Procedure for the Elimination of Remazol Black by Coagulation-Flocculation Based on the Methodology of Experimental Designs

Dyes are omnipresent in everyday life, in clothing, cosmetics and food. Synthetic dyes, recalcitrant in nature, pose an environmental problem. The objective of this work is to find, from experimental designs, the optimal conditions for the elimination of Remazol black by coagulation-flocculation. The method used is based exclusively on experimental designs. After the Hadamard design for the identification of the factors influencing the phenomenon, we used several factorial designs to optimize the treatment. The results allowed us to retain three factors: the concentration of the dye (Remazol), the concentration of the coagulant (Al3+) and the volume of coagulant (VAl3+) which influence the elimination of Remazol in solution. A modeling of the same phenomenon using a composite design (surface and response design) was then carried out to optimize these factors. The conditions are as follows: 38.77 mg/L for the dye concentration, 41.3 g/L for the coagulant concentration and finally 1.7 mL for the coagulant volume. These optimal conditions made it possible to obtain a Remazol reduction rate of 98.15 %.