ADSORPTION DU ROUGE DE CRESOL SUR CHARBON ACTIF, ETUDE EXPERIMENTALE, MODELISATION PAR PLAN D’EXPERIENCE EN UTILISANT DESIGN EXPERT

Abstract

This work aims to study the adsorption of Cresol Red and the active ingredient, which is Paracetamol, from an aqueous solution. The work is divided into four parts: The first part is the study of the adsorption of RC and PA focused on the parameters influencing adsorption by calculating the elimination rate (R%). The study revealed that adsorption is of low efficiency for an initial pollutant concentration below 4 mg/l; the initial amount of the three adsorbents used is less than 0,1 g; the contact time between the adsorbate and the adsorbent is less than 25 minutes. On the other hand, under optimal conditions, a very high yield is observed for the RC equal to 88,22% at 120 minutes for an initial concentration of 6 mg/l and 0,1 g of activated carbon. In addition, the PA reacts in the same manner under the previous condition with a yield of 98,6%. In the second part, we will focus only on the Langmuir and Freundlich models that correspond to our experimental results, for the adsorption of RC and PA with activated carbon, bentonite, and kaolin, the obtained Adj R2 values are respectively 0,998-0,989-0,979 for RC and 0,997-0,995-0,994 for PA. The isotherms follow the Freundlich law on bentonite and the Langmuir law on activated carbon and kaolin. The third part represents the kinetic model that studies the adsorption phenomenon of RC and PA. According to the results, it is observed that the pseudo-first-order kinetics is the best model for studying the adsorption kinetics of the dye and paracetamol on the three chosen adsorbents with an Adj R2 equal to 0,998-0,976-0,975 respectively for CHA, BENT, and KAL for the dye and 0,970-0,995-0,972 for the paracetamol. In the fourth part, we relied on BOX-BEHNKHEN experimental design modeling to determine the optimal factors for the following: contact time; amount of activated carbon; initial concentration of the dye. After modeling, we found that the best yields are between 75 and 120 minutes for the contact time. For the initial amount of activated carbon, the yield values are significant above 0,1 g, and in the case of the initial concentration of RC, an increase is observed starting from 6 mg/l.