Catalytic oxidation of phenol in wastewater-A new application of the amorphous Fe 78Si 9B 13 alloy

Abstract

The amorphous Fe 78Si 9B 13 alloy was used as a heterogeneous Fenton catalyst in the process of phenol degradation. The influences of main operating parameters such as reaction temperature, catalyst amount, hydrogen peroxide dosage and initial pH of solution on phenol degradation rate were investigated. The maximum mineralization of phenol was achieved at 60°C, 6 g/L Fe 78Si 9B 13, 0. 31 mol/L hydrogen peroxide, with an initial pH of 2.5. More than 99% of phenol was completely removed under the optimum conditions within 10 min for a solution containing 1000 mg/L of phenol. Batch experiments for solutions containing phenol concentrations ranging from 50 to 2000 mg/L were investigated under the above conditions and the same excellent degradation rate was obtained. The Fe 78Si 9B 13 showed better catalytic activity than iron powder and Fe 2+. Addition of n-butannol (hydroxyl radical scavenger) decreased the degradation rate of phenol, which demonstrates that hydroxyl radicals were mainly responsible for the removal of phenol. We demonstrated that phenol may be degraded by hydroxyl radicals decomposed by hydrogen peroxide on the surface of Fe 78Si 9B 13 and illustrated the reaction mechanism for this process. This amorphous alloy exhibited high stability in recycling experiments and showed excellent reuse performance even after continuous operations of 8 cycles. © 2012 Science China Press and Springer-Verlag Berlin Heidelberg.