Steffens, JulianaOldoni, Bianca Trindade2021-02-242021-02-242020http://repositorio.uricer.edu.br/handle/35974/276The dairy industry is one of the main sectors of world food production, receiving great prominence in Brazil. However, it is among the biggest polluters because of the high rates of effluent emissions due to the use of water in various stages of its processes. In view of the reduction of environmental impacts and the current legislation on the release of effluents, these industries seek to carry out sustainable and more viable treatments of these residues, such as the application of natural coagulants in their processes. The most common methods for treatment are the coagulation-flocculation physicochemicals, characterized by the clarification of waters and the concentration of solids in the form of flakes, driven by the use of inorganic or organic coagulants. In this context, the present work aimed to evaluate the efficiency of the application of natural tannin-based coagulant (Tanfloc SG) in relation to the application of inorganic coagulants (aluminum sulfate, aluminum polychloride and ferric chloride) in the treatment of liquid dairy effluent. For this purpose, independent coagulation tests were performed between two distinct brands of powdered milk that simulated the effluent, through the use of the coagulants of tannin, aluminum sulfate, aluminum polychloride and ferric chloride. In this way, the most effective brand was selected, in addition to the minimum dosages required for each coagulant. This followed to a simple coagulation-flocculation procedure based on the minimum concentration found for the coagulants. In response to the efficiency of the process, the parameters of pH, color, turbidity, total solids (ST), suspended solids (SS), sedimentable solids (SSed), total organic carbon (COT) and total nitrogen (NT) were proceeded, in addition to percentages of color removal, turbidity, COT and NT. The analysis showed that the treatments generated a post-treatment effluent that comply with the standards established by the legislation for release into water bodies, except for the necessary adjustment of the pH for some samples coagulated with ferric chloride and aluminum sulfate. Reductions in color and turbidity (~ 99%) were observed for all coagulants used. For COT and NT, more effective reductions for tannin and aluminum polychloride can be seen, between 80 and 90%, respectively. The coagulants were later compared for economic viability based on the cost per m³, bringing the tannin as of lower value. Therefore, based on the results found, tannin is found to be a cheaper, viable and effective treatment alternative to chemical coagulants, in addition to causing less damage to the environment as it is of natural origin, being considered sustainable.pt-BREngenharia QuímicaEefluente líquido de laticínioCoagulação-floculaçãoTaninoTrabalho de Conclusão de Curso