| Environnement, ingénierie & développement |  |
N°10 - 2ème Trimestre 1998
1. Éditorial n°10 Déchets Sciences et Techniques: « Lentement, mais sûrement, les mécanismes du fonctionnement de la revue se mettent en place et s'améliorent sans pour autant perdre de vue la nécessité d'améliorer la qualité et d'ouvrir de nouvelles perspectives de développement »
Nous voilà au numéro 10. Lentement, mais sûrement, les mécanismes du fonctionnement de la revue se mettent en place et s'améliorent sans pour autant perdre de vue la nécessité vitale d'améliorer la qualité et d'ouvrir de nouvelles perspectives de développement.La procédure d'évaluation des articles proposés est maintenant définie. Je tiens à remercier vivement tous ceux que nous sollicitons pour la pertinence de leurs analyses et la célérité dont ils font preuve. Si certains d'entre vous souhaitent participer à ce travail, signalez-nous le, notre fichier d'évaluateurs est loin d'être saturé.Il en va de même pour les articles proposés qui ne sont pas encore en nombre suffisant. De nombreux domaines de l'activité de recherche sur les déchets, au sein desquels les travaux sont nombreux et variés ne donnent pas lieu, à notre sens, à suffisamment de propositions d'articles. Nos moyens d'incitation sont hélas limités et nous sommes convaincus que le « bouche à oreille » pourrait nous aider à enrichir notre « matelas » d'articles.
2. Collectes sélectives multi-matériaux de déchets ménagers: Approche des coûts de tri (en centre de tri)
The paper simulates the cost and the employment in a Sorting Centre of the product of multi-matérial separate collection of household refuse in relationship with some assumptions (cases study).
3. Les déchets médicaux diffus et la notion de risque: Quelle analyse développer ?
Diffuse medical waste is at the centre of much vigorous discussion. Despite the evolution in the perception of waste-related dangers over the ages and with changes in usage, the association of risk with diffuse medical waste in particular continues to be widespread. There are two dimensions to the risk in question: objective and its corollary, perceived dimension, both of which are in need of appraisal. The RI/FS method lent itself to the appraisal of objective risk, whereas the risk as perceived by independent health practitioners in Greater Lyon was assessed by means of a survey. The results of this survey were compared against the results of a study on the objective risk presented by these types of waste in relation to similar risks presented by household refuse. It emerged that practitionners overestimate the objective risk, and this difference enables the measure of perceived risk to be gauged. Several scenarios may be put forward for diffuse medical waste management on the basis of these results.
4. Compostage des boues de station d'épuration urbaine en France: État des lieux
Composting of municipal sludge from waste water treatment plants enables this by-product to be commercialised. This article details how this system operates within France and is based upon replies obtained from site exploiter in 1996. It has noticably shown the diversity of applications in this domain (initial substrates, processes, markets, etc.).
5. Le devenir des mâchefers d'incinération d'ordures ménagères: Partie 1 : caractérisation des mâchefers
The present work has focused on physico-chemical characterisation (elementary analysis and leaching behaviour) of four bottom ashes originated from different incinerators. In other hand, we have studied the distribution of polluting potential in various grain size fractions. It has been possible to show that the finest grain-size fractions are the most loaded in pollution (danger potential and risk potential). Nevertheless, by accounting the grain-size distribution and therefore the weight percent of each grain-size fraction, it emerges that the pollution is distributed at the rate of 10, 30, 50 and 70% between the fractions of 0-0,08; 0-1; 0-2 and 0-4 mm. The sifting of bottom ashes by removal of the 0-4 mm fraction would allow to reduce the polluting potential by 30-60%. On other hand, this treatment can constitute a complementary step to the maturation treatment when the former does not allow to obtain bottom ashes of V-class. In these conditions, bottom ashes have all chance to become V-class materials.
6. Vers une prise en compte de la notion d'impact dans l’évaluation de la stabilisation/solidification des déchets
In order to ensure a safety long term disposal of the solidified/ stabilized wastes it is necessary to evaluate the pollutants release flux to the environement (animal life, flora and drinking water resources). We introduce in this paper the first results of the source term evaluation and mainly the pH dependency on the pollutants solubilization. The buffering capacity of the material plays an important role concerning especially the amphoteric metal release by the waste.
7. La microsublimation: Nouvelle voie pour l’analyse des composés organiques volatils (VOC) et composés organiques volatils halogénés (VOCX) dans les sols contaminés
An apparatus for microsublimation under reduced pressure has been adapted and improved for the quantitative analysis of VOC that are present in solid matrices, such a soil.
8. Le logiciel Traces : un outil d'aide à la gestion des risques liés aux sites et sols pollués
The two last centuries of uncontrolled industrialization have produced large amounts of brownfields, wastes dumps, landfills... in most of occidental countries. These sites, having used or produced hazardous or toxic substances, are potentially contaminated sites. The last official inventory of the Ministry of Environment in France has established 896 polluted sites for an estimated 200,000 potentially contaminated sites from the professionals of this domain.The problem related to these sites is the capability of the pollution to migrate from the soil to the surface water, the groundwater, and the air and finally to have an impact on living organisms (human, fauna, flora). Questions which are to be solved are then the extent and impact of the contamination and the alternatives to remediate it.The scientific and technical complexity added to the lack of (public or private) money make it hard to correctly manage these sites.For this purpose, a decision support system was developed in order to provide a rational, standardized and easy approach of potentially contaminated sites, and was called Traces (Tool for Risk Assessment from Chemical Exposure to Soils).
9. Les animateurs de collectes sélectives: Partie 2 : autres points d'appui ; complémentarité et concurrences
The creation of new jobs for young people in the frame of the development of separate collections of households refuse lets appear possible complementarity but (at the reverse) areas of competition with other actors, depending on the tasks and the local context. Another task is source reduction, i.e. home composting. From a more general viewpoint, the dynamics to organize is a matter of social engineering.