and Ecology, Hunan Agricultural University, Changsha 410128, China
| | - Thomas William Seviour
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark
| | - Zheng Guo
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark
| | - Lars D M Ottosen
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark
| | - Zongsu Wei
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000 Aarhus C, Denmark.
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Arana Juve JM, Li F, Zhu Y, Liu W, Ottosen LDM, Zhao D, Wei Z. Concentrate and degrade PFOA with a photo-regenerable composite of In-doped TNTs@AC. Chemosphere 2022; 300:134495. [PMID: 35390412 DOI: 10.1016/j.chemosphere.2022.134495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 12/17/2021] [Revised: 03/28/2022] [Accepted: 03/31/2022] [Indexed: 06/14/2023]
Abstract
"Concentrate-and-degrade" is an effective strategy to promote mass transfer and degradation of pollutants in photocatalytic systems, yet suitable and cost-effective photocatalysts are required to practice the new concept. In this study, we doped a post-transition metal of Indium (In) on a novel composite adsorptive photocatalyst, activated carbon-supported titanate nanotubes (TNTs@AC), to effectively degrade perfluorooctanoic acid (PFOA). In/TNTs@AC exhibited both excellent PFOA adsorption (>99% in 30 min) and photodegradation (>99% in 4 h) under optimal conditions (25 °C, pH 7, 1 atm, 1 g/L catalyst, 0.1 mg/L PFOA, 254 nm). The heterojunction structure of the composite facilitated a cooperative adsorption mode of PFOA, i.e., binding of the carboxylic head group of PFOA to the metal oxide and attachment of the hydrophobic tail to AC. The resulting side-on adsorption mode facilitates the electron (e‒) transfer from the carboxylic head to the photogenerated hole (h+), which was the major oxidant verified by scavenger tests. Furthermore, the presence of In enables direct electron transfer and facilitates the subsequent stepwise defluorination. Finally, In/TNTs@AC was amenable to repeated uses in four consecutive adsorption-photodegradation runs. The findings showed that adsorptive photocatalysts can be prepared by hybridization of carbon and photoactive semiconductors and the enabled "concentrate-and-degrade" strategy is promising for the removal and degradation of trace levels of PFOA from polluted waters.
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Affiliation(s)
- Jan-Max Arana Juve
- Centre for Water Technology (WATEC), Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000, Aarhus C, Denmark
| | - Fan Li
- Environmental Engineering Program, Department of Civil & Environmental Engineering, Auburn University, Auburn, AL, 36849, USA; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Science and Engineering, Peking University, Beijing, 100871, China
| | - Yangmo Zhu
- Environmental Engineering Program, Department of Civil & Environmental Engineering, Auburn University, Auburn, AL, 36849, USA
| | - Wen Liu
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Science and Engineering, Peking University, Beijing, 100871, China
| | - Lars D M Ottosen
- Centre for Water Technology (WATEC), Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000, Aarhus C, Denmark
| | - Dongye Zhao
- Environmental Engineering Program, Department of Civil & Environmental Engineering, Auburn University, Auburn, AL, 36849, USA.
| | - Zongsu Wei
- Centre for Water Technology (WATEC), Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000, Aarhus C, Denmark.
