The aim of this work is modeling and optimizing the removal nickel ions from aqueous solutions on the phosphogypsum. For this, a physicochemical study of the adsorption was carried out by studying the effect of some parameters on the clearance to aqueous solutions, in particular the adsorbent dosage, contact time and initial Ni(II) concentrations, on the adsorption capacity. The adsorption isotherms according to the model of Langmuir, Freundlich and Temkin were studied. The obtained results show that the adsorption of Ni(II) on the phosphogypsum follows the Freundlich isotherm. A Central Composite Design (CCD) was applied to evaluate the interactive effects of adsorption variables and to optimize the adsorption process of Ni(II) ions from aqueous solutions onto phosphogypsum. The optimal condition obtained was located and the optimum adsorption factors were predicted as a contact time of 19.02 min, initial Ni(II) concentrations of 111.80 mg/l and an adsorbent dosage of 13.90 g/l.