ÉLIMINATION DES COLORANTS SYNTHÉTIQUE DES EFFLUENTS AQUEUX PAR EXTRACTION LIQUIDE-LIQUIDE

Abstract

The main objective of this work is to study the removal of synthetic dyes, which are hazardous pollutants for health and the environment, from aqueous solutions using the liquid-liquid extraction (LLE) technique. An experimental study of LLE was conducted to determine the influence of the following operating parameters: equilibrium time, initial dye concentration, volumetric ratio, and medium pH. The experiments were carried out under ambient conditions (temperature and pressure). Various organic solvents were tested for their effectiveness in dye extraction. The results showed that the best extraction of methylene blue (MB) is achieved with salicylic acid in dichloromethane, with an equilibrium time of 5 minutes and at a natural pH (pH=7). For methyl red (MR), the parameters that yield the maximum efficiency are: an equilibrium time of 5 minutes, an initial concentration of 10 mg/L, and a volumetric ratio Vaq /Vorg of 1:1. The optimal solvent for MR extraction is xylene in an acidic medium. This study demonstrates the effectiveness of liquid-liquid extraction for the depollution of waters contaminated by synthetic dyes, highlighting the optimal conditions to maximize extraction efficiency.