Decolorisation of Reactive Red 120 by hydrodynamic cavitation

Decolorisation of reactive red 120 (RR120), was investigated using hydrodynamic cavitation (HC). Present works mainly study effect of various geometrical parameters of orifice plates on decolorisation of RR120 in aqueous solution. For this purpose seven orifice plates having different diameter and number of holes were used in present study. After optimizing orifice geometry effect of operating conditions such as operating pressure, initial concentration of dye in liquid, initial temperature of liquid, operating pH and addition of oxidizing agent (H2O2) on percentage decolorisation of RR120 have been investigated and optimum conditions were determined. Kinetic analysis suggests decolorisation of RR120 using hydrodynamic cavitation follow first order kinetics. Almost 74% decolorisation was obtained by using HC alone with orifice plate 2 at 3.5 kg/cm(2), 30 degrees C, pH of 2 & 10 mgl(-1) of dye concentration in aqueous solution. After adding oxidizing agent H2O2 decolorisation rate increases to 97.5% at optimum concentration of 120 mgl(-1) of H2O2. (C) 2018 Elsevier Ltd. All rights reserved.