There are numerous types of water and wastewater (supply water, industrial effluents consisting of colloidal suspensions, wastewater contaminated with dissolved organic macromolecules, or oil-in-water (O / W) emulsions) capable of being treated by coagulation, an operation aimed at achieving the destabilization of pollutants through their interaction with a reagent (generally, Al (III) salts). In order to evaluate the removal of organic matter in the pretreatment phase of said wastewater, coagulation, flocculation and sedimentation tests were carried out using inorganic salts such as Aluminum Sulfate and Aluminum Polychloride using different doses of each coagulant, and varying the pH 5 to 9, solutions were prepared with the aluminum salts in a concentration of 30% w / v. With the addition of 25 ml of Aluminum Sulfate for every 500 ml of wastewater and adjusting to pH 7, it was possible to remove 96.40% turbidity in the wastewater, obtaining a 92.72% decrease in the oils and fats present in the wastewater.