Operation method of flocculation sedimentation tank for raw water pretreatment

Abstract

Disclosed is a method for operating a flocculation and sedimentation tank for raw water pretreatment, in which fishes are cultured in a sedimentation zone of the flocculation and sedimentation tank, the fishes move in the sedimentation zone, consume algae on the surface of an inclined tube filler by means of their metabolism, and, due to the up-and-down movement of the fishes, the algae on the surface of the inclined tube filler can be removed by means of the up-and-down movement of the fishes. Fish excrement and slime adhered to the inclined tube filler are swept to the bottom of the pond.

Description

Technical Field

[0001] The present invention relates to the optimized operation of a flocculation sedimentation tank of a raw water pretreatment device in the metallurgical industry, and more particularly to an operation method of a flocculation sedimentation tank for raw water pretreatment. Background Art

[0002] The raw water of the flocculation sedimentation tank comes from the surface water of rivers. There are a large number of algae and other aquatic organisms and microorganisms in the water. During the operation of the flocculation sedimentation tank, it is very easy to attach to the inclined tube filler and grow rapidly. Algae multiply in large numbers on the surface of the inclined tube filler. In severe cases, the entire sedimentation area can be blocked, which seriously affects the water treatment effect. The sedimentation area needs to be emptied and the inclined tube cleaned before re-operation. Generally, the filler needs to be cleaned once every half a month in summer and once a month in winter, otherwise the algae mixed with mud will grow in the inclined tube filler, seriously affecting the treatment effect of the flocculation sedimentation tank. The cleaning process requires a large amount of water resources to be discharged to the wastewater station for treatment, resulting in a waste of costs and resources. We have studied a way to create a stable growth environment for scavengers and tilapia in the flocculation sedimentation tank, achieve an ecological balance between the number of fish and the growth of algae, and at the same time, the method will not affect the water quality of the effluent due to excessive number of fish and excrement, so as to reduce or avoid frequent cleaning of the flocculation sedimentation tank.

[0003] We have tried adding bleaching powder as a bactericide and algaecide through dosing pumps and placing chlorine cakes at fixed points, but none of them have achieved the desired effect. The algae reproduction in the flocculation sedimentation tank still needs to be dealt with by emptying and cleaning. Summary of the invention

[0004] The object of the present invention is to provide an operating method for a flocculation sedimentation tank for raw water pretreatment, which can remove algae grown on the inclined tube filler and mixed sludge, and maintain the normal operation of the flocculation sedimentation tank without the need for overall emptying and cleaning.

[0005] A method for operating a flocculation sedimentation tank for raw water pretreatment, wherein fish are cultured in the sedimentation zone of the flocculation sedimentation tank, and the fish use algae on the filler as food, and sweep away the slime attached to the inclined tube filler when swimming. The fish move in the sedimentation zone, consume the algae on the surface of the inclined tube filler, and due to the up and down movement of the fish, the fish excrement and the slime attached to the inclined tube filler are swept to the bottom of the tank.

[0006] The fish is one or both of scavenger fish and wild tilapia.

[0007] Specifically, 10 scavengers of different sizes and 20 wild tilapia are put above the inclined tube filler in the sedimentation area, and the individual size is larger than the outlet hole of the water outlet trough in the sedimentation area.

[0008] After the fish are released, they are first cultivated to adapt to the environment. During the cultivation stage, the water inflow of the sedimentation tank is reduced to allow the algae to grow fully, and the fish are fed with algae on the inclined pipe, the tank wall, and the outlet tank wall. At the same time, the fish are provided with necessary food. After about 1 week, the fish grow stably and can survive stably, and the original water inflow of the sedimentation area is restored.

[0009] Preferably, the water inflow into the sedimentation tank is reduced to less than 50% of the original water inflow.

[0010] During the operation of the flocculation sedimentation tank, the sludge only needs to be discharged once per shift, and there is no need to empty the sedimentation tank as a whole and clean the filler.

[0011] Advantages of the present invention:

[0012] Q = 1000m 3 / h flocculation sedimentation tank as an example, the length, width and height are 20.5 meters, 20.3 meters and 5.8 meters respectively. Each cleaning needs to discharge about 2413 cubic meters of wastewater. Calculated based on two cleanings per month, 57912m3 of water can be saved per year 3 Each cleaning of the inclined tube packing requires half a day of labor, which can save 12 days of labor per year. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a cross-sectional view of a flocculation sedimentation tank.

