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We investigated the capacity of a consortium of ascomycetous strains, Doratomyces nanus, Doratomyces purpureofuscus, Doratomyces verrucisporus, Myceliophthora thermophila, Phoma eupyrena and Thermoascus crustaceus in the mycoremediation of historically contaminated soil and sediment by polychlorinated biphenyls (PCBs). Analyses of 15 PCB concentrations in three mesocosms containing soil from which the fungal strains had previously been isolated, revealed significant PCB depletions of 16.9% for the 6 indicator PCBs (i-PCBs) and 18.7% for the total 15 PCBs analyzed after 6months treatment. The degradation rate did not statistically vary whether the soil had been treated with non-inoculated straw or colonized straw or without straw and inoculated with the consortium of the six strains. Concerning the sediment, we evidenced significant depletions of 31.8% for the 6 i-PCBs and 33.3% for the 15 PCB congeners. The PCB depletions affected most of the 15 PCBs analyzed without preference for lower chlorinated congeners. Bioaugmented strains were evidenced in different mesocosms, but their reintroduction, after six months treatment, did not improve the rate of PCB degradation, suggesting that the biodegradation could affect the bioavailable PCB fraction. Our results demonstrate that the ascomycetous strains potentially adapted to PCBs may be propitious to the remediation of PCB contaminated sites.

This paper presents an application of the ELECTRE III decision-aid method in the context of choosing a sustainable demolition waste management strategy for a case study in the city of Lyon, France. This choice of waste management strategy takes into consideration the sustainable development objectives, i.e. economic aspects, environmental consequences, and social issues. Nine alternatives for demolition waste management were compared with the aid of eight criteria, taking into account energy consumption, depletion of abiotic resources, global warming, dispersion of dangerous substances in the environment, economic activity, employment, and quality of life of the local population. The case study concerned the demolition of 25 buildings of an old military camp. Each alternative was illustrated with different waste treatments, such as material recovery, recycling, landfilling, and energy recovery. The recommended solution for sustainable demolition waste management for the case study is a selective deconstruction of each building with local material recovery in road engineering of inert wastes, local energy recovery of wood wastes, and specific treatments for hazardous wastes.

International audience; Predicting the impact on the subsurface and groundwater, of a pollutant source such as municipal solid waste (MSW) incineration ash, requires a knowledge of the so-called "source term". The source term describes the manner in which concentrations in dissolved elements in water percolating through waste evolve over time, for a given percolation scenario (infiltration rate, waste source dimensions, etc.). If the source term is known, it can be coupled with a model that simulates the fate and transport of dissolved constituents in the environment of the waste (in particular in groundwater), in order to calculate potential exposures or impacts. The standardized laboratory upward-flow percolation test is generally considered as a relevant test for helping to define the source term for granular waste. The LIMULE project (Multiple-Scale Leaching) examined to what extent this test, performed in very specific conditions, could help predict the behaviour of waste at other scales and for other conditions of percolation. Three distinct scales of percolation were tested: a laboratory upward-flow percolation column (30 cm), lysimeter cells (1-2 m) and a large column (5 m) instrumented at different depths. Comparison between concentration data collected from the different experiments suggests that for some non-reactive constituents (Cl, Na, K, etc), the liquid versus solid ratio (L/S) provides a reasonable means of extrapolating from one scale to another: if concentration data are plotted versus this ratio, the curves coincide quite well. On the other hand, for reactive elements such as chromium and aluminium, which are linked by redox reactions, the L/S ratio does not provide a means of extrapolation, due in particular to kinetic control on reactions. Hence extrapolation with the help of coupled chemistry-transport modelling is proposed.

In the recycling industry, the recuperation of zinc from electric arc furnace dust by the Waelz process generates important quantities of slag. This slag presents good mechanical properties, and for the most siliceous slag, a high stability that would enable its use by total or partial substitution of certain granulates in civil engineering. Our study (within the framework of a European program, co-funded by the European Commission — DGXII) concerns the physico-chemical and mineralogical characterization and leaching behaviour of several types of Waelz slag. The leaching tests used are regulatory tests and specific characterization tests of leaching behaviour. They take into account the influence of several main parameters of the valorization scenarios envisaged for the slag (e.g. pH, Redox potential, chemical nature of the leachant, type of contact — liquid/solid etc). The influence of the chemical nature of the alkaline leachant (lime or NaOH) is particularly important in the case of release of lead (strongly leached by a lime solution), of zinc and of arsenic. The agreement between ANC test results and controlled pH test results can be noted. Leachability is largely controlled by pH in solution. Alkaline slags are more sensitive to the influence of pH. The low buffer capacity of the silica-rich slags implies that application or disposal of untreated slag in acid environments (pH 4–6) should avoided. To optimize integration of slags in materials, it will be necessary to orient research towards less alkaline binders than classical OP cements. A concrete with low limestone content where the alkalinity in the porewater would have a less corrosive effect on the vitreous phases of slags would seem more appropriate.

