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International audience; Understanding the environmental profile of a product computed from the Life Cycle Assessment (LCA) framework is sometimes challenging due to the high number of environmental indicators involved. The objective here, in guiding interpretation of LCA results, is to highlight the importance of each impact category for each product alternative studied. For a given product, the proposed methodology identifies the impact categories that are worth focusing on, relatively to a whole set of products from the same cumulated database. The approach extends the analysis of Representativeness Indices (RI) developed by Esnouf et al. (2018). It proposes a new operational tool for calculating RIs at the level of impact categories for a Life Cycle Inventory (LCI) result. Impact categories and LCI results are defined as vectors within a standardized vector space and a procedure is proposed to treat issues coming from the correlation of impact category vectors belonging to the same Life Cycle Impact Assessment (LCIA) method. From the cumulated ecoinvent database, LCI results of the Chinese and the German electricity mixes illustrate the method. Relevant impact categories of the EU-standardized ILCD method are then identified. RI results from all products of a cumulated LCI database were therefore analysed to assess the main tendencies of the impact categories of the ILCD method. This operational approach can then significantly contribute to the interpretation of the LCA results by pointing to the specificities of the inventories analysed and for identifying the main representative impact categories.

Les ateliers d’engraissement porcins ont de forts impacts environnementaux. Une piste d’amélioration résidedans la conduite individuelle, en particulier pour programmer les départs à l'abattoir. Nous avons développé unmodèle capable i) de simuler les performances individuelles des porcs en interaction avec les pratiques del'éleveur et la conduite de l'élevage et ii) d'évaluer les résultats techniques, économiques et environnementauxde l’atelier. Les pratiques représentées dans le modèle ont été choisies à partir d'enquêtes en élevage (conduite en bandes, pratiques d'allotement et d'alimentation, pratiques de départ à l'abattoir et de gestion des porcs les plus légers). Un modèle individu-centré a été adapté du modèle InraPorc®. Les impacts environnementaux ont été calculés à partir des résultats de chaque porc par ACV. Le modèle a été étudié avec i) 8 simulations visant à évaluer l'intérêt de l'approche individu-centré pour estimer les résultats de l'atelier et ii) une évaluation par comparaison entre valeurs prédites et observées dans 21 ateliers d'engraissement. Les résultats montrent que les simulations avec variabilité inter-individus reproduisent mieux le fonctionnement de l'atelier, en particulier pour le poids d'abattage moyen, le nombre de départs à l'abattoir par bande et la marge de l'atelier. Le modèle a été calibré pour les 21 élevages enquêtés en 6 étapes. L'erreur de prédiction du modèle après calibration est inférieure ou égale à 2% de la moyenne pour le poids moyen d'abattage, le gain moyen quotidien, l'indice de consommation et le taux moyen de muscle des pièces. Le pourcentage de porcs abattus dans la gamme optimale de paiement reste moins bien prédit, en raison d’un manque d'information sur les pratiques d'alimentation et/ou sur la fiabilité de l'estimation du poids de chaque porc par l'éleveur. Ce modèle est en cours d'intégration dans un premier outil d'aide à la décision associé à une base de données de 480 simulations, à destination des conseillers en élevage. Une version future de l'outil permettra de faire directement les simulations souhaitées avec le modèle.

Sustainable structural design considers all actions and decisions pertaining to the economic, social and environmental impacts throughout the service life of a structure. For bridges, life-cycle analysis (LCA) includes an inspection and maintenance scenario for bridge components. The assessment of the average service life for each component is generally based on the experience of experts so that the applied measures and actions maintain the whole bridge in a good condition. However, this approach is limited. Firstly, defining a standard framework for maintenance does not take all uncertainties (epistemic and random) into account in terms of the degradation of different bridge components in varying types of environment. Secondly, some degradation processes accelerate or decelerate over time, so kinetic modelling is needed. Thirdly, it is not flexible enough to be included in an optimization process where different maintenance actions and intervals are sought (e.g. minimizing economic, environmental and societal impacts, maximizing accessibility and service level of a structure, etc.) while satisfying quality constraints. The approach proposed in this paper intends to resolve these three issues and is illustrated through the design of steel-concrete composite bridges.

Background: The parasite Varroa destructor represents a significant threat to honeybee colonies. Indeed, development of Varroa infestation within colonies, if left untreated, often leads to the death of the colony. Although its impact on bees has been extensively studied, less is known about its biology and the functional processes governing its adult life cycle and adaptation to its host. We therefore developed a full life cycle transcriptomic catalogue in adult Varroa females and included pairwise comparisons with males, artificially-reared and non-reproducing females (10 life cycle stages and conditions in total). Results: Extensive remodeling of the Varroa transcriptome was observed, with an upregulation of energetic and chitin metabolic processes during the initial and final phases of the life cycle (e.g. phoretic and post-oviposition stages), whereas during reproductive stages in brood cells genes showing functions related to transcriptional regulation were overexpressed. Several neurotransmitter and neuropeptide receptors involved in behavioural regulation, as well as active compounds of salivary glands, were also expressed at a higher level outside the reproductive stages. No difference was detected between artificially-reared phoretic females and their counterparts in colonies, or between females who failed to reproduce and females who successfully reproduced, indicating that phoretic individuals can be reared outside host colonies without impacting their physiology and that mechanisms underlying reproductive failure occur before oogenesis. Conclusions: We discuss how these new findings reveal the remarkable adaptation of Varroa to its host biology and notably to the switch from living on adults to reproducing in sealed brood cells. By spanning the entire adult life cycle, our work captures the dynamic changes in the parasite gene expression and serves as a unique resource for deciphering Varroa biology and identifying new targets for mite control.

L’alimentation du bétail est au cœur des problématiques environnementales des élevages. Pour les porcs et les volailles, elle explique entre 50 et 98% de leurs impacts environnementaux au portail de la ferme. Pour les bovins, leurs concentrés représentent 17% des 12.3 millions de tonnes d’aliments composés produits dans le Grand Ouest. Ainsi, cette étude évalue les bénéfices environnementaux associés à la production d’éco-aliments, c’est-à-dire d’aliments avec des impacts environnementaux réduits. Une base de données a été créée sur les impacts environnementaux de 150 intrants alimentaires du bétail calculés par Analyse de Cycle de Vie. Ces données ont été mobilisées dans une fonction multiobjectif pour formuler les aliments en prenant en compte des critères environnementaux en plus du critère prix habituel. Des bénéfices environnementaux et des coûts liés à ces éco-aliments ont été obtenus pour différentes stratégies alimentaires de porc à l’engrais, de poulet de chair, de vaches laitières et de jeunes bovins, à la tonne d’aliment et au kilogramme de produit. Une mise en œuvre à l’échelle du Grand Ouest considérant tous les aliments composés fabriqués et toutes les filières animales montre, à la tonne d’aliment moyen, une réduction possible du changement climatique de 7% pour un surcoût de 2%., Feeding is central for the environmental aspects of animal production. For pig and poultry, feeds explain between 50 and 98% of the environmental impacts of animal product at farm gate. For cattle, the concentrated feeds account for 17% of the 12.3 million tons of compound feeds produced in the West of [br/] France. This study looked at the environmental benefit of eco-feeds which are feeds with lower environmental impacts. A database was built concerning the environmental impacts of 150 feedstuffs calculated by Life Cycle Assessment. Those data were used in a multiobjective function in order to formulate feed with environmental criteria and the usual cost criteria. The environmental benefits and the costs due to eco-feed were obtained for different feeding strategies of fattening pigs, broilers, dairy cows and young cattle at the scale of the ton of feed and the kilogram of animal product. An implementation at territory scale was also performed in the West of France by considering all the feeds and the animal productions: the results showed for instance a possible reduction of 7% for the impact climate change of the average ton of compound feed for an extra cost of 2%.

Le cadre d'Analyse du Cycle de Vie (ACV) est une approche multicritères visant à évaluer tous les impacts environnementaux potentiels de toute activité humaine. Dans un cadre normalisé, une activité humaine est alors décrite sur toute sa chaîne de valeurs (de l'extraction des matières premières, en passant par le traitement des matières premières, la distribution, les étapes d'utilisation et la gestion des déchets) et toutes les émissions vers l'environnement ainsi que toutes les consommations de ressources, aussi nommées flux élémentaires, sont quantifiées et regroupées dans un Inventaire du Cycle de Vie (ICV). La traduction des flux élémentaires en un nombre réduit de scores ayant chacun une signification environnementale est effectuée lors de la phase d'Evaluation de l'Impact sur le Cycle de Vie (EICV) à l'aide des méthodes d’EICV. Cependant, la nature holistique de l'ACV, qui a entrainé le développement de nombreuses méthodes d’ECVI avec chacune un certain nombre de catégories d'impact environnemental, peut rendre non évidente la sélection d’une méthode d’EICV et des catégories d'impact pour le praticien ACV. En bénéficiant de regroupement d'ICVs au sein de base de données, ce travail de thèse a permis de développer un Indice de Représentativité (IR) qui évalue, d'un point de vue géométrique, l'adéquation des méthodes d’ECVI et de leurs catégories d'impact pour un ICV donné. Cette approche innovante repose sur la contextualisation des ICVs et des catégories d'impact par rapport à une base de données d’ICVs et sur une mesure angulaire au sein d’un espace vectoriel. La pertinence des résultats de l'IR est testée en analysant leurs tendances au sein d'une base de données et en l'appliquant à un cas d'étude sur la production d’un agro-carburant à partir de macro-algue., The Life Cycle Assessment framework (LCA) is a multi-criteria approach aiming to assess all the potential environmental impacts of any human activities. Within a standardized framework, a human activity is described throughout its values chain: from raw material extraction, through materials processing, distribution, use stages, to waste management. Then, all emission flows to the environment as well as all resource consumption flows, all defined as elementary flows, are quantified in a Life Cycle Inventory result (LCI). Translation of LCI results into a reduced number of scores that each has an environmental meaning is carried out at the Life Cycle Impact Assessment (LCIA) phase using LCIA methods. However, the holistic nature of LCA, which has induced the development of many different LCIA methods with quite a few environmental impact categories each, can make the LCIA method and impact categories selection challenging for LCA practitioners. By benefiting from a huge compilation of LCI results within cumulated LCI database, the present work develops the Representativeness Index (RI) that assesses, from a geometrical point of view, the appropriateness of LCIA methods and their impact categories for any LCI result. This innovating approach relies on the contextualization of LCI results and impact categories regarding a database and on an angular measurement within a vector space. The relevance of the RI results is tested by analysing RI trends from an entire database and by applying it to a biofuel study case.