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Ahmmed MS, Jensen MB, Kofoed MVW, Ottosen LDM, Batstone DJ. Hydrodynamic analysis of full-scale in-situ biogas upgrading in manure digesters. Water Res 2021; 203:117528. [PMID: 34399247 DOI: 10.1016/j.watres.2021.117528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 03/25/2021] [Revised: 07/14/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
The addition of hydrogen to anaerobic digesters is an emerging technique for the sustainable upgrading of biogas to biomethane with renewable electricity. However, it is critically dependent on the effective gas-liquid transfer of hydrogen, which is a sparingly soluble gas. Very little is known about the impact of liquid and gas flow and bubble size on gas-liquid transfer during H2 injection in full-scale anaerobic digesters. A computational fluid dynamic model was developed using a two-fluid approach for non-Newtonian liquid in the open-source computational fluid dynamics (CFD) platform, OpenFOAM. The newly developed model was validated against published experimental data-sets of a gas-mixed, laboratory-scale anaerobic digester, with good agreement between the numerical and experimental velocity fields. The hydrodynamics of the full-scale in-situ biomethanation system using venturi ejectors for H2 injection was then simulated to investigate gas-liquid dynamics, including gas-liquid mass transfer, at different operational conditions. Gas-liquid mixing is mainly controlled by the gas-plumes interaction, which promotes turbulence at the interaction zone, resulting in increasing gas bubbles mixing with the liquid and the gas-liquid interfacial area. However, beyond the plume interaction zone, the digester had flow short-circuiting and inactive zones. It was found that, due to this short-circuiting behaviour, an increase in gas flow-rate may not be an effective option in reducing inactive zones, although it can increase the gas-liquid interfacial area. Comparative analysis of the impact of gas flow and bubble size indicated that gas flow had a linear effect on both kLa and gas holdup, but that bubble size had a non-linear impact, with higher kLa values achieved at bubble sizes less than 2 mm. Comparison against measured data in the same system indicated the predicted kLa values were at the same level as measured kLa, at a bubble size of 2 mm.
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Affiliation(s)
- Mohammad Shakil Ahmmed
- Australian Centre for Water and Environmental Biotechnology (formerly AWMC), The University of Queensland, Australia.
| | - Mads Borgbjerg Jensen
- Department of Biological and Chemical Engineering, Aarhus University, Hangovej 2, Aarhus N DK-8200, Denmark.
| | - Michael V W Kofoed
- Department of Biological and Chemical Engineering, Aarhus University, Hangovej 2, Aarhus N DK-8200, Denmark.
| | - Lars D M Ottosen
- Department of Biological and Chemical Engineering, Aarhus University, Hangovej 2, Aarhus N DK-8200, Denmark.
| | - Damien J Batstone
- Australian Centre for Water and Environmental Biotechnology (formerly AWMC), The University of Queensland, Australia.
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Maegaard K, Garcia-Robledo E, Kofoed MVW, Agneessens LM, de Jonge N, Nielsen JL, Ottosen LDM, Nielsen LP, Revsbech NP. Biogas upgrading with hydrogenotrophic methanogenic biofilms. Bioresour Technol 2019; 287:121422. [PMID: 31085427 DOI: 10.1016/j.biortech.2019.121422] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [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: 03/05/2019] [Revised: 05/02/2019] [Accepted: 05/03/2019] [Indexed: 06/09/2023]
Abstract
Hydrogen produced from periodic excess of electrical energy may be added to biogas reactors where it is converted to CH4 that can be utilized in the existing energy grid. The major challenge with this technology is gas-to-liquid mass transfer limitation. The microbial conversions in reactors designed for hydrogenotrophic methanogenesis were studied with microsensors for H2, pH, and CO2. The H2 consumption potential was dependent on the CO2 concentration, but could partially recover after CO2 depletion. Reactors with 3-dimensional biofilm carrier material and a large gas headspace allowed for a methanogenic biofilm in direct contact with the gas phase. A high density of Methanoculleus sp. in the biofilm mediated a high rate of CH4 production, and it was calculated that a reactor filled with 75% carrier material could mediate a biogas upgrading from 50 to 95% CH4 within 24 h when an equivalent amount of H2 was added.
