With increasing population growth and industry progress, water scarcity has become a crisis. In the meantime, the increase in industrial waste mainly containing heavy metals has contributed to this crisis. Therefore, industrial wastewater treatment can solve this problem. Nanoparticles have been considered as one of the most effective adsorbents in the process of adsorption of heavy metals, with the development of nanotechnology in various fields, including water and wastewater treatment. In the present study, adsorption of zinc, lead and copper ions simultaneously by magnetic iron oxide nanoparticles in fixed bed and discontinuous systems was investigated. After the nanoparticles were saturated to reuse, the experiments continued with the desensitization of the nanoparticles. The results of the adsorption process in the discontinuous system indicate that the optimum pH for removal of heavy metals is about 6, because at pH less than 6 the absorption efficiency decreases and begins to precipitate at pH above 6 heavy metal salts. The results also show that after 25 minutes about 50, 40 and 10% of lead, copper and zinc have been adsorbed respectively. After this time, the steepness of the heavy metals concentration change is low, so the optimal time for the adsorption of this number was reported. On the other hand, the effects of factors such as the change in the concentration of heavy metals and the amount of nanoparticles have been investigated, which indicate that these two counteracting behaviors are different in the sense that the adsorption efficiency increases with increasing the amount of nanoparticles and decreases with increasing concentrations of heavy metals. Another result obtained in this study is the different selectivity of nanoparticles, which tend to decrease the adsorption of nanoparticles for lead, copper and zinc, due to the difference in their electronegativity. The adsorption capacity for lead ions, copper and zinc is 31, 16 and 3 milligrams per gram of absorbent, respectively. In the fixed bed system, due to the discontinuous part of the results, the effect of two factors on the amount of nanoparticles and the change in wastewater flow was investigated. The results showed that with increasing of discharge, the adsorption efficiency decreased and with increase in the amount of nanoparticles, the adsorption efficiency increased. One of the important characteristics of the adsorption process is the possibility of recovery and reuse of the adsorbent. An acid solution should be used for the desorption process of the nanoparticles. Among existing acids, Hydrochloric Acid it was selected for availability and application in research. In the discontinuous system, experiments showed that hydrochloric acid with a concentration of 0.007 molar and a volume of 150 milliliters was an appropriate restorer for the desorption of nanoparticles from three lead, copper and zinc ions. After recovering concentrations and volumes of recovery, successive adsorption and desorption cycles in the fixed bed system were investigated, which indicated that, for at least 5 consecutive cycles, the hydrochloric acid as a reducing agent had the ability to completely restore the nanoparticle capacity Keywords : Adsorption process, heavy metals Zn, lead and copper, magnetic nanoparticles, iron oxide nanoparticles, fixed bed process, desorption process