Potential of Canola Stalk as Biosorbent for the Removal of Remazol Black B Reactive Dye from Aqueous Solutions

Abstract

In this study, the possible use of canola stalks, which are agricultural residues available in large quantities, for the removal of Remazol Black B (RBB) was investigated. Batch adsorption studies were carried out to examine the influence of various parameters. The results indicated that adsorption was strongly pH-dependent but slightly sorbent dose- and contact time-dependent. The Freundlich and Langmuir adsorption models were used for the mathematical description of adsorption equilibrium and isotherm constants at 25°C. Both models were applicable for the description of dye adsorption isotherm in the concentration range studied. However, the Langmuir model showed a higher correlation coefficient than the Freundlich model. According to the Langmuir model, the highest adsorption capacity was found to be 32.8 mg/g. Kinetic models, pseudo-first order and pseudo-second order were employed to describe the adsorption mechanism. The adsorption data followed the pseudo-second order kinetic model with regression coefficient (R² ) higher than 0.999. In conclusion, the results showed that canola stalks could be used as a promising and cost-effective biosorbent for treatment of wastewater containing dye.

Keywords:

• Canola stalks
• reactive dye
• adsorption isotherm
• pseudo-second order
• kinetics