Fate and Transport of Engineered Nanoparticles in Porous Media

Abstract

This chapter presents the leading processes that control the fate and transport of engineered nanoparticles (ENPs) in soil and groundwater. Because all future scenarios indicate fast development of new ENPs, and increased production and applications of currently available ENPs, their unavoidable release to soil and groundwater is expected to grow. A complex interplay between soil solution, soil characteristics, and the ENP properties determines the leading retention mechanism(s) and the extent of the mobility of ENPs in porous media. In this chapter, we first introduce selected ENPs that are relatively common in soil and groundwater environments. We then offer an overview of the leading weathering scenarios of ENPs considering aggregation, chemical transformations, coating, and interactions with other components of the soil solution. We discuss the principal transport and retardation modes of ENPs. This part focuses on four retention mechanisms: physical straining, physicochemical interactions, film straining, and attachment to the air–water interface. Finally, we present cotransport of ENPs where relatively mobile ENPs can facilitate the mobility of potential pollutants that could amplify contaminant spreading.