| Environnement, ingénierie & développement |  |
N°27 - 3ème Trimestre 2002
1. Éditorial n°27 Déchets Sciences et Techniques: La science au service d’un développement durable ?…
« La Science au service d'un développement durable » est le titre d'un rapport (www.recherche.gouv.fr/rapport/devdurable) préparé à l'occasion du Sommet de la Terre réuni récemment à Johannesbourg. Ce document a été réalisé par les principaux organismes de recherche français à la demande du ministère chargé de la recherche. Sa lecture est très intéressante pour tous ceux qui se posent (encore ?) des questions sur le contenu « tangible » du concept de développement durable et sur son opérationnalité.Le rapport dresse un bilan très complet des actions engagées en France, en particulier depuis le sommet de Rio, en abordant tous les domaines concernés, classés selon les trois enjeux majeurs : i) lutte contre la pauvreté et promotion de modes de substance viables, ii) modes de consommation et de production durables, iii) gestion plus responsable des ressources naturelles. La France a une longue tradition de travaux de recherches orientés vers les besoins des pays du sud, comme le démontre l’existence de l’Institut de recherche pour le développement (IRD) ou bien celle du Centre de coopération internationale en recherche agronomique (Cirad). Les autres principaux organismes participent aussi très largement aux recherches concernant l’environnement (changement climatique, ressource en eau, énergie, procédés propres, impacts écologiques…) et les sociétés humaines (agriculture, démographie, impacts sanitaires…).Les […]
2. Modélisation et simulation de la gestion et du traitement des déchets ménagers
The management of household waste is evolving rapidly under the regulatory pressure, which was initiated in France by the 1992 law. Traditionally based on standard collections and landfilling, it now involves new treatment techniques such as incineration, recycling or composting. When adapting their waste management system, local communities are facing difficult decisions. Choices have to be made regarding the treatment techniques and waste collection schemes. But it is often difficult to evaluate the technical, environmental and financial consequences of these choices. For that reason, a computer simulation system was developed at the Ecole nationale supérieure des mines de Saint-Etienne. Its main features are presented together with examples of simulation results. Among the situations that can lead to the use of this computer tool we can mention the comparison of different treatment scenarios on a financial or environmental basis or the assessment of decisions such as the union of waste treatment syndicates. The proposed model is based on the combination of individual models of treatment units and of mater and money fluxes. Each of these models has to be chosen according to the simulation goals in a database which can be increased with time to better reflect the diversity of situations.
3. Optimisation du traitement des boues: Usine de traitement des effluents de distillerie Mohan Meakin Ltd., Uttar Pradesh, Inde
The present sludge treatment of the distillery waste water treatment plant Mohan Meakin Ltdd (550 m3/d), India, is not adapted; the secondary sludge, which volume flow rate is not measured, are directly sent on four drying beds, presenting a total surface equal to 204 m2: the final dryness, not measured, is inferior to 20% since the sludge are not shovellable after drying.These sludge are presently end used for agriculture,without any stabilisation.The proposed solutions are the measure of thesludge draw off, the sludge thickening by means ofa new cylindro conical settling tank, drying byseven drying beds, presenting a total surface equalto 1120 m2, and finally a stabilisation by means ofcomposting with household refuses.The final stabilised sludge dryness should be equal to 65%.
4. Étude comparative de la faisabilité de biotraitements des sols pollués par des produits pétroliers
This comparative study of the feasibility of biotreatments is focused on the soils of two moldavian oil deposits. After the determination of soil characteristics to be processed, the study has been undertaken with five laboratory scale reactors by applying adapted different methods. The continuation of the process is developed and a comparative statement on the efficiency of the process is done. We have studied possibilities of bioremediation of two moldavian oil deposits: the site of Vatra is polluted with gasoline and diesel oil and Orhei disused site is polluted by mineral oils.
5. Étude expérimentale de la biorestauration des sols souillés par les hydrocarbures
The biodegradation is considered an efficient and economic tool in resolving hydrocarbons soil contamination problems. The feasibility study of this technique for four soil types, which are particularly exposed to this risk, is the main object of this work. It is shown from the experimental study that many factors affects this phenomenon. The hydrocarbons biodegradation rate is related to the nature of the solid matrix, the hydrocarbon type, initial concentration of the contaminated soil and the availability of nutriments.Thus, for the same soil type, the petrol is the most biodegradable hydrocarbon with a rate of 50 %, than comes the diesel oil with 33 % and the fuel with a rate of 17.6 % relatively to the non evaporated hydrocarbon fraction. The clayey soils are the most unfavourable for the biological remedial of hydrocarbons pollution, the least biodegradation rates are recorded in these soils.The control of bacteria populations growth in time has permitted to define an optimal time period for ending a biological treatment plan of an hydrocarbon contaminated soil.
6. Identification de nouveaux composés phénoliques présents dans les rejets liquides d’huileries d’olive (margines)
Olive mill wastewaters (OMW) constitute a major environmental problem particularly in Mediterranean countries. Most of the biological treatment processes, physico-chemical treatment or valorisation methods of OMW showed some limitations. This could be partly due to the heavy load in organic compounds and to the high load in polyphenols of these sewages. The phenolic compounds are toxic for fauna and flora, inhibitory of the biological activity and their biodegradation is very difficult. The analysis by GC/MS of different samples of OMW, permitted to identify a big variety of phenolic compounds. Several of these have been identified for the first time. In this work we analysed a variety of phenolic compounds depending on the different processes of olive oil extraction and the influence of storage time.
7. Vulnérabilité face aux risques liés au transport de matières dangereuses : apports de deux méthodes multicritères d’aide à la décision
The study aims at establishing a method of assessment of the vulnerability of the territory faced with hazmat risks. Hazards linked to the transport ofdangerous goods (TDG), unlike other technologicalhazards, present the specificity of having a mobilesource of danger, implying various risks with a diffusenature. In the framework of terrestrial TDG, focusingthe attention on the territory allows to handlethe TDG risks globally. Consequently, the places ofhazard are constituted by the transport axes e.g.rail and road routes and several elements are liableto be exposed within the territory, and particularlyin the borders of the TDG routes. A preliminary study of the concerned territory allows us to foresee the latter elements according to the following typology: human, material and environmental targets, and to anticipate clusters of consequences, potentially resulting from the effects of a TDG accident on the targets. Target sensitivity to differenttypes of effects and predictable consequences serveas indicators of territory sensitivity. The applicationof two multicriteria decision support methods –Analytic Hierarchy Process [SAA 80], Satisfaction –Regret Method [FUS 94] [FUS 00] – to this problematicprovides a prioritisation of the different targetsaccording to their level of vulnerability. Thisspatial analysis method connected with both a geographicalinformation system and a risks simulationsoftware is intended for the French civil security.