The heavy metals found in contaminated waters are dangerous for the environment and human health, so it is necessary to seek and apply techniques to remove these pollutants, using adsorption techniques with natural biopolymers such as cocoa shells,characterizing the adsorption by infrared spectroscopy, obtaining values of (k) Freundlich's constant whose highest value is for the lead cation and the lowest for the more hydrated cation such as copper, presenting an opposite behavior for the exponent "n" of Freundlich's equation. The use of the cocoa shell as an adsorbent is an alternative to remove these contaminants from the water.