Poly(vinyl alcohol) (PVA)-based nanofibers materials for azo dye adsorption: an overview

The contamination of the water sources and the environment degradation by the organic dyes from different industries has become a serious problem. A wide variety of chemical, physical and biological treatments have been explored for decontamination of dye-laden wastewater. Among these treatments, adsorption received tremendous interest because of its efficiency, possible recyclability and inexpensiveness. Electrospun nanofibers adsorbents emerged as the preferred candidates in treating the dye-impacted wastewater satisfactorily because of their inherent and intrinsic features, such as large surface area, high surface-to-volume ratio and ease functionalization for specificity. The modification of PVA nanofibers, adsorbent dosage, dye concentration, pH value and temperature are found to be equally essential to achieve desired efficiency. As a result, the present review aims to provide an overview on the preparation of the PVA nanofibers and the factors influencing the dye removal efficacy. Most importantly, the literature search over the last decade on the performance of the electrospun PVA-based nanofibers as adsorbent for the removal of azo dyes from wastewater is also discussed. In light of their improved adsorption capacity, the PVA-based nanofibers will finally find their way in industrial dye-impacted water treatment and other appropriate applications in the near future.