Guinea The Function and Use of Defoaming Agents for Electroplating Wastewater Treatment(4)
agent
wear-resistant
recoating
not
leveling
The study of foam can be traced back to Plato's time, but for hundreds of years, people have not formed a unified understanding of the definition of foam. American colloid chemist L · I · Osipow and Dow Corning's R · F · Smith defined foam from the density of foam; Japan's Koichi Ito defined foam from the perspective of foam structure, but ignored the correlation between bubbles; Professor Zhao Guoxi, a famous surface physicist in China, defined foam as: foam is a dispersion system in which gas is dispersed in liquid, gas is a dispersed phase (discontinuous phase), and liquid is a dispersion medium (continuous phase). Bubbles in liquid rise to the liquid surface, forming a bubble aggregate composed of a small amount of liquid that separates gas with liquid film. Scholars at home and abroad agree that foam itself is a thermodynamic unstable system. When the gas enters the solution containing surfactant, it will form a long-term stable foam system.
black
Guinea 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.