Degradation of Rhodamine B Using UV/Cu2+/H202 System

It is difficult to treat industry wastewater which contains both heavy metals and refractory organic compounds. However, the Fenton-like reaction system using heavy metal ions in wastewater to decompose organics seems a promising method, which would have a positive effect on pollution reduction and wastes re-utilization. This paper is set out to comparatively study the effectiveness of UV/H₂O₂/metal ion systems on a representative substrate as Rhodamine B. Results show that the UV/Cu₂+/H₂O₂ system exhibited high degradation efficiency on Rhodamine B which was completely degraded in 30 min. Also the degradation obeyed first-order kinetic equation. Furthermore, influences of Cu²⁺ concentration, methods of H₂O₂ addition, pH and UV radiation on RhB degradation were studied, respectively, for the UV/Cu²⁺/H₂O₂ system. Optimal reaction conditions were found to be [Cu²⁺]=0.324 mmol/L, [H₂O₂]=0.118 mmol/L and ways of adding H2O2 by two or more times rather than one, pH=3, necessity of UV radiation. Moreover, the coexistence of Mn²⁺ with UV/Cu²⁺/H₂O₂ enhanced the degradation efficiency.