Do not confuse several precipitation phenomena of laboratory comprehensive wastewater treatment equipment

   The emergence of laboratory comprehensive wastewater treatment equipment helps the laboratory to solve the problem of wastewater treatment, so that the chemical toxic substances in the wastewater can be treated. During the operation of the laboratory comprehensive wastewater treatment equipment, according to the concentration, properties and flocculation performance of suspended particles in the water, the sedimentation phenomenon is divided into 4 categories. one time.

(1) Free sedimentation: The concentration of suspended solids is low, and the sedimentation process does not adhere to each other, and does not change the shape, size and density of the particles, such as the sedimentation of particles in the grit chamber.

(2) Flocculation and sedimentation: The effect of coagulation or flocculation can occur during the sedimentation process. The sedimentation degree of the floating particles with low concentration, due to the increase of the mass of the left and right particles by flocculation, the sedimentation speed is accelerated, and the sedimentation speed increases with the depth. The precipitation of particles in water after chemical flocculation is called flocculation precipitation. The sedimentation velocity keeps increasing. There is no relational expression describing particle flocculation sedimentation. When solving practical problems, the flocculation sedimentation is usually divided into several layers. In each layer, it is considered that the particle sedimentation adopts the free sedimentation velocity formula. When the settled particles are similar to flocculated particles, the more layers, the smaller the error.

(3) Interface precipitation: After the concentration of suspended solids in the wastewater increases to a certain value, due to the influence of the mutual interference between the particles, all the particles are precipitated as a whole, and a clearly visible mud-water interface is formed between the mud and water. The particles have the same settling speed and are precipitated at the same speed, and the lower part of the activated sludge second settling belongs to this type.

(4) Compaction sedimentation: Occurs in the sedimentation process of high-concentration floating particles. Due to the high SS, the particles aggregate into a clump structure and support each other. The water between the lower particles is affected by the gravity, water depth and It is pressed out under the action of its own gravity, so that the sludge is concentrated. There is compression sedimentation in the concentration process in the sludge hopper of the secondary sedimentation tank of the laboratory wastewater treatment equipment and the concentration process of the sludge in the concentration tank. General availability zone interface settlement velocity formula.

The above are the four precipitation phenomena of the laboratory comprehensive wastewater treatment equipment. The operator must master the necessary theoretical knowledge and related technical information to better use the equipment.