Chitosan and polycaprolactone electrospun nanofibrous composites for sustainable decolorization of textile wastewaters

Abstract

A new approach for textile wastewater remediation via adsorption with electrospun nanofibers is presented in this work. Chitosan (Ch) and poly-ε-caprolactone (PCL) were electrospun to obtain a nanocomposite, and different deposition methods of the polymers were tested in order to optimize their mechanical and adsorptive properties. A layered structure showed higher capacities for dye adsorption compared to the monolayer structures, achieving full decolorizations with efficiencies over 98%, for a wide range of concentrations and temperatures. The developed fibrous structures were characterized via ATR-FTIR, SEM, TGA and measurements of the wettability, porosity and mechanical performance. Experimental data best fit to the pseudo-second order kinetic model and the Langmuir isotherm, with the maximum adsorption capacities found to be 69.5 mg/g at 25 °C. Desorption was possible using alkali media, recovering up to 25% of the dye. Sorbents could be used for at least 3 cycles without loss on the removal efficiency, which shows the potential of these new nanocomposites as reusable, versatile and stable eco-friendly adsorbents.