International audience; Evaluating holistically environmental impacts of land planning policies implies to take into account several aspects, intimately related both to territorial features and to production-consumption patterns, which have a specific local character and a potential impact at different scales. To address these chal- lenges, life cycle thinking and assessment methods are crucial. Indeed, beyond the traditional application of Life Cycle Assessment as a product-oriented methodology, a new LCA-based approach called "terri- torial LCA" has gradually emerged to assess geographically or administratively defined systems. This paper aims to analyze how this new LCA-based approach differs from conventional LCA, highlighting main differences and added values. Territorial LCAs can be divided into two main approaches, i.e., i) type A, which focuses on the assessment of a specific activity or supply chain anchored in a given territory, and ii) type B, which attempts to assess all production and consumption activities located in a territory, including all environmental pressures embodied in trade flows with other territories. These two ap- proaches are described and compared according to the four LCA phases to highlight differences and similarities with conventional LCA. This comparison is based on a detailed case study analysis for each territorial LCA type and it shows that most of the differences are in the goal and scope definition, especially for the territorial LCA of type B where the functional unit definition is no more the starting point of the assessment. Concerning territorial LCA of type A, there are no main divergences with conventional LCA as territorial contextualization already exists in some LCA applications, even if not systematically applied. Improvements in the application may entail a comprehensive contextualization of the four LCA phases, developing the synergies with the use of Geographic Information System (GIS) tools. Other specific challenges affecting both type A and B are related to i) territorial unique intrinsic multi- functionality determined by all human activities located within its boundaries, ii) specific territorial characteristics (i.e., spatial variability and organization), and iii) multiscale issues and the consideration of interactions between territories.

The code to perform the simulations described in this paper is accessible on the ZENODO data warehouse (https://zenodo.org/record/890623#.WcuRoWekFcg).To view supplementary material for this article, please visit https://doi.org/10.1017/S1751731117002920; European pig production continues to encounter economic and environmental challenges. To address these issues, methods have been developed to assess performances of pig production systems. Recent studies indicate that considering variability in performances among pigs improves the accuracy and reliability of results compared with modelling an average animal. Our objective was to develop a pig fattening unit model able to (i) simulate individual pig performances, including their variability in interaction with farmers’ practices and management, and (ii) assess their effects on technical, economic and environmental performances. Farmer practices included in the model were chosen from a typology generated from on-farm surveys focused on batch management, pig allocation to pens, pig feeding practices, practices of shipping to the slaughterhouse, and management of the remaining pigs. Pigs are represented using an individual-based model adapted from the InraPorc® model. To illustrate the model’s abilities, four scenarios were simulated that combine two feed rationing plans (ad libitum, restricted to 2.5 kg/day) and two feed sequence plans (two-phase, 10-phase). Analysis of variance was performed on the simulated technical, economic and environmental indicators (calculated via Life Cycle Assessment). The feed rationing plan and feed sequence plan significantly affected all indicators except for the premium per pig, for which the feed sequence plan did not have a significant effect. The ‘restricted 10-phase’ scenario maximised gross margin of the fattening unit (14.2 €/pig) and minimised environmental impacts per kg of pig produced. In contrast, the ‘ad libitum two-phase’ scenario generated the lowest margin (8.20 €/pig) and the highest environmental impacts. The model appears to be a promising tool to assess effects of farmers’ practices, pig characteristics and farm infrastructure on technical, economic and environmental performances of the fattening unit, and to investigate the potential of improvement. However, further work is needed, based on virtual experiments, in order to evaluate the effects of a larger diversity of practices.

Purpose Despite the farm being considered by many as the most suitable level of decision-making and strategic management in agriculture, there is an increasing interest in evaluating agricultural management strategies at the regional level. Recent initiatives attempted to aggregate and generalise farm-level lifecycle inventory (LCI) data and lifecycle impact assessment (LCIA) results to describe the environmental performance of agricultural regions. This article describes our development and application of a regional statistics-based approach for constructing virtual representative farms (VRFs), representing dominant farm types for a given region, as a tool for comparing alternative regional agricultural strategies in contexts of insufficient farm (e.g. LCI) data. Methods Based on statistical sources, we constructed VRFs of the dominant farm types in the largely agricultural region of Brittany, France. Environmental impacts of different agricultural management strategies were estimated at the regional level by modelling the strategies as changes in VRF-based LCIs, calculating LCIAs and extrapolating their mean per-ha impacts to the total land use in the region. Based on this assessment, performed using a regional lifecycle assessment framework, we analysed relative environmental impacts of each management strategy on the region. A strategy-comparison table was built to allow decision makers to understand the potential regional environmental consequences of implementing each strategy. Results and discussion Once VRFs impact assessment results were extrapolated to the regional level, all strategies show environmental impacts per ha similar to those of the baseline, with differences ranging from −15 to +6%. The scenario featuring centralised fodder drying by 50% of cattle farms (50FOD) is the only one featuring surpluses for all products, due to associated cattle diet adjustments including reduced maize silage intake and partial substitution of concentrate feeds. The scenario featuring grass specialisation by all cattle farms (100GRA) shows a large deficit of grassland products, suggesting that a region-wide extensification strategy would not be self-sufficient. Conclusions The method developed enables comparing environmental consequences of region-wide implementation of agricultural strategies, yet, for our case study, it is particularly difficult to identify a “best” one. Nonetheless, the method serves as an initial step for preselecting strategies to investigate at a more detailed level. Prioritisation of a given strategy would likely be based on the environmental pressures considered most pressing by regional decision makers.

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]INSPIRE [ADD1_IRSTEA]Équiper l'agriculture; International audience; Mediterranean countries are undergoing dietary and nutritional changes that affect their inhabitants' health, while facing massive environmental challenges. The increasing demand of water in agriculture, the capacity to maintain local food production, and the growing dependence on food imports are interconnected issues that must be addressed to ensure food security and nutrition in the Mediterranean region. Here, we present the conceptual framework and methodologies developed by the MEDINA-Study Group for rethinking food systems toward sustainable consumption and production modes. Based on its multidisciplinary expertise, the MEDINA-Study Group designed a " fork-to-farm " multi-scale approach, stemming from current dietary habits and examining how some options to nutritionally improve these habits might affect the food systems. This approach was developed for research activities in the South of France and Tunisia, two areas with very different diet-agriculture-environment nexus. The conceptual framework is based on the analysis of elements of the food systems (from consumption to production) at different levels (individual, household, regional and national levels). The methods include: (i) modeling options of dietary changes at different scales, in order to nutritionally optimize food consumption-production without increasing the environmental impact, (ii) translating the best-choice changes into possible policy actions, (iii) testing the acceptability and feasibility of these actions with several stakeholders, and (iv) producing guidelines for sustainable food choices and production. The MEDINA-Study Group identified additional issues that could be included in a future framework to help designing ambitious agricultural, food and health policies in the Mediterranean region.

International audience; On a previous study, the carbon footprint (CF) of all production and consumption activities of Galicia, an Autonomous Community located in the north-west of Spain, was determined and the results were used to devise strategies aimed at the reduction and mitigation of the greenhouse gas (GHG) emissions. The territorial LCA methodology was used there to perform the calculations. However, that methodology was initially designed to compute the emissions of all types of polluting substances to the environment (several thousands of substances considered in the life cycle inventories), aimed at performing complete LCA studies. This requirement implies the use of specific modelling approaches and databases that in turn raised some difficulties, i.e., need of large amounts of data (which increased gathering times), low temporal, geographical and technological representativeness of the study, lack of data, and presence of double counting issues when trying to combine the sectorial CF results into those of the total economy. In view of these of difficulties, and considering the need to focus only on GHG emissions, it seems important to improve the robustness of the CF computation while proposing a simplified methodology. This study is the result of those efforts to improve the aforementioned methodology. In addition to the territorial LCA approach, several Input-Output (IO) based alternatives have been used here to compute direct and indirect GHG emissions of all Galician production and consumption activities. The results of the different alternatives were compared and evaluated under a multi-criteria approach considering reliability, completeness, temporal and geographical correlation, applicability and consistency. Based on that, an improved and simplified methodology was proposed to determine the CF of the Galician con- sumption and production activities from a total responsibility perspective. This methodology adequately reflects the current characteristics of the Galician economy, thus increasing the representativeness of the results, and can be applied to any region in which IO tables and environmental vectors are available. This methodology could thus provide useful information in decision making processes to reduce and prevent GHG emissions.

