Functionalized poly(vinyl alcohol) based nanofibers for the removal of arsenic from water

Abstract

Arsenic is a potent contaminant in waterways across the world. In this investigation, Fe³⁺ ion immobilized poly(vinyl alcohol) (PVA) nanofibers were used for the removal of arsenic (As) from water. Nanofiber mats were prepared from a PVA/Fe³⁺ mixture using an electrospinning technique and cross-linked in a desiccator saturated with ammonia vapour. The fibers showed a smooth surface morphology and were 600–800 nm in diameter. An increase in the glass transition temperature along with a lowering of the melting peak enthalpy with an increase in the concentration of Fe³⁺ ions was observed. The nanofibers extracted As(III) and As(V) compounds from spiked aqueous solutions. The maximum capacity of the nanofibers for arsenic removal was found to be 67 mg g⁻¹ for As(III) and 36 mg g⁻¹ for As(V). The effect of pH on the adsorption behavior was compared for both acidic and basic conditions. The effect of coexisting anions such as silicate ions on the adsorption behavior showed significant interference, whereas humic acid had no significant effect on the adsorption behavior. The FTIR and XPS spectroscopic analyses demonstrated that arsenic ions were adsorbed on the sorbent surface. Hence, these modified PVA nanofibers are efficient for removing arsenic from water and may be used for water purification.