Removal of erythrosine B dye from wastewater using chitosan boric acid composite material: Experimental and density functional theory findings
Hüseyin Fatih Çetinkaya, Meltem Sarıoğlu Cebeci, Savaş Kaya, Nida Shams Jalbani, Mikhail M. Maslov, Riadh Marzouki
Abstract
Abstract In this study, the chitosan boric acid ( Ch‐B ) composite has been prepared and characterized with sophisticated analytical techniques such as FT‐IR, SEM, and EDX. The prepared Ch‐B adsorbent was applied for the adsorption of erythrosine B ( EB ) dye from water samples under the optimized parameters of pH, adsorbent dosage, time, and temperature. Results shows that the Ch‐B adsorbent removes 96.5% of EB dye at pH 5, using 0.05 g of adsorbent. The adsorption equilibrium data have been subject to the Langmuir, Freundlich, and D‐R adsorption equilibrium models, which demonstrates that the Freundlich model was the best fit with good correlation coefficient value ( R 2 = 0.991), while energy E (9.18 KJ·mol −1 ) calculated from D‐R model suggested that the physical adsorption nature of the adsorption. Beside this, the thermodynamic and kinetic experiments were performed to check the feasibility and adsorption mechanism of EB‐dye onto Ch‐B adsorbent, which shows that the adsorption is endothermic (∆ H = 0.124) and spontaneous in nature due to the negative values of Gibbs free energy (i.e., ∆ G KJ·mol −1 = −13.01, −17.06, and −17.60). The kinetic models show that the adsorption equilibrium is best fitted with pseudo second order kinetic model due to good correlation coefficient ( R 2 = 0.99). Moreover, the interaction phenomenon between adsorbent and adsorbate was analyzed through DFT calculations.