Strategy Optimization And Model Study Of Aeration Removal Of CO₂ In Water

The acidity and alkalinity of most water bodies are determined by the components of the carbon dioxide system.When the water is acidic because they dissolve a large amount of carbon dioxide,the dissolved carbon dioxide can be removed to restore the pH to neutral or alkaline water.Aeration removal of CO₂ in water is a common method in water treatment process.The basic principle is to drum a large amount of air into the water to be treated,make the dissolved CO₂ out of the water into the air,and reduce the concentration of carbonate in the water and increase the pH.In this paper,the process of scale removal based on the acid and alkali balanced aeration method was studied.On this basis,a subsequent aeration stripping test was carried out.The main conclusions of this paper are as follows:?1?Based on the fact that the total volume ratio of gas to water is the same,and the aeration tank handles the water in and out of normal operation,a intermittent aeration test is proposed:aeration stop aeration.By increasing the aeration flow rate,the CO₂can be removed in the lower part of the aeration tank.When the aeration stops,the treatment water continues to rise,the remaining CO₂ contacts with the air and diffuses in the surface,and then continues to remove CO₂ with large flow aeration.In the intermittent aeration experiment,the total removal volume of gas and water is better than that of continuous aeration at the same time,and the removal effect is stable.The removal efficiency of CO₂ is better than that of continuous aeration.When the total volume ratio of gas and water is 4:1,the removal rate of effluent CO₂,pH and continuous aeration strategy are similar to that of 6:1 in the total volume ratio of gas to water,and the CO₂ removal rate and the range of pH fluctuation are within 2%and 0.03respectively.?2?Through the experimental observation and data analysis,the mechanism of the packing in the acid and alkali balanced aeration method is understood:the bubble rises in the way of the packing block and stagnates,many bubbles contact and fuse,and the final volume breaks through the packing block to continue to rise.When the packing height is low,the bubble is exposed to the filler prematurely.In the subsequent rise,the specific surface area is greatly reduced and the removal effect is reduced.After the packing height increases,the bubble is raised in a small diameter,and the surface area of the gas and liquid contact is large.When contact with the filler,the air bubble is intercepted to extend the contact with the water.To improve the effect of removal.?3?Aeration strategy plays a major role in the aeration strategy compared with the influence of the packing.Intermittent aeration to stop aeration period,the effluent pH without placing filler and filler placed close,guess is when there are no aeration,no air bubbles in water,the filler can not play a role in the process,and when the aeration,placed high on the bubble of filler will make the pH interception,to further improve the filler;low place,early change of bubble shape,reduce the contact area between bubbles and water,making water pH decreased.?4?According to the theory of solute permeation model,the model of carbon dioxide stripping is obtained,and it is verified by the test.Through the experimental fitting,the value of the influence factor K is 6.79×10^-4.The static model deviation rate is within 10%,and the continuous flow model deviation rate is within 3%,which has certain practicability and reference.