Adsorption-coupled Fenton type reduction of bromate in water by high-yield polymer-derived ceramic-supported nano-zerovalent iron

Nano-zerovalent iron (nZVI) is a promising material for the removal of both organic and inorganic pollutants from contaminated water. This study investigates the potential of a novel composite of nZVI on a polymer-derived supporting ceramic (nZVI-PDC) synthesized via the liquid-phase reduction method for the simultaneous adsorption and Fenton-type reduction of bromate anion (BrO 3 − ) in water. The nZVI nanoparticles were effectively anchored onto the PDC by impregnating high-yield carbon in a ferrous sulfate solution . The PDC facilitated the uniform dispersion of nZVI nanoparticles due to its multiple active sites distributed within mesocarbon cavities. The developed nZVI-PDC composite exhibited a high specific surface area of 837 m 2  g −1 and an ordered mesoporous structure with a pore volume of 0.37 cm 3  g −1 . As an adsorbent, the nZVI-PDC composite exhibited a maximum adsorption capacity (q e ) of 842 mg g −1 and a partition coefficient (K H ) of 10.2 mg g −1 μM −1 , as calculated by the pseudo-second-order model. As a catalyst, the composite demonstrated a reaction kinetic rate of 43.5 μmol g −1 h −1 within 6 h at pH 4, using a dosage of 60 mg L −1 nZVI-PDC and a concentration of 0.8 mmol L −1 H 2 O 2 . Comparatively, PDC exhibited a q e of 408 mg g −1 , K H of 1.67 mg g −1 μM −1 , and a reaction rate of 20.8 μmol g −1 h −1 , while nZVI showed a q e of 456 mg g −1 , K H of 2.30 mg g −1 μM −1 , and a reaction rate of 27.2 μmol g −1 h −1 . The modelling indicated that the nZVI-PDC composite followed pseudo-second-order kinetics. The remarkable removal efficiency of the nZVI-PDC composite was attributed to the synergistic effects between PDC and nZVI, where PDC facilitated charge transfer, promoting Fe 2+ generation and the Fe 3+ /Fe 2+ cycle. Overall, this work introduces a promising adsorption technology for the efficient removal of BrO 3 − from contaminated aqueous solutions, highlighting the significant potential of the nZVI-PDC composite in water purification applications.