A novel Fenton-like system of Fe2O3 and NaHSO3 for Orange II degradation

A new Fenton-like catalysis system consisting of Fe2O3 and NaHSO3 was designed, tested and established as a catalyst for the degradation of Orange II dye. The results of the degradation showed that the treatment efficiency was considerable under different conditions but with a significant increase under alkaline or strongly alkaline conditions compared to that under the acidic condition. A color removal efficiency of more than 90% was obtained after 20 min and 30 min of treatment when the pH was adjusted to 8 and 10, respectively. The catalytic ability and the applicability of the system under strongly alkaline or acid conditions were investigated. The effective degradation of dyes with various factors was explored under extreme conditions. A potential mechanism of Orange II degradation by the Fe2O3/NaHSO3 system was proposed and verified with the experimental results. The range of pH values for Fenton-like oxidation was extended and the leaching of iron from the synthesized Fe2O3 after degradation was found to be negligible and therefore, can overcome the shortcoming of traditional Fenton reaction in a wide pH range as this Fenton-like system could be used on all kinds of wastewater treatment.