Decolorizing kinetics of reactive black SRE by UV/TiO2

Photocatalysis with TiO2 (UV/TiO2) was employed to treat Reactive Black SRE (RB SRE) in aqueous solution. The effects of TiO2 loading, initial concentration of PB SRE and pH on the photocatalytic activity were investigated. The RB SRE degradation intermediate products were ana);zed by ultraviolet visible spectrum (UV-vis), gas chromatography-mass spectrometry (GC-MS), and ion chromatography (IC). The results show the optimum TiO2 loading was 0.15 g L-1 and acidic medium could improve the removal of RB SRE, and the rise of RB SRE initial concentration decreased color removal. The main intermediate products were 2,5-difitrobenzoic acid and 3,5,5-trimethylhexanoic acid. The primary inorganic ions were Cl-, NO3- and SO42- The photocatalytic degradation rate followed pseudo-fist order at different loadings of TiO2 and initial concentrations of RB SRE. On the basis of Langmuir model, the limiting rate of the reaction at maximum coverage (k(v) and the equilibrium constant for adsorption (K-e) of RB SRE are 1.129 mg L-1 min(-1) and 0.01789 Lmg(-1) respectively. (c) 2008 American Institute of Chemical Engineers Environ Prog, 27: 104-110, 2008.