Narbonne, France
Narbonne, France

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Riggio S.,French National Institute for Agricultural Research | Riggio S.,University of Cassino and Southern Lazio | Riggio S.,University Paris Est Creteil | Hernandez-Shek M.A.,Naskeo Environnement | And 6 more authors.
Bioresource Technology | Year: 2017

Anaerobic digestion of spent cow bedding in batch leach-bed reactors (LBRs) was compared in mesophilic and thermophilic conditions for the first time. Results show that the use of thermophilic conditions enhanced only the degradation kinetics of easily-degradable matter during the first days of the digestion, whereas similar methane yields (80% of the Biomethane Potential) were reached after 42 days at both temperatures. Therefore, the anaerobic digestion in LBRs of spent cow bedding, a substrate rich in slowly-degradable compounds, was not improved in term of methane production considering the overall digestion time. Moreover, the high initial biogas production rate in thermophilic reactors was found to significantly reduce the energetic performance of the cogeneration unit at industrial scale, leading to a 5.9% decrease in the annual electricity production when compared to a mesophilic one. © 2017 Elsevier Ltd


Gonzalez-Fernandez C.,French National Institute for Agricultural Research | Sialve B.,Naskeo Environnement | Bernet N.,French National Institute for Agricultural Research | Steyer J.P.,French National Institute for Agricultural Research
Bioresource Technology | Year: 2013

Biogas production is one of the means to produce a biofuel from microalgae. Biomass consisting mainly of Scenedesmus sp. was thermally pretreated and optimum pretreatment length (1h) and temperature (90°C) was selected. Different chemical composition among batches stored at 4°C for different lengths of time resulted in organic matter hydrolysis percentages ranging from 3% to 7%. The lower percentages were attributed to cell wall thickening observed during storage for 45days. The different hydrolysis percentages did not cause differences in anaerobic digestion. Pretreatment of Scenedesmus sp. at 90°C for 1h increased methane production 2.9 and 3.4-fold at organic loading rates (OLR) of 1 and 2.5kgCODm-3day-1, respectively. Regardless the OLR, inhibition caused by organic overloading or ammonia toxicity were not detected. Despite enhanced methane production, anaerobic biodegradability of this biomass remained low (32%). Therefore, this microalga is not a suitable feedstock for biogas production unless a more suitable pretreatment can be found. © 2012 Elsevier Ltd.


Gonzalez-Fernandez C.,French National Institute for Agricultural Research | Sialve B.,Naskeo Environnement | Bernet N.,French National Institute for Agricultural Research | Steyer J.P.,French National Institute for Agricultural Research
Bioresource Technology | Year: 2012

Ultrasound at 20. Hz was applied at different energy levels (Es) to treat Scenedesmus biomass, and organic matter solubilization, particle size distribution, cell disruption and biochemical methane potential were evaluated. An Es of 35.5 and 47.2. MJ/kg resulted in floc deagglomeration but no improvement in methane production compared to untreated biomass. At an Es of 128.9, cell wall disruption was observed together with a 3.1-fold organic matter solubilization and an approximately 2-fold methane production in comparison with untreated biomass. Thermal pretreatment at 80. °C caused cell wall disruption and improved anaerobic biodegradability 1.6-fold compared to untreated biomass. Since sonication caused a temperature increase in samples to as high as 85. °C, it is likely that thermal effects accounted for much of the observed changes in the biomass. Given that ultrasound treatment at the highest Es studied only increased methane production by 1.2-fold over thermal treatment at 80. °C, the higher energy requirement of sonication might not justify the use of this approach over thermal treatment. © 2012 Elsevier Ltd.


Vasseur C.,Montpellier University | Bougaran G.,French Research Institute for Exploitation of the Sea | Garnier M.,French Research Institute for Exploitation of the Sea | Hamelin J.,French National Institute for Agricultural Research | And 6 more authors.
Bioresource Technology | Year: 2012

Association of microalgae culture and anaerobic digestion seems a promising technology for sustainable algal biomass and biogas production. The use of digestates for sustaining the growth of microalgae reduces the costs and the environmental impacts associated with the substantial algal nutrient requirements. A natural marine algae-bacteria consortium was selected by growing on a medium containing macro nutrients (ammonia, phosphate and acetate) specific of a digestate, and was submitted to a factorial experimental design with different levels of temperature, light and pH. The microalgal consortium reached a maximum C conversion efficiency (i.e. ratio between carbon content produced and carbon supplied through light photosynthetic C conversion and acetate) of 3.6%. The presence of bacteria increased this maximum C conversion efficiency up to 6.3%. The associated bacterial community was considered beneficial to the total biomass production by recycling the carbon lost during photosynthesis and assimilating organic by-products from anaerobic digestion. © 2012 Elsevier Ltd.


