Eficiência dos processos de flotação e filtração com uso de coagulante natural e químico no tratamento de efluente de laticínio

Abstract

The dairy industry constitutes a significant portion of the worldwide food industry, particularly when it comes to production volume. This high production also brings an elevated sewage production with big pollutant potential, due mainly to the large amount of organic matter present in the effluent. However, there are some problems associated with the use of chemical coagulants in wastewater treatment, which has aroused the interest of researchers to seek alternative ways for its use. Among the most studied forms, there may be mentioned natural coagulants such as Moringa oleifera seed, which has stood out in the water treatment as well in effluent treatment. The aim of this study was the treatment of dairy effluent through the techniques of coagulation / flocculation / flotation / filtration using Moringa oleifera coagulant and chemical coagulant polyaluminum chloride (PAC), comparing their performances. Through trials with floteste and sand filters, different concentrations of each coagulant were applied to the present effluent and the effectiveness of treatment in removing the parameters pH, apparent color, turbidity, electrical conductivity, COD and number of solid was evaluated. It was found that the chemical coagulant had a strong influence on the pH and electrical conductivity, unlike natural coagulant. For the other parameters evaluated, in general, the highest concentrations of coagulant showed better efficiency. For COD, the natural coagulant reached 16.82% removal after filtration the concentration 3. Moringa oleifera showed a removal of 34.7% to the apparent color, 40.4 % to for turbidity and 92.8% for volatile solids. To PAC, obtained removal of 90.5%, 90.85% and 72.3% for the same parameters, and, in general, more efficient than Moringa oleifera. Although the natural coagulant was not as efficient as the chemical coagulant, the positive results of removal efficiency with the use of Moringa oleifera make it a potential alternative for the treat ment of dairy industry effluent that can be used as a supplement to the chemical coagulant.