Oxidative Decomposition of Reactive Blue C.I. 19 with Sodium Hypochlorite

摘要

Reaction kinetics of Reactive Blue C.I. 19 (RB 19) dye and sodium hypochlorite (NaOCl) were investigated.nDecline of RB 19 was monitored continuously by an ultraviolet (UV)-Vis spectrophotometer to avoid samplingnerrors. The purpose of this study is to develop a kinetic model for reactor and process design to establishnhypochlorite oxidation as a viable alternative to advanced oxidation processes for textile effluent decolorization.nResults were in agreement with 0.5-order reaction kinetics with respect to the RB 19 concentration. The lumpednrate constant of the pseudo-0.5-order reaction is proportional to the NaOCl concentration. The Arrhenius acti-nvation energy obtained from the slope of the best-fit line is 76.6 kJ=mol, with a corresponding preexponentialnfactor of 1.388u00011010n. The reaction rate is strongly affected by the pH of the solution. During the oxidationndecomposition process, color was rapidly removed by the NaOCl but chemical oxygen demand (COD) resistednthe treatment. A molar ratio of more than 44 is essential for OClnu0002 to completely decompose the dye moleculesnthus removing COD from the solution. A system of liquid chromatography mass spectrometry (LC=MS) wasnused to determine the intermediates in the initial steps of the decomposition process.