The Freundlich equation is a mathematical model used to describe the adsorption of molecules onto surfaces. It is particularly useful in understanding how different substances interact with solid materials, such as activated carbon or soil. The equation indicates that the amount of substance adsorbed increases with concentration, but at a decreasing rate, reflecting a non-linear relationship. This model is often applied in fields like environmental science and chemical engineering to optimize processes such as water treatment and pollutant removal. By using the Freundlich equation, researchers can predict how effectively a material will adsorb contaminants from various solutions.