Fouilland E.,Montpellier University | Vasseur C.,Montpellier University | Leboulanger C.,Montpellier University | Le Floc'h E.,Montpellier University | And 4 more authors.
Biomass and Bioenergy | Year: 2014

Coupling algal biomass production and anaerobic digestion is one of the most promising bioprocesses for economically viable algal production. This study assesses the production rates of some native microalgae growing in media supplemented with algal digestate, urban wastewater or digested sludge. Native microalgal populations isolated from temperate freshwaters (Scenedesmus spp.) and marine ecosystems (Nannochloris spp.) had the highest potential production rates (about 100mg DWL-1d-1) with algal digestate at about 20% loading ratio. However, no growth was measured for Nannochloris spp., when the ammonium concentration exceeded 100mgL-1 although Scenedesmus spp. appeared to be tolerant to higher NH4 + concentrations. Very low production rates, or no growth, were measured when microalgae isolated from high salinity waters (Dunaliella salina, Lyngbya aestuarii) were used, suggesting that populations well adapted to extreme environmental conditions are not suitable candidates for growing on wastewater or anaerobic digestate. © 2014 Elsevier Ltd.


Grant
Agency: European Commission | Branch: FP7 | Program: BSG-SME | Phase: SME-1 | Award Amount: 1.79M | Year: 2009

Current procedures for the design of WWTP controllers are usually based on long and very expensive experimental studies. In this respect, the availability of WWTP simulation tools specific for control design would allow automation companies to establish and complement experimental procedures with enhanced procedures based on mathematical modeling and simulation. In addition, WWTP simulation software companies will find in automation companies a further potential market for selling their software products. Accordingly, the objective of this proposal is to design, implement and validate new simulation tools for practical control. Based on this WWTP virtualization, it will be feasible to manufacture enhanced and cost-effective control products, tested by simulation previous to their full-scale implementation. To achieve these objectives, 3 software layers will be developed: Mass, Instrumentation and actuation & Automation and control layers. These developments will then be tested both at industrial and urban WWT scenarios. This work will be driven by 3 SME developers (M4W, software simulator, MSI, automation company, and NASKEO, environmental engineering) and 2 end user (SCAD, SME as industrial WWTP, and AGIPUZKOA as urban WWTP). They trust in the know-how of 3 key RTDs in this sector (CEIT, mathematic modeling and conventional control expert, UGENT, computer science expert, and INRA, advanced control and anaerobic digestion expert). Due to this project, 3 exploitable results will be developed: (1) WWTP Software simulator, (2) Advanced controllers and (3) Enhanced treatment technologies. IPR has been divided among partners in order to maximize impact at European level. If this project is successful, the gathered knowledge will put Europe in pole position with respect to tackling optimisation of wastewater treatment processes in a sustainable way. In this sense, exploitable results can be commercialized together in a joined offer or as separate results.


PubMed | Naskeo Environnement, University of Cassino and Southern Lazio, French National Institute for Agricultural Research and University Paris Est Creteil
Type: | Journal: Waste management (New York, N.Y.) | Year: 2016

Spent animal bedding is a valuable resource for green energy production in rural areas. The properties of six types of spent bedding collected from deep-litter stables, housing either sheeps, goats, horses or cows, were compared and their anaerobic digestion in a batch Leach-Bed Reactor (LBR) was assessed. Spent horse bedding, when compared to all the other types, appeared to differ the most due to a greater amount of straw added to the litter and a more frequent litter change. Total solids content appeared to vary significantly from one bedding type to another, with consequent impact on the methane produced from the raw substrate. However, all the types of spent bedding had similar VS/TS (82.3-88.9)%, a C/N well-suited to anaerobic digestion (20-28, except that of the horse, 42) and their BMPs were in a narrow range (192-239NmLCH


Gonzalez-Fernandez C.,Laboratoire Of Biotechnologie Of Lenvironnement | Sialve B.,Naskeo Environnement | Bernet N.,Laboratoire Of Biotechnologie Of Lenvironnement | Steyer J.-P.,Laboratoire Of Biotechnologie Of Lenvironnement
Biofuels, Bioproducts and Biorefining | Year: 2012

Among biofuel production processes using microalgal biomass, biogas generation seems to be the least complex. This review summarizes information regarding anaerobic digestion of different microalgae species. Various operational parameters and microalgae characteristics (macromolecular distribution and cell wall) are reviewed in the light of their effects on methane production. Additionally, the enhancement of methane production rates achievable by applying biomass pre-treatments and codigestion of substrates is also reported. The review finally covers the so-claimed similarities of microalgal biomass and activated sludge as a substrate for anaerobic digestion. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd.


Gonzalez-Fernandez C.,Laboratoire Of Biotechnologie Of Lenvironnement | Sialve B.,Naskeo Environnement | Bernet N.,Laboratoire Of Biotechnologie Of Lenvironnement | Steyer J.-P.,Laboratoire Of Biotechnologie Of Lenvironnement
Biofuels, Bioproducts and Biorefining | Year: 2012

Microalgae are now the focus of intensive research because of their potential as a renewable feedstock for biofuel production. This review briefly examines the effect of reactor design, nutrient, and light regimens on microalgae productivity and macromolecular composition. Downstream processing including common biofuel production as well as life cycle assessment and technoeconomical aspects are discussed. Even though algal biofuels are more environmentally friendly than fossil fuels, economical feasibility is a challenging issue. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd.

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