Fluoride adsorption from aqueous solution by aluminum alginate particles prepared via electrostatic spinning device

In this study, aluminum alginate particles adsorbent was prepared via a high voltage electrostatic spinning device and its adsorption performance was tested by batch experiment. The physical and chemical properties of the adsorbent were investigated by SEM, FTIR, TG, and EDX. Batch of experiments was performed under different adsorption conditions: solution pH, adsorbent dose, initial fluoride concentration, contact time, and adsorption temperature. The average particle size of adsorbent was found to vary from 1.0 mm to 1.3 mm. Aluminum alginate exhibited encouraging the maximum uptake capacity (79.30 mg/g) under suitable adsorption conditions. The equilibrium sorption data were analyzed using the adsorption isotherms model of Langmuir and Freundlich. In order to understand the mechanism of adsorption, thermodynamic parameters such as Delta H-0 and Delta S-0, Delta G(0) was calculated according to the study of adsorption thermodynamics. Results showed that the adsorption system was well described by the Langmuir model. Meanwhile, the pseudo-first-order kinetic model and pseudo-second-order kinetic model were applied to test the kinetic data, and the results revealed that the pseudo-second-order rate model fitted the adsorption kinetic data better. Thermodynamic parameters indicated the system was an exothermic process. Furthermore, the adsorption of fluoride onto aluminum alginate may be the combination of chemical adsorption and physical adsorption. (C) 2014 Elsevier B.V. All rights reserved.