Degradation of Rhodamine B in water by heat/persulfate process

This investigation concerns the effectiveness of the heat/persulfate process in the degradation of Rhodamine B (RhB) in water. The dependences of the efficiency and rate of degradation of RhB by the heat/persulfate process on the temperature, initial concentration of RhB, and Na2S2O8 concentration were examined. The degradation of RhB by the heat/persulfate process followed pseudo-first-order kinetics. The efficiency and rate of degradation of RhB at 70 °C dramatically exceeded those at 30 °C. At 70 °C, increasing the initial concentration of RhB reduced the efficiency and rate of degradation of RhB. At 70 °C, the efficiency and rate of degradation of RhB increased with Na2S2O8 concentration. The heat/persulfate process at 70 °C with an initial concentration of RhB of 5 mg/L and an Na2S2O8 concentration of 32 mM completely degraded RhB in 7 min, revealing that the heat/persulfate process is highly effective in the degradation of RhB in water.