Transport of Reactive Solute in Soil and Groundwater

Abstract

The extensive impacts to soil and groundwater by contaminants such as chlorinated solvents and petroleum hydrocarbons can be attributed to their widespread use in the United States and to their persistence in the environment. Understanding the fate and transport of these pollutants and other solutes is essential for the protection of water supplies and successful field site remediation. Subsurface solute fate and transport is dictated by processes that fall into the general categories of hydrodynamic, abiotic, and biotic. Hydrodynamic processes that include advection and dispersion influence flow patterns through the vadose zone and in groundwater. Those processes that impact solute interactions with the surrounding aquifer matrix, such as sorption or the composition of the contaminant itself, are known as abiotic. The biotic category is variable based on available substrates and nutrients, but under certain favorable conditions, these microbial processes can have a profound impact on contaminant structures and their longevity in the environment. Transport processes are extremely difficult to quantify because of the vast heterogeneities encountered in the field; however, improving our comprehension continues to be an area of extensive research for many science and engineering fields.