Over the last three decades, several studies were carried out to identify the dominant mechanisms controlling the fate and overall behavior of heavy metals in the soil-water environment. Most investigations focused on describing the sorption and transport of heavy metals under field conditions and in laboratory and greenhouse experiments. Adsorption-desorption on the surface of solid minerals and organic matters is one of the dominant reactions impacting the fate and transport of heavy metals in soils. Most efforts focused on describing the transport and retention of one heavy metal species only. Such an assumption implies that all other interactions that occur in the soil do not greatly influence the behavior of the heavy metal species under consideration. This simplification is unrealistic and does not represent the soil environment, which contains many chemical species having various interactions.