The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Xavier Lefebvre - One of the best experts on this subject based on the ideXlab platform.
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Exploring synergism between anaerobic mesophilic and aerobic hyperthermophilic populations for an increased sludge biodegradation
2013Co-Authors: Claire Dumas, Etienne Paul, Sergio Perez Fabiel, Xavier LefebvreAbstract:Increasing the intrinsic biodegradability of activated sludge represents an important challenge for decreasing sludge production. In this framework, the capacity of an hyper thermophilic (65°C) aerobic process coupled with a mesophilic (35°C) digester was evaluated for the activated sludge degradation and was compared to that of a conventional mesophilic anaerobic digester (MAD). For two Sludge Retention Times (SRT), 21 and 42 days, the Chemical oxygen demand (COD) solubilisation and biodegradation processes, the Methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days, for which the COD removal yield was 30 % higher with the Mesophilic Anaerobic Digestion / Thermophilic Aerobic Reactor (MADTAR) co-treatment compared to the conventional AD. An increase of the sludge intrinsic biodegradability is also observed (20 – 40 %), showing that the unbiodegradable COD in mesophilic conditions, becomes bioavailable to thermophilic aerobic bacteria. However, the Methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the total reaction volume of digestion for an equivalent efficiency.
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combined thermophilic aerobic process and conventional anaerobic digestion effect on sludge biodegradation and methane production
Bioresource Technology, 2010Co-Authors: Claire Dumas, Etienne Paul, Serge Perez, Xavier LefebvreAbstract:Abstract The efficiency of hyper-thermophilic (65 °C) aerobic process coupled with a mesophilic (35 °C) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation processes, the Methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic Anaerobic Digestion/Thermophilic Aerobic Reactor (MAD–TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20–40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the Methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the volume of digester with an equivalent efficiency.
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Combined thermophilic aerobic process and conventional anaerobic digestion: effect on sludge biodegradation and methane production
Bioresource Technology, 2010Co-Authors: Claire Dumas, Etienne Paul, Serge Perez, Xavier LefebvreAbstract:The efficiency of hyper-thermophilic (65 degrees Celsius) aerobic process coupled with a mesophilic (35 degrees Celsius) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation processes, the Methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic Anaerobic Digestion/Thermophilic Aerobic Reactor (MAD-TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20-40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the Methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the volume of digester with an equivalent efficiency.
Etienne Paul - One of the best experts on this subject based on the ideXlab platform.
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Exploring synergism between anaerobic mesophilic and aerobic hyperthermophilic populations for an increased sludge biodegradation
2013Co-Authors: Claire Dumas, Etienne Paul, Sergio Perez Fabiel, Xavier LefebvreAbstract:Increasing the intrinsic biodegradability of activated sludge represents an important challenge for decreasing sludge production. In this framework, the capacity of an hyper thermophilic (65°C) aerobic process coupled with a mesophilic (35°C) digester was evaluated for the activated sludge degradation and was compared to that of a conventional mesophilic anaerobic digester (MAD). For two Sludge Retention Times (SRT), 21 and 42 days, the Chemical oxygen demand (COD) solubilisation and biodegradation processes, the Methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days, for which the COD removal yield was 30 % higher with the Mesophilic Anaerobic Digestion / Thermophilic Aerobic Reactor (MADTAR) co-treatment compared to the conventional AD. An increase of the sludge intrinsic biodegradability is also observed (20 – 40 %), showing that the unbiodegradable COD in mesophilic conditions, becomes bioavailable to thermophilic aerobic bacteria. However, the Methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the total reaction volume of digestion for an equivalent efficiency.
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combined thermophilic aerobic process and conventional anaerobic digestion effect on sludge biodegradation and methane production
Bioresource Technology, 2010Co-Authors: Claire Dumas, Etienne Paul, Serge Perez, Xavier LefebvreAbstract:Abstract The efficiency of hyper-thermophilic (65 °C) aerobic process coupled with a mesophilic (35 °C) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation processes, the Methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic Anaerobic Digestion/Thermophilic Aerobic Reactor (MAD–TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20–40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the Methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the volume of digester with an equivalent efficiency.
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Combined thermophilic aerobic process and conventional anaerobic digestion: effect on sludge biodegradation and methane production
Bioresource Technology, 2010Co-Authors: Claire Dumas, Etienne Paul, Serge Perez, Xavier LefebvreAbstract:The efficiency of hyper-thermophilic (65 degrees Celsius) aerobic process coupled with a mesophilic (35 degrees Celsius) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation processes, the Methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic Anaerobic Digestion/Thermophilic Aerobic Reactor (MAD-TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20-40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the Methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the volume of digester with an equivalent efficiency.
Serge Perez - One of the best experts on this subject based on the ideXlab platform.