L'alimentation animale peut représenter de 30 à 95 % des impacts environnementaux des produits animaux en sortie de ferme. Des données d’impacts environnementaux des matières premières ont été publiées mais il n’existait pas de données adaptées aux productions françaises. Le projet ECOALIM propose une base de données d’impacts environnementaux des matières premières utilisées en alimentation animale en France (154 matières premières disponibles). Dans le projet, une méthodologie de formulation multiobjectif a été développée pour produire des éco-aliments à impacts réduits et à prix maitrisé. Les impacts des aliments calculés à la tonne d'aliment sont ainsi modifiés de − 6 à − 14 % en production de porcs charcutiers et de + 4 à − 18 % en poulet de chair selon l'impact considéré, par rapport à une formulation à moindre coût classique et en considérant la disponibilité actuelle des MP. Dans le même temps, le prix de l'aliment est augmenté en moyenne d'1% en porc charcutier et de 3 % en poulet de chair. En biphase, avec restriction en porc charcutier, les impacts du kg de poids vif en sortie de ferme sont alors réduits de − 2 % à − 10 %. En poulet de chair, avec une alimentation classique en 3 phases, les impacts du kg de poids vif en sortie de ferme sont quant à eux réduits de − 2 à − 14 % (sauf pour l’occupation des terres qui augmente de 3%). À l’échelle territoriale, la réduction des impacts des aliments n’excède pas − 10 % en raison des compétitions entre filières pour les matières premières à faibles impacts., Animal feeding accounts for 30 to 95 % of environmental impacts of animal products when leaving the farm. Data have been published so far but no data were available for the French context. The ECOALIM project produced a database on the environmental impacts of feed ingredients used for animal nutrition in France (154 feed ingredients). A methodology for multiobjective feed formulation has been developed to produce ecofeeds with reduced impacts and cost control. Feed impacts were modified by − 6 to − 14 % in growing pig production and by + 4 % to – 18 % in broiler production depending on the impact considered and relative to the lowest cost formulation and current availability of feed ingredients. Simultaneously, feed price was increased by 1 % on average in pig production and 3 % in broiler production. With restricted 2-phase feeding, the impacts of the kilogram of growing pig when leaving the farms were reduced by − 2 to – 10 %. With 3-phase feeding, the impacts of the kilogram of broiler when leaving the farm were reduced by − 2 to − 14 % (except for land occupation which was increased by + 3 %). At the regional scale, the reduction of feed impact did not exceed – 10 % due to competition for low impact feed ingredients between livestock supply chain.

International audience; Water utilities draw different water sources (surface and groundwater), including increased use of alternative sources (e.g. desalinated water, reused water, inter-basin water transfers) to supply freshwater to different users (domestic, agriculture, etc.). The combination of water sources and technologies (including infrastructures and energy) results in a regional water supply mix (WSmix) for each specific use. Existing Life Cycle Inventory (LCI) databases used in Life Cycle Assessment (LCA), do not include these mixes when modelling processes, leading to a poor representation of water supply systems and related environmental impacts. To fill this gap, this paper proposes a consistent framework for modelling a regional WSmix at worldwide scale. The WSmix framework includes the scope and system boundaries definition as well as a standardisation of terminology and classification of water sources and users. To facilitate implementation of theWSmix, this paper provides a worldwide database of water source mixes per user and a technology matrix linking water sources to water production technologies, including the connection with the local electricity mix. The relevance of including the WSmix in LCI databases for proper water-use impact assessment is demonstrated with an illustrative case study. The paper finally concludes on the need of using the regionalized WSmix in routine LCA, which is just as straightforward as the use of the regionalized electricity supply mix. Besides, the developed WSmix provides interesting insights beyond the LCA scope to support the strategic management of water sources at various scales including the global scale.

International audience; Over the past decade, the exponential growth in the production of biomass for energy use has raised concerns as to the environmental impacts of this type of land use, as well as the potential land-use changes (LUC) associated with an extension of agricultural land areas. Determining the environmental impacts of an expanding bioenergy sector requires reconstructing the chains of cause and effect from the determinants of land-use change (both direct and indirect) and land-use practices through to the impacts of those practices. Conducting an exhaustive literature review from 1975 to 2014, we identified 241 articles relevant to this causal chain, thus enabling an analysis of the environmental impacts of LUC for bioenergy. This chapter presents the results of a detailed literature analysis and literature review of the 52 articles within this corpus specifically addressing impacts on soils. The variation in soil organic carbon (SOC) is the most commonly used impact indicator, followed by soil loss to erosion and, to a lesser extent, the potential for environmental acidification as determined by life-cycle assessments. Background and transitional SOC levels during LUC affect the predictive value of estimated final SOC variations but are not generally accounted for in default static stock-difference approaches. Perennial crops tend to be better at maintaining or even improving SOC levels, but results vary according to pedoclimatic and agronomic conditions. The mechanisms involved notably include protection of the soil surface with a dense perennial cover and the limitation of tillage operations, especially deep plowing; accumulation of organic matter and SOC linked to biomass production, especially belowground production of rhizomes and deep, dense root systems; associated reductions in nutrient loss via runoff and erosion. Nevertheless, additional research is needed to improve our understanding of and ability to model the full range of processes underlying soil quality and LUC impacts on soil quality.

International audience; Many new damage oriented methods have recently been developed to address environmental consequences of water consumption in life cycle assessment (LCA). However, such methods can only partially be compared and combined, since their modelling structure and metrics are inconsistent. Moreover, they focus on specific water sources (e.g. river) and miss description of transport flows between water compartments (e.g. from river to atmosphere via evaporation) and regions (e.g. atmospheric advection). Consequently, they provide a partial regard of the local and global hydrological cycle and derived impacts on the environment. This paper proposes consensus-based guidelines for a harmonised development of the next generation of water consumption LCA indicators, with a focus on consequences of water consumption on ecosystem quality. To include the consideration of the multimedia water fate between compartments of the water cycle, we provide spatial regionalisation and temporal specification guidance. The principles and recommendations of the paper are applied to an illustrative case study. The guidelines set the basis of a more accurate, novel way of modelling water consumption impacts in LCA. Environmental relevance of this LCA impact category will improve. Yet, much research is needed to make the guidelines operational.

International audience; Waste 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 concept

Les ateliers d’engraissement porcins ont de forts impacts environnementaux. Une piste d’amélioration réside dans la conduite individuelle, en particulier pour programmer les départs à l'abattoir. Nous avons développé un modèle capable i) de simuler les performances individuelles des porcs en interaction avec les pratiques de l'éleveur et la conduite de l'élevage et ii) d'évaluer les résultats techniques, économiques et environnementaux de l’atelier. Les pratiques représentées dans le modèle ont été choisies à partir d'enquêtes en élevage (conduite en bandes, pratiques d'allotement et d'alimentation, pratiques de départ à l'abattoir et de gestion des porcs les plus légers). Un modèle individu-centré a été adapté du modèle InraPorc®. Les impacts environnementaux ont été calculés à partir des résultats de chaque porc par ACV. Le modèle a été étudié avec i) 8 simulations visant à évaluer l'intérêt de l'approche individu-centré pour estimer les résultats de l'atelier et ii) une évaluation par comparaison entre valeurs prédites et observées dans 21 ateliers d'engraissement. Les résultats montrent que les simulations avec variabilité inter-individus reproduisent mieux le fonctionnement de l'atelier, en particulier pour le poids d'abattage moyen, le nombre de départs à l'abattoir par bande et la marge de l'atelier. Le modèle a été calibré pour les 21 élevages enquêtés en 6 étapes. L'erreur de prédiction du modèle après calibration est inférieure ou égale à 2% de la moyenne pour le poids moyen d'abattage, le gain moyen quotidien, l'indice de consommation et le taux moyen de muscle des pièces. Le pourcentage de porcs abattus dans la gamme optimale de paiement reste moins bien prédit, en raison d’un manque d'information sur les pratiques d'alimentation et/ou sur la fiabilité de l'estimation du poids de chaque porc par l'éleveur. Ce modèle est en cours d'intégration dans un premier outil d'aide à la décision associé à une base de données de 480 simulations, à destination des conseillers en élevage. Une version future de l'outil permettra de faire directement les simulations souhaitées avec le modèle.

CICE 2018, 9th International Conference on Fibre-Reinforced Polymer (FRP) Composites in Civil Engineering, Paris, FRANCE, 17-/07/2018 - 19/07/2018; This paper presents some results obtained in the Infravation research project called 'Fast and effective solution for steel bridges life-time extension' (FASSTbridge). The aim of this project is to develop and demonstrate a reliable, preventive, cost-effective and sustainable solution for steel bridges fatigue life-time extension. Original sustainable preventive strengthening techniques will be tested to help postpone difficult, resource-consuming and costly retrofitting and repair interventions and demolitions of the steel and composite steel bridges stock. This paper addresses the definition of the needed data and the methodology for the realization of an actual cost-benefit analysis and a life cycle analysis of the CFRP solution compared with traditional techniques (use of steel plates) and considering the economic and environmental profit of the preventing policy.

Ce numéro comprend les articles correspondant aux présentations du Colloque Casdar 2018; Feeding is central for the environmental aspects of animal production. For pig and poultry, feeds explainbetween 50 and 98% of the environmental impacts of animal product at farm gate. For cattle, theconcentrated feeds account for 17% of the 12.3 million tons of compound feeds produced in the West of France. This study looked at the environmental benefit of eco-feeds which are feeds with lowerenvironmental impacts. A database was built concerning the environmental impacts of 150 feedstuffscalculated by Life Cycle Assessment. Those data were used in a multiobjective function in order toformulate feed with environmental criteria and the usual cost criteria. The environmental benefits andthe costs due to eco-feed were obtained for different feeding strategies of fattening pigs, broilers, dairycows and young cattle at the scale of the ton of feed and the kilogram of animal product. Animplementation at territory scale was also performed in the West of France by considering all the feedsand the animal productions: the results showed for instance a possible reduction of 7% for the impactclimate change of the average ton of compound feed for an extra cost of 2%.; L’alimentation du bétail est au cœur des problématiques environnementales des élevages. Pour lesporcs et les volailles, elle explique entre 50 et 98% de leurs impacts environnementaux au portail de laferme. Pour les bovins, leurs concentrés représentent 17% des 12.3 millions de tonnes d’alimentscomposés produits dans le Grand Ouest. Ainsi, cette étude évalue les bénéfices environnementauxassociés à la production d’éco-aliments, c’est-à-dire d’aliments avec des impacts environnementauxréduits. Une base de données a été créée sur les impacts environnementaux de 150 intrantsalimentaires du bétail calculés par Analyse de Cycle de Vie. Ces données ont été mobilisées dans unefonction multiobjectif pour formuler les aliments en prenant en compte des critères environnementauxen plus du critère prix habituel. Des bénéfices environnementaux et des coûts liés à ces éco-alimentsont été obtenus pour différentes stratégies alimentaires de porc à l’engrais, de poulet de chair, devaches laitières et de jeunes bovins, à la tonne d’aliment et au kilogramme de produit. Une mise enœuvre à l’échelle du Grand Ouest considérant tous les aliments composés fabriqués et toutes lesfilières animales montre, à la tonne d’aliment moyen, une réduction possible du changement climatiquede 7% pour un surcoût de 2%.

