Contaminations by Staphylococcus aureus in food industry environments have been extended to industrial Effluent Treatment Plant (ETP). The methodologies used in ETP for bacterial removals and quality parameters adjustment commonly use products toxic to the environment, being mostly inefficient against virulent bacteria such as S. aureus. Seeds of Moringa oleifera Lam. (MO) have potential to be used in ETP as an alternative to harmful products, as it has both the ability to regulate the physicochemical parameters of water and has antibacterial action. Functionalization of MO with magnetite magnetic nano particles (Fe₃O₄) at nano scale focusing on coagulation and flocculation of wastewater has been gaining prominence. Therefore, the present study evaluated the potential use of the magnetic coagulant MO-Fe₃O₄ in the elimination of S. aureus in synthetic dairy effluent; concomitantly sought to adjust the quality levels of physicochemical parameters. MO-Fe₃O₄ added to synthetic dairy effluent at different concentrations amounted to 16 treatments, which were evaluated for removal of color, turbidity, UV_254nm and S. aureus on the effluent surface and sludge after 30 min of sedimentation. The results confirmed the efficient elimination of S. aureus simultaneously with a significant reduction of the physicochemical values, with constant efficiency up to 30 min. Scanning electron microscopy images confirm the removal of S. aureus on the effluent surface and sludge. Thus, this study was able to present a natural coagulant capable of remove bacteria and adjust the quality levels of the effluent after 10 min of sedimentation, making this biotechnological innovation highly applicable to ETP. GRAPHICAL ABSTRACT