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combined thermophilic aerobic process and conventional anaerobic digestion effect on sludge biodegradation and methane production
Bioresource Technology, 2010Co-Authors: Claire Dumas, Etienne Paul, Serge Perez, Xavier LefebvreAbstract:Abstract The efficiency of hyper-thermophilic (65 °C) aerobic process coupled with a mesophilic (35 °C) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation processes, the Methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic Anaerobic Digestion/Thermophilic Aerobic Reactor (MAD–TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20–40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the Methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the volume of digester with an equivalent efficiency.
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Combined thermophilic aerobic process and conventional anaerobic digestion: effect on sludge biodegradation and methane production
Bioresource Technology, 2010Co-Authors: Claire Dumas, Etienne Paul, Serge Perez, Xavier LefebvreAbstract:The efficiency of hyper-thermophilic (65 degrees Celsius) aerobic process coupled with a mesophilic (35 degrees Celsius) digester was evaluated for the activated sludge degradation and was compared to a conventional mesophilic digester. For two Sludge Retention Time (SRT), 21 and 42 days, the Chemical Oxygen Demand (COD) solubilisation and biodegradation processes, the Methanisation yield and the aerobic oxidation were investigated during 180 days. The best results were obtained at SRT of 44 days; the COD removal yield was 30% higher with the Mesophilic Anaerobic Digestion/Thermophilic Aerobic Reactor (MAD-TAR) co-treatment. An increase of the sludge intrinsic biodegradability is also observed (20-40%), showing that the unbiodegradable COD in mesophilic conditions becomes bioavailable. However, the Methanisation yield was quite similar for both processes at a same SRT. Finally, such a process enables to divide by two the volume of digester with an equivalent efficiency.
Pascal Grouiez - One of the best experts on this subject based on the ideXlab platform.
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une analyse de filiere des dynamiques de revenus de la Methanisation agricole
Notes et Etudes Socio-Economiques, 2021Co-Authors: Pascal GrouiezAbstract:Cet article presente les principaux resultats du projet de recherche Metha’revenus, finance par le ministere de l'Agriculture et de l'Alimentation, et commande en 2019 au laboratoire Ladyss (CNRS). Il adopte une approche institutionnaliste dite « de filiere » pour rendre compte de la dynamique de revenu de la Methanisation agricole en France. Il distingue deux periodes : celle de l’emergence de la Methanisation, portee par des eleveurs pionniers et soutenue par les politiques publiques a partir des annees 2000 ; celle du developpement de la filiere marque par une augmentation du nombre des intermediaires, par une logique d’optimisation du pouvoir methanogene et une plus grande concurrence entre les agriculteurs-methaniseurs d’une part, et entre agriculteurs et industriels d’autre part apres 2015. Nos resultats montrent une diversite de manieres de degager un revenu de la Methanisation agricole en France, du fait de l’histoire de l’emergence et du developpement de la filiere. Ils soulignent aussi que cette filiere connait actuellement une logique d’industrialisation et d’extension – au sens d’une augmentation du nombre de segments et donc d’acteurs. Cette dynamique se traduit par une plus grande difficulte, pour certains agriculteurs, a degager un revenu de cette activite non agricole, en particulier pour ceux situes en amont de la filiere et qui n’ont pas reussi a internaliser au maximum les differentes etapes du processus de production. Il n’est pas certain que les agriculteurs, a terme, parviennent a etre des acteurs dominants de la Methanisation et a en degager un revenu significatif, quelles que soient leurs specificites.
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revenus issus de la Methanisation agricole dans un contexte de developpement de l injection
Analyse. Centre d'études et de prospective, 2020Co-Authors: Pascal Grouiez, Alexandre Berthe, Mathilde Fautras, Sabina Issenahne, Mickael HugonnetAbstract:La recherche Metha’Revenus, realisee dans le cadre d’un appel a projets de recherche lance par le ministere de l’Agriculture et de l’Alimentation, etudie les conditions de la stabilisation du revenu des agriculteurs via l’investissement dans des unites de Methanisation. Quels niveaux de revenu les agriculteurs peuvent-ils esperer en tirer ? Quelles categories d’agriculteurs sont prioritairement concernees ? Quelles sont les consequences des evolutions techniques recentes de la filiere ? Telles sont les questions auxquelles Metha’Revenus apporte des elements de reponse.
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determinants et mesure des revenus agricoles de la Methanisation et positionnement des agriculteurs dans la chaine de valeur biomasse energie
2020Co-Authors: Pascal Grouiez, Alexandre Berthe, Mathilde Fautras, Sabina IssehnaneAbstract:Comptant aujourd’hui plus de 700 unites de Methanisation agricoles, la filiere "biomasse-energie" se structure en France depuis une dizaine d’annees a la faveur du soutien des politiques publiques, en s’appuyant sur une diversite de modeles economiques des methaniseurs. Ce rapport identifie quatre strategies de revenu mises en place par les agriculteurs qui sont autant de modeles economiques d'unites de Methanisation en s’appuyant sur 53 entretiens semi-directifs menes aupres d’agriculteurs du Grand-Est, de l’Ile-de-France et de la Nouvelle Aquitaine et 40 entretiens conduits aupres d’acteurs institutionnels. Ce resultat permet de questionner le devenir des differents modeles d’unite de Methanisation agricole dans le contexte de reconfiguration en cours de la filiere et notamment de l'emergence d'unites de Methanisation industrielles. Sur la base d'une analyse prospective, le rapport met en evidence le risque d'une homogeneisation des unites de Methanisation agricoles. Ces dernieres augmentant en taille, elles pourraient a termes conduire au basculement des unites de Methanisation vers un modele industriel (non-agricole) dans lequel les agriculteurs seraient de simples apporteurs de substrats a methaniser.
