| Environnement, ingénierie & développement |  |
N°13 - 1er Trimestre 1999
1. Éditorial n°13 Déchets Sciences et Techniques: Vers une écologie industrielle ?
Dans un récent ouvrage, Suren Erkman1 présente, de façon très pédagogique, une vision originale de l'activité industrielle telle qu'elle pourrait se développer dans un futur plus ou moins proche (ou lointain !). Il s'appuie sur l'analyse d'une bibliographie déjà abondante dont la qualité et les références ne laissent aucun doute sur le sérieux et la pertinence des chercheurs concernés.En rupture totale avec l'habitude actuelle d'analyser les rapports entre le « système industriel » et la « biosphère » en termes de conflits et d'interactions néfastes, l'auteur expose les bases d'une approche baptisée « Écologie industrielle » qui considère le système industriel comme un cas particulier d'écosystème. L'approche écologie industrielle a pour préalable le concept de « métabolisme industriel » qui consiste à analyser l'ensemble des composants biophysiques du système industriel. De nature analytique et descriptive, cette analyse vise à comprendre la « dynamique des stocks de matière et d'énergie liées aux activités humaines depuis l'extraction et la production des ressources jusqu'à leur retour inévitable, tôt ou tard, dans les processus biogéochimiques ».L'étape suivante, qui est celle de l'écologie industrielle s'inspire de connaissances sur les écosystèmes et la biosphère et permet de déterminer les transformations susceptibles de […]
2. Prendre en compte, gérer, maîtriser les déchets de la filière habillement
In 1995, Cetih proposed a research on the recycling of clothing waste in France. From a general observation (ecology, government's role, environment within companies, etc.), the following assumption was made: clothing industries can manage their waste providing that they implement a specific management system. The development of such an assumption makes us wonder how to endow not well-known waste with a value of exchange. In the first place, it is necessary to know clothing waste qualitatively as well as quantitatively. Therefore, to carry out a study of the economic, technical and regular constraints is essential. As a result, a tool of diagnosis has been developed and applied to 12 companies to get environmental data on this sector. In the second place, to move from an initial situation (waste eliminated in refuse tip) to a deeper recycling, it is necessary to determine the available or future opportunities of recycling. An analysis of recycling procedures with a technical and economic determination of their conditions of acceptance is proposed. Finally, a general method to help companies implement a waste management is forecast. It will allow companies to determine the most adapted solution among different possibilities of improvement. This method is based on the application of the tools previously mentioned and on a decision-making algorithm. This method is validated in the field within a clothing company.To conclude, the advantages and limits of the use of this […]
3. Recyclage du calcin (verre cassé): Recherche de débouchés alternatifs
The recovery of households packaging glass (cullet) is expanding in the industrial countries, notably with outlets in the frame of a closed-loop recycling scheme: the bottles are transformed into new bottles. However some questions remain concerning the outlets:- limits of a closed-loop system when the cullet is not sorted by colours;- valorisation of tiny pieces of broken glass when it is not desirable to introduce them into the melting furnace;- valorisation of the cullet in the islands, and in nonindustrial countries, where an industrial recycling plant does not exist.The objective of this paper is to explore some alternative possibilities of cascade recycling (when closed-loop recycling is not feasible). Moreover a distinction will be made according to the fact that a (re-) melting process is needed or not.
4. Étude des représentations de la population, riveraine d'une usine d'incinération: L’exemple d'Athanor
Twenty in-depth interviews have been made with people living in the vicinity of a solid waste incinerator. They have been asked about their conception of the environment, pollution and nuisances and then their perception of the incinerator. Although the incineration plant has been quite well accepted, some reserves are associated not directly with pollution risk, but with more general issues related to modernity and technical systems (technological and political-economic opacity). Two types of reactions are induced; the first illustrates the need of a higher degree of citizen participation in waste management, the other the social scapegoat role of the waste industry. Some explanatory elements of these attitudes have been researched by using the work of anthropologist René Girard on the link between ritual sacrifice and social order.