The objective of the study is to characterize pollutant retention in wastes solidified with hydraulic binders in order to predict the long term leaching behavior. The stabilized/solidified wastes are APC MSW (air pollution control residues from municipal solid waste incineration), lead secondary smelting slag and different salts. The binders used are ordinary Portland cement (OPC 55) or blast furnace slag cement (CLK 45) and additives, such as metakaolin. Leaching tests are used in the characterization procedure. Modelling of the observed leaching behavior is conducted to improve the description of the physical and chemical phenomena involved in the release of soluble species. The main results of the study allow a distinction to be made between the species whose solubility is not sensitive to the chemical context of the porewater, and the other species, such as amphoteric metals, whose solubility is sensitive to the context (especially the pH). In the first case, a diffusion or shrinking front model is appropriate. In the second case, a coupled solubilization/diffusion model must be developed in order to describe the leaching behavior of heavy metals (lead, etc.) contained in the stabilized/solidified wastes.

Ashes produced by thermal treatments of sewage sludge exhibit common properties with cement. For example, major elements present in SSA are the same of major elements of cement. Hydraulic properties of SSA are quite the same of cement ones. They may therefore be used to substitute part of cement in concrete or other cementitious materials, provided that technical prescriptions are satisfied and that environmental risks are not significantly increased. The objective of the present study was to determine the appropriate substitution ratios to satisfy both technical and environmental criteria. In a first step, the elemental composition and particle size distribution of the ashes were measured. Then the ashes were used along with Portland cement and sand at different ratios of substitution to produce mortar and concrete which were cured for up to 90 days into parallelepipedic or cylindrical monoliths. The mechanical properties of the monoliths were measured using standard procedures for flexural and compressive strengths, and compared to blanks containing no ashes. The environmental criteria were assessed using leaching tests conducted according to standard protocols both on the ashes and the monoliths, and compared to the blanks. Results showed that the characteristics of the ashes ranged between those of cement and sand because of their larger particle size and higher content in SiO2 as compared to cement. The monoliths made with the highest substitution ratios exhibited a significant decrease in flexural and compressive strengths. However, when the ashes were used in partial substitution of cement at appropriate ratios, the concrete monoliths exhibited similar compressive strengths as the blank samples. The most appropriate ratios were found to be 10% substitution of cement and 2% substitution of sand. The leaching tests conducted on the ashes in their powdery form revealed that amongst the potential contaminants analyzed only Mo and Se were leached at concentrations above the threshold limits considered. The leaching tests conducted on concrete monoliths showed however that none of the contaminants monitored, including Mo and Se, were leached above the limits. In addition, whether concrete recipe incorporated ashes or not, similar concentrations were measured for each potential contaminant in the leachates. This result indicated that mixing ash with cement and sand to produce mortar or concrete induced a stabilization of Mo and Se and thereby constituted in itself a good treatment of the ashes.

