Coupling Effect Of Temperature And PH On The Reaction Between Bromate-Sulfite-Permanganate

Earth's life system is the result of the interaction of oscillations.Each living tissue contains hundreds of chemical oscillations.In some biological macromolecules,such as DNA,RNA,and proteins,not only pH is required during self-assembly.Changes also require greater temperature changes.From this point of view,this article systematicallystudiedandanalyzedthedynamicbehaviorof bromate-sulfite-permanganate reaction system from the aspects of experiment,mechanism analysis and model simulation.The autocatalytic process of proton and bromide mixing in the reaction system and the negative feedback process initiated by the permanganate negative feedback agent determine its nonlinear dynamic behavior.In the experiment,the method of premixing the sulfite-sulfuric acid solution into the reactor effectively weakens the local acidification.This article from three aspects:homogeneous closed system dynamics,CSTR?Continuous flow Stirred Tank Reactor?dynamics and simulation of open system dynamics,using a closed reactor,CSTR reactor and Berkeley Madonna program software for bromate-Asia The kinetic behavior of the sulfate-permanganate reaction system was systematically studied and simulated.First,changing the concentration of each reactant in a homogeneous closed system has a corresponding effect on the kinetic curve of the system.With the increase of the concentration of the reactants,the time for the temperature and the pH curve to reach the steady state gradually decreased during the experiment.Second,tow phenomena were found in the CSTR experiment:temperature oscillation,pH and temperature coupling.With the oscillation temperature of the pH exhibiting a corresponding oscillation phenomenon,the rapid drop and increase of the pH in each oscillation cycle correspond to the rapid decrease and increase of the temperature.The periodic oscillation of temperature can be explained by the periodic exothermic reaction of the system and the constant temperature water bath heat exchange.The amplitude of the temperature oscillation can vary from 0.1°C to 5°C,with[BrO₃^-]=0.21M,[SO₃^2-]=0.20 M,t=45.0°C,[MnO₄^-]=0.015 M,[H⁺]=The larger amplitude of pH and temperature generated at 0.026 M is 4.7°C,which mainly depends on the change of control parameters such as the initial concentration of reactants,flow velocity,and constant temperature.The oscillation period of the system generally shows an increasing trend when the flow rate is gradually increased.The temperature and pH amplitudes produced at the same concentration and at different temperatures are also different.In addition,the experiment also found that the maximum temperature and the constant temperature of the pH amplitude generated by the initial concentrations of the different reactants are not the same.At this isothermal temperature,not only is the temperature and pH amplitude generated greater and the period is shorter.Finally,the homogenous dynamics of the open system was simulated in the Madonna program using a simplified six-step reaction mechanism model and energy conservation equation.The simulation results reproduce the main phenomena and characteristics in the experiment.Using these mechanisms can better explain the phenomenon of chemical oscillations in life processes.