Experimental and numerical investigation on the disinfection characteristics of a novel rotor-radial groove hydrodynamic cavitation reactor

Hydrodynamic cavitation was considered as a new efficient and green water treatment technology, which doesn’t produce any disinfection by-products. In the present paper, the disinfection characteristics of a novel rotor-radial groove hydrodynamic cavitation reactor were evaluated. The effects of various rotor speeds, flow rates, and initial bacterial concentrations on the removal of Escherichia coli were analyzed on the basis of experimental research and numerical simulation. The possible mechanism of hydrodynamic cavitation disinfection was explained. 93.3% disinfection rate of Escherichia coli can be obtained at 3900 rpm and 2 m 3 /h in 20 min for 15 L water of simulated effluent. With the increase of flow rate, the disinfection effect of the reactor was improved based on the cavitation effect and the exposure time of bacteria in the bubble collapse area (passing times). The disinfection of Escherichia coliisbased on the micro jet, shock wave, and shear stress generated by hydrodynamic cavitation. The findings of the present study can provide support for the application development of hydrodynamic cavitation disinfection and the theoretical development of rotational hydrodynamic cavitation reactors.