La capacité de prise en compte de la pluri-performance (environnementale, qualité des produits, économique) est un facteur clef de compétitivité des entreprises agricoles ; elle suppose de disposer de méthodes d’évaluation multicritère permettant l’évaluation conjointe de ces performances. L’objectif central du projet Qualenvic a été de développer une méthodologie d’évaluation multicritère (Contra Qualenvic) combinant évaluation de la performance environnementale et évaluation de la qualité des produits et appliquée à deux types de production : le lait de vache et le vin. La méthode a été éprouvée sur 30 exploitations laitières de Bretagne et du Cantal et sur 20 itinéraires techniques viticoles du Val de Loire et d’Alsace. L’évaluation environnementale a été réalisée par la méthode d’analyse de cycle de vie adaptée à chacune des filières et l’évaluation de la qualité conduite à travers un ensemble d’indicateurs spécifiques à chacun des produits évalués et définis avec des groupes d’experts scientifiques et professionnels. La méthode Contra Qualenvic mise en œuvre sur l’ensemble de nos cas d’étude a montré tout son intérêt dans la possibilité d’identifier les itinéraires techniques ou exploitations présentant les meilleurs « trade off » entre performance environnementale et qualité des produits. La méthode reste cependant à ajuster en adaptant notamment le système d’évaluation et de notation qui semble trop sévère pour l’instant, par exemple en qualité du lait (lait UHT et fromage) et qualité du raisin., The capacity of consideration of the multi-performance (environmental, quality of products, economic) is a key factor of competitiveness of the agricultural sector and requires assessment method multi-criteria allowing the joint evaluation of these performances. The central objective of the project Qualenvic was to develop a methodology of multi-criteria evaluation (Contra Qualenvic) combining evaluation of the environmental performance and quality of products applied to two types of production: cow milk and wine. The method was applied on 30 dairy exploitations of Brittany and Cantal and on 20 vine technical management routes of the Val de Loire and Alsace. The environmental assessment was performed by the method of life cycle analysis adapted to each sector and the evaluation of the quality driven through a set of indicators specific to each product estimated and defined with groups of scientific and professional experts. The implemented method Contra Qualenvic on the set of our study cases showed all its potential in the possibility of identifying the technical practices or the exploitations presenting the best "trade-off" between environmental performance and quality of products. The method remains however to be adjusted by adapting in particular the system of evaluation and scoring which seems too severe at the moment, for example as the milk (milk and cheese) and quality of the grape.

Vers un outil d'aide à la décision pour concilier qualité des produits animaux et environnement. Journées Francophones de Nutrition (JFN)

Masonry refers to the technique consisting in fitting blocks together, with or without a mortar. Masonry construction stands for an important part of built heritage, not only in the building sector, but also in transportation, energy or hydraulic infrastructure. However, the behaviour of these structures remains fairly unknown, which makes it difficult to maintain existing heritage, and promote the development of new construction. This habilitation thesis presents the research undertaken to enhance the knowledge of masonry structures in civil engineering. The first three chapters are dedicated to the development of models to characterise the mechanical performance of this type of structure, in terms of durability, using finite element method, or safety, based on yield design theory. The last chapter considers the environmental performance of masonry constructions, meeting eco-design requirements. Further perspectives on this work are given as a conclusion., Le terme maçonnerie désigne la technique de construction consistant en la pose de blocs, assemblés avec ou sans liant. Les constructions en maçonnerie représentent une part importante du patrimoine bâti, dans le domaine du bâtiment bien sûr, mais aussi dans celui des Infrastructures de transport, de l'énergie ou de l'hydraulique. Pourtant, le fonctionnement de ces ouvrages reste assez méconnu, ce qui rend difficile la gestion de l'existant et freine le développement de la construction neuve. Ce mémoire d'habilitation retrace les recherches entreprises pour apporter un éclairage sur le comportement des ouvrages en maçonnerie du génie civil. Les trois premiers chapitres sont consacrés au développement de modèles pour caractériser la performance mécanique de ce type de structures, que ce soit en termes de durabilité, par la méthode des éléments finis, ou de sécurité, en s'appuyant sur la théorie du calcul à la rupture. Le dernier chapitre amorce un virage dans ce travail, en engageant une réflexion sur la performance environnementale des constructions en maçonnerie au regard des exigences d'éco-conception. Ce travail s'achève sur les perspectives à venir dans un domaine en plein renouveau.

Some remote areas in Côte d’Ivoire are not covered by the interconnected grid. For these areas, the electricity needs of people are met by diesel generators. There are some risks with the use of diesel as fossil fuel such as the threat to the electricity supply of these areas and the increase of greenhouse gas emissions. These risks make alternative energy a major concern. Among the solutions that could be considered, we propose the jatropha biodiesel as energy source used in the diesel generators to produce electricity in these remote areas. However, it’s important before considering such a project to study its feasibility. It is the work dedicated to this thesis where the environmental and energy performances of jatropha biodiesel used as fuel by diesel generator have been studied through the life cycle assessment completed by an exergy analysis, technical analysis and economical analysis.; Les besoins en électricité des populations ivoiriennes vivant en milieu rural non couvert par le réseau électrique interconnecté sont satisfaits par des groupes électrogènes fonctionnant au gazole. L’utilisation de cette source d’énergie fossile comporte des risques à savoir la menace sur l’approvisionnement en électricité de ces zones et l’accroissement des émissions de gaz à effet de serre. Face à ces risques, la recherche de sources d’énergies alternatives reste une préoccupation majeure. Parmi les solutions, nous proposons comme source d’énergie d’utiliser le biodiesel de jatropha pour alimenter ces groupes électrogènes en zones rurales isolées. Cependant, avant d’envisager un tel projet, il importe d’en étudier la faisabilité et la pérennité. C’est le travail abordé dans cette thèse où les performances environnementales et énergétiques du biodiesel de jatropha utilisé comme combustible par un groupe électrogène servant à produire de l’électricité pour une localité ivoirienne isolée ont été étudiées à partir de la méthode de l’analyse du cycle de vie complétée par une analyse exergétique et une analyse technico-économique.

Human activities produce wastewater that generates sludge, a waste recycled on agricultural soils or for energy recovery. Extensive research is currently undergone on sludge to develop processes that can convert it into products with high-added value. In this context, sludge could move from a fatal waste status to the status of an expected co-product of wastewater treatment. This paradigm shift has implications for the assessment of environmental impacts of "sludge-based" materials with Life Cycle Assessment. Indeed, sludge becomes an expected co-product from the wastewater treatment plant and the environmental burden of their production must be distributed among co-products by means of an allocation factor. This thesis aims at defining a mathematical construction of this allocation factor by combining process- and product-related parameters, integrating de facto the causal relationships between process operations and products generation and the technological reality of the process. The result is a matrix of which each element associates, for each inventory data, an allocation factor to each of the generated co-products. Applied to the production of sludge-based phosphate fertilizers, LCA highlights the major contribution of the production stage compared to the stages of treatment and recovery of the sludge. Nevertheless, the method developed within this thesis to allocate an environmental load to each co-products of an indivisible production system paves the way for a more coherent environmental assessment of waste-based products. This methodology can also be used effectively in the environmental assessment of thermal, chemical or physical separation processes.; Les activités humaines produisent des eaux usées dont le traitement génère des boues d’épuration urbaines. Ces boues font l’objet de recherches visant à les transformer en produits à forte valeur ajoutée. Elles pourraient ainsi passer d’un statut de déchet fatal au statut de coproduit attendu à l’issue de l’épuration des eaux. Ce changement de paradigme a des conséquences sur l’évaluation environnementale par Analyse du Cycle de Vie (ACV) des produits « boue-sourcés ». La boue devient un coproduit attendu de la station de traitement des eaux et la charge environnementale liée à leur production doit pouvoir être répartie entre coproduits au moyen d’un facteur d’allocation. Cette thèse propose une construction mathématique de ce facteur d’allocation en combinant des paramètres « procédés » et « produits », intégrant de facto les relations causales entre conduite du procédé et obtention des produits, reflétant la réalité technologique du procédé. La résultante se présente sous la forme d’une matrice dont chaque élément associe, pour chaque donnée d’inventaire, un facteur d’allocation à chacun des coproduits générés. Appliquée à la production de fertilisants phosphatés boue-sourcés, l’ACV réalisée a permis de mettre en lumière la contribution majeure de l’étape de production par rapport aux étapes de traitement et valorisation de la boue. Cette méthodologie de construction d’un facteur d’allocation permet toutefois d’attribuer une charge environnementale à chacun des coproduits d’un système de production indivisible et peut également être utilisée de manière pertinente lors de l’évaluation environnementale des procédés de séparation de nature thermique, chimique ou physique.

