Effects of operational parameters on decolorisation of C.I. Reactive Black 5 in UVTiO2 system

摘要

This study utilises a UV/TiO2 system to decolorise C.I. Reactive Black 5 (RB5). The effects of TiO2ndosage, pH, RB5 concentration and light power on the decolorisation efficiency using the UV/TiO2nsystem were determined. IO4nu0002 was employed as an oxidant to increase the photodegradationnefficiency of UV/TiO2. The decolorisation rate constants (k) of RB5 in the UV/TiO2 system arenconsistent with pseudo-first-order kinetics. The k values of 0.1, 0.5, 1.0 and 2.0 g/l TiO2 weren0.53, 0.52, 0.69 and 0.68 hu00021, respectively. The rate constant increases with decreasing pH fromn10 to 4. The decolorisation rate approximates linear relationship with RB5 concentration, as givennby k紏1.05[1/RB5]0.98; it varies nonlinearly with light power, as given by k紏0.178[power]0.63.nThe experimental results reveal that the rate of decolorisation obtained using UV/TiO2/IO4nu0002nexceeds that obtained using UV/TiO2.