Comparison of the Optimization of the Coagulation-Flocculation and Electrocoagulation Treatment of Slaughterhouse Wastewater Using the Response Surface Method

Abstract

In this work, the coagulation-flocculation and electrocoagulation treatments were compared in the removal of pollutants from wastewater from the Conchucos slaughterhouse, Lima. For the coagulation-flocculation treatment, we worked with 4 independent variables with their respective experimental ranges, coagulant dose (600-1000 mg / L), flocculant dose (4-8 mg/L), fast stirring speed (250-350 rpm), slow stirring speed (80-100 rpm), for electrocoagulation the parameters of stirring speed (250-350 rpm) and stirring time (15-30 rpm). The central compound design method (DCC) optimizing by response surface (RSM) was used as an experimental method for the reduction of pollutants as a function of chemical oxygen demand (% COD), a jar test equipment was used for the coagulation-flocculation and a one-liter shaker with aluminum plate electrodes at 30 V. The results show that coagulation/flocculation and electrocoagulation presented statistical models with F-values of 5.33, 20.30, significance p<0.05, with adjustments of R² of 0.6179, and 0.7571 for an optimal arrangement with %COD reduction prediction, respectively. The electrocoagulation treatment presented a reduction of 75.43% similar to the predicted model, of the 2 treatments compared, the electrocoagulation is below the maximum admissible values (VMA) in COD, BOD and Oils and Fats, complying with the necessary parameters for the discharge to the sewerage system.