Removal of Cr(VI) ions by adsorption onto sodium alginate-polyaniline nanofibers

In the present study, sodium alginate-polyaniline (SAP) nanofibers are evaluated as an adsorbent for the removal of Cr(VI) ion from aqueous solution by batch mode. The SAP nanofibers are characterized using FTIR, SEM, EDX and XRD techniques. The influences of various parameters such as pH, dosage, co-anions, contact time and concentration on Cr(VI) removal efficiency are investigated. The results of FTIR, SEM and EDX analysis reveals the removal of Cr(VI) ions by SAP nanofibers. Also, the existence of the electrostatic interaction between the Cr(VI) ions and SAP nanofibers is further proved by FTIR analysis. The equilibrium data obtained from the experiments are well fitted to the Freundlich isotherm than Langmuir isotherm. The values of Q degrees, k(F) and thermodynamic parameters reveal the endothermic nature of the Cr(VI) removal process. The Langmuir maximum sorption capacity of SAP nanofibers for Cr(VI) ion at 303 K is calculated to be 73.34 mg g(-1). The kinetic data are well expressed by pseudo-second-order model. Desorption and regeneration experiment shows that the SAP nanofibers can be reused for more than three successive cycles. (C) 2014 Elsevier B.V. All rights reserved.