Evaluación de residuos vegetales de papa, yuca, camote y plátano, como coagulantes naturales para el tratamiento de aguas residuales procedentes de la industria láctea.

Abstract

The objective was to evaluate residues of potato, cassava, sweet potato and banana, as natural coagulant in the treatment of waste water from the dairy industry. The residues were dehydrated and ground to obtain pulverized Dehydrated Vegetable Residues (RVD), moisture, ash, protein, fiber, digestible carbohydrates and fat were evaluated. Tests of the coagulation-flocculation process with RVD were divided into two stages. In the first one, the optimum dose of utilization and the RVD of greater potential were determined, for this it was used dilutions of the RVD to 2% and 10% in water, it was dosed from 1mL to 10mL per liter of milk residual water and by the jar test it was determined that all RVD had potential coagulant and its optimal oscillated 7mL and 10mL/L at 10% dilution. The Dehydrated Plantain Vegetable Residue (RVDP) using 10mL/L of residual water, presented superior results compared to the other residues, in terms of pH, turbidity, color, SST (Total Suspended Solids), ST (Total Solids). In the second stage, it is investigated to potentiate the coagulant power of RVDP by varying the pH (4-5; 9-10) and with the flocculation aid (0, 5% anionic polymer and a dose of 0,5mL/L). Measured the parameters already mentioned and also BOD5 (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), oils and fats. The results of this stage showed a better action of RVDP in an acid environment, with a 98% removal of turbidity, 82% of color, 99% of SST, 84% of ST, 76% BOD5, 54% COD, and 95% of oils and fats. It is recommended to perform studies with RVD inanother type of wastewater, thereby replacing or decreasing the excessive use of chemical coagulants.