Improper disposals of hazardous wastes in the subsurface are threatening the environment and public health worldwide. In situ treatment technologies for restoring groundwater quality are often based on the delivery of chemical substances into the contaminated media to promote favourable reactions. Local heterogeneities and the presence of well-connected permeable structures typically prevent those chemicals from fully mixing within the contaminated media, i.e., the injected compounds cannot access the contamination trapped in low permeability areas. The rationale of the proposal contends that by inducing temporal fluctuations of water fluxes through a set of extraction/injection wells one can enhance the delivery and subsequent mixing of chemical compounds into the contaminated media. Moreover, for sites contaminated with heavy metals, these temporal fluctuations of water fluxes can further disperse the precipitation front associated with immobilization techniques, retarding clogging effects and enlarging the area of application. This project proposes a combined numerical-theoretical analysis to examine the potential applicability of such techniques. The project tackles basic research questions as well as the development of new modeling methodologies and tools aimed at making proper predictions of this type of remedial efforts. Basic research will analyse the effects of enhanced mixing and delivery due to temporal fluctuations of water fluxes, and their corresponding effects on the precipitation front formed during metal remediation. First, solute tansport experiments perfomed in large-scale experimental tanks with synthetic heterogeneous aquifers will be used to identify and characterize processes so as to better quantify the efficiencies obtained during the application of such techniques. These processes will be incoporated into efficient reactive transport codes that can properly describe in detail natural heterogeneity as well as geochemical reactions. These models will be used to interpret the experiments and to study unknwon processes.
Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2008-2011
Biodiversidad, Ciencias de la Tierra y Cambio Global
Ciencias de la Tierra
Proyectos de investigación y acciones complementarias-CGL (BTE). Proyectos de investigación
Gobierno De España. Ministerio De Economía Y Competitividad, Mineco