What's the matter with the different colors of the foam in the aeration tank?

What's the matter with the different colors of the foam in the aeration tank?

1. Brown-yellow foam

Phenomenon

When the foam is generated, the amount is small, and a small amount is generated near the liquid level around the aeration mass, which gradually dissipates along the radiation direction, and starts to accumulate in the surrounding corners.

Reason

The activated sludge is in an aging state, and part of the activated sludge disintegrates due to aging, is suspended in the activated sludge mixture, and evenly adheres to the foam under aeration state, resulting in prolonged foam bursting, which creates conditions for foam accumulation .

2. Grey-black foam

Phenomenon

Foam quantity, production process, accumulation, friability are the same as tan-yellow foam, but with a black component in its color, and the accumulated product is also gray-black.

reason

The activated sludge is in an anoxic state, which can cause a local anaerobic reaction in the activated sludge. The activated sludge that was originally in the aerobic state will die in the process of this transformation, and it will also adhere to the air during aeration. Bubbles are on.

3. White foam

Phenomenon

The phenomenon of white foam is relatively common, and there are many reasons, which need to be analyzed from a variety of situations.

Reason

Excessive load: foam with a non-breakable viscosity, the color of the foam at this time is bright and white, and the stacking property is good

Over-aeration: The activated sludge is over-aerated, and the foam color at this time is old white, and the accumulation is poor, and only local accumulation occurs.

Detergent influx: The presence of detergent increases the surface tension of the water body, which can lead to the formation of foam.