Human activities produce wastewater that generates sludge, a waste recycled on agricultural soils or for energy recovery. Extensive research is currently undergone on sludge to develop processes that can convert it into products with high-added value. In this context, sludge could move from a fatal waste status to the status of an expected co-product of wastewater treatment. This paradigm shift has implications for the assessment of environmental impacts of "sludge-based" materials with Life Cycle Assessment. Indeed, sludge becomes an expected co-product from the wastewater treatment plant and the environmental burden of their production must be distributed among co-products by means of an allocation factor. This thesis aims at defining a mathematical construction of this allocation factor by combining process- and product-related parameters, integrating de facto the causal relationships between process operations and products generation and the technological reality of the process. The result is a matrix of which each element associates, for each inventory data, an allocation factor to each of the generated co-products. Applied to the production of sludge-based phosphate fertilizers, LCA highlights the major contribution of the production stage compared to the stages of treatment and recovery of the sludge. Nevertheless, the method developed within this thesis to allocate an environmental load to each co-products of an indivisible production system paves the way for a more coherent environmental assessment of waste-based products. This methodology can also be used effectively in the environmental assessment of thermal, chemical or physical separation processes.; Les activités humaines produisent des eaux usées dont le traitement génère des boues d’épuration urbaines. Ces boues font l’objet de recherches visant à les transformer en produits à forte valeur ajoutée. Elles pourraient ainsi passer d’un statut de déchet fatal au statut de coproduit attendu à l’issue de l’épuration des eaux. Ce changement de paradigme a des conséquences sur l’évaluation environnementale par Analyse du Cycle de Vie (ACV) des produits « boue-sourcés ». La boue devient un coproduit attendu de la station de traitement des eaux et la charge environnementale liée à leur production doit pouvoir être répartie entre coproduits au moyen d’un facteur d’allocation. Cette thèse propose une construction mathématique de ce facteur d’allocation en combinant des paramètres « procédés » et « produits », intégrant de facto les relations causales entre conduite du procédé et obtention des produits, reflétant la réalité technologique du procédé. La résultante se présente sous la forme d’une matrice dont chaque élément associe, pour chaque donnée d’inventaire, un facteur d’allocation à chacun des coproduits générés. Appliquée à la production de fertilisants phosphatés boue-sourcés, l’ACV réalisée a permis de mettre en lumière la contribution majeure de l’étape de production par rapport aux étapes de traitement et valorisation de la boue. Cette méthodologie de construction d’un facteur d’allocation permet toutefois d’attribuer une charge environnementale à chacun des coproduits d’un système de production indivisible et peut également être utilisée de manière pertinente lors de l’évaluation environnementale des procédés de séparation de nature thermique, chimique ou physique.

Trout farming is the main fish production system in France. This article describes a system to classify trout farms based on environmental impacts calculated by life cycle assessment and technical and economic indicators. Since the number of surveyed farms was too small for a robust assessment, we combined principal component analysis (PCA) with a non-parametric bootstrap technique. French trout farms were surveyed to collect technical and economic indicators. The representativeness of the survey was verified by comparing it to a national inventory. Life cycle assessment was used to estimate environmental impacts of farms and the contribution of each production stage to impacts. PCA was used to evaluate both technical-economic and environmental indicators of the trout farms, which were separated into three groups based on the size of fish produced (pan-size, large and mixed-size, and very large). Non-parametric bootstrap was used to compare the groups and to test the significance of PCA results. Results validated the fish-farm classification system based on the size of fish produced and indicated that farm operations and fish feeding contributed the most to environmental impacts. The PCA method distinguished three groups via their technical indicators, with non-significant differences among the groups in environmental impacts. However, environmental indicators showed strong links with technical and economic indicators. In conclusion, bootstrapped PCA offers the ability to assess groups of trout production system when the sample size is too small and provides more conservative results by considering uncertainty. Future studies should focus on providing reliable data to reduce uncertainty.[br/]

Currently, materials collected from end-of-life (EoL) products are recycled into raw material for reusing in a new production cycle. However, energy consumptions of recycling sectors remain important. The added values and energy used in the manufacture of original parts are also lost during the material recycling process. Nowadays, additive manufacturing techniques are sufficiently efficient and allow the manufacture of products with a material compatible with the use. Taking into account the performances of these techniques in a sustainable strategy can open the ways to modify parts and reuse them directly without returning to the raw material level. This thesis aims to develop a sustainable strategy, which allows giving a new life to an EoL part (or an existing part) by transforming it directly into a new part intended for another product. In order to develop such a strategy, the works of the thesis aims to solve the following scientific issues : the first scientific issue is related to the technological feasibility : is it possible to deposit material on an existing part using additive manufacturing technologies to obtain the new part with good material health ? This question is solved by carrying out an experimental study on the observation of microstructures and mechanical properties of the samples, which are manufactured by adding new features into an existing part in EBM. The second scientific issue is related to the study of the complete manufacturing chain from a technological point of view. How to design the process planning for additive and subtractive manufacturing combination to manufacture the expected part from the existing part ? To solve this question, a methodology to design the process planning for combining these manufacturing processes has been proposed based on the concept of additive manufacturing and machining features.The third scientific issue is linked to the sustainability and does the new strategy have advantages in comparison to the conventional strategy in terms of sustainability ? An approach based on the Life Cycle Assessment (LCA) method has also been developed to assess environmental impacts. The criteria for qualifying the domain of the proposed strategy vis-a-vis the conventional strategy were also identified, Actuellement, les matériaux collectés à partir de produits en fin de vie sont recyclés en matière première pour être réutilisés dans un nouveau cycle de production. Cependant, la consommation énergétique des filières de recyclage reste importante. Le processus du recyclage fait aussi perdre la valeur ajoutée et l’énergie utilisée durant la fabrication de pièces originales. Aujourd’hui, les techniques de fabrication additive sont suffisamment performantes et permettent une fabrication de produits avec un matériau compatible avec l’usage. La prise en compte des performances de ces nouvelles techniques dans une stratégie soutenable peut ouvrir des pistes pour modifier les pièces et les réutiliser directement sans retourner au niveau de matière première. Cette thèse a pour objectif de développer une stratégie soutenable, qui permet de donner une nouvelle vie à une pièce en fin de vie (ou une pièce existante) en la transformant directement en une nouvelle pièce destinée à un autre produit. Afin de développer une telle stratégie, les travaux menés de la thèse visent à résoudre les verrous scientifiques suivants :Le premier verrou scientifique est lié à la faisabilité technologique : est-il possible de déposer de la matière sur une pièce existante en utilisant les techniques de fabrication additive pour obtenir la nouvelle pièce avec une bonne santé de matière ? Cette question a été résolue en réalisant une étude expérimentale sur l’observation de microstructures et de propriétés mécaniques des éprouvettes, qui sont fabriquées par ajout de nouvelles entités sur une pièce existante en EBM. Le deuxième verrou scientifique est lié à l’étude de la chaîne complète de fabrication d’un point de vue technologique. Comment concevoir des gammes de fabrication en combinant intelligemment des opérations additives et soustractives pour obtenir la pièce attendue à partir de la pièce existante ? Une méthode de conception des gammes de fabrication combinant les procédés additifs et soustractifs a été proposée en s’appuyant sur le concept d’entités de fabrication additive et soustractive. Le troisième verrou scientifique est lié à la soutenabilité et la stratégie présente-t-elle des avantages par rapport à la stratégie conventionnelle en termes de soutenabilité ? Une approche s’appuyant sur la méthode d’Analyse du Cycle de Vie (ACV) a aussi été développée pour évaluer des impacts environnementaux. Des critères permettant de qualifier le domaine de la stratégie proposée vis-à-vis de la stratégie conventionnelle ont été identifiés

Feed production represents more than 70% of several environmental impacts estimated by Life Cycle Assessment (LCA) in pig (P) and broiler (B) productions. Yet, least cost feed formulation (LCF) is not relevant to reduce the environmental impacts of P and B feeds. Optimising feed composition while taking into account environmental impacts of feedstuffs (FS) is a way to do so. This study describes a new method, multiobjective formulation (MOF), based on the simultaneous use of an economic index (based on feed cost) and an environmental index (using LCA impacts) in a single objective function to minimize. A weighting coefficient (α) allows giving more or less influence to these indexes. The best trade-off was considered to be reached for an optimal weighting coefficient (αopt) set to be the coefficient beyond which the marginal increase of the economic index exceeds the marginal decrease of the environmental index. In the actual French context of FS availability, important reductions in impacts of P and B feeds were achieved with MOF in comparison with LCF. In B, at αopt, reductions by 12, 18, 7, 4, and 12% were achieved for ‘climate change’ (CC), ‘non-renewable energy use’, ‘eutrophication’, ‘acidification’ and ‘phosphorus consumption’ impacts, respectively, for an extra cost of 3%. In P, similar reductions of these impacts were achieved at αopt: -14, -13, -11, -7, and -6%, respectively, for an extra cost of 1%. For ‘land occupation’ impact, MOF had little effect in B (+4%) whereas in P, it decreased by 13%. LCA impacts at farm gate of one kg of live weight of B and P fed with these eco-feeds were also assessed. They confirmed that MOF reduces the environmental impacts of P and B productions (e.g. for CC, -7 and -10%, respectively) without pollution swapping and with moderate extra costs (e.g. +1% and +2% in P and B, respectively). Greater reductions of impacts are even possible when FS availabilityis less limiting (e.g. -19% for CC in B), questioning the actual availability of low-impact FS such as pea or sorghum.

