Development of Nanofibers Composed of Chitosan/Nylon 6 and Tannin/Nylon 6 for Effective Adsorption of Cr(VI)

In this study, novel nanofiber materials composed of chitosan/nylon 6 and tannin/nylon 6 were synthesized by the Forcespinning® method and were used as adsorbents for effective removal of chromium(VI) from aqueous solutions. The nanofibers showed similar production rates of 3.5 g h−1. The diameters of the nanofibers ranged from 100 to 800 nm. Under the experimental conditions tested, chromium(VI) adsorption was favored at pH 3 (chitosan/nylon 6 nanofibers) and pH 2 (tannin/nylon 6 nanofibers), at a temperature of 328 K. The most suitable models for description of the kinetic data were the pseudo-second order model (chitosan/nylon 6 nanofibers) and the Elovich model (tannin/nylon 6 nanofibers). For both nanofibers, the equilibrium isotherms could be fitted by the Langmuir model. The maximum adsorption capacities were 23.9 and 62.7 mg g−1 for the chitosan/nylon 6 and tannin/nylon 6 nanofibers, respectively. The thermodynamic parameters showed that the adsorption was spontaneous, favorable, and endothermic. The findings indicated that these nanofibers produced using a centrifugal technique offer excellent potential as adsorbents, with high adsorption capacities for chromium(VI).