Dominica The Function and Use of Defoaming Agents for Electroplating Wastewater Treatment(4)

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Defoaming mechanism of hydrophobic solid particles
Hydrophobic solid particles in the foam system will first attract the hydrophobic end of the surfactant, making the hydrophobic solid particles become hydrophilic, thus reducing the concentration of surfactant in the foam film and promoting the foam to burst. This defoaming mechanism cannot explain the action mechanism of other defoaming agents, which is too one-sided. [4] Other reasons for the bursting of foam are the impact caused by the expansion of defoamer, the solubilization of surfactant and the collapse of electrolyte, and the bursting of electric double layer on the liquid film surface. [4] It can be seen from the above defoaming mechanisms that each defoamer has different emphasis on different foam systems, but defoaming is achieved by destroying the stability factors of foam

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    Dominica Chemical foam in electroplating wastewater treatment is due to the existence of many surfactants such as detergent and colloidal organic matter in the wastewater, which have strong foaming ability. Therefore, under the conditions of water flow speed, fall, aeration, blowing off, etc., a large number of small and light white brown foam will appear on the surface of the wastewater, which is unstable. There are still some differences between biological foam and chemical foam in appearance, usually showing soil brown or grayish brown. There are many reasons for this kind of foam, such as the soil brown foam caused by the low dissolved gas in the biochemical tank. Grey brown foam produced by low MLSS. Foam caused by microbial factors such as microbial abnormalities. Filamentous bacteria grow abnormally, mix and accumulate with foaming and floc particles to form foam that is difficult to eliminate, etc. The defoamer for electroplating wastewater treatment uses modified silicon polyether and modified oxane as the main raw materials to eliminate foam. It can achieve good results for chemical foam and biological foam that may appear in the electroplating wastewater system.