| Environnement, ingénierie & développement |  |
N°17 - 1er trimestre 2000
1. La conduite automatisée de fours d’incinération d’ordures ménagères : Une solution à la réduction des rejets de dioxines
The treatment of household refuse is one of the ecological goals for the end of this century. A methodology is proposed in this article which makes it possible to control efficiently and automatically a household refuse incinerator with grids. The automatic control is based on a structure of cascaded regulation loops. It ensures good combustion in the incinerator by monitoring, on the one hand, the furnace temperature around a given set point, and on the other hand, the household refuse charge adjusted to its inferior calorific value. It also guarantees a rational use of combustion and cooling air flow rates. The experimental results show that the combustion regulation, which has been implemented for more than one year, is totally satisfactory. The proposed regulation strategy brings indeed more safety, improves the efficiency of the incinerator and has made possible a considerable reduction of the rate of dioxins.
2. Bilan matière-énergie de la filière de traitement des véhicules hors d’usage (VHU)
This article presents a modelling of the present French treatment method of end of live vehicles (or VHU). The final analysis matter-energy, which in this article takes into consideration the treatment of a reference VHU as well as the treatment of the corresponding quantity of steel scrap for shredder (or FAB) was accomplished by the application of the Life Cycle Assessment (LCA) method. This leads to the conclusion that the present valorisation rate of the reference VHU (the average VHU emptied of fuel) is 81.4 %. On the other hand, it was shown that crushing consumed 50 % of the electric energy used by the treatment method. Concerning the diesel oil consumption itself, 60 % was accountable for place to place transportation and 40 % for the treatment sites. Finally, the energetic valorisation of the products being disposed in landfill nowadays should allow to release as much energy than the treatment method consumes to guarantee its own functioning.
3. Bioremédiation des métaux lourds par les bactéries sulfato-réductrices
The treatment of soils and ground water polluted by heavy metals is of economical and environmental interest. The development of new processes using micro-organisms may offer alternative ecological solutions less expensive than usual chemical processes. In addition to the chemical indirect reduction due to the production of H2S, sulfate-reducing bacteria can also reduce metals directly by an enzymatic way. So, these bacteria are good candidates for industrial metal removal. The characterization of competent enzymes for metal reduction will improve the bioremediation process. Among them, a low redox potential tetrahemic cytochrome c3 is a constitutive enzyme of the sulfate-reducing bacteria. The reduction of U (VI) and Cr (VI) by this cytochrome has already been demonstrated. Studies presented here show that others homologous cytochromes can reduce V (V), Mn (IV), Fe (III) and Cr (VI). The results indicate that only the low redox potential cytochromes present in sulfate-reducing bacteria can act as metal-reductases. We also observed that sulfatereducing bacteria rapidly reduce chromate. Growth with Cr (VI) induces morphological changes and a decrease in the growth rate of the bacteria.
4. Global Symposium on Recycling, Waste Treatment and Clean Technology - Rewas’99: San Sebastian, Espagne, du 5 au 9 septembre 1999
Afin d’améliorer la synergie entre les communautéstechniques et scientifiques axant leurs recherches sur la réduction des impacts environnementaux des 5 continents, les organisateurs de REWAS ont décidé de focaliser l’édition 99 sur le recyclage, le traitement des déchets et les technologies propres.
5. Éditorial n°17 Déchets Sciences et Techniques: « Une approche exclusivement scientifique et technique des problématiques environnementales est trop focalisée »
Le concept de développement durable, initié dès 1970 a été officiellement consacré par le sommet de Rio en juin 1992. Ce concept qui repose sur la trilogie Environnement – Économie – Équité sociale, vise à éclairer les décisions politiques pour « gouverner » notre planète et la transmettre en « bon état » aux générations futures. En quoi les scientifiques et les techniciens du déchet que sont les lecteurs de cette revue sont-ils concernés par le développement durable ?Une première réponse, évidente mais réductrice est que mieux gérer les impacts environnementaux permet bien sûr d’améliorer la performance environnementale des systèmes industriels et par là même de mieux assurer un fonctionnement respectueux des milieux physiques et vivants. À cela s’ajoute une gestion plus économe des ressources naturelles.Une réponse plus profonde peut aussi être apportée : une approche exclusivement scientifique et technique des problématiques environnementales est trop focalisée ; elle doit s’intégrer dans une démarche multidisciplinaire qui tient compte du contexte sociétal et économique dans lequel elle s’inscrit. On doit alors développer les outils nécessaires au management de l’environnement (réglementation, évaluation environnementale, analyse du cycle de vie, etc.) qui trouve sa place dans une démarche de développement durable.
6. Droit et politique des déchets industriels analyse comparative de six stratégies nationales en Europe
This comparative analysis of six national strategies (Germany, Belgium, Spain, France, Italy, Luxembourg) <law and polities of industrial waste in the countries of the European Union, has the benefit of the colloboration of many specialists in the environmental sector:– CL&A (Cournot, Lemétais & Associés) Business lawyers practice regulary called to intervene in the province of environmental law, a member of Pannone Law Group - an international network, in collaboration with Mr José Santamaria of the Bufete Pinto Ruiz practice and Maître Maude Vézina of CL&A,– Tredi: French leader of environmental treatment of special industrial waste difficulties.
7. Marché des déchets : une concentration croissante: Faits et causes
A trend to concentration (by merging of firms) is observable for example in France, Europe and the USA. The causes or factors of concentration are surveyed. Among the keys of success, one can retain a global offer and financial capacities. Moreover the French case provides an example of clever duopoly: to a complete war between the duopolists are preferred wins in the rest of the world and an increase of the global volume of the market, by pushing up the price and the quality of the service (a win-win issue). However the measurement of the concentration andthe assessment of its effects for the community needmore precise instruments and in depth analyses.