Mechanism Analysis And Reaction Kinetics Study Of Copper Like Fenton Reaction Coupled With Cavitation Impact Flow

As a new hydraulic cavitation technology,cavitating impinging stream can effectively cooperate with Advanced oxidation process to remove refractory organic pollutants from wastewater.In order to further investigate the coupling mechanism between cavitation impinging stream technology and chemical oxidation methods,this article couples cavitation impinging stream with copper like Fenton reaction for the first time.Through the derivation of a single bubble model and the simulation of cavitation impinging stream flow field,the supercritical state of the fluid at the moment of bubble collapse and the turbulent oscillation form of the flow field are studied.The reaction dynamics characteristics are studied through experiments,The mechanism of cavitation impinging stream to increase the rate of copper like Fenton reaction and promote the movement of chemical equilibrium is revealed,which provides a theoretical basis for the "physical catalysis" of cavitation impinging stream technology to degrade pollutants.The specific research content and results are as follows:(1)The single bubble model was analyzed,and the force balance condition of the bubble,the maximum pressure and temperature when the bubble collapses,the dynamic potential energy,and the generation amount of hydroxyl radicals in the bubble group were derived.(2)Analyze the flow field in the cavitation area of the cavitation impact stream,use Fluent software to simulate the flow field in three watersheds: the front section of the cavitation impact stream nozzle,the rear section of the cavitation impact stream nozzle,and the cavitation impact stream impact zone.Analyze the pressure changes in each region of the cavitation impact stream,point out the occurrence and collapse of bubbles in each region,and determine whether the turbulent oscillation inside the cavitation impact stream nozzle and the high-speed jet collision in the external impact zone are cavitation collapse The key to producing hydroxyl radical.(3)Three reaction systems,namely cavitating impinging stream,copper Fenton and cavitating impinging stream coupling copper Fenton,were studied at different temperatures;Calculate the reaction rate constants of the three systems at 25 ℃,35 ℃,45 ℃,and55 ℃,and fit the degradation reaction kinetics curve.The enhancement factors of the cavitation impact flow coupled copper like Fenton reaction are 2.33,2.68,3.39,and 2.61,respectively.The synergistic effect is strongest at 45 ℃,and the degradation reactions of the three systems all comply with the first-order reaction kinetics equation.(4)Establish a mathematical model for the activation energy corresponding to the reaction rate constant and temperature changes,and compare the activation energy of copper Fenton with that of copper Fenton coupled with cavitation impact flow.Under the physical catalytic effect of cavitation impact flow on copper Fenton reaction,the required activation energy is reduced by about 25% compared to the required activation energy for copper Fenton degradation reaction alone.Through the analysis of cavitation characteristics and experimental research on reaction kinetics of cavitation impact flow,it is believed that the supercritical state generated at the moment of bubble collapse and the turbulent oscillation form of the flow field inside and outside the nozzle jointly form a homogeneous reaction system within a certain range.Its enhanced mass transfer effect reduces the intermolecular confinement effect,and it is confirmed that cavitation impact flow technology has synergistic and physical catalytic effects on copper Fenton reactions,Promoting the positive progression and rate improvement of pollutant degradation reactions.