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Affiliation(s)
- Karen Maegaard
- WATEC, Section of Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Emilio Garcia-Robledo
- WATEC, Section of Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark; Department of Biology, University of Cadiz, Cadiz, Spain
| | - Michael V W Kofoed
- Biological and Chemical Engineering, Department of Engineering, Aarhus University, Aarhus, Denmark
| | - Laura M Agneessens
- Biological and Chemical Engineering, Department of Engineering, Aarhus University, Aarhus, Denmark
| | - Nadieh de Jonge
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Jeppe L Nielsen
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Lars D M Ottosen
- Biological and Chemical Engineering, Department of Engineering, Aarhus University, Aarhus, Denmark
| | - Lars Peter Nielsen
- WATEC, Section of Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Niels Peter Revsbech
- WATEC, Section of Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
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Aryal N, Kvist T, Ammam F, Pant D, Ottosen LDM. An overview of microbial biogas enrichment. Bioresour Technol 2018; 264:359-369. [PMID: 29908874 DOI: 10.1016/j.biortech.2018.06.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [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: 04/07/2018] [Revised: 06/05/2018] [Accepted: 06/06/2018] [Indexed: 05/07/2023]
Abstract
Biogas upgrading technologies have received widespread attention recently and are researched extensively. Microbial biogas upgrading (biomethanation) relies on the microbial performance in enriched H2 and CO2 environments. In this review, recent developments and applications of CH4 enrichment in microbial methanation processes are systematically reviewed. During biological methanation, either H2 can be injected directly inside the anaerobic digester to enrich CH4 by a consortium of mixed microbial species or H2 can be injected into a separate bioreactor, where CO2 contained in biogas is coupled with H2 and converted to CH4, or a combination hereof. The available microbial technologies based on hydrogen-mediated CH4 enrichment, in particular ex-situ, in-situ and bioelectrochemical, are compared and discussed. Moreover, gas-liquid mass transfer limitations, and dynamics of bacteria-archaea interactions shift after H2 injection are thoroughly discussed. Finally, the summary of existing demonstration, pilot plants and commercial CH4 enrichment plants based on microbial biomethanation are critically reviewed.
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Affiliation(s)
- Nabin Aryal
- Biological and Chemical Engineering, Aarhus University, Hangovej 2, DK-8200 Aarhus N, Denmark; Danish Gas Technology Centre, Dr. Neergaards Vej 5B, DK-2970 Horsholm, Denmark
| | - Torben Kvist
- Danish Gas Technology Centre, Dr. Neergaards Vej 5B, DK-2970 Horsholm, Denmark
| | - Fariza Ammam
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, United Kingdom
| | - Deepak Pant
- Separation and Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, Mol 2400, Belgium
| | - Lars D M Ottosen
- Biological and Chemical Engineering, Aarhus University, Hangovej 2, DK-8200 Aarhus N, Denmark.
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Garcia-Robledo E, Ottosen LDM, Voigt NV, Kofoed MW, Revsbech NP. Micro-scale H2-CO2 Dynamics in a Hydrogenotrophic Methanogenic Membrane Reactor. Front Microbiol 2016; 7:1276. [PMID: 27582736 PMCID: PMC4987362 DOI: 10.3389/fmicb.2016.01276] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/02/2016] [Indexed: 11/21/2022] Open
Abstract
Biogas production is a key factor in a sustainable energy supply. It is possible to get biogas with very high methane content if the biogas reactors are supplied with exogenous hydrogen, and one of the technologies for supplying hydrogen is through gas permeable membranes. In this study the activity and stratification of hydrogen consumption above such a membrane was investigated by use of microsensors for hydrogen and pH. A hydrogenotrophic methanogenic community that was able to consume the hydrogen flux within 0.5 mm of the membrane with specific rates of up to 30 m3 H2 m-3 day-1 developed within 3 days in fresh manure and was already established at time zero when analyzing slurry from a biogas plant. The hydrogen consumption was dependent on a simultaneous carbon dioxide supply and was inhibited when carbon dioxide depletion elevated the pH to 9.2. The activity was only partially restored when the carbon dioxide supply was resumed. Bioreactors supplied with hydrogen gas should thus be carefully monitored and either have the hydrogen supply disrupted or be supplemented with carbon dioxide when the pH rises to values about 9.