[0014] Figure 2 This is a top view of the flocculation sedimentation tank. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with specific embodiments.

[0016] like Figure 1-2 As shown: Q = 1000m 3 / h flocculation sedimentation tank as an example, the length, width and height are 20.5 meters, 20.3 meters and 5.8 meters respectively. Each cleaning needs to discharge about 2413 cubic meters of wastewater. Calculated based on two cleanings per month, 57912m3 of water can be saved per year 3 Each cleaning of the inclined tube packing 2 requires half a day of labor, which can save 12 days of labor per year.

[0017] The flocculation sedimentation tank has been in operation for more than 15 days without being cleaned. Green algae have adhered to the inclined tube filler 2. When the minimum temperature is above 10℃, the basic conditions for the survival of scavengers and tilapia are met.

[0018] Put 10 scavengers of different sizes and 20 wild tilapia above the inclined tube filler 2 of the sedimentation area 1, and the individual size is larger than the outlet hole of the outlet trough 3. In the cultivation stage, first reduce the water inflow of the sedimentation tank to less than 50%, let the algae grow fully, let the fish eat the algae on the inclined tube, the pool wall, and the outlet trough wall, and provide the necessary food for the fish. After about 1 week, the fish grow stably and can survive stably, and the normal water inflow of the sedimentation area 1 is restored. Fish move in the sedimentation area 1, consume the moss growing on the surface of the inclined tube filler 2, and because of the up and down activities of the fish, the fish excrement and the mud adhered to the inclined tube filler 2 are swept to the bottom of the pool. During the operation of the flocculation sedimentation tank, it is normal to discharge mud once per shift, and there is no need to empty the sedimentation tank as a whole and clean the inclined tube filler 2. Normal sewage discharge in the sedimentation area of ​​the flocculation sedimentation tank can ensure that the sewage discharge hole is not blocked.

[0019] During operation, the number of fish can be increased or decreased depending on the fish production situation to ensure the normal growth of the fish and the cleanliness of the inclined tube filler 2.

Claims

1. A method for operating a flocculation sedimentation tank for raw water pretreatment, characterized in that: Fish are cultured in the sedimentation zone of the flocculation sedimentation tank. The fish move in the sedimentation zone, consume algae on the surface of the inclined tube filler, and move up and down. The fish excrement and the slime adhered to the inclined tube filler are swept to the bottom of the tank.

2. The method for operating a flocculation sedimentation tank for raw water pretreatment according to claim 1, characterized in that: The fish is one or both of scavenger fish and wild tilapia.

3. The method for operating a flocculation sedimentation tank for raw water pretreatment according to claim 2, characterized in that Ten scavengers of different sizes and 20 wild tilapia are put into the inclined tube filler in the sedimentation zone.

4. The method for operating a flocculation sedimentation tank for raw water pretreatment according to claim 2 or 3, characterized in that: The individual sizes of the scavengers and wild tilapia are larger than the outlet holes of the outlet troughs in the sedimentation area.

5. The method for operating a flocculation sedimentation tank for raw water pretreatment according to claim 1, characterized in that: After the fish are released, they first go through a cultivation stage to allow the fish to adapt to the environment and grow stably.

6. The method for operating a flocculation sedimentation tank for raw water pretreatment according to claim 5, characterized in that: During the cultivation stage, the water inflow of the sedimentation tank is reduced to allow the algae to grow fully, and the fish are allowed to feed on the algae on the inclined tube filler, the tank wall and the outlet trough wall. At the same time, the fish are provided with necessary food. After one week, the fish grow stably and survive stably, and the original water inflow of the sedimentation area is restored.

7. The method for operating a flocculation sedimentation tank for raw water pretreatment according to claim 6, characterized in that: The water inflow of the sedimentation tank is reduced to less than 50% of the original water inflow.

8. The method for operating a flocculation sedimentation tank for raw water pretreatment according to claim 1, characterized in that: During the operation of the flocculation sedimentation tank, sludge is discharged once per shift.

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