Sewage disposal plant combining coagulation and air flotation

Abstract

The invention discloses a sewage disposal plant combining coagulation and air flotation, comprising a pipeline mixer, a gas dissolving device, an extending section remaining coagulation zone and a decreased section air flotation area; sewage passes through the device to directly enter a desilter so as to realize solid-liquid separation. The invention has the characteristics of simple equipment, small floor area, low energy consumption, easy control, high air flotation efficiency and the like and is especially suitable for processing sewage with smaller flow.

Description

technical field [0001] The invention relates to a sewage treatment device, in particular to a sewage treatment device integrating coagulation and air flotation. Background technique [0002] The air flotation method is one of the new international water treatment methods at present. It can be used in sewage treatment occasions where the sedimentation method is not applicable to separate suspended solids with a specific gravity close to water and difficult to settle, such as oil, fiber, algae, etc. It can also be used To concentrate activated sludge. Its working principle is to dissolve a large amount of air in water under pressure to form dissolved air water. As a working medium, the dissolved air releaser is suddenly decompressed and released quickly to generate a large number of microbubbles. The micro-bubbles adhere to the condensate in the coagulation reaction sewage, so that the specific gravity of the floc is lower than that of water and floats on the water surface, s...

AI Technical Summary

Problems solved by technology

[0005] There are three problems in this traditional pressurized dissolved air flotation method: first, coagulation tank and air flotation tank are required at the same time, which occupies a large area; second, about 10% of the return water is used as dissolved air water, such as figure 1 As shown, the air-dissolving device needs a pressure of 5-6kg, the dissolved air pressure is high, and the energy consumption is high; thirdly, the pressure of the dissolved air water is reduced from 5-6kg to normal pressure, and the pressure difference at the outlet of the dissolved air is large, and the gas is released quickly and easily. The formation of large bubbles affects the air flotation efficiency

Fourth, it is necessary to return part of the purified water after air flotation treatment to the dissolved air tank to generate dissolved air water, such as figure 1 As shown, the dissolved air water entering the air flotation tank from the dissolved air tank and the sewage entering the air flotation tank through the coagulation tank tend to mix unevenly, resulting in different sizes and uneven distribution of microbubbles, which makes the flocculation formed in the local area of ​​sewage The network structure of the body has a large mesh, and it is difficult to remove suspended solids with small particle size

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