International audience; WASCON est le congrès international de référence concernant la problématique de l’intégration des matières premières secondaires dans le domaine du génie civil. C’est en 1991 qu’un groupe de scientifiques d’Europe du Nord et nord américains fondèrent ISCOWA (International Scientific Society for Construction with Waste) et WASCON, la principale activité d’ISCOWA. Cette initiative a été le début d’un important mouvement pour la valorisation des déchets. En effet la même année, les Pays Bas ont initié la normalisation de tous les essais de lixiviation pour l’évaluation environnementale des matériaux, intégrés depuis aux réglementations « décharge » et à l’étude du comportement des déchets en scénarios d’élimination ou de valorisation. Ces mêmes essais sont aujourd’hui en cours de normalisation dans le cadre de l’évaluation des émissions de substances dangereuses à partir des produits de construction (dans le cadre du TC351). On mesure donc l’importance du mouvement qui a été alors initié.Très peu de français étaient présents en 1991. Au cours des éditions suivantes de WASCON (tous les 3 ans), les contributions françaises mais aussi de l’Europe du Sud (Espagne, Italie, Portugal, Grèce) se sont développées. La période 1995-2000 a été la plus productive. Les scientifiques et les industriels français très actifs alors dans le domaine de la stabilisation ont organisés deux congrès internationaux sur le sujet : Nancy95 et Stab&Env à Lyon en 99.L’importance des actions de recherche développement en cours en France dans le domaine de la valorisation en génie civil des matières de substitution et l’importante implication des industriels, producteurs, écoindustries ou opérateurs du génie civil, justifie pleinement maintenant qu’EEDEMS (Evaluation Environnementale des Déchets, Matériaux, Sols et Sédiments pollués), regroupant l’INSA de Lyon, l’Ecole Nationale des Travaux Publics de l’Etat, le CSTB, le BRGM et l’Ecole des Mines de Saint-Etienne, ait co-organisé avec ISCOWA l’édition 2009 de WASCON.Les 4 thèmes de WASCON 2009 ont été les suivants :1. Quantification et modélisation des émissions2. Développement de nouveaux produits et procédés pour l’utilisation de déchets en construction3. Nouveaux scénarios ou nouveaux gisements de déchets (sédiments, pneus…)4. Evaluation environnementale, sanitaire et socioéconomiqueEn compléments 3 ateliers ont été organisés :1. Méthodologie et politiques internationales d’évaluation environnementale des émissions à partir de produits de construction (USA, Chine, Pays Bas…)2. Application des essais de percolation pour l’évaluation d’émissions à partir de produits de construction3. Retour d’expérience industrielle des pratiques de valorisation de déchets en génie civil112 contributions scientifiques de 28 pays différents ont été présentées.Une sélection d’articles en anglais présentés par des auteurs francophones est présentée dans ce numéro spécial pour lequel je remercie Pierre Moszkowicz, rédacteur en chef, et la Société Alpine de Publications, éditrice de la revue Déchets, Sciences et Techniques.

In 2005 the European Commission mandate CEN to prepare test methods with which construction products can be tested with respect to the potential release of dangerous substances to water, soil and to indoor air. A horizontal approach is considered the best route for such test development. Horizontal approach means that it is product independent and consists of the development of a test method applicable for different products used in a certain scenario. This action will satisfy the needs resulting from Essential Requirement n° 3, on Hygiene, Health and Environment, as specified in the Construction Products Directive. In this context, the aim of the work presented here is to study the release mechanisms and the parameters which could influence the leaching of pollutants from construction products towards soil and water, in order to provide information for the development of a horizontal test. The research has been carried out on monolith products, based on three types of matrices: concrete, wood and metal (zinc). For the concrete products, one of the choice criteria was the presence of trace metals (e.g. chromium VI); the wood products are pertinent candidates for our study because of the preservation treatment, which by definition is toxic for some form of life (biocidal substances are used for the treatment); as for the zinc based products, research on contributions of the different sources of urban run-off pollution, showed a very high concentration of zinc (up to 6 mg/L in a catchment in Paris) in roof run-off. Also, this source represents a very high percentage among other urban run-off pollution sources (92% from roof vs. 8% from yard and street run-off).

Demolition waste materials are one of the major industrial waste deposits in many countries and represent an important quantity of potential resources that are not exploited, because the major part of these wastes go to landfill. Indeed, recycling or recovery of demolition waste can reduce the need of primary natural resources. This article gives indicators and a method to analyse demolition waste management with regard to the use of resources contained in these wastes. Demolition wastes are characterized by their contents in energy and raw materials. This content is quantified on the basis of the sum of energy and raw materials necessary for the construction of the building considering the non-renewable character of materials contained in wastes. In fact, this content represents the environmental investment which was necessary to construct the building. An energy balance and a mass balance, with this concept of `raw material and energy' content, can allow a strategy of waste management to be determined in order to salvage the most important parts of energy and raw materials contained in demolition waste, and so identify the strategy which permits a maximum fraction of the initial environmental investment to be saved. Five waste management scenarios concerning building demolition were assessed with this method and these indicators, and the results are presented in this article.

Recently, a demand regarding the assessment of release of dangerous substances from construction products was raised by European Commission which has issued the Mandate M/366 addressed to CEN. This action is in relation with the Essential Requirement No. 3 “Hygiene, Health and Environment” of the Construction Products Directive (89/106/EC). The potential hazard for environment and health may arise in different life cycle stages of a construction product. During the service life stage, the release of substances due to contact with the rain water is the main potential hazard source, as a consequence of the leaching phenomenon. The objective of this paper is to present the development of a coupled chemical-transport model for the case of a concrete based construction product, i.e. concrete paving slabs, exposed to rain water under outdoor exposure conditions. The development of the model is based on an iterative process of comparing the experimental results with the simulated results up to an acceptable fit. The experiments were conducted at laboratory scale (equilibrium and dynamic leaching tests) and field scale. The product was exposed for one year in two types of leaching scenarios under outdoor conditions, “runoff” and “stagnation”, and the element release was monitored. The model was calibrated using the experimental data obtained at laboratory scale and validated against measured field data, by taking into account the specific rain water balance and the atmospheric CO2 uptake as input parameters. The numerical tool used in order to model and simulate the leaching behaviour was PHREEQC, coupled with the Lawrence Livermore National Laboratory (LLNL) thermodynamic data base. The simulation results are satisfying and the paper demonstrates the feasibility of the modelling approach for the leaching behaviour assessment of concrete type construction materials.

