【Daily Question】Wastewater Knowledge-109 (June 26) (2 points for answering, 4 points for a correct answer)

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The subsequent settling of activated sludge in the secondary sedimentation tank belongs to _A__. A. Coalescent settling B. Compression settling C. Flocculent settling D. Free settling

The sedimentation of activated sludge in the later stage of the secondary sedimentation tank belongs to A

The subsequent settling of activated sludge in the secondary sedimentation tank belongs to _A_. A. Cluster settling B. Compression settling C. Flocculation settling D. Free settling

The sedimentation of activated sludge in the secondary sedimentation tank occurs in a later stage and is classified as _A. Cluster sedimentation__. Cluster sedimentation (also known as stratified sedimentation) takes place when the concentration of suspended particles in the wastewater reaches a certain level; at this point, the sedimentation of each particle is affected by the presence of particles around it, resulting in a decrease in their sedimentation velocity. If the concentration increases further, the interference between particles intensifies, and even particles with a higher sedimentation velocity are unable to move faster than those with a lower velocity. Under the influence of cohesive forces, these particles combine into a single unit, maintaining their relative positions as they settle together. A clear interface is formed between the liquid and the particle cluster. The precipitation process is essentially the process of this interface descending. The sedimentation of activated sludge in the later stage of the secondary sedimentation tank falls into this category.

The subsequent sedimentation of activated sludge in the secondary sedimentation tank belongs to __A_