5. Analyse de PCDD, PCDF, chlorophénols, et chlorobenzènes dans des unités d'incinération d'ordures ménagères
Municipal Solid Waste lncineration (MSWI) is one source of pollutants. Among toxic compounds, polychloro dibenzo dioxins (PCDD) and polychloro dibenzo furans (PCDF) emissions are more and more controlled. These products are formed in the incinerator at low temperature (200-300°C), especially in the particle collection equipments (Electrostatic precipitators: ESP).This study, conducted by Ademe (Agence De l'Environnement et de la Maîtrise de l'Energie), derives from the need for a better understanding of the mechanisms and parameters involved in the formation of PCDD and PCDF in the post-combustion stage. With this goal in view, Ineris (Institut National de l'Environnement Industriel et des Risques) carried out samplings in two MSWI. The concentrations in PCDD, PCDF, PolyChloro Benzenes (PCBz) and PolyChloro Phenols (PCPh) were measured by Carso (Centre d'Analyse et de Recherche sur les Substances Organiques). Incinerator operating parameters, like working conditions and the size of the electrostatic precipitator, as well as operating conditions of the kiln were varied.Several parameters are involved in the formation of PCDD and PCDF in the incinerator. Among them, the residence time of fly ashes (ESP size), the operating conditions of incinerator (kiln breakdown) and the electric fields intensity in ESP clearly affect the amounts of PCDD and PCDF emitted.Finally, the disappearance of PCBz and PCPh and the subsequent formation of PCDD and PCDF in the ESP […]
6. Fractions fines et ultra-fines de mâchefers d'incinération d'ordures ménagères : caractérisation, lixiviation et analyses de surfaces
This note presents the results of the physico-chemical characterization (global chemical analysis, ORX, SEM, BET) of the fine fractions (< 4 or 5mm), obtained by sieving two raw samples of bottom ash. The first one (C) is classified as V-type (reusable as backfill material) whereas the second one (R) belongs to the M-type (intermediate). Each fraction (except the finest ones) allowed, after ultrasonic treatment in ethanol, to separate the fraction < 100μm, defined as the « ultra-fine fraction ». These particles, 80% (on volume basis) of which are < 70μm, have a high contamination potential. Combined with the finest sieved fraction, they represent only 16% of the R bottom ash weight (0- 4mm), but release more than half the heavy metals during leaching. We interpret these ultra-fine fractions as deposited fly ash. The presence of a thin (a few nanometres) coating of Sn on these particles, as shown by XPS analyses, is further evidence for this hypothesis. Finally, the practical implications of this conclusion are emphasized.
7. Évaluation de la toxicité des eaux usées industrielles de tanneries: Impact du traitement chimique
The purpose of our investigation was the acute toxicity evaluation of the chromium tanning and liming-deliming wastewaters before and after chemical treatment. The invertebrate Daphnia pulex was used for toxicity test. The toxicity due to these industrial wastewaters was revealed by the equations of the regression lines. The results of the toxicity test showed that the investigated chromium tanning and liming-deliming presented higher toxicity with respective ICSO 24hr values of 0.15 and 3.36. This toxicity could be explained by higher levels of heavy metals (Cr, Cu and Pb), sulphides and organic matter in these sewages. After processing by chemical precipitation, ICSO 24hr increased from 0.15 to 26.58 and from 3.36 to 11.1 respectively for chromium tanning and the epilage-coat. Consequently, these processed sewages can be classified as little toxic rejects. This diminution of the toxicity is linked to dejection percentages of MES (95%), DCO (55%), Cr (90%) and sulphides (50%).
8. Méthode de réduction des rejets aqueux des ateliers de traitement de surface
The metal finishing industries generate a large quantity of wastewater usually polluted by toxic chemicals. In order to reduce the effluents and to respect the laws, we have built a method which helps professionals to reduce the amount of wastewater. Afterwards, a computer tool was developed in order to carry out the optimization.