Poly(ethylene-co-vinyl alcohol) Functional Nanofiber Membranes for the Removal of Cr(VI) from Water

Poly(ethylene,co-vinyl alcohol) (EVOH) nanofibers with average diameter Of 260 nm were initially fabricated through the melt-blending extrusion Of immiscible blends. The resulting films obtained by layer deposition technology were then functionalized by in Situ oxidative polymerization of pyrrole monomer in hydrochloric acid solution for hexavalent chrormium [Cr(VI)] adsorption from water. Scanning electron microscopy and Fourier-transform infrared spectroscopy were :used to characterize the morphology and structure of functionalized nanofiber membranes. Adsorption experiments were conducted to test the effects of solution pH, dose of adsorbents, water temperature, adsorption contact time, and initial concentration of Cr(VI) and to determine the Cr(VI) adsorption mechanism. The experimental results denoted that the adsorption process was endothermic, spontaneous, and highly pH dependent; and the kinetics data fitted well with a pseudo-second-order model. The adsorption equilibrium time was less than 100 min, and the maximum adsorption capacities Were 90.74 mg/g from the adsorption kinetics study. The adsorption Isotherm data followed the Langmuir isothermal model. Desorption results exhibited excellent reusability of the membrane for Cr(VI) adsorption.