C. Mbareck, D. Maatala, A. Sbai, E.C. S’ID, M. Djegué

A low-cost adsorbent, Mauritanian Aeschynomene Aspera (AeAs), was used to remove methylene blue (MB) from water. Ionic exchange capacity, swelling and porosity ratios, and adsorption properties of AeAs were investigated. The experimental results show that the average value of ionic exchange capacity of AeAs was 0.3 meq/g. The average swelling and porosity ratios were 78% and 92%, respectively. The adsorption process was found to follow Langmuir model as the correlation coefficient (R2) was higher than 0.99 whereas the mechanism of adsorption followed the pseudo second order. Results of Attenuated total reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy support the presence of carboxylic groups embedded on adsorbent. Therefore, the adsorption of MB onto AeAs can be assigned to intermolecular interactions between cationic groups embedded on dye molecules and various groups such as carboxylic groups into AeAs material. The maximum adsorption capacity reached 91 mg/g and the values of Langmuir separation factor (RL) were in the range 0.04-0.217.

Adsorption, methylene blue, Aeschynomene aspera, dyes removal, adsorption isotherm

Pages: 33-42