Experimental Study Of Killing Pathogenic Microorganism By Hydrodynamic Cavitation Due To Circular Multi-Orifice Plates

In rencent years,the pollution of water is becoming more and more serious.The security of drinking water has caused more and more people's attention.So there are a lot of disinfection technology to remove the pathogenic microorganisms in the water,such as chlorine disinfection,ultraviolet disinfection and czone disinfection,they will take a certain disinfection by-products.The technology of hydraulic cavition is a new kind of water treatment technology,in recent years.The shock wave,micro-jet and cavitating water turbulence produced by cavitation collapse can kill the pathogenic microorganismas in the water.Mean while,it has the advantages of fast no water pollution and other advantages.In this study,a self-developed circular orifice-plate hydrodynamic cavitation reactor was used to study the killing of pathogenic microorganisms in raw water.The test raw water was taken from Shangtang River water as test water.The study mainly consists of two parts:The first part is based on circular orifice perforated plate hydrodynamic,cavitationdevice,highspeedcamer,ParticlImageVelocimetry,SINOCERA-YE6263 pressure device data acquisition system and so on to reveal the mechanism of hydrodynamic cavitation to kill pathogenic microorganisms.Flow velocity distribution,turbulence intensity,turbulent shear stess and the influence of the geometric parameters of the porous plate on the characteristics of cavitation water flow was discussed.In the second part,the experimental study on the killing of pathogenic micro organisms by using the agar plate counting method,biological microscope,multi-parameter water quality analyzer and ultraviolet sepectrometer was carried out in a circular hole porous plate hydrodynamicreactor.And researching,the relationship of the initial concentration of the pathogenic micro-organisms,the velocityof the orifice,the time of cavitation,the number of orifices,the size of the orifice,the arrangement of the orifice,the distribution of the orifice between the killing rate and the rate of killing of pathogenic microorganisms.The results show that the hydrodynamic cavitation can rapidly kill the pathogenic microorganism in the raw water,and it does not produce disinfection by-products compared with other disinfection processes.It is a new dringking water disinfection technology with great application prospect.