Degradation of refractory pollutants by hydrodynamic cavitation: Key parameters to degradation rates

Abstract

Degradations of refractory pollutants by hydrodynamic cavitation were experimentally carried out in a self-developed hydrodynamic cavitation reactor with Venturi tubes, multi-orifice plates and their combinations. Effects of hydraulic elements of cavitation due to the Venturi tube on degradation of refractory hydrophobic pollutant were studied, and an optimal throat length corresponding to the maximum degradation rate was obtained. Effects of cavitation due to number, size and distribution of orifice for the multi-orifice plates on degradation of refractory hydrophilic pollutant were investigated, and comparisons and analyses were made. Effects of cavitation due to different combinations of the Venturi tubes with the triangular multi-orifice plates on degradation of hydrophilic and hydrophobic mixtures were studied, and an appropriate combination was determined. Also, effects of cavitation duration, pH value and initial concentration on the refractory pollutants were explored.