Sulfate radicals from Fe3+/persulfate system for Rhodamine B degradation

The Fe3+/persulfate system for Rhodamine B (RhB) oxidative degradation has been investigated. The catalytic mechanism in the Fe3+/persulfate system was proposed as follows: Fe3+ was restored to Fe2+ by the generated intermediate products during the degradation process. The influence parameters were examined in batch experiments, including Fe3+ and persulfate concentration and initial pH. The results indicated that the Fe3+/persulfate system exhibited good performance for RhB degradation and followed first-order kinetics. 95.91% of the RhB was removed within 30min under the following conditions: [Fe3+](0)=1mM, [persulfate](0)=1mM and pH 3.0. The RhB degradation efficiencies increased as the Fe3+ and persulfate concentrations increased. In addition, the RhB degradation was inhibited in the presence of inorganic anions, which was primarily due to a complex reaction between Fe3+ and various anions except for NO3-.