Degradation of patent blue V using cavity-bubble oxidation reactor induced by glass balls

A cavity-bubble oxidation reactor was used to study the degradation of patent blue V. The generation of cavity-bubbles by glass balls and flow-rate-induced jet were the degradation mechanisms used in this reactor. Initially, basic operating parameters were optimized by varying the initial concentration (10–40 ppm) and solution pH 2–12. The extent of degradation (22.6%) at 20 ppm was reduced to 11.4% when the initial concentration was increased to 40 ppm. Following that, combined treatment strategies for process intensification of the degradation process were investigated. It was found that lower initial concentrations and acidic conditions favored the degradation of patent blue V. Under the optimal conditions of a concentration of 20 ppm and a pH of 2, the combined effect of the cavity-bubble oxidation reactor and chemical oxidation processes, such as hydrogen peroxide, gave a 95.38% extent of degradation at optimum H2O2 loading (2.5 g/L), which was 4.5 times greater than that obtained using cavity bubble oxidation reactors alone. The highest degree of degradation (98.48%) was achieved with a cavity-bubble oxidation reactor coupled with an optimum loading of the Fenton reagent (0.125 g/L FeSO4 and 2.5 g/L hydrogen peroxide). With the exception of the Fenton process, the kinetic analysis revealed that the degradation of patent blue V followed first-order reaction kinetics in all cases.