Industrial effluents are sewage from industrial processes, such as polluted cooling waters and waters used for cleaning. It is extremely important that these contaminated waters undergo treatment to allow for water reuse or safe disposal, without damage to the environment. In the present work, the efficacy of coagulating/flocculating aqueous solutions containing reactive black 5 (RB5) dye was evaluated using protein fractions derived from Moringa oleifera seeds (albumin and globulin) as natural coagulants functionalized with iron oxide magnetic nanoparticles. The application of a magnetic field during sedimentation allowed for faster settlement of the dye particles and their separation. Variations in parameters such as the protein concentration, nanoparticle concentration, solution pH, dye concentration, and the presence or absence of an alkalizing agent were assessed. Moreover, the sedimentation time was analyzed with and without the magnetic field and with the reuse of iron oxide nanoparticles. The functionalized magnetic coagulants were able to remove more than 90 % of RB5 dye within 5 min of sedimentation.