The main method of electroplating wastewater treatment is air floatation

[Participant question] The main method of electroplating wastewater treatment is air floatation?

[Answer] The air flotation method is to pass air into the water to produce tiny bubbles. Due to the adhesion between the bubbles and the fine suspended matter, a flotation body is formed. The floatation effect of the bubbles is used to float up to the water surface to form foam or float. Slag, so that the suspended matter in the water can be separated. According to the different ways of bubble generation, it can be divided into three types: inflatable air flotation, dissolved air flotation and electrolytic air flotation.

Air flotation method is a new type of solid-liquid separation method instead of precipitation method. In 1978, Shanghai Tongji University first applied air flotation method to treat electroplating heavy metal wastewater successfully. Subsequently, due to the continuity of the treatment process, compact equipment, small footprint, and easy automation, it has been widely used.

The air-floatation solid-liquid separation technology is highly adaptable and can treat chromium plating wastewater, chromium-containing passivation wastewater and mixed wastewater. Not only can remove heavy metal hydroxides, but also other suspended solids, emulsified oils, surfactants, etc. The principle of air flotation for the treatment of chromium-plating wastewater is: under acidic conditions, ferrous sulfate and hexavalent chromium undergo oxidation-reduction reactions, and then flocculates are generated under alkaline conditions, and the floccules float out under the action of countless fine bubbles The water surface makes the water quality clear.

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