John Libbey Eurotext

Environnement, Risques & Santé


Toward rational management of excavated soil contaminated by metal trace elements Volume 11, issue 1, Janvier-Février 2012


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Université de Toulouse INP-ENSAT Avenue de l’Agrobiopôle 31326 Castanet-Tolosan France, UMR 5245 CNRS-INP-UPS EcoLab (Laboratoire d’écologie fonctionnelle) INP-ENSAT Avenue de l’Agrobiopôle BP 32607 31326 Castanet-Tolosan France, STCM (Société de traitements chimiques des métaux) 30, avenue de Fondeyre 31200 Toulouse France

In France, the metallurgical industry is often responsible for soil contamination by metal trace elements (MTE) either deposited from the atmosphere or due to waste storage. Previously located on urban outskirts, some sites are now abandoned inside cities and can present environmental health risks to surrounding populations. Governments and society in general are becoming increasingly aware of the need to rehabilitate these brownfields, especially in view of the value of the land they pollute. Remediation of soils contaminated by MTE can involve different processes: stabilization, washing, etc. For urban sites, however, excavation is almost routine. The excavated earth can then be handled in two ways: sent to landfills, which is an expensive and energy-intensive solution, or reused or recycled, in a strategy of sustainable development. The choice depends on the nature, concentration and speciation of the soil pollutants. The greater the contamination and the potential for leaching, the greater the hazard. The landfill destination may then become inevitable, and will require substantial outlays to ensure its security. In view of the costs of transporting and storing these wastes, companies should optimize the particle size separation of excavated soil to reduce the amount of pollution and, simultaneously, the risks to people and the environment. This study presents the example of a battery recycling plant and describes the efficacy of size-screening of MTE-polluted soils to promote and maximize reuse.