Degradation of bromamine acid by a heterogeneous Fenton-like catalyst Fe/Mn supported on sepiolite

Abstract

A heterogeneous Fenton-like catalyst, Fe/Mn supported on sepiolite, was proved to be effective in the degradation of bromamine acid aqueous solution. The catalyst was prepared with a complex sol-gel method using sepiolite as a carrier and citric acid as a complexing agent. The prepared catalyst was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), and the results showed that the existence forms of Fe and Mn were γ-Fe₂O₃ and MnO and they were distributed evenly on the surface of sepiolite. In the degradation of bromamine acid aqueous solution, the catalyst could possess high catalytic activity when the initial pH of the solution ranged between 3 and 11. In addition, the degradation results showed that there was a synergistic effect between Fe and Mn. The inorganic ions inhibited the degradation efficiency in the early reaction period because of the scavenging effects on ^•OH, but the inhibition effect became weaker with the reaction time because of the fixation of metal ions on sepiolite.

Keywords:

• Fe/Mn/sepiolite
• Heterogeneous Fenton-like process
• Bromamine acid aqueous solution
• pH scope
• Inorganic anions

Acknowledgments

We are grateful for the supports of this research from Tianjin Institute of Urban Construction, Tianjin Key Laboratory of Aquatic Science and Technology and Tianjin Binhai Science and Technology plan project (No. 2011-BH140003).