Optimization of feeding strategies (S) is an effective option to reduce the environmental impacts of livestock. Itcan be performed, by using multi-objective feed formulation (MOF) to select feedstuffs according to their priceand environmental impacts, and by adapting dietary composition to animal requirements during the rearing period. This study investigates the combination of those feeding strategies on the environmental impacts of pig (P) and broiler (B) productions. Different S for conventional farms were specified in B and for fattening period in P. In P, the S were: 2-phases feeding (S1); multiphase feeding with two (S2) or four (S3) pre-diets, mixed together in different proportions during time; and 2-phases feeding with a reduction of energy (S4) or amino acid (S5) content. In B, the S were: 3-phases feeding (S6) and 3-phases feeding with lysine and energy contents respectively increased and decreased (S7). For each S, feeds were formulated using least-cost optimization (LC) and MOF. The environmental impacts of the kg of BW at farm gate were assessed by Life Cycle Assessment and compared to the reference scenarios: LC-S1 and LC-S6 for P and B, respectively. S with LC formulation showed impacts between -19% and +13% compared to the reference impacts. MOF reduced impacts per kg of feed by up to 30%, and final impacts per kg of BW by 1 to 20%, except for Acidification and Climate Change (S4), and for Land Occupation (S7). Three criteria explain these contrasted results among S and LCA impacts at the kg of BW scale. The first one is the contribution of feed to impacts per kg of BW (34% to 98%). The second one is feed conversion ratio as it reflects the overall efficiency of the system, and thus impacts nutrient excretion and manure gas emission. The last one is nutritional balance of feed (protein, amino acids composition), explaining nitrogen excretion (S2, S3). This study underlines the need for optimizing S while considering simultaneously the consequences on economics and environmental performances at animal scale.

The global consumption of carbon-fiber reinforced plastic (CFRP) is constantly growing since the last decade, leading to the need to create a recycling sector able to manage the amount of carbon fibers currently consumed and representing the amount of waste to be treated in the future. This thesis focus on the creation of a methodology for evaluating the sustainability potential for the implementation of a carbon fiber reinforced plastics recycling (CFRP) sector. CFRP coming from the aeronautics sector as well as other sectors such as the automobile and wind-energy industries. This methodology aims at identifying the most relevant indicators and associated methods, but also aims at the creation and adaptation of indicators to best assess the environmental and socioeconomic impacts of this recycling sector. The final result of this work, is the creation of a sustainability assessment methodology dedicated to the carbon fiber recycling sector, considering the different sustainability pillars. However this methodology also define more widely a tool that helps to identify sustainability performance indicators and that can be applied to other sectors if necessary.; La consommation globale de plastique renforcé de fibres de carbone (PRFC) est en constante augmentation, ce qui induit la nécessité de créer un secteur de recyclage capable de traiter l’ensemble des fibres de carbone actuellement consommées et qui représente la quantité de déchets à traiter en devenir. Cette thèse porte sur le développement et l'application d’une méthodologie d’évaluation multicritère du développement durable pour la création d’une filière de recyclage des plastiques renforcés de fibres de carbone (PRFC) issus du secteur aéronautique, mais aussi des autres secteurs consommateurs de fibres de carbone tels que l’automobile et l’éolien. Cette méthodologie a pour but d’identifier les indicateurs les plus pertinents ainsi que les méthodes qui leurs sont associés, c'est-à-dire qu’elle vise à la création et l’adaptation d’indicateurs clé de performance du développement durable pour caractériser au mieux les impacts environnementaux et sociaux-économique de cette filière de recyclage. Le résultat final de ce travail est la création d’une méthodologie d’évaluation du développement durable dédiée à la filière de recyclage des fibres de carbone par la considération des différents aspects de celui-ci. Cette méthodologie, aidant à l’identification et la définition des indicateurs clé de performances du développement durable peut être aussi appliquée à d’autres secteurs souhaitant s’implanter en suivant les principes de ce développement.

Environmental policies often include exemptions for some firms, e.g. the small emitters. This paper explores the implications of such exemptions in the case of an emission tax, and in the presence of monitoring, reporting, and verification (MRV) costs. We develop an analytical framework capturing the trade-off between the cost-effectiveness of a broader tax base, and the savings on MRV costs enabled by a partial coverage. Second-best partial coverage is defined by a threshold value of some characteristic of the firms below which firms are exempted. We characterize the optimal threshold and discuss its welfare implications. Since determining this threshold is demanding in terms of information regarding firm-level MRV and abatement costs, we show how limited knowledge about these costs at the aggregate level can be used in practice to approximate the optimal threshold. We apply this framework to assess the welfare implications of such an instrument in the case of greenhouse gas emissions from European agriculture. The findings indicate that exempting the small emitters may provide significant savings on MRV costs compared to the full coverage, while still incentivizing cost-effective reductions in emissions.

Environmental impacts of livestock systems, especially pig production, have come under increasing debate in recent years. The challenge is in meeting the growing demand for food at an affordable cost, without compromising environmental integrity. Previous studies have shown that feed production is responsible for the majority of CO2-eq. emission resulting from pig farming systems. This seems to indicate that feed strategies could be an effective tool to achieve the sustainability of the pork chain. Therefore, dietary crude protein reduction, through the addition of industrial amino acids, lessens the nitrogen excretion by pigs and, consequently, could mitigate the effects on the environment of pig production. In this sense, to effectively evaluate the environmental impacts of pig production systems, life cycle assessment has been widely used in agriculture, but the effects of feed are still understudied in Brazilian conditions. Owing to the importance and the great concern in this research area, we presented in this paper an updated review focusing on the nutritional techniques and their potential to reduce the global warming potential of pig production, considering both the direct effects, related to the choice of feed ingredients and the indirect effects, related to changes in the efficiency of use of nutrient by the animals., O impacto ambiental da produção animal, especialmente da suinocultura, vêm sendo objeto de crescente debate nos últimos anos. O desafio é atender a crescente demanda por alimentos a um custo acessível, mas sem comprometer a integridade ambiental. Estudos vêm demonstrando que a produçao de rações é responsável pela maior parte das emissões de CO2-eq. do sistema de produção de suínos. Isso parece indicar que estratégias de alimentação podem ser ferramentas eficientes para alcançar a sustentabilidade da cadeia suinícola. Dessa forma, a redução do conteúdo de proteína bruta da dieta através da inclusão de aminoácidos industriais, leva à diminuição da excreção de nitrogênio em suínos e, consequentemente, pode mitigar o impacto ambiental do sistema de produção de suínos. Neste sentido, para avaliação efetiva do impacto ambiental do sistema produtivo, a análise do ciclo de vida vem sendo amplamente utilizada na agricultura, mas os efeitos da alimentação ainda são pouco estudados nas condições brasileiras. Devido a importância e a grande preocupação nesta área de pesquisa, este artigo trás uma revisão atualizada com foco nas técnicas de nutrição e principalmente no seu potencial em reduzir o potencial de aquecimento global da produção de suínos, considerando ambos os efeitos diretos, relacionados à escolha dos ingredientes da ração, e os efeitos indiretos, relacionados às mudanças na eficiência de uso de nutrientes pelos animais.

This thesis investigates the environmental impacts of an emerging renewable energy technology, the enhanced geothermal systems (EGS), using a life cycle assessment (LCA) approach.Following the analysis of several EGS case studies, we developed a parameterized LCA model able to provide a global overview of the life cycle impacts of the EGS technology. The greenhouse gas emissions of EGS are found comparable with other renewable energy systems and far better than those of power plants based on fossil fuels.In a second stage, we developed a methodological framework for the application of global sensitivity analysis (GSA) to the LCA of emerging technologies like the EGS, taking into account the high uncertainties related to their description. We applied our new GSA approach to generate a simplified LCA model, aimed at decision makers, allowing a rapid estimation of the life cycle impacts of EGS from only five key parameters: installed capacity, drilling depth, number of wells, flow rate and lifetime.The methodological approach developed in this thesis is applicable to other technologies and opens large research perspectives in the field of environmental assessment.; Cette recherche vise à étudier les impacts environnementaux d'une technologie émergente de production d’électricité basée sur une source renouvelable, les systèmes géothermiques stimulés (EGS), par l’analyse de leur cycle de vie (ACV).Après avoir analysé plusieurs études de cas, nous avons développé un modèle ACV paramétré capable de caractériser les performances environnementales de la filière EGS. Nos résultats montrent que les émissions de gaz à effet de serre des EGS sur leur cycle de vie sont bien inférieures à celles des centrales utilisant des combustibles fossiles.Dans un deuxième temps, nous avons mis au point un cadre méthodologique pour appliquer l'analyse de sensibilité globale (GSA) à l’ACV des technologies émergentes comme les EGS, prenant en compte les incertitudes élevées liées à leur caractère innovant. Nous avons appliqué notre nouvelle approche GSA pour développer un modèle ACV simplifié, à destination des décideurs, permettant une estimation rapide des impacts des EGS à partir de seulement cinq paramètres clefs: capacité installée, profondeur de forage, nombre de puits, débit géothermal et durée de vie.L'approche méthodologique développée dans cette thèse est applicable à d'autres technologies et ouvre de larges perspectives de recherche dans le domaine de l'évaluation environnementale.

This thesis investigates the environmental impacts of an emerging renewable energy technology, the enhanced geothermal systems (EGS), using a life cycle assessment (LCA) approach.Following the analysis of several EGS case studies, we developed a parameterized LCA model able to provide a global overview of the life cycle impacts of the EGS technology. The greenhouse gas emissions of EGS are found comparable with other renewable energy systems and far better than those of power plants based on fossil fuels.In a second stage, we developed a methodological framework for the application of global sensitivity analysis (GSA) to the LCA of emerging technologies like the EGS, taking into account the high uncertainties related to their description. We applied our new GSA approach to generate a simplified LCA model, aimed at decision makers, allowing a rapid estimation of the life cycle impacts of EGS from only five key parameters: installed capacity, drilling depth, number of wells, flow rate and lifetime.The methodological approach developed in this thesis is applicable to other technologies and opens large research perspectives in the field of environmental assessment.; Cette recherche vise à étudier les impacts environnementaux d'une technologie émergente de production d’électricité basée sur une source renouvelable, les systèmes géothermiques stimulés (EGS), par l’analyse de leur cycle de vie (ACV).Après avoir analysé plusieurs études de cas, nous avons développé un modèle ACV paramétré capable de caractériser les performances environnementales de la filière EGS. Nos résultats montrent que les émissions de gaz à effet de serre des EGS sur leur cycle de vie sont bien inférieures à celles des centrales utilisant des combustibles fossiles.Dans un deuxième temps, nous avons mis au point un cadre méthodologique pour appliquer l'analyse de sensibilité globale (GSA) à l’ACV des technologies émergentes comme les EGS, prenant en compte les incertitudes élevées liées à leur caractère innovant. Nous avons appliqué notre nouvelle approche GSA pour développer un modèle ACV simplifié, à destination des décideurs, permettant une estimation rapide des impacts des EGS à partir de seulement cinq paramètres clefs: capacité installée, profondeur de forage, nombre de puits, débit géothermal et durée de vie.L'approche méthodologique développée dans cette thèse est applicable à d'autres technologies et ouvre de larges perspectives de recherche dans le domaine de l'évaluation environnementale.

International audience; Reducing the environmental impact of animal products is a major challenge for animal production chains. Tohandle strategies of impact mitigation, it is necessary to have accurate references on environmental impact offeed ingredients (FI) utilized in animal nutrition. The ECOALIM database provides life cycle inventories andenvironmental impact of FI utilized in France. Based on life cycle assessment methodology, it calculates theimpacts on climate change, eutrophication, acidification, non-renewable energy use, phosphorus consumptionand land use for different system boundaries: at the field gate, stored agencies gate, harbour gate, and production plant gate. Technical data from 2008 to 2012 were utilized. The database contains 150 values including 62 national average FI, 27 variants and 10 foreign FI. The impacts of average FI are consistent with our expert knowledge and international bibliography. The utilization of technical leverages should be chosen in accordance with the environmental issue at the local level. The ECOALIM database relies on precise and homogenous data. It provides for the first time to our knowledge all the minor components and allows to construct full formulas and to investigate innovative feed formulas accounting for economic and environmental criteria. These values will be incorporated into the next tables of composition INRA-AFZ as well in the European environmental database for animal nutrition (GFLI).; La réduction des impacts environnementaux des produits animaux est un enjeu important pour les filièresanimales. Pour raisonner les stratégies de réduction des impacts des aliments, il est nécessaire de disposer deréférences fiables d’impacts environnementaux des matières premières (MP). La base de données ECOALIMfournit les inventaires de cycle de vie et les impacts environnementaux des MP utilisées pour l’alimentationanimale en France. Elle repose sur la méthodologie d’Analyse du Cycle de Vie, et calcule les impactschangement climatique, eutrophisation, acidification, consommation d’énergie non renouvelable, consommationde phosphore et occupation des terres pour différents périmètres : sortie champ, sortie organisme stockeur, rendu port français et sortie usine de production. Les données techniques de la période 2008-2012 ont été utilisées. La base de données contient 150 valeurs dont 62 MP moyennes, 27 valeurs de déclinaisons et 10 MP étrangères. Les impacts moyens des matières premières sont cohérents avec la bibliographie. La base de données ECOALIM repose sur des données précises et homogènes. Elle fournit pour la première fois l’ensemble des produits minoritaires (soja français, sorgho français…) et permet ainsi de réaliser des formules complètes en France et d’explorer des formules innovantes d’aliments, prenant en compte des critères économique et environnementaux. Ces valeurs seront incluses dans la prochaine version des tables nutritionnelles INRA-AFZ et dans la base de données européenne pour l’alimentation animale (GFLI).

Multiobjective formulation (MOF) of feed is based on the use of an economic indicator (feed price) andenvironmental indicators (LCA impacts) simultaneously in a single objective function to minimize. Such amethod allows the simultaneous decrease of several environmental impacts associated to the production ofpoultry feed, with a limited impact on feed cost. In order to conclude on the final benefits of this method,economic and environmental consequences at product scale should be studied. 120 broiler diets were formulatedusing MOF. Economic and environmental consequences of these diets were then assessed for one ton of liveweight at farm gate using a production cost simulator and Life Cycle Analysis, respectively. Results confirm thatfeed production is the main contributor to several environmental impacts (phosphorus consumption, 97%; landoccupation, 87%; climate change, 80%; energy use, 75%; eutrophication, 63%) and production cost of livebroiler (52%). When animal performance is not modified by nutritional characteristics of feed, the economic andenvironmental optimum identified at feed scale during MOF is the same at product scale. Moreover, the decreaseof environmental impacts at product scale is directly proportional to the decrease at feed scale using MOF (theproportionality coefficient being the contribution of feed to the total impact). MOF of feed is thus a relevantmethod to reduce environmental impact of poultry production.; La formulation multiobjectif (FMO) permet de formuler des aliments en minimisant une fonction objectifincluant le prix de l’aliment et des impacts environnementaux de l’aliment. Ainsi, il devient possible de réduireconjointement plusieurs impacts environnementaux associés à la production d’aliments pour volaille, avec unimpact modéré sur le prix de l’aliment. Cependant, pour pouvoir conclure sur les bénéfices finaux de cetteapproche, les conséquences sur les performances économiques et environnementales du produit final doivent être évaluées. Un total de 120 aliments moyens pour poulet de chair, a ainsi été formulé à l’aide de la FMO. Les conséquences environnementales et économiques de ces aliments ont ensuite été évaluées à l’échelle de la tonne de poulet de chair vif, à l’aide respectivement de la méthode d’Analyse du Cycle de Vie et d’un calculateur du coût de production. Les résultats confirment la contribution majoritaire de la fabrication d’aliment pour la plupart des impacts environnementaux (consommation de phosphore, 97% ; occupation des terres, 87% ; changement climatique, 80% ; consommation d’énergie, 75% ; eutrophisation : 63%) et pour le coût deproduction du poulet vif (52%). Lorsque les performances des animaux ne sont pas modifiées (i.e. pas demodification des caractéristiques nutritionnelles de l’aliment), l’optimum économique et environnementalidentifié à l’échelle de l’aliment lors de la FMO est le même à l’échelle du produit final. La réduction desimpacts environnementaux à l’échelle du produit est par ailleurs directement proportionnelle à celle permise par la FMO des aliments (le coefficient de proportionnalité étant égal à la contribution de l’aliment à l’impact final). Ainsi, la FMO des aliments est une approche pertinente pour réduire les impacts environnementaux de la production avicole.

International audience; Nowadays, eco-designing products is increasingly practiced. The next challenge for sustain- ability is to optimize production processes. Biorefi neries are particularly concerned with this improve- ment, because they use renewable resources. To identify the contribution of transformation processes to the overall environmental impacts, Life Cycle Assessment (LCA) appears as the adequate method. A literature review highlights that LCA is mainly performed on biorefi neries to compare biomass feed- stocks between them and to a fossil reference. Another part of environmental LCA compares the impacts of different processing routes. Nevertheless, these evaluations concern already designed pro- cesses. Generally, processes are considered as a unique operation in assessments. However, some criteria like operating can notably modify environmental burdens. The eco-design of biorefi nery pro- cesses can be guided by coupling process simulation to LCA. This method has been emerging in the chemical sector in recent years. Consequently, this paper proposes a new methodological approach to assessing the complete sustainability of biorefi nery processes, since its fi rst design stages. In addi- tion to coupling process simulation and environmental LCA, the other pillars of sustainability will be assessed. Indeed, Life Cycle Costing and Social Life Cycle Assessment can be performed to obtain an integrated methodological framework. The simultaneous optimization of the environmental, economic, and social performances of the process can lead to antagonist ways of improving. Consequently, compromises should be realized. Thereby, the multi-objective optimization can be accomplished by a metaheuristic method supported by a decision-making tool. Finally, the main limits of this method and some perspectives and ways for improving are discussed.

Modeling of recycling – and allocation in general – is a heavily debated topic in the Life Cycle Assessment (LCA) domain. This thesis aimed to find a coherent scientific approach to model recycling in LCA that provides relevant information to companies. Existing allocation procedures are captured by mathematical formulas and linked to an LCA goal and an attributional or consequential approach in a systematic framework. A review of official guidelines showed that none of them provides recommendations on allocation that is consistent with this framework. A partitioning approach was identified for attributional LCA (a-LCA). This approach is based on subjective assumptions, which are made explicit by axioms. In consequential LCA (c-LCA), the market-price ratio between the recycled and substituted primary material is introduced as a new indicator to identify whether additional recycling substitutes the production of primary materials or avoids waste treatment. The processes that are affected by a changing demand for a product are identified by a causal loop diagram, which also includes stockpiling as a new element in c-LCA. The application of the allocation procedures is demonstrated by a case study of the recycling of rare earth elements (REEs) from used fluorescent lamps. The a-LCA indicated that recycled REEs are more sustainable than primary REEs. The c-LCA showed that recycling is environmentally beneficial as long as the REEs are used in fluorescent lamps that substitute less energy-efficient halogen lamps. This demonstrates that both LCA approaches provide different but useful information for companies. Suggestions are given for policy measures when the market situation does not stimulate environmentally beneficial behavior. It is recommended, among other options, to extend the causal loop diagram of c-LCA to include additional mechanisms, such as rebound effects.; La modélisation du recyclage - et l'allocation en général - est un sujet très débattu dans le domaine de l’analyse du cycle de vie (ACV). Cette thèse a pour objectif le développement d’une approche scientifique et cohérente pour la modélisation du recyclage en ACV afin de fournir des informations pertinentes aux entreprises. Ainsi, un cadre systématique est établi pour catégoriser les procédures d'allocation existantes en fonction de l’objectif de l’ACV et de l’approche attributionelle (ACV-A) ou conséquentielle (ACV-C). Une revue critique des directives officielles a montré qu'aucun d'entre elles ne recommande des procédures d’allocation conforme à ce cadre. L’approche d’imputation basée sur un schéma axiomatique qui explicite toute hypothèse subjective a été identifiée comme la méthode la plus pertinente pour l’ACV-A. Dans le cas de l'ACV-C, le ratio entre le prix du marché du matériau recyclé et celui du matériau primaire substitué est présenté comme un nouvel indicateur pour identifier si le recyclage permet de substituer la production de matériau primaire ou d’éviter son traitement en tant que déchet. Les processus qui sont affectés par une demande changeante pour un produit sont identifiés avec un diagramme de boucle causale, qui inclut également les stocks anthropiques comme un nouvel élément dans l’ACV-C. L'application des procédures d’allocation est démontrée par une étude de cas portant sur le recyclage des éléments de terres rares (ETR) des lampes fluorescentes. Les deux approches d’ACV fournissent des informations différentes et utiles aux entreprises.

Life cycle assessment (LCA) has been used in many studies to evaluate the effect of feeding strategy on the environmental impact of pig production. However, because most studies have been conducted in European conditions, the question of possible interactions with the context of production is still under debate. The objective of this study was to evaluate these effects in two contrasted geographic contexts of production, Brazil and France. The LCA considered the process of pig fattening at the farm gate, including production of feed, rearing of animals, and manure management. The functional unit considered was one kg of body weight gain. Performance of pigs was simulated for each scenario using the InraPorc® population model (1000 castrated males and 1000 females per scenario). The scenarios combined in each country 4 feeding programs (2-phase, 4-phase, multiphase and precision feeding), 12 formulation strategies (2 protein sources x 2 origins of soybean x 3 levels of amino acid (AA) addition). The results indicate that for some impacts there are clear interactions between effects of feeding program, origin of soybean and location of production. For climate change, the interest of phase feeding and incorporation of AA is limited and even counterproductive in Brazil when using soybean from South (without deforestation), whereas it is a more interesting strategy in Europe, and in all situations with soybean from Center West (with deforestation). Rather similar effects, as for climate change, were observed for cumulative energy demand. Conversely, potential eutrophication and acidification impacts were reduced by phase feeding and AA addition in a similar way in all situations. For all impacts, precision feeding was the most effective approach for reducing the LCA impacts of pig fattening.; Différentes études récentes ont évalué par analyse de cycle de vie (ACV) les effets de l'alimentation sur les impacts environnementaux de la production porcine. Cependant, la plupart de ces études ont été conduites en Europe et la question des interactions avec le contexte de production reste posée. L'objectif de ce travail était d'évaluer ces effets dans deux situations contrastées, le Brésil et la France. L'ACV considérait la phase d'engraissement des porcs jusqu’à la porte de l'élevage : production des aliments, élevage des animaux, gestion des effluents, l'unité fonctionnelle étant un kg de gain de poids vif. Les performances des animaux étaient simulées à l'aide du modèle population d’InraPorc® (1000 mâles castrés et 1000 femelles par scénario). Les scénarios testés combinaient, dans chaque pays, quatre programmes d'alimentation (2 phases, 4 phases, multiphase, alimentation de précision), 12 modalités de formulation (2 sources de protéines x 2 origines du soja x 3 niveaux d'addition d'acides aminés(AA)). Les résultats montrent des interactions significatives entre programme alimentaire, origine du soja et localisation de la production. Pour l'impact changement climatique, l'intérêt de l'alimentation par phases et de l'addition d'AA est limité et même contreproductif au Brésil lorsque le soja provient du sud (sans déforestation), alors que c'est une stratégie intéressante en Europe et, dans tous les cas, lorsque le soja provient du centre-ouest, avec déforestation. Des effets similaires sont observés pour la demande en énergie. A l'inverse, l'alimentation par phases et l'addition d'AA réduisent significativement les impacts eutrophisation et acidification, de la même manière dans les deux pays. Pour tous les impacts, l'alimentation de précision est toujours la stratégie la plus efficace pour réduire les impacts environnementaux.

The production of feed ingredients for pig feeds has a major contribution to climate change, energy use and the land occupation impacts of the animal products. Nonetheless, the traditional least-cost (LC) feed formulation methods minimize the cost of the feed mix, without consideration of its environmental impacts. The objective of this study was to estimate the potential mitigation of environmental impacts calculated by Life Cycle Assessment through a multi-objective formulation (MinMO) of pig feeds. The linear programming model built searches the best feed formula under nutritional constraints with a multi-objective function including an economic price index and an environmental impact index. A weighting coefficient α of the environmental index and (1-α) of the price index has been included for the objective function. Impact values of feed ingredients came from the ECOALIM dataset of AgriBalyse® v1.3. Growing and finishing feeds were formulated within two scenarios of feed ingredient availability (current limited LIM, increased NLIM) with LC formulation and MinMO formulation. In NLIM-LC vs. LIM-LC the environmental index is reduced on average by 3% and the price index by 1%. In MinMO with α=0.5 vs. LC, the environmental index of both feeds decreases by 10% in LIM and 22% in NLIM. Simultaneously, the price of the feed mix increases by 1.5% in LIM and 1.7% in NLIM.For α higher than 0.5, the environmental index is not further reduced. Multi-objective formulation of pig feeds may be an efficient method to produce low-impact feeds. Further work will account for the additional needs for some feed ingredients and possible interactions with the requirements for the other livestock species, at the territory level.; Les matières premières (MP) utilisées dans l’alimentation contribuent majoritairement aux impacts changement climatique, consommation d’énergie et utilisation des terres du kg de porc produit. La méthode traditionnelle de formulation (MinPrix) minimise le coût du mélange des MP, sans considérer les impacts environnementaux. L’objectif de cette étude était de développer une méthode de formulation multiobjectif (MinMO) minimisant à la fois le prix et les impacts environnementaux des MP calculés par Analyse du Cycle de Vie. Le modèle de programmation linéaire construit recherche la meilleure formule d’aliment souscontraintes nutritionnelles et de disponibilité des MP avec une fonction multiobjectif qui inclut un index de prix et un index environnemental. Un facteur de pondération de l’index environnemental (α) et de l’index de prix (1-α), a été inclus à la fonction. Les impacts des MP proviennent du jeu de données ECOALIM inclus dans AgriBalyse® v1.3. Des aliments croissance et finition ont été formulés avec 2 scénarios de disponibilité des MP (disponibilité actuelle limitée LIM ou disponibilité accrue NLIM) selon une formulation MinPrix et une formulation MinMO. En NLIM-MinPrix vs. LIM-MinPrix l’index environnemental est réduit en moyennede 3% et l’index de prix de 1%. En MinMO avec α=0,5 vs. MinPrix, l’index environnemental des deux aliments diminue de 10% en LIM et de 22% en NLIM. Simultanément, le prix du mélange augmente de 1,5% en LIM et de 1,7% en NLIM. Pour α supérieur à 0,5, l’index environnemental n’est quasiment plus réduit. La formulation multiobjectif semble être une méthode efficace pour produire des aliments à impacts réduits. Les résultats seront modulés dans le futur en tenant compte des besoins accrus en certaines MP et des interactions possibles avec les besoins des autres espèces animales.

The objective of this thesis is to improve understandings of toxicity of various engineered nanoparticles (ENPs) to human and ecosystem. It is realized via coordinating toxicological data and a scientific consensus environmental model -- the USEtox model. As an important element in life cycle impact assessment, the characterization factor (CF) is employed as a toxicity indicator for human and ecosystem in this work. To obtain the firsthand dose-response phenomena and human toxicological data, in vitro experiments have been conducted by exposing freshly isolated porcine neutrophils to three kinds of ENPs (i.e. copper, nickel and aluminum oxide nanoparticles). The morphologies, mortality rates, and chemiluminescence, of neutrophils are observed or monitored. Additionally, to estimate the persistence time of ENPs in freshwater ecosystem, a fate model on the basis of colloid science is developed. It takes nano-specific behaviors of ENPs into account and includes recommendations of regionalized hydrological parameters. Finally, a comprehensive literature survey is accomplished to collect the ecotoxicological data of various ENPs. Under the framework of USEtox model, the non-carcinogenic human toxicological CFs for Copper NPs and the ecotoxicological CFs for 14 ENPs are recommended. These CF values could be useful in the future when evaluating the environmental impacts of products containing ENPs.; L'objectif de cette thèse est d'améliorer la compréhension de la toxicité de diverses nanoparticules de synthèse (ENPs) pour l'homme et l'écosystème. Les travaux réalisés s’appuient sur la combinaison de données toxicologiques et d’un modèle environnemental - le modèle USEtox. En tant qu'élément important de l'évaluation de l'impact du cycle de vie, le facteur de caractérisation (CF) a été utilisé, dans ce travail, comme indicateur de toxicité pour l'homme et l'écosystème. Pour avoir accès aux courbes dose-réponse et à différentes données toxicologiques, des expériences in vitro ont été réalisées en exposant des neutrophiles porcins fraîchement isolés à trois types de nanoparticules de synthèse. Les modifications morphologiques, les taux de mortalité et la chimioluminescence des neutrophiles ont été évaluées. De plus, pour estimer le temps de persistance des nanoparticules de synthèse dans l'écosystème eau douce, un modèle basé sur la science des colloïdes a été développé. Il prend en compte les comportements spécifiques des nanoparticules de synthèse et inclut des recommandations sur le choix des paramètres hydrologiques régionaux. Enfin, une enquête documentaire exhaustive a été réalisée pour recueillir les données écotoxicologiques de diverses nanoparticules de synthèse. Dans le cadre du modèle USEtox, le CF toxicologique non cancérogène pour cuivre NPs et les CF écotoxicologiques pour 14 ENPs sont recommandés. Ces valeurs des CF pourraient être utiles à l'avenir pour évaluer les impacts environnementaux des produits contenant des ENPs.