Abstract: Heavy metal contamination in agricultural systems - soil and irrigation water - is a challenging problem with serious consequences on food safety and human health. Unlike most traditional treatment methods, engineered nanomaterials provide a unique opportunity to prevent and remediate heavy metal contamination in water and farm soils. However, there is a wide knowledge gap on the fundamentals of interactions between nanoparticles and dissolved toxic metallic ions in complex agricultural matrices. This dissertation focuses on understanding the unique chemistry of interactions between nanoscale zerovalent iron (NZVI) and metallic contaminants in water and farm soils and demystifies NZVI-based treatment.