Méthodologie d'éconconception pour un procédé innovant: la bioélétrosynthèse des déchets organiques

International audienceBulk chemicals and liquid fuels are currently produced almost exclusively from petrochemical feedstock. In the light of emission reduction targets and the dependence on non renewable resources, the production of the same or functionally equivalent chemicals from renewable resources may play an important role [1, 2]. The project BIORARE (Bioelectrosynthesis for the refinery of residual waste) was set up to contribute to this objective. Its purpose is to use microbial electrosynthesis for the direct production of fuels and chemicals from organic waste and CO2 (see figure 1). Ecoconception is used to help to make choices. This is this work which is study.In a first step, we had to determine which parameters of the Bioelectrosynthesis (BES) could be the most impacting ones to define the priorities to be considered to minimize the potential impacts of the entire process. Some flows could be sensitive: the nature and the quantity of outputs, the nature and the quantity of materials, and the amount of energy used. The inventory of these flows had to be the first step. Thanks to databases and literature four have been identified as sensitive: electrodes, membrane, energy and chemicals produced.After determining this, we have to design the model for coupling anaerobic digestion to the BES. This was realized using Life Cycle Assessment approach. The goal of this assessment is to determine the relative influence of various target parameters on the impacts of the process. For example, results will allow assessing if the choice of a material for the electrode could have a significant influence on total impacts. Our methodology illustrates to what extend Life Cycle Assessment could help for the conception of a process, through the evaluation of the contribution of various parameters to the impacts. After, it is possible to integrate them into a model to determine what impacts they could have on the whole production chemicals or fuels from organic waste system.ACV de production de bioéthanol par bioélectrosynthèse de déchets organiques

Lattice Kinetics of Diffusion-Limited Coalescence and Annihilation with Sources

We study the 1D kinetics of diffusion-limited coalescence and annihilation with back reactions and different kinds of particle input. By considering the changes in occupation and parity of a given interval, we derive sets of hierarchical equations from which exact expressions for the lattice coverage and the particle concentration can be obtained. We compare the mean-field approximation and the continuum approximation to the exact solutions and we discuss their regime of validity.Comment: 24 pages and 3 eps figures, Revtex, accepted for publication in J. Phys.

The Role of Oxidation Compounds in Biofilm Growth on Polyethylene Geomembrane Barriers Used in Landfill

In a model study, polyethylene was preoxidized and incubated for a period of 7 months at 40°C in two different municipal solid waste leachates. During the postexperimental analyses, specific attention was paid to the carbonyl species and carboxylic acid depletion during the environmental exposure because it is well known that carboxylic acids are believed to be a potential substrate for the development of microorganisms. The results showed that the carbonyl as well as the carboxylic acid depletion observed follows first-order kinetics. The biofilm formation was characterized using a suite of analytical techniques, and its formation was compared with the carboxylic acid and carbonyl depletion profil

Metaproteomics of anaerobic microbial communities degrading long-chain fatty acids

The anaerobic conversion of long-chain fatty acids (LCFA), and specifically the difference between the degradation of unsaturated- and saturated-LCFA, is not fully understood. In this work, syntrophic degradation of stearate (C18:0) and oleate (C18:1) was studied. A comparative metaproteomics approach, in which proteins were analyzed by LC-MS/MS, was combined with 16S rRNA gene pyrosequencing. Saturated- and unsaturated-LCFA were converted to methane by the anaerobic consortia. 16S rRNA gene pyrosequencing revealed differences in the microbial composition of sludges incubated with stearate and oleate, separately. Abundance of microorganisms within Deltaproteobacteria and within Synergistia taxa was higher in stearate and oleate incubations, respectively. Methanosaeta was the most abundant methanogen in both conditions. Metaproteomics results were similar and comparable distributions of COG functional categories were found for both samples. Archaeal proteomes were much better identified than bacterial ones, with five times more proteins retrieved. Most of the proteins identified belong to Methanosaeta concilli and Syntrophobacter fumaroxidans, two organisms that have their genome sequenced. Syntrophobacter belongs to Deltaproteobacteria, however this group was not dominant in oleate incubation as determined by pyrosequencing results. Studying metaproteomes of complex microbial communities is still a big challenge especially because most of the genomes are not sequenced which hinders protein identification

