Tratamento de efluente de frigorífico bovino utilizando a técnica de eletrocoagulação

Abstract

In recent years, a significant growth in industrial demand has been observed, mainly in the processed food industry. However, this increase in production, especially in the meat processing industries, has resulted in a negative consequence: the generation of solid and liquid waste, which often represent a potential source of pollution for water bodies. In view of this, these wastewaters must receive appropriate treatment before being released into rivers. In this context, the electrocoagulation technique has been gaining prominence as an alternative for the treatment of agro-industrial effluents. In the study presented, the use of this technique was evaluated in the treatment of effluent from a bovine slaughterhouse, using mixed aluminum and graphite electrodes. In a first step, with the aluminum electrode connected to the positive pole (anode), the influence of the variables potential, time and distance between electrodes on color removal and ultraviolet absorbance at 254 nm (UV254nm) was studied. After optimizing these variables, a study was carried out comparing the efficiency in the treatment of the effluent, inverting the polarity of the electrodes. Therefore, in addition to the evaluation of color removal and UV254nm, analyzes of total solids, Imhoff Cone, Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD) were carried out. Using aluminum as the anode, the best results for color removal (87.27%) and absorbance (88.8%) were achieved using a power of 25.0 V, in a time of 90 min and distance of 0.5 cm between electrodes. In addition, an efficient removal of COD (55.02%) and BOD (82.30%) was obtained. The results obtained by reversing the polarities of the electrodes (aluminum as cathode) were also promising, but a little less efficient in removing parameters. However, for purposes of operational cost analysis, the application of the technique using the aluminum electrode on the cathode proved to be more economically viable. This study proves that the electrocoagulation technique can become an alternative with low installation and operating costs for the treatment of effluents from slaughterhouses.