Demolition wastes are generally disposed of in unlined landfills for inert waste. However, demolition wastes are not just inert wastes. Indeed, a small fraction of demolition waste contains components that are hazardous to human health and the environment, e.g., lead-based paint, mercury-contained in fluorescent lamps, treated wood, and asbestos. The objective of this study is to evaluate the release potential of pollutants contained in these hazardous components when they are mixed with inert wastes in unlined landfills. After identification of the different building products which can contain hazardous elements and which can be potentially pollutant in landfill scenario, we performed leaching tests using three different lysimeters: one lysimeter containing only inert wastes and two lysimeters containing inert wastes mixed with hazardous demolition wastes. The leachates from these lysimeters were analysed (heavy metals, chlorides, sulphates fluoride, DOC (Dissolved Organic Carbon), phenol index, and PAH). Finally, we compared concentrations and cumulative releases of elements in leachates with the limits values of European regulation for the acceptance of inert wastes at landfill. Results indicate that limit values are exceeded for some elements. We also performed a percolation column test with only demolition hazardous wastes to evaluate the specific contribution of these wastes in the observed releases.

Cette étude a pour objectif de mettre en place des indicateurs afin d'évaluer le contenu « matières premières et énergie » des déchets issus de la démolition de bâtiments. Ce contenu est caractérisé d'une part par la totalité des matières premières et de l'énergie nécessaires à la fabrication d'un bâtiment (désigné respectivement par intensité matérielle et énergie grise), et d'autre part par le caractère « épuisable » des matériaux contenus dans les déchets de démolition. Ces caractéristiques « contenu matières premières et énergie » sont des indicateurs d'impacts environnementaux globaux tels que l'épuisement des ressources naturelles abiotiques et la consommation d'énergie non renouvelable. Ils permettent, grâce à un bilan matière et énergie, de mesurer la performance environnementale globale des filières de traitement de déchets, performance qui sera ensuite utilisée comme critère de décision dans le cadre d'une recherche sur l'optimisation des stratégies de gestion des déchets de démolition.

According to the European Construction Products Directive (89/106/EC), construction products must satisfy specified essential requirements (ER). To comply with ER 3, on hygiene, health and environment, the construction works must be designed and built in such a way that they will not be a threat to the hygiene and health of the occupants and neighbours, nor to the environment. Standardised test methods for the release of substances that are hazardous to health and environment need to be developed at the European level. A horizontal approach is considered the best route for such test development and consists of the development of a test method applicable for different products used in a certain scenario (across the fields of different Technical Committees). The work presented here regards the emission of pollutants towards soil and water and has been carried out on monolith products, based on three types of matrices: concrete, wood and metal (zinc). The aim of the work is to study the parameters (nature of leachant, temperature, liquid-to-solid ratio) that could influence the release behaviour of substances in water. The knowledge acquired from these tests will allow the identification of some parameters needed for the development of a horizontal test.

