Dye pollution in waste waters causes serious environmental and health risk, legislation problems and is a serious challenge to environmental scientists. In this work the treatment of waste waters resulted from ink jet cartridges manufacturing, using different nanocrystalline ferrites MIIFe2O4 (MII = Mg, Cu) as adsorbent materials, has been investigated. The ferrites were obtained by thermal decomposition at 500°C of the magnesium and copper ferrioxalate coordination compounds. The nanocrystalline ferrites powder was investigated by various methods such as XRD, IR, SEM and EDX. The discoloration of the waste waters has been spectrophotometrically studied. The ferrites could be removed easily after adsorption by using a magnetic filtration process. The results indicated that the maximum adsorption efficiency was obtained after 60 min of treatment, magnesium ferrite showing a higher efficiency than the copper ferrite in the treatment process of waters resulted from ink jet cartridges manufacturing.