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Affiliation(s)
- Emilio Garcia-Robledo
- Section of Microbiology, Department of Bioscience, Aarhus University Aarhus, Denmark
| | - Lars D M Ottosen
- Biological and Chemical Engineering, Department of Engineering, Aarhus University Aarhus, Denmark
| | | | - M W Kofoed
- Danish Technological Institute Aarhus, Denmark
| | - Niels P Revsbech
- Section of Microbiology, Department of Bioscience, Aarhus University Aarhus, Denmark
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Højgaard A, Ottosen LDM, Kesmodel U, Ingerslev HJ. Patient attitudes towards twin pregnancies and single embryo transfer a questionnaire study. Hum Reprod 2007; 22:2673-8. [PMID: 17766921 DOI: 10.1093/humrep/dem173] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The present trend towards selective single embryo transfer (SET) calls for evaluation of patient attitudes towards twins and how the patients balance advantages and disadvantages of one or two embryos in IVF/ICSI treatment. METHODS The study was conducted in a Danish public fertility clinic, where the common practice was double embryo transfer (DET), and the number of reimbursed treatments was limited to three. Referred patients were given oral and written information about the IVF/ICSI treatment including twin probability following DET and the risk of preterm delivery and neonatal complications associated with twins. In order to evaluate patients and partners attitudes towards twins and SET, an anonymous survey was conducted, and 588 couples were invited to participate. RESULTS Four hundred and fourteen women (70.4%) and 404 men (68.7%) answered the questionnaire adequately for analysis. About 58.7% preferred having twins to having one child at a time (37.9%). Primary reasons for preferring twins were desire for siblings (23.3%), a positive attitude towards twins (22.5%), and a wish to minimize physical and psychological stress through having as few IVF treatments as possible (19.3%). Economic considerations were not important. CONCLUSIONS Obligatory single embryo policy would be in conflict with patient interests and wishes. More carefully prepared information seems to be needed. The challenge consists in balancing clinical considerations with unbiased information on twin pregnancy, respecting patient autonomy and enabling informed decision-making.
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Affiliation(s)
- Astrid Højgaard
- The Fertility Clinic, Department of Obstetrics and Gynaecology, Aarhus University Hospital, Skejby Sygehus, Brendstrupgaardsvej, DK-8000 Arhus N, Denmark.
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Abstract
Exposure to visible light (400-700 nm wavelengths) is an unnatural stress factor to preimplantation embryos cultured in vitro. This study investigated the spectral composition and intensity of light during IVF procedures, and calculated radiation doses reaching the embryo during handling and manipulation. The study shows that normal IVF procedure may result in stressing radiation doses, unless filters are applied. This is at present not sufficiently recognised. No Danish IVF clinics use filters to protect embryos against visible light. 95% of the radiation was from microscopes. Ambient light, in contrast, was not a significant contributor to light stress and the use of dark laboratories is not justified.
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Affiliation(s)
- Lars D M Ottosen
- The Fertility Clinic, Department of Gynecology and Obstetrics, Aarhus University Hospital Skejby Sygehus, Brendstrupgaardsvej 8200 Arhus N, Denmark.
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Ottosen LDM, Hindkjaer J, Lindenberg S, Ingerslev HJ. Murine pre-embryo oxygen consumption and developmental competence. J Assist Reprod Genet 2007; 24:359-65. [PMID: 17636441 PMCID: PMC3454938 DOI: 10.1007/s10815-007-9138-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 04/23/2007] [Indexed: 10/23/2022] Open
Abstract
PURPOSE In search for a new marker of preimplantation embryo viability the present study investigated oxygen consumption of individual cleavage stage murine embryos, and evaluated the predictive value regarding subsequent development to expanded blastocysts. METHODS In all, 248 embryos were investigated from 2 cell stage until blastocyst stage with individual measurement of oxygen consumption and recording of developmental stage. Cleavage stage embryos and morula were divided in groups according to their oxygen consumption, and odds ratios (OR) for subsequent development to expanded blastocyst were calculated. RESULTS Cleavage stage (2-8 cell) individual oxygen consumption was 0.16-0.20 nl O(2) h(-1), with a significant increase to 0.21-0.23 nl O(2) h(-1) at the morula stage followed by a more than twofold increase for the expanded blastocyst 0.47 nl O(2) h(-1). A significantly higher chance of reaching the expanded blastocyst stage was found in 4-cell embryos with high oxygen consumption, than embryos with low consumption (OR 2.25, 95% CI 1.04-4.90). Among 2-cell embryos the chance of low and high consumers was not significantly different. The method used in the present study somewhat compromised embryo development (51% blastocyst rate) compared to controls (80% blastocystrate) which could make our results less robust. CONCLUSION Preliminary data from the present study suggest that oxygen consumption in cleavage stage embryos may be an indicator, but a not a strong predictor, of subsequent development to expanded blastocysts.
