CN217148903U

CN217148903U - Low-energy-consumption enhanced phosphorus removal improved MBR system

Info

Publication number: CN217148903U
Application number: CN202220584923.6U
Authority: CN
Inventors: 张昊; 王发珍; 王艳; 林虹; 秦栽根
Original assignee: Beijing Enterprises Water China Investment Co Ltd
Current assignee: Beijing Enterprises Water China Investment Co Ltd
Priority date: 2022-03-17
Filing date: 2022-03-17
Publication date: 2022-08-09
Anticipated expiration: 2032-03-17

Abstract

An improved MBR system with low energy consumption and enhanced phosphorus removal belongs to the field of sewage treatment. It is characterized by comprising: an SBR tank (1), a coagulating sedimentation tank (2), an immersed super filter (3) and the like. The SBR tank (1) is provided with a decanter (13), an aerator (14) and a stirrer (15), an aeration fan (4) is connected with the aerator, and then the SBR tank is connected with the coagulating sedimentation tank (2). The coagulating sedimentation tank (2) is divided into 3 parts of mixing, flocculation and sedimentation, the mixing part is provided with a dosing device (5) and a mixing stirrer (16), the flocculation is provided with a flocculation stirrer (17), and the connecting coagulating sedimentation tank (2) is connected with the immersed super filter (3) through a water outlet pipe (10) of the coagulating sedimentation tank. The immersed ultrafiltration tank is provided with a membrane scrubbing fan and a membrane component. The immersed ultrafiltration pool is connected with a suction pump through an immersed ultrafiltration suction pipe; the suction pump is also connected with a water production pipe (12). The sludge of the system is convenient to dehydrate, and the medicament consumption and the transportation and disposal cost are lower.

Description

Low-energy-consumption enhanced phosphorus removal improved MBR system

Technical Field

This system belongs to the sewage treatment field.

Background

Tradition A ² O + MBR process problem

In municipal sewage treatment projects, A is applied for the purpose of achieving quasi-IV or higher standards and reasons for the indexes of control land ² The O + MBR process is common. However, the process has high investment, high operation cost, poor biological phosphorus removal effect and large influence of membrane cleaning agents on the environment, and is not improved well at present.

1) Improved direction

The advantages of the process are high sludge concentration up to 8000mg/L, high load, small tank capacity and low civil engineering investment. The improved system should