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les formes d unites de Methanisation en france typologies et scenarios d avenir de la filiere
Agronomie Environnement & Sociétés, 2020Co-Authors: Alexandre Berthe, Pascal Grouiez, Mathilde Fautras, Sabina IssehnaneAbstract:Comptant aujourd’hui plus de 700 unites de Methanisation (UM), la filiere de la Methanisation se structure en France depuis une dizaine d’annees a la faveur du soutien des politiques publiques, en s’appuyant sur une diversite grandissante des modeles economiques de Methanisation. L’article propose une revue de litterature des classifications existantes d’UM en montrant qu’elles s’appuient principalement sur des criteres techniques et juridiques. Pour aller au-dela, l’article s’appuie sur 53 entretiens semi-directifs menes aupres d’agriculteurs du Grand-Est, de l’Ile-de-France et de la Nouvelle Aquitaine et 40 entretiens conduits aupres d’acteurs institutionnels. Il presente de nouvelles classifications basees sur les strategies et les motivations des acteurs, des connaissances plus subjectives et qualitatives, permettant de mieux apprehender l’evolution de la filiere. L’article se termine alors sur une discussion sur le devenir des differents modeles d’UM dans le contexte de reconfiguration en cours de la filiere.
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les upgradings strategiques des firmes subordonnees dans les cgv le cas des eleveurs investissant dans des unites de Methanisation
Revue d'économie industrielle, 2018Co-Authors: Alexandre Berthe, Pascal Grouiez, Louis DupuyAbstract:Cet article porte sur l’analyse des strategies d’upgrading en se focalisant sur l’echelle des firmes subordonnees, a la difference de son etude plus classique a l’echelle de la chaine globale de valeur (CGV). Cette approche conduit a developper le concept d’« upgrading strategique », a etudier l’environnement institutionnel des firmes subordonnees et a mobiliser les concepts propres a l’economie industrielle tels que les logiques de differenciation, de diversification, de specialisation pour comprendre les strategies de ces firmes. Il s’agit de reconsiderer ainsi l’upgrading inter-chaine, c’est-a-dire l’amelioration de la position d’acteurs au sein d’une CGV en integrant une autre CGV. Nous confrontons cette proposition a une etude de cas territorialisee sur le developpement de la Methanisation par des exploitants agricoles ardennais. Nous montrons que ces agriculteurs s’inserent dans la CGV-biomasse energie emergente en fonction de leur experience d’acteurs « captifs » dans la chaine CGV agro-industrielle. En particulier, ils ont dimensionne leur unite de Methanisation pour etre autonomes vis-a-vis des agro-industriels. Cette nouvelle activite a par ailleurs des effets retour sur leur positionnement dans la CGV agro-industrielle. Classification JEL : L22, L23, Q13, Q16, Q42.
Tong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Thermophilic microbial cellulose decomposition and methanogenesis pathways recharacterized by metatranscriptomic and metagenomic analysis
Scientific Reports, 2014Co-Authors: Yu Xia, Huanzi Zhong, Herbert H. P. Fang, Tao Jin, Yubo Wang, Tong ZhangAbstract:The metatranscriptomic recharacterization in the present study captured microbial enzymes at the unprecedented scale of 40,000 active genes belonged to 2,269 KEGG functions were identified. The novel information obtained herein revealed interesting patterns and provides an initial transcriptional insight into the thermophilic cellulose methanization process. Synergistic beta-sugar consumption by Thermotogales is crucial for cellulose hydrolysis in the thermophilic cellulose-degrading consortium because the primary cellulose degraders Clostridiales showed metabolic incompetence in subsequent beta-sugar pathways. Additionally, comparable transcription of putative Sus-like polysaccharide utilization loci (PULs) was observed in an unclassified order of Bacteroidetes suggesting the importance of PULs mechanism for polysaccharides breakdown in thermophilic systems. Despite the abundance of acetate as a fermentation product, the acetate-utilizing Methanosarcinales were less prevalent by 60% than the hydrogenotrophic Methanobacteriales. Whereas the aceticlastic methanogenesis pathway was markedly more active in terms of transcriptional activities in key genes, indicating that the less dominant Methanosarcinales are more active than their hydrogenotrophic counterparts in methane metabolism. These findings suggest that the minority of aceticlastic methanogens are not necessarily associated with repressed metabolism, in a pattern that was commonly observed in the cellulose-based methanization consortium, and thus challenge the causal likelihood proposed by previous studies.