Phase transition in exotic nuclei along the N=ZN=Z line

The abrupt structure change from the nuclei of $N=Z \le 35$ to those of $N=Z \ge 36$ is investigated by means of shell model calculations. The basic features of the even-even and odd-odd nuclei under consideration are nicely reproduced. A sudden jump of nucleons into the upper $g_{9/2}d_{5/2}$ shell at $N=Z=36$ is found to be the main reason that causes the qualitative structure difference. It is argued that the structure change can be viewed as a decisive change of the mean field, or a phase transition, along the $N=Z$ line.Comment: 4 pages, 5 figures, submitted to Phys. Rev. Let

Structure of isomeric states in 66As and 67As

Strong residual correlations between neutrons and protons in N ~ Z systems can lead to unusual structure. Using the spherical shell model, we show that a low-excitation shape isomer can occur in the odd-odd N=Z nucleus 66As. This extends the picture of shape coexistence beyond even-even nuclei. Furthermore, it is demonstrated that in 66As and in the N=Z+1 nucleus 67As, a new type of isomer, which we term j-isomer, can be formed. The underlying mechanism for the isomerism formation is structure change in the isomeric states, which involves either an alignment of a neutron-proton pair from the high-j intruder orbitals, or a simultaneous occupation of these neutron and proton high-j orbitals.Comment: 11 pages, 2 figure

Analyse du cycle de vie d'un système bioélectrochimique en tant que plate-forme technologique innovante pour la production d'acide succinique à partir de déchets

International audienceWaste management is a key environmental and socio-economic issue. Environmental concerns are encouraging the use of alternative resources and lower emissions to air, water and soil. Innovative technologies to deal with waste recovery that produce marketable bioproducts are emerging. Bioelectrochemical synthesis systems (BESs) are based on the primary principle of transforming organic waste into added-value products using microorganisms to catalyse chemical reactions. This technology is at the core of a research project called BIORARE (BIoelectrosynthesis for ORganic wAste bioREfinery), an interdisciplinary project that aims to use anaerobic digestion as a supply chain to feed a BES and produce target biomolecules. This technology needs to be driven by environmental strategies. Life Cycle Assessment (LCA) was used to evaluate the BIORARE concept based on expert opinion and prior experiments for the production of biosuccinic acid and waste management. A multidisciplinary approach based on biochemistry and process engineering expertise was used to collect the inventory data. The BES design and the two-step anaerobic digestion process have many potential impacts on air pollution or ecotoxicity-related categories. The comparison of the BIORARE concept with conventional fermentation processes and a water-fed BES technology demonstrated the environmental benefit resulting from the use of both the BES technology and a waste-based substrate as input thus supporting the BIORARE concept. Some trade-offs among the impact categories were identified but led to options to improve the concept. BES design and synergy management may improve the environmental performance of the BIORARE concep

MEMPHYS:A large scale water Cerenkov detector at Fr\'ejus

A water \v{C}erenkov detector project, of megaton scale, to be installed in the Fr\'ejus underground site and dedicated to nucleon decay, neutrinos from supernovae, solar and atmospheric neutrinos, as well as neutrinos from a super-beam and/or a beta-beam coming from CERN, is presented and compared with competitor projects in Japan and in the USA. The performances of the European project are discussed, including the possibility to measure the mixing angle $\theta_{13}$ and the CP-violating phase $\delta$.Comment: 1+33 pages, 14 figures, Expression of Interest of MEMPHYS projec

Functional analysis of syntrophic LCFA-degrading microbial ecosystems

ICBM 2014 - 2nd International Conference on Biogas Microbiology[Excerpt] Introduction and Aim: Long-chain fatty acids (LCFA) are present in lipid rich wastewater and can be converted to methane anaerobically, coupling wastewater treatment to bioenergy production. Differences in the degradation of saturated and unsaturated long-chain fatty acids (LCFA) by anaerobic consortia are not completely understood. Previous studies showed a segregation on the microbial community composition when the same inoculum sludge was incubated with saturated- or with unsaturated-LCFA (Sousa et al., 2007), suggesting differences in their degradation pathways. In order to get more insights on this and aiming linking microbial community structure to function, a comparative shotgun metaproteomics study of a mesophilic anaerobic sludge incubated with saturated- and unsaturated-LCFA was conducted. Additionally, the metaproteome of a defined co-culture of Syntrophomonas zehnderi and Methanobacterium formicicum growing on saturated- and unsaturated-LCFA to methane was also analyzed. [...]The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013, the project “BioEnv - Biotechnology and Bioengineering for a sustainable world”, REF. NORTE-07-0124-FEDER-000048” co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER and the project FCOMP-01-0124-FEDER-014784, financed by the FEDER funds through the Operational Competitiveness Programme (COMPETE) and by national funds through the FCT.info:eu-repo/semantics/publishedVersio