Geochemical prediction of metal dispersion in surface and groundwater systems

Abstract

Dispersion of contaminants in an aquatic system refers to a process by which dissolved phase concentrations are reduced by the spreading of the plume and hydrodynamic through mixing with cleaner, surrounding water. Thus, metal dispersion in the environment is very distinct and environment dependent but dictated by physical-chemical processes that influence sorption and redox reactions. The reduction in plume concentrations of metal contaminants by dispersion, for instance in groundwater flowing in aquifer sands and gravel, is a very weak process compared to the turbulent mixing processes that occur in the open channel flow of surface water systems like streams. In a nutshell, effective geochemical, geotechnical background including the bedrock and material composition and properties, physical features like topography and the hydrological regime, as well as containment transport dynamics. Further, the climatic factors play a crucial role in the overall predictions. Prediction of metal dispersion is necessary in pollution-prone environments, like mining sites, for establishing early warning systems when the contaminants would reach receiving environments of interest, as well as designing preventive and remediation strategies. This chapter discusses fundamentals in designing effective predictions of metal dispersion in both surface and groundwater.