resumo
The growing concern about the sustainability of soil remediation technologies and operations lead to the development of different support decision methods. Life cycle assessment (LCA) methodologies have well-developed methods for assessing environmental impacts for emissions to air, surface water, and surface soil, but deep soil emissions and emissions to groundwater have received little attention. Regional impact of groundwater extractions has largely not been considered in LCA as well, nor their relation to surface water bodies and groundwater-dependent ecosystems. These aspects are now compulsory in the management of water resources in Europe, under EU Water Framework Directive. Future developments in LCA will necessarily have to include these relations in the characterization of the impacts. Given the strong retardation that many pollutants undertake in the soil, the temporal factor is relevant in the groundwater compartment, as contamination may extend for decades. Moreover, groundwater contamination due to industrial sources, including soil remediation, tends to be spatially concentrated, dispersing from the point of origin depending on hydrogeologic conditions, soil retention capacity, pollutant’s degradation rates, and time. Exposure to contaminated groundwater is frequently assessed by modeling; however, the proposed models require detailed information about soil properties, which is usually not available, nor is it possible to obtain in the scope of a life cycle assessment. Simpler methods are therefore needed. The present article discusses some of these alternatives, in particular applied to soil remediation with electrokinetic methods. The use of in situ electrokinetics for the remediation of fine-grained soils requires contaminants to move from their initial location to an electrode. The migration path can be long and there could be stagnant zones between wells where the rate of migration is slow, both of which can result in an incomplete remediation and to potential impacts on groundwater.
autores
L M Nunes, H I Gomes, M Ribau Teixeira, C Dias-Ferreira, A B Ribeiro
nossos autores
Célia Maria Dias Ferreira
Bolseiro de pós-DoutoramentoGrupos