A comparative study on the performance of dye removal, from aqueous suspension, using (2-hydroxypropyl)-β-cyclodextrin-CS, PVP-PVA-CS, PVA-CS, PVP-CS and plain CS microspheres

Abstract

This paper reports the results of the study on the performance of the removal of Cibacron Brilliant Yellow 3G-P and Calmagite, from aqueous solution, using either prepared 2-hydroxypropyl-β-cyclodextrin-chitosan [HPβCD-CS], poly(vinylalcohol)-polyvinylpyrrolidone-chitosan [PVA-PVP-CS], Poly(vinylalcohol)-chitosan [PVA-CS], polyvinylpyrrolidone-chitosan [PVP-CS] or plain chitosan microspheres [CS]. Modified CS molecules were analysed using FT-IR and TG-DTA techniques. Adsorption experiments were carried out and compared through varying mass ratio, contact time, initial dye concentration and temperature. Among the five studied adsorbents, the highest adsorption capacity was reached using HPβCD-CS. Kinetic equations were applied and the first-order model was shown to fit the adsorption phenomenon. The applicability of Langmuir, Freundlich, Temkin and Dubinin–Radushkevich equations was tested and the Langmuir isotherm exhibited the best fit with the experimental data. Data gleaned from both modelling and thermodynamic results indicate that the adsorption follows a physical and exothermic process.

Keywords:

• cibacron brilliant yellow 3G-P
• calmagite
• HPβCD-CS
• PVA-PVP-CS
• PVA-CS
• PVP-CS
• dyes
• kinetics
• isotherms