Natural Coagulant Functionalized with Magnetic Nanoparticles Better Treated Dairy Wastewater Compared to Bioremediation

Several wastewater treatments are available nowadays, and the comparison among them is important when choosing the most suitable one. We investigated two emerging treatments for dairy wastewater, bioremediation, and coagulation/flocculation/sedimentation (C/F/S) using a natural coagulant functionalized with magnetic nanoparticles, applied as a single step and also as a sequence. In the enzymatic treatment, lipases (500 U L⁻¹) were used to hydrolyze fats at 96 h at 37 °C, while C/F/S evaluated different biocoagulant preparations, differing the salt and concentration used but with lower times (< 1 h). Bioremediation was the best one for total organic carbon removal, however, for every other investigated parameter, including the toxicity test with Artemia salina, C/F/S was even better than the sequential process. The results achieved with this treatment include a turbidity removal of 86.8%, and 74.0% oils and grease removal. Thus, C/F/S proved to be an excellent primary treatment since satisfactory results were achieved in a much shorter time compared to bioremediation. The proper dairy wastewater treatment aid in the maintenance of a balanced environment, contributing to the worldwide preservation purpose, while maintaining the social and economic relevance of this sector.