| Environnement, ingénierie & développement |  |
N°35 - 3ème Trimestre 2004
1. Le commerce extérieur et intra-Union Européenne de matériaux et produits de récupération: Statistiques et essai d'analyse structurelle
On the basis of statistics from Eurostat, the paper is relating at first for the year 2001 the main exchanges (flows) intra-EU and with the rest of the world (extra-EU), including by countries (for the main countries which are concerned), tonnage and value, by categories of recovered materials and products; a synoptic table is established, the results are summarized and first comments are provided. Moreover the evolution from 1995 to 2001 is related.The available data (even if their reliability is questionable) allow to bring to the fore structural characteristics and some changes:– the part of the metals is paramount (nearly 80%): ferrous in tonnage and value and non-ferrous in value; wastepaper is another important material in the exchanges;– the trade balance with the rest of the world which was in deficit in 1995 has become in excess: it remains in deficit for the metals but has become in excess or the excess increases for most of the other materials and products, due to increasing exports;– concerning the metals, EU imports mainly from other European (extra-EU) countries, while it exports (mainly non-ferrous) to Asia, notably China;– Asia (in particular China) is the major destination for the exports of wastepaper and plastics too;– the textiles show a contrasted picture: exports of old clothes but imports of wiping rags (by-products from sorting old clothes);– EU exports used and retreaded tyres;– EU exports mainly to less developed countries; the […]
2. Approche méthodologique de l'évaluation des risques écotoxicologiques des effluents hospitaliers vis-à-vis de la Step locale et de l'écosystème aquatique récepteur
Chemical substances used in hospital for medical purposes as diagnostics and research reach the wastewater after application. This form of elimination is not exempted of risks for aquatic organisms in contact with the effluents. The aim of this study was to present (i) the steps of an ecological risk assessment and management framework related to hospital effluents evacuated into Wastewater Treatment Plant (WWTP); and (ii) the results of its application on wastewater from an infectious and tropical diseases department of a hospital of a big city of the southeast of France. The procedure called upon a characterization of the hospital effluents in function of their chemical composition, bacterial flora, and their toxicity on different representative organisms of the target ecosystems. In order to characterize the effects, two assumptions have been made. They are related to: (a) the effects on biological treatment process of WWTP, particularly on the community of organisms in charge of the biological decomposition of the organic matter; (b) the effects on aquatic organisms (Vibrio fischery, Pseudokirchneriella subcapitata, Daphnia). The scenario allows to a semi-quantitative risk characterization. The first methology needs to be improved on some aspects, particularly those linked: to ecotoxicological interactions between pharmaceuticals, disinfectants used both in diagnostics and in cleaning of surfaces, and detergents used in cleaning of surfaces; to the interactions into the […]
3. Élimination du phosphore, de l'ammonium et des nitrates par alternance de phases dans des réacteurs biologiques
This article concern the elimination of orthophosphates, ammonia and nitrates in waste water. A sample of activated sludge has been taked from biological reactor of a classical plant of waste water treatment to sow two tanks of our installation. A nutritious solution enriched in substrates (PO43- and NH4+) has been prepared to be introduced in the tanks. The volume of the biological reactor has been optimised by reducing the de-nitrification time in favour of the nitrification time. The alternation of phasis aerated and non-aerated into a pH zone essentially basic (near by 9) had been respected. After acclimatization of the microorganisms and their multiplication during this stage, the cultures had been injected continuously by the prepared solution. The results has showed: a totally transformation of ammonia, an elimination of 99% of orthophosphates; the speed of dephosphatation has rised 83,40 mgP.g-1VMS.d-1, the speed of de-nitrification has rised 379 mg N-NO3-.g-1VMS.d-1. The interest of this study is to deal with the orthophosphates, ammonia and nitrates discharges in a small- sized tanks.
4. Stockage des déchets dangereux en centres collectifs en France: Quels impacts sur l'environnement ?
Industrial players in the field of hazardous waste landfill, as represented in the French federation on waste services and remediation (Fnade), in partnership with the French environmental agency (Ademe), evaluated the environmental impacts of this activity. This study applied an internationally recognised Life Cycle Analysis approach to establish a true and objective picture of the environmental interactions. The LCA indicates that overall, the environmental impacts are lesser than for other activities operating at a national scale for which bibliographical data is available. The study also pointed to areas of improvement in environmental performance for the activity as a whole, for example by substituting by partially substituting raw materials used in the stabilization process with industrial by-products.
5. La banque de données CIBLEX, une compilation de paramètres d'exposition de la population française au voisinage d'un site pollué
In addition to the identification of the potential exposure pathways of the population, the quantitative impact assessment of a soil pollution requires the best available knowledge of the daily exposure parameters for the people living in or near the polluted area. Aiming to characterize in this way the French population, the French Agency for Environment and Energy Management (Ademe) and the Institute for Radioprotection and Nuclear Safety (IRSN) collaborated to produce the computer databank Ciblex. It describes the exposure parameters of the population (age, sex, activities, dietary habits…) as a function of the land use (artificial areas, semi-natural land, water surfaces…) and its corresponding vocation (residential, professional, leisure…). These data can be consulted individually for several geographical levels, or they can be extracted from the bank in correspondence with an exposure scenario, which is defined by the user for a reference group. The Ciblex bank constitutes a consultative tool developed in priority for experts involved in risk assessments associated with the management of area polluted by chemicals or radionuclides. But it is equally very interesting for most of the environmental problems that need to characterize a site or a population.