Tratamento de águas residuais de uma indústria de biodiesel. Método combinado de coagulação, floculação e flotação por ar dissolvido

Abstract

The aim of this research was to evaluate the efficiency of the treatment of waste water from purification of biodiesel following a combined method of coagulation, flocculation and air flotation. The effect was evaluated through the analysis of the following parameters: dose of coagulant, pH, dose and type of polymer and saturated water used. This experiment had three phases, the first consisted of the assessment of the quality of wastewater from a biodiesel plant, the second was the choice of a more efficient polymer for the removal of turbidity, and the third a verification of the efficiency of the treatment through the analysis of color removal. In the first model all the factors influenced the effectiveness of the treatment and it was observed that by fixing two factors, pH and saturated water, and varying the dose of coagulant and polymer, we would get a more efficient treatment. The removal of the turbidity reached 99.99%, the values of 21NTU, and in the color an average removal of 99,9% up to 141 NC. Thus, this treatment could be used for clarification of waste water, when followed by another treatment in order to allow further use, or discharge in natural streams.