Experimental Study On Degradation Of Refractory Wastewater By Hydrodynamic Cavitation Due To Circular Multi-orifice Plates

Using cavitation effect to degrade wastewater is a kind of technology without additional reagent addition, which conforms to the green environment idea,so it has a good application prospect.However, the influence factors of this technique in wastewater degradation do not study enough in-depth, in addition, its mechanism has not been clear yet.All these have brought some difficulties for its industrialization.This paper present a study on the influence factors of hydrodynamic cavitation in wastewater degradation, which provide reference for the application of this technology and the optimization design of the hydrodynamic cavitation device.At first, we used the circular multi-orifice plates as the reactor of hydrodynamic cavitation to degrade wasterwater. Experimental study is performed on two kinds of wastewater: one is artificial nitro phenol wastewater;the other is the chemical wastewater taken from the local enterprise.We explored the relationship between the degradation rate of wastewater and the geometric design parameters of circular multi-orifice plates(orifice number、orifice size、orifice arrangement) as well as that the degradation rate of wastewater between the degradation reaction conditions(processing time、initial concentration、velocity of orifices、pH value、cavitation number). Analysis of the experimental data found that wastewater degradation rate is affected by all these factors.Then, in order to explore the relationship between hydroxyl radical productions and wastewater degradation rate, we selected the MB to capture hydroxyl radicals due to hydrodynamic cavitation and performed quantitative analysis.The experimental data showed that properly increasing hydroxyl radicals can improve the degradation rate of wastewater.In order to explore the relationship between cavitation number and wastewater degradation rate, we used pressure data acquisition system for real-time acquisition liquid internal pressure behand the circular multi-orifice plates.The experimental data showed that properly decreasing cavitation number can improve the degradation rate of chemical industrial wastewater.