| Environnement, ingénierie & développement |  |
N°6 - 2ème Trimestre 1997
1. La communication sur les déchets industriels
This article brings up the conclusions of a socio-anthropological study, conducted with elected representatives, associations members and private individuals in the Lyon's area. The sleeping partner of this study was the « REseau COopératif de Recherche sur les Déchets » (Research Cooperative Network on Waste) which was interested in the communication on industrial waste.This study was aimed at estimating the level of vocabulary knowledge on the industrial waste classification and management. It also aimed at analysing the industrial waste social representations in the unfamiliar public.The industrial waste communication problem is set out in the conclusions at several levels: linguistic, social, political, and cultural.
2. Faut-il encore avoir peur de nos déchets ménagers ? Un risque redoutable : la dispersion incontrôlée
With real examples in a french department it is seen that household refuse and other similar refuses are not so ordinary that it can be thought. Their scattering dilutes discharges, but often goes with no treatment and then increases health and environment risks. This scattering concerns as much products as refuses which follows from them.
3. Appareils électroménagers en fin de vie. Méthodes d'estimation des flux
The flows of the electrical domestic appliances at the end of their life may be estimated:• directly, by quantification of the waste flows which are collected or/and treated,• indirectly, by two methods:- knowledge of the sales of (new) appliances and estimation of their lifelength,- knowledge and time comparison of the successive states of the households equipment (to estimate the output). The paper examines the advantages and the limits or constraints of these methods and gives quantitative results which have been obtained by indirect way.
4. Stabilisation des résidus solides de l’incinération par le procédé TREDI-ASH
Tredi-ASH is a chemical leaching process used to extract mobile metal pollutants from industrial wastes incineration slags. An exchange reaction with CaCl2, obtained from wet gas cleaning neutralization allows to detoxify and to stabilize an important fraction of slag's original weight (70 to 95% dry weight), reducing ultimate waste volume as described in a previous article (Venditti et al., 1996). The removal of soluble metals and related compounds contained in the slag leachates is performed in a “biosorption” process: metals are adsorbed and complexed on the biochemical components (-SH, -COOH, -OH) of dead biomasses, as described herein.
5. Hétérogénéité et homogénéité. Application à l’échantillonnage de mâchefer issu de l’incinération de déchets industriels
The mathematical equivalence between homogeneity of any matter and uniqueness of experimental results obtained from repeating the test with different samples involve that the study of the sampling is required only if the matter is heterogeneous regarding the property which is being studied. Thus the sampling of slag from the industrial wastes of the Tredi Plant (in Strasbourg) must be carried out regarding the determination of the content and the leaching but is not needed regarding the heat treatment and leaching of the heat-treated slag in the testing conditions.
6. Étude de la répétabilité de la réponse à un test de lixiviation sur du mâchefer d'UIOM
For this study, a great number of leaching test has been done on the same waste to energy bottom ash. The influence of sampling on the results is very important. Despite many precautions, the whole repetitiveness (sampling, leachting test, analysis), is not enough regarding some chemical parameters, if standard Afnor X-31 210 is strictly applied (4 mm crushing).
7. Déchets de chantier de bâtiment. Les actions de la Fédération nationale du bâtiment
For our modern society, waste management becomes more and more a priority. Meanwhile, the legal framework is old: law of July 15, 1975 - anybody producing or keeping waste (...) has to manage the waste disposal. In a first step, the public Authorities action was oriented towards domestic waste disposal and in a second time aimed to dangerous waste of the industrial activities. Due to their own specificity, construction and demolition waste (about 25 millions tuns a year) couldn’t take place among the above categories, leaving alone the building firms: closing down of the dumping waste, difficulties to find places to get rid of and as well, growth of elimination costs reaching about 1 to 6% of the turnover construction. ln this downward trend, building contractors and their professional Organization are involved to set up a management in order to eliminate construction and demolition waste at the best price.
8. La gestion des déchets sur les chantiers verts
The Green Building Sites launched by PCA and followed up by CSTB, are construction and maintenance experimentations, which aim is to test ways of reducing waste production, of improving their recovery and of organizing their sorting on the building sites. Here are examples of solutions tested.
9. Étude de l’impact de la mise en décharge de déchets de démolition contenant du plâtre
The gypsum included in building demolition wastes stored in « class Ill » waste disposals could increase the sulphate content of the leach. This leach could percolate into the substratum of the waste disposal site to an aquifer and represent a potential pollution source. Hydrogeological modelling has been used to quantify the consequences of the sulphate transport in geological layers. A second consequence of the sulphate pollution could be a geochemical effect between releasing water, the substratum and groundwater flow. A geochemical modelling has simulated and specified these kind of interactions.
10. Biotraitement en réacteur de polluants organiques contenus dans les sols argileux
Static bioremediation of clayey soils polluted by contaminating organics is very difficult because, most of the time, both reagents and reaction products mass transfer between the solids particles and the aqueous or gaseous phases are limited. Dynamic treatment, by means of agitated and aerated bioreactors, applied to the remediation of sludge or soils represents an attractive alternative process route.
11. Étude du devenir des composés organostanniques butylés et phénylés Au cours d'un dragage portuaire: Cas du Port d'Audenge
The legislation introduced in 1982, prohibiting the use of tributyltin (TBT)-containing paints on vessels under 25 meters lengths, did not totally eliminate this biocide, toxic to aquatic life, in marine environment. TBT, preferably absorbed on finest particles in mud and sediments, is a potential source of contamination during civil engineering works such as dredgings. The results of an analytical study, realised during the dredging of the port of Audenge, has pointed out that the sludge treatment process, including both air oxidation and light exposure, minimizes organotin contents of the water effluent.