Adsorption isotherms or, more accurately, sorption isotherms are convenient ways to graphically represent the amount of an adsorbed compound, or adsorbate, in relation to its concentration in the equilibrium solution or adsorbent. In other words an adsorption isotherm is a relationship relating the concentration of a solute on the surface of an adsorbent to the concentration of the solute in the liquid with which it is in contact at a constant temperature. Freundlich and Langmuir sorption isotherms are extensively used to describe sorption isotherms for a wide range of chemicals. Knowledge of sorption isotherms and adsorption phenomena is essential for understanding heavy solute retention and transport in soils and geological media. It is crucial for assessing the environmental risk of contamination and pollution provoked by these elements. Studies on solutes adsorption in soils are often conducted as one-component systems, where the ions or molecules are treated individually, or they can be conducted as a multicomponent system, where the ions are subjected to competition among them.