Predicting the impact on the subsurface and groundwater, of a pollutant source such as domestic waste incineration residues, requires a knowledge of the so-called “source term”. The source term describes the manner in which concentrations in dissolved elements emitted by the waste evolve over time, for a given percolation scenario. If the source term is known, it can be fed to a model that simulates the fate and transport of dissolved constituents in the subsurface and the groundwater, in order to calculate a potential impact. The standardized laboratory upward-flow percolation test is generally considered as the relevant test for defining the source term for granular materials. The LIMULE project (Multiple-Scale Leaching) examined to what extent this test, performed in very specific conditions, could help predict the behaviour of the waste at other scales and for other percolation conditions. Three distinct scales of dynamic percolation were tested: the scale of the laboratory upward-flow percolation column, that of lysimeter cells and that of a large instrumented column of five meters height. The comparison between the concentration data collected from the different experiments suggests that for the case of soluble salts (Cl, Na, K, ...), the liquid versus solid ratio (L/S) allows an extrapolation from one scale to the other: if concentration data are plotted versus this ratio, the curves coincide reasonably well. On the other hand, in the case of reactive elements and in particular of chromium and aluminum, which are linked by oxydo-reduction reactions, the L/S ratio does not provide a means of extrapolation because of kinetic controls on the reactions. Hence an attempt to extrapolate with the help of coupled transfer-chemistry modelling is proposed., La prévision de l’impact sur le sous-sol et les eaux souterraines d’une source de polluants inorganiques tels que des résidus d’incinération d’ordures ménagères, nécessite une connaissance de ce qu’on appelle le « terme source ». Le terme source décrit comment les concentrations en éléments dissous émis par les résidus évoluent dans le temps, pour un scénario de percolation donné. Si le terme source est connu, il peut être associé à un modèle de simulation du devenir et du transfert des éléments dissous dans le sous-sol et les eaux souterraines afin de calculer un impact potentiel. L’essai normalisé de percolation ascendante en laboratoire est généralement considéré comme étant pertinent pour appréhender le terme source des solides granulaires. Le projet LIMULE (Lixiviation Multi-Echelles) a examiné dans quelle mesure cet essai, réalisé dans des conditions bien spécifiques, pouvait permettre une prévision du comportement du déchet à d’autres échelles et d’autres conditions de percolation. Trois échelles distinctes de percolation dynamique ont été étudiées : l’échelle de la colonne de percolation ascendante en laboratoire, celle de casiers lysimétriques et celle d’une grande colonne instrumentée de cinq mètres de hauteur. La comparaison entre les données de concentration collectées aux différentes échelles suggère que pour le cas des sels solubles (Cl, Na, K, ...), le ratio liquide sur solide (L/S) permet d’extrapoler entre les différentes conditions expérimentales. En effet, lorsque les données de concentrations sont exprimées en fonction de ce ratio, les courbes coïncident de manière relativement satisfaisante. Par contre, pour le cas des éléments réactifs et en particulier le chrome et l’aluminium qui sont liés par des réactions d’oxydo-réduction, le ratio L/S ne permet pas l’extrapolation entre les échelles en raison de l’influence des cinétiques de réaction. Dès lors, une tentative d’extrapolation à l’aide de la modélisation couplée transfert-chimie est proposée.

The aim of this study is to assess the long term release of contaminants from cement based stabilised wastes. According to the methodology proposed by the European standard ENV 12 920, the impact of waste in disposal/utilisation scenarios has to be evaluated before being exposed to the environment. For this objective we propose a combined experimental and modelling procedure. Firstly a “tool box” consisting of some tests as the Pore Water simulation test (PW), the Maximum Leachable Fraction test (MLF), the Acid Neutralisation Capacity test (ANC), and the Monolithic Leaching Test (MLT) is used to characterise the waste containing material. Secondly the results of the tests are the necessary input parameters for the coupled physico-chemical leaching model that provides the long-term leaching behaviour. For applying the tool box and the model validation, Ordinary Portland Cement with additives was used to prepare the samples containing 25% of binder, 1% of Pb, and sand. The release mechanisms are described. The model provides the long-term release amounts of pollutants as well as the expected concentrations of pollutants in surrounding natural water over several centuries in the considered scenario conditions.

This project aims to identify parameters controlling the release of pollutants contained in the solid waste by means of a « toolbox » comprising some simple laboratory leaching tests. The leaching tests : Pore Water simulation test (PW), Maximal Mobile Fraction test (MMF), Acid Neutralization Capacity test (ANC) and Leaching Test on Monolith (LTM) have been performed in order to characterize materials obtained by wastes stabilization using hydraulic binders. Three types of binders were used : the CPA-CEM I, the CPJ-CEM II and a binder from road construction. 1 % of PbO were added in all materials. The interpretation of results showed that the release of the pollutant species Pb (II) was controlled by the chemical context of the pore water relating to the type of cements. The setting tests allowed us to determine the fundamental parameters to initialize an environmental behavioural model for a long-term prediction of pollutant release., Cette étude vise à identifier les paramètres contrôlant le relargage des polluants contenus dans les déchets solides massifs à l’aide d’une « boîte à outils » comportant des tests de lixiviation simples. Les tests de lixiviation : test de l’eau des pores (EP), test de fraction maximale mobilisable (FMM), test de capacité de neutralisation acide (CNA) et test de lixiviation sur monolithe (TLM) ont été effectués afin de caractériser des matériaux à base de déchets stabilisés/solidifiés (S/S) par liants hydrauliques. Trois types de liants ont été utilisé à la fabrication des matériaux étudiés : le CPA-CEMI, le CPJ-CEM II et un liant routier. Le plomb (1 %) a été ajouté sous forme de PbO dans les matériaux. Les résultats des tests ont été interprétés d’une manière qualitative ; le comportement des trois matériaux a été comparé. Les tests proposés permettent de déterminer les paramètres physico-chimiques nécessaires pour l’évaluation du comportement à la lixiviation des matériaux.

