One of the essential directions of research to be addressed in the coming decades is the sustainable water management. Due to the growing industrial activities, the water pollution became one of the most serious ecological threats we face today. Thus, as water resources are important to both society and ecosystems, it may suffer drastic variations in the near future. In this context, a major issue is represented by the treatment of wastewaters containing high heavy metal ions or various organic loads. Besides the chemical and biological methods to remove pollutants from wastewaters, physical adsorption is an effective process. However, in spite of the performant sorption, a major drawback is the recovery of the sorbent from the water. Thus, the magnetic separation is a challenge to solve such inconvenient, being an inexpensive alternative for conventional separation technologies. In this respect, rare earth - doped ferrites modified with a chitosan shell are studied as potential adsorbents due to their appropriate physical characteristics and facile separation under external magnetic fields. The proposed rare earth - doped ferrites are obtained by sol-gel auto-cmobustion method, where occurs the substitution of iron by rare-earth cations, resulting in the formation of nanocomposites during sintering. The prepared composite nanoparticles are then coated with a chitosan shell, characterized by various techniques and tested as sorbents for heavy metals in simulated wastewaters.