Utilization of Recyclable Photocatalysts for Selenium Removal from Industrial Wastewater

Herein, we demonstrate excellent selenium (Se) removal efficacy through photocatalytic reduction of selenate (SeO42-) as a treatment method for selenium (Se) removal from flue gas desulphurization wastewater (FGDW). The simultaneous generation of elemental selenium (Se0) and hydrogen selenide (H2Se) through two consecutive first-order reductions is reported over a photocatalyst (P25 Aeroxide TiO2). In this work, we demonstrate the ability to reduce selenate in FGDW with concentrations of many co-existing ions >2,500x that of selenate. Through a robust understanding of the reaction mechanisms the complete removal (2,500x that of selenate. Through a robust understanding of the reaction mechanisms the complete removal (< 1 µg L-1) of selenate through photocatalytic reduction over TiO2 in FGDW was shown, for the first time. In addition, we demonstrate a new approach to nanoparticle catalyst recovery, combining the advantages of flocculation with magnetic separation to enable simple collection of non-magnetic nanoparticles.