Escalation of degradation of malachite green and Methyl violet using hydrodynamic cavitations using different orifice geometry

The degradation of malachite green and methyl violet solution was studied using hydrodynamic cavitation. Effect of inlet pressure, oxidizing agent, geometry of the orifice, cavitation number and pH were studied with the aim of maximizing degradation. Studies were done individually and in combination with H₂O₂. It was found that there was an obvious synergetic effect of H₂O₂ and hydrodynamic cavitation in the degradation of dyes. With the increase in pressure the degradation was found to be increased and with decrease in orifice diameter and cavitation number the degradation was found to be increased. It was observed that maximum of 98.42% and 62.48% of malachite green and methyl violet solution degraded without oxidant at 5 kg/cm² using 2 mm orifice. 2 mm orifice was found to give maximum degradation. Degradation increased with increase in pH and temperature. At pH 11, 100% degradation of green solution was observed at the end of 40 minutes and 95.22% degradation of violet dye solution at end of 60 minutes was found, when operated at 5 kg/cm² pressure using 2 mm orifice.