Étude caractéristique d’un biosorbant à base de la gousse de fève et évaluation de sa capacité d’adsorption en vers la Rhodamine B

Abstract

The objective of this work is to study the possibility of using bean peel in the removal of Rhodamine B. The effect of each of changes in pH, the primary concentration of the contaminant and the amount of substance (S/L ratio) on the adsorption capacity has been proven experimentally. The results of infrared analysis showed the presence of several chemical bonds on the adsorbent surface. The value of the pH zero charge point was experimentally set to 6.2, and the titration results showed that the adsorbent has an amphoteric characteristic. The increase of the amount of bean peel from 1 to 20 g/l, negatively, affects the adsorption capacity from 41.9 to 2.17 mg/g at equilibrium. It was noted that the removal of the pollutant has the same effect in both acid and basal medium. Many isotherm models such as Langmuir, Freundlich, Temkin and BET which have been applied to achieve balance data, it was also observed that bean peel showed a very high adsorption capacity for Rhodamine B, in low and high concentrations where the adsorption efficiency was 95.71% and 99.16% at concentrations 180 and 1000 mg / L respectively. It was also shown that the studied adsorption process on bean peel followed second-order kinetics. Through this study, we have confirmed that bean peel has a large capacity for adsorption, making it an effective and inexpensive bioadsorbent in the removal of basic colorants such as Rhodamine B in aqueous solutions.