Insight into the highly-selective separation of Fe(III) with cinnamon-like blended fiber

The separation and recovery of Fe(III) in heavy metal mixtures is a great challenge due to its strong ion exchange property. In this study, we developed a novel cinnamon-like blended fiber (PAN/PEG) using electrostatic spinning and dissolution post-treatment, which exhibited highly selective separation properties and satisfactory adsorption capacity for Fe(III). Owing to the preferential coordination of Fe(III) with both cyanide and hydroxyl groups, PAN/PEG possessed such excellent adsorption capacity as 1.12 mmol/g. Notably, the infinite selective separation coefficient between Fe(III) and other heavy metal ions (HMIs) achieved even from the octa-mixed metal systems. Furthermore, PAN/PEG demonstrated good anti-interference ability against coexisting inorganic salts. In addition, PAN/PEG was highly effective in removing lower concentration Fe(III) from complex PTA wastewater with super-high selectivity, which enabled the subsequent purification of Co(II) and Mn(II). Overall, PAN/PEG could be prepared and recovered facilely, and had great potential in the exclusive separation of Fe(III).