CN100369829C - Internal circulation dynamic membrane bioreactor - Google Patents

Abstract

The invention provides an internal circulation dynamic membrane bioreactor, comprising an outer cylinder body, an inner cylinder body, a membrane module, an aeration tube and a backwash aeration tube; the lower end of the outer cylinder body is sealed, the upper end is open, and the lower part is provided with a water inlet ;The inner cylinder is installed in the outer cylinder, the upper and lower ends are open, and its bottom is a certain distance away from the bottom surface of the outer cylinder; the membrane module is arranged in the inner cylinder, and its upper end is provided with a water outlet pipe extending out of the outer cylinder. A water outlet is provided, and a backwash aeration pipe is connected to the water outlet pipe; the aeration pipe is arranged between the inner and outer cylinders. The invention can effectively reduce the dead zone of the reactor, increase the uniformity of the mixed sludge, increase the cross-flow velocity of the mixed liquid in the inner cylinder, improve the scouring of the dynamic membrane, delay the membrane fouling, and prolong the backwash cycle of the reactor. Increase the stability of reactor operation.

Description

Internal circulation dynamic membrane bioreactor

technical field

The invention relates to a dynamic membrane bioreactor and belongs to the technical field of membrane bioreactors.

Background technique

The currently used dynamic membrane bioreactors all adopt the form of lateral aeration, that is, a baffle is installed in the reactor, and the baffle divides the reactor into two parts, the left and the right, and the two parts are connected up and down. A membrane module is installed at one end, water is fed into the other end, aeration is made at the water inlet end, and water is discharged by using the water pressure difference between the liquid level of the reactor and the water outlet of the membrane module. When the dynamic membrane bioreactor with the above structure is in operation, the dead zone rate of the reactor is large, the activated sludge is mixed unevenly, and the removal effect on pollutants is poor; Small, the flushing of the dynamic membrane is not enough, and it is easy to cause membrane fouling.

Contents of the invention

Aiming at the above-mentioned shortcomings in the operation of the existing dynamic membrane bioreactor, the present invention provides an internal circulation dynamic membrane bioreactor with uniform activated sludge mixing, good effect on removing pollutants, and less likely to cause membrane fouling.

The internal circulation dynamic membrane bioreactor of the present invention adopts the following technical solutions:

The internal circulation dynamic membrane bioreactor includes an outer cylinder, an inner cylinder, a membrane module, an aeration tube and a backwash aeration tube; the lower end of the outer cylinder is sealed, the upper end is open, and the lower part is provided with a water inlet; the inner cylinder is installed on the outer cylinder In the body, the upper and lower ends are open, and the distance between the bottom end and the bottom surface of the outer cylinder is 1/10 of the total height of the outer cylinder; the membrane module is arranged in the inner cylinder, and the upper end is provided with a water outlet pipe extending out of the outer cylinder. A water outlet is provided on the water pipe, and a backwash aeration pipe is connected to the water outlet pipe; the aeration pipe is arranged between the inner and outer cylinders.

Membrane modules are made of sieve silk.

During the operation of the above-mentioned internal circulation dynamic membrane bioreactor, the aeration pipe plays the role of supplying oxygen to the mixed liquid, and at the same time, the mixed liquid at the bottom between the inner and outer cylinders flows upward under the action of aeration, and after reaching the top, it flows from The downward flow of the inner cylinder can increase the scouring of the dynamic membrane, thereby delaying membrane fouling. Under the action of the pressure difference between the liquid surface of the outer cylinder and the water outlet, the mixed sludge passes through the dynamic membrane to filter the water. When backwashing is required, close the water outlet, open the aeration pipe for backwashing, and the gas provided by backwashing enters the membrane module through the outlet pipe, and then discharges into the reactor through the sieve. When the gas passes through the membrane substrate, it is crushed into tiny bubbles, and the dynamic membrane is destroyed by the tiny bubbles, thereby reducing membrane fouling and restoring membrane flux.

The invention can effectively reduce the dead zone of the reactor, increase the uniformity of the mixed sludge, increase the cross-flow velocity of the mixed liquid in the inner cylinder, improve the flushing of the dynamic membrane, delay membrane fouling, and prolong the backwash cycle of the reactor. Increase the stability of reactor operation.

Description of drawings

Accompanying drawing is the structural representation of the present invention.

In the figure: 1. Water inlet, 2. Outer cylinder, 3. Inner cylinder, 4. Membrane module, 5. Outlet pipe, 6. Valve, 7. Water outlet, 8. Aeration pipe, 9. Backwash aeration Trachea, 10, valve.

