Narges Keikha, - Catalyst research laboratory, Department of Chemistry, Faculty of Science, University of Birjand,P.O. Box ۹۷۱۷۹-۴۱۴, Birjand, Iran
Abdolreza Rezaeifard - Catalyst research laboratory, Department of Chemistry, Faculty of Science, University of Birjand,P.O. Box ۹۷۱۷۹-۴۱۴, Birjand, Iran
Maasoumeh Jafarpour - Catalyst research laboratory, Department of Chemistry, Faculty of Science, University of Birjand,P.O. Box ۹۷۱۷۹-۴۱۴, Birjand, Iran

Dyes are extensively used in printing, textile and food industries. It is estimated that about 10 –15% of unused dyes are discharged into the water environment during production and utilization [1]. Several methods such as adsorption, coagulation and biodegradation have been investigated and developed for dye wastewater treatment [1]. But due to their limitations, these methods were not efficient to destructively degrade dyes. Advanced oxidation processes (AOPs) have been proven to be effective technologies for the degradation of dyes in recent years [2]. Persulfate (S2O82-) was investigated as a suitable oxidant for the degradation of organic pollutants such as azo dye, diphenylamine and trichloroethylene [3]. In this study, Fe(III)salophen complexe supported on γ-Fe2O3 was synthesized as heterogeneous catalyst to activate persulfate to effectively degrade Rhodamine B (RhB).The effects of some operational parameters such as initial solution pH, amount of catalyst, initial concentration of RhB and persulfate, and reaction temperature were studied. Finally, the free radicals participating in the process were classified by radical quenching studies, and a rational mechanism was proposed based on obtained results to understand the catalytic process