The study on the adsorption of Cd(II) ion waste in the presence of Mg(II) dan Cu(II) simultaneously ions by dithizone-immobililized natural zeolite has been conducted. The results were compared with those adsorbed by unmodified active natural zeolite. The study included modification and characterization of adsorbent, pH optimization, kinetics, and adsorption isotherm. The modification of natural zeolite was done by refluxing it with dithizone in toluene. Adsorbent characterization was perfomed X-ray diffraction and infrared spectrometry. The results showed that dithizone was successfully immobilized on to the surface of natural zeolite and the immobilization did not significantly affect zeolitecristalinity. Optimum pH for the adsorption of Cd(II) ion waste in the presence Mg(II) and Cu(II) simultaneously was 5. Adsorption kinetics was studied using Langmuir-Hinshelwood simple model of order 1. Adsorption kinetics parameters showed that Cd(II) adsorption rate constant of adsorbent active and dithizone-immobilized zeolite was 1.00 x 10-4 minute-1 dan 3.00 x 10-3 minute-1, respectively. Equilibrium constant of active and dithizone-immobilized zeolite was 2.95 x 104 L/mol and 3.96 x 104 L/mol, respectively. Adsorption of Cd(II) in the presence of Mg(II) and Cu(II) simultaneously on active and dithizone-immobilized zeolite was believed to be chemisorption, with the adsorptionenergy of 30.17 kJ/mol and 32.11 kJ/mol, respectively. In general, it was shown that the ability of dithizone-immobilized natural zeolite for the adsorption of Cd(II) in the presence Mg(II) and Cu(II) simultaneously was better than the active natural zeolit