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Affiliation(s)
- Lars D M Ottosen
- The Fertility Clinic, Department of Obstetrics and Gynaecology, Aarhus University Hospital Skejby Sygehus, Brendstrupgaardsvej, 8200, Arhus N, Denmark.
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Ottosen LDM, Kesmodel U, Hindkjaer J, Ingerslev HJ. Pregnancy prediction models and eSET criteria for IVF patients--do we need more information? J Assist Reprod Genet 2006; 24:29-36. [PMID: 17165151 PMCID: PMC3455082 DOI: 10.1007/s10815-006-9082-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2006] [Accepted: 11/06/2006] [Indexed: 11/29/2022] Open
Abstract
PURPOSE The purpose of the present study was to evaluate statistical prediction models and simple allocation criteria, based on predictors for pregnancy, as tools to identify a good prognosis group in a possible eSET setting. METHODS A pregnancy prediction model based on logistic regression models was generated by analysis of 1675 DET treatment cycles. The model was evaluated and compared to simple eSET allocation criteria. RESULTS Embryo quality, patient age, and basal FSH were identified as significant predictors (at 5% significance level) of pregnancy. Although comparable to previously generated models, the predictive ability of the present model was relatively poor and practically similar to simple allocation criteria based on age and embryo quality. CONCLUSIONS Existing prediction models, or simple allocation criteria, are limited in identifying good prognosis patients. Future studies of the applicability of improved pregnancy prediction models will need very comprehensive and detailed patient and embryo information.
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Affiliation(s)
- Lars D M Ottosen
- The Fertility Clinic, Department of Obstetrics and Gynaecology, Aarhus University Hospital, Skejby Sygehus, Brendstrupgaardsvej, DK-8200, Arhus N, Denmark.
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Ottosen LDM, Hindkaer J, Husth M, Petersen DE, Kirk J, Ingerslev HJ. Observations on intrauterine oxygen tension measured by fibre-optic microsensors. Reprod Biomed Online 2006; 13:380-5. [PMID: 16984770 DOI: 10.1016/s1472-6483(10)61443-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Understanding the biology of reproductive organs is essential for the development of assisted reproductive techniques. There is at present no direct evidence for either the concentration and dynamics of intrauterine oxygen tension at the endometrial surface, nor its importance for the receptiveness of the endometrium. In this study a new method measured mid-cycle (ranging from day 12-18) endometrial surface oxygen tension in 21 patients referred to intrauterine insemination (IUI). Time series was measured online for a period of 5-10 min. The (mean) individual oxygen tension among patients varied from 4 to 27% air saturation. Overall mean oxygen tension among all patients was 11.8% air saturation. Within the same patient, considerable time-related variations were observed. Some patients exhibited rhythmic oscillations with a frequency in the order of 1 min, whereas others did not show any regular patterns. A good description of endometrial surface oxygen concentration and dynamics was thus obtained, but given the relatively small number of participants, an association with pregnancy following insemination could not be established. Further studies using this new method could elucidate the association between individual intrauterine activity, embryo implantation and endometrial surface oxygen tension.
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Affiliation(s)
- Lars D M Ottosen
- The Fertility Clinic, Department of Obstetrics and Gynaecology, Aarhus University Hospital Skejby Sygehus, Brendstrupgaardsvej, DK-8200 Aarhus N, Denmark.
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