The new landfill Directive integrating the potential delisting of hazardous wastes based on their “stable and non-reactive” behaviour, the ENV 12920 European pre-standard proposing a methodological framme to access the predictive behaviour of wastes/materials within disposal and utilisation scenarios, the industrial application of the ecocompatibility concept and the human health stakes consideration are the most outstanding elements of a true ongoing revolution in the definition of wastes/materials management. STAB&ENV'99 was a first event to reflect this mutation. Let's get ready to confirm it in 2002!, La nouvelle Directive décharge prévoyant le déclassement des déchets dangereux sur la base de la vérification de leur comportement « stable et non réactifs », la norme européenne ENV 12920 proposant un cadre méthodologique pour l'évaluation du comportement prédictif des déchets/matériaux en scénarios de stockage et d'utilisation, l'entrée en application industrielle du concept d'éco compatibilité et la prise en compte des enjeux pour la santé humaine sont les éléments les plus marquants d'une véritable révolution en cours dans la définition des modes de gestion des déchets/matériaux. STAB&ENV 99 a été un premier reflet de cette mutation. Il faut transformer cet essai en 2002 !

« Vous me dites qu'il n'y aura pas de pollution pendant 5000 ans, oui mais après ? »« La ceinture, les bretelles, le parapluie ...et quoi d'autre ? »

Leaching tests are essential in the environmental assessment of stabilized wastes. Research programmes were conducted on their interpretation in order to develop tools for the evaluation of long term release of pollutants contained in solidified wastes. Models for the leaching of porous materials are discussed in this paper according to the specificity of the chemical species (i.e. transport model with total dissolution of species-diffusional model; transport model with progressive dissolution of species due to limitation of solubility-shrinking core model; and the model coupling transport and chemical phenomena). The leaching behaviour of pollutants (i.e. lead) solidified in a cement matrix was studied under different chemical conditions. Results have shown that the release of species whose solubilities depend on the physico-chemical conditions, and especially the pH (e.g. amphoteric metals), is governed by the solubility of the species in the pore water at local conditions and by the pH evolution within the matrix. A coupled dissolution/diffusion model was developed to describe the release of chemically complex species contained in a porous medium in contact with water. Leaching tests of cement matrices and artificial porous matrices containing calcium hydroxide and pollutants were conducted in order to validate the coupled dissolution/diffusion model. A good assessment of the retention of some pollutants contained in cement matrices could then be obtained by the association of two tests: solubilization of the pollutants related to the chemical context (pH) under steady state conditions and monolithic long term dynamic leaching tests in order to characterize the evolution of the chemical context (pH) and consequently the release of pollutants. The objective is to integrate this approach in the standardization process (CEN TC 292- WG 6, in progress).

1. Abstract In the recycling industry, the recuperation of zinc from Electric Arc Furnace dust by the Waelz process generates important quantities of slag. This slag presents good mechanical properties, and for the most siliceous slag, a high stability which would enable its use by total or partial substitution of certain granulates in civil engineering. Our study (within the framework of a european programme, cofunded by the European Commission – DGXII) concerns the physico-chemical and mineralogical characterization and leaching behaviour of several types of Waelz slag. The leaching tests used are regulatory tests and specific characterization tests of leaching behaviour. They take into account the influence of several main parameters of the valorization scenarios envisaged for the slag (e.g. pH, Redox potential, chemical nature of the leachant, type of contact – liquid/solid etc).

The application (first partial then total) of the new regulation concerning Final Special Industrial Waste (SIW) landfilling has brought to light the radical increase in management costs (stabilization + landfillmg). This has led industry to reconsider waste generating processes (reduction at the source, pretreatment) to reduce either the quantity or the polluting character of the wastes (authorizing, for example, admission as they stand). In certain extreme cases, this has led to questioning the process itself, leading to the abandon of the considered waste. As far as management of the “unavoidable” Final SIW is concerned, 3 fields of reflection are now open to industry: (1) Delisting of the stabilized waste (either classified as “M” assimilated to household waste, allowing landfilling in class II sites, or potentially as “I” inert, allowing landfilling in class III sites). (2) Valorization of the stabilized waste, thereby economizing the cost of landfill and even fixing a sale price for the material. (3) Valorization of the waste as it stands, thereby economizing the cost of stabilization.