Detailed ways

Example 1

As shown in the drawings, the internal circulation dynamic membrane bioreactor of the present invention includes an outer cylinder 2 , an inner cylinder 3 , a membrane module 4 , an aeration pipe 8 and a backwash aeration pipe 9 . The lower end of the outer cylinder body 2 is sealed, the upper end is open, and the lower part is provided with a water inlet 1 . The upper and lower ends of the inner cylinder body 3 are all open, and are contained in the outer cylinder body 2, and the distance between the bottom end and the inner bottom surface of the outer cylinder body 2 is 1/10 of the total height of the outer cylinder body. Membrane module 4 is made of sieve silk, set in the inner cylinder 3, its upper end is provided with a water outlet pipe 5 protruding from the outer cylinder, the end of the water outlet pipe 5 is a water outlet 7, and the front of the water outlet 7 is provided with a valve 6 . A backwash aeration pipe 9 is also connected to the water outlet pipe 5 , and a valve 10 is arranged on the backwash aeration pipe 9 . The aeration tube 8 is set at the bottom between the inner and outer cylinders to supply oxygen to the mixed liquid and promote the circulation of the mixed liquid. The mixed liquid at the bottom between the inner and outer cylinders flows upward under the action of aeration, and after reaching the top The downward flow from the inner cylinder 3 can increase the scouring of the dynamic membrane, thereby delaying membrane fouling.

During operation, the mixed sludge passes through the dynamic membrane module 4 to filter out water under the action of the pressure difference between the liquid surface of the outer cylinder body 2 and the water outlet 7 . When backwashing is required, close the valve 6 and open the valve 10, the gas provided by the backwashing aeration pipe 9 enters the membrane module 4 through the outlet pipe 5, and then discharges into the reactor through the sieve. When the gas passes through the membrane substrate, it is crushed into tiny bubbles, and the dynamic membrane is destroyed by the tiny bubbles, thereby reducing membrane fouling and restoring membrane flux.

The above-mentioned internal circulation dynamic membrane bioreactor adopts constant flux filtration. The MLSS of the reactor is 8000mg/L, the DO is 2.0-4.0mg/L, the influent COD is 300mg/L, and the influent ammonia nitrogen is 50mg/L. During operation, when the gas-water ratio is 40:1, the effluent COD is 25mg/L, the effluent ammonia nitrogen is 1.0mg/L, and the effluent turbidity is 4NTU. The backwash cycle of the reactor can be stabilized at 90h.

Example 2

The structure of the internal circulation dynamic membrane bioreactor is the same as in Example 1. The MLSS of the reactor is 8000mg/L, the DO is 2.0-4.0mg/L, the COD of the influent is 500mg/L, and the ammonia nitrogen in the influent is 80mg/L. During operation, when the gas-water ratio is 40:1, the effluent COD is 28mg/L, the effluent ammonia nitrogen is 1.5mg/L, and the turbidity of the effluent is 4NTU. The backwash cycle of the reactor can be stabilized at 90h.

Example 3:

The structure of the internal circulation dynamic membrane bioreactor is the same as in Example 1. The MLSS of the reactor is 8000mg/L, the DO is 2.0-4.0mg/L, the COD of the influent is 150mg/L, and the ammonia nitrogen in the influent is 50mg/L. During operation, when the gas-water ratio is 40:1, the effluent COD is 22mg/L, the effluent ammonia nitrogen is 1.0mg/L, and the turbidity of the effluent is 4NTU. The backwash cycle of the reactor can be stabilized at 90h.

Example 4:

The structure of the internal circulation dynamic membrane bioreactor is the same as in Example 1. The MLSS of the reactor is 8000mg/L, the DO is 2.0-4.0mg/L, the COD of the influent is 300mg/L, and the ammonia nitrogen in the influent is 50mg/L. During operation, when the gas-water ratio is 60:1, the effluent COD is 30mg/L, ammonia nitrogen is 1.5mg/L, and the effluent turbidity is 6NTU. The backwash cycle of the reactor can be stabilized at 110h.

Example 5:

The structure of the internal circulation dynamic membrane bioreactor is the same as in Example 1. The MLSS of the reactor is 8000mg/L, the DO is 2.0-4.0mg/L, the COD of the influent is 300mg/L, and the ammonia nitrogen in the influent is 50mg/L. During the operation, the gas-water ratio is 20:1, the effluent COD is 21mg/L, ammonia nitrogen is 0.9mg/L, and the turbidity of the effluent is 3NTU. The backwash cycle of the reactor can be stabilized at 75h.

Claims (1)

1. An internal circulation dynamic membrane bioreactor, comprising an outer cylinder, an inner cylinder, a membrane module, an aeration tube and a backwash aeration tube; it is characterized in that the lower end of the outer cylinder is sealed, the upper end is open, and the lower part is provided with Water inlet; the inner cylinder is installed in the outer cylinder, the upper and lower ends are open, and the distance between the bottom end and the bottom surface of the outer cylinder is 1/10 of the total height of the outer cylinder; the membrane module is arranged in the inner cylinder, and the upper end is provided with The water outlet pipe protruding from the outer cylinder is provided with a water outlet, and the backwash aeration pipe is connected to the water outlet pipe; the aeration pipe is arranged between the inner and outer cylinders.

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