Lead and zinc primary smelters in Europe produce and dump every year about 1 Mt of slag. The industrial objectives of the Brite Euram project that is reported in this chapter are to valorize the primary lead and zinc slags, and to avoid their dumping through their use in safe construction and civil engineering materials representing high tonnages. To maintain its competitiveness regarding overseas competitors, the European non-ferrous metallurgy industry has to avoid the burden of dumping cost, and must hence develop beneficial uses for its slags. While in recent years, significant improvements in both “conventional” (lead blast furnace or ISF) or “new” (Kivcet - QSL) processes have been achieved, the solid slags generated by these processes are still largely dumped. The main goal is to work toward a common approach and understanding of the leaching properties of “metallurgical slag”. This implies a better understanding of the phenomena involved in the leaching process to be able to adapt, if necessary, the metallurgical process to produce a slag whose chemical composition, particle size and morphology, will result in reduced leachability. And moreover to develop cost effective processes and techniques to use the non-ferrous slags in environmentally compatible construction and civil engineering materials, as a partial or total substitute to quarry raw materials. Slags from other industrial processes such as blast furnace slag, steelslag, and phosphate slag are used in coastal protection and in roadbase applications. The environmental consequences of these applications have been shown to meet strict utilization criteria.

Understanding mechanisms which control release of inorganic contaminants from stabilized/solidified wastes is important for predicting the long-term leaching of contaminants in the field. Frequently, release is assumed to be controlled either by solubility or diffusivity as limiting cases. These assumptions also dictate the interpretation of laboratory test methods. The consistency of testing and interpretation methods was evaluated using a synthetic solidified matrix spiked with lead chloride, using both batch extractions on size reduced materials, where equilibrium was anticipated, and tank leaching tests, where diffusion controlled release was anticipated. Differing approaches to determining availability, solubility and dynamic release are compared.

The release of soluble species contained in solidified/stabilized wastes are assessed by leaching tests. Interpretation of experimental results must be supported by precise modeling of the different phenomena involved hydrodynamics, dissolution, chemical interaction, diffusive transport. The models are presented, which can apply according to the leaching scenario (with or without advection). - solubilization shrinking core model, - diffusionnal model, - coupled dissolution/diffusion model.

Leaching tests are essential in the environmental assessment of stabilized wastes. Research programs are conducted on their interpretation in order to develop tools for the evaluation of long term release of pollutants contained in solidified wastes., Les tests de lixiviation sont essentiels dans l'évaluation environnementale des déchets stabilisés. Des études sur leur interprétation ont été menées afin de développer les outils de modélisation visant à prédire le comportement à long terme des déchets solidifiés.

In the framework of the new French technical and regulatory requirements of industrial waste landfilling, solidification/stabilization processes are expected to be one of the main tools to render wastes physically and chemically compatible with the Environment on the long term. Consequently, it appears necessary to propose a comprehensive qualification procedure to assess the real performances of the different industrial processes in front of the wide range of industrial wastes to stabilize. This paper presents the main steps of the procedure, proposed by ADEME (French Agency for the Environment and Energy Management) and designed by POLDEN and L.C.P.A.E.(INSA de Lyon).

Leaching procedures of wastes solidified with hydraulic binders are expected to allow the assessment of the safety of the long term storage. The Dutch procedures (Availibility Test and Tank Leaching Test) or the Canadian one (close to ANS 16.1) are based on diffusion model and determine the two parameters De and Co from two different experiments : one on crushed materials and the other one on a monolithic sample. The present study, jointly conducted by a Dutch team (ECN) and a French one (POLDEN, LCPAE INSA Lyon), has been funded by RE.CO.R.D. Its two main aims were: - to point out the influence of the chemical properties of the binders and the wastes upon the release of the pollutants. - to define the application field of the diffusion model in order to predict the long term leaching behavior of the solidified products.

The planet is in a particularly worrying state of degradation of ecosystems, depletion of resources, demographic tension and a climate emergency. The decoupling of the consumption of raw materials with economic activity is a relevant action lever. By reducing the pressure on the scarcity of raw materials, the circular economy can participate in the fight against climate change. Although recycling alone cannot solve resource depletion, it is essential to implement solutions to regenerate the materials present in our waste. However, the current organization of the end-of-life sector does not seem to meet the needs of the world economy.The first challenge in deploying recycling solutions in the circular economy is based on evaluating the performance of recycling scenarios. The proposed methodology is based on several analytical tools: Material Flow Analysis (MFA), Life Cycle Assessment (LCA) and Life Cost Costing (LCC) in a technical reference framework based on the evaluation of environmental technologies (ETV). This work applies in partnership with the company MTB. Three performance axes were chosen: technical, economic and environmental.This multi-criterion assessment, integrated into the MTB design process, allows communication in the form of key performance indicators (KPI). By providing additional performance indicators it is possible to quickly quantify the eco-efficiency, to support decision-making by designers during the development of the recycling pathway., La planète se trouve dans un état de dégradation des écosystèmes, d’épuisement des ressources, de tension démographique et d’urgence climatique particulièrement préoccupant. Le découplage de la consommation de matières premières avec l’activité économique est indispensable. En réduisant la pression sur la raréfaction des matières premières, l’économie circulaire peut participer à la lutte contre le dérèglement climatique. Bien que le recyclage ne puisse solutionner seul l’épuisement des ressources, il est indispensable de mettre en œuvre des solutions pour régénérer les matières présentes dans nos déchets. Or l’organisation actuelle de la filière de fin de vie ne semble pas répondre aux besoins de l’économie-monde.Le premier challenge pour déployer des solutions de recyclage en économie circulaire repose sur l’évaluation de la performance des scénarios de recyclage. La méthodologie proposée repose sur plusieurs outils d’analyse : analyse de flux de matières (MFA), Analyse de Cycle de Vie (ACV) et Analyse de coûts (LCC) dans un cadre technique de référence basé sur l’évaluation des écotechnologies (ETV). Ce travail s’applique en partenariat avec la société MTB. Trois axes de performances ont été retenus : technique, économique et environnemental.Cette évaluation multicritères, intégrés dans la démarche de conception de MTB, permet une communication sous la forme d’indicateurs clés de performances (KPI). Ces indicateurs supplémentaires permettent de quantifier rapidement l’éco-efficience d’un scénario, pour accompagner la prise de décisions des concepteurs lors de la construction de l'offre et du développement des solutions scénarios de recyclage.

High quantity (4.12 million kg in France in 2008) of ashes produces from the incineration of sewage sludge. The reutilization of these ashes as secondary raw materials in the building and public works was studied. A physical, chemical, mineral, and behavioral characterization showed that the sewage sludge ash have an intermediate behavior between the cement and sand, near the pozzolan. Most elements had lower release rates than limited value of inert waste or non-hazardous waste, with the exception of the leachable fraction of Se and Mo. A relationship between solubilization of elements and mineralogy of materials were studied by modeling for phase identification of the ashes. A technique part was studied to evaluate the influence of the residue (sewage sludge ash) on the mechanical properties of materials. The activity index of the ash met the specification of EN450-1 in 28 days. The strength of the mortar decreased when the substitution increased due to the high amount of water added and the low CaO content in the ash. For concrete with a substitution of 10%, the compression strength was comparable to the blank sample, and was satisfactory to the threshold of construction projects. However, the durability test showed a strong decrease of mechanical strength for the concrete containing the ashes after a freeze/thaw. An assessment of environmental impacts associates with the observation of the leaching behavior of these materials. The leaching test at laboratory scale and pilot scale were investigated. The cumulative leaching quantities of each pollutant and anions were below the threshold, without significant environmental impact, acceptable for the construction in Netherlands en in France., Des quantités importantes de cendres (4,12 million kg en France en 2008) sont issues de l’incinération des boues de station d’épuration. La valorisation de ces cendres comme matière première secondaire pour l’élaboration de matériau dans le domaine du bâtiment et des travaux publics (BTP) a été étudiée dans cette thèse. La caractérisation physique et chimique des cendres et l’étude de leur réactivité ont révélé un comportement intermédiaire entre le ciment et le sable, proche du comportement de matériaux pouzzolaniques. Les tests de lixiviation réalisés sur les cendres ont montré qu’à l’exception du Se et du Mo, les éléments présents dans les cendres sont solubilisés à des concentrations inférieures aux seuils définis règlementairement pour les déchets inertes ou non-dangereux. Les liens entre la solubilisation des éléments et la minéralogie des matériaux ont été étudiés à travers la modélisation géochimique réalisée sous PhreeqC. L’influence du taux de substitution du ciment par les cendres sur les propriétés mécaniques des matériaux a également été étudiée. L’indice d’activité à 28 jours de la cendre est conforme à la spécification de la norme EN 450-1. La résistance du mortier diminue quand le taux de substitution augmente à cause de la faible teneur en CaO dans les cendres et de l’apport supplémentaire d’eau nécessaire. Pour le béton avec un taux de substitution de 10 %, la résistance est comparable à celle du béton témoin. L’essai de durabilité des matériaux cimentaires incorporant les cendres révèle une forte diminution de résistance mécanique sous l’effet de la sollicitation au gel/dégel. Une évaluation environnementale de ces matériaux a été réalisée par l’essai de lixiviation à l’échelle du laboratoire et à l’échelle pilote. Les quantités relarguées cumulées des éléments polluants et des anions sont inférieures aux seuils sans impact environnemental, acceptables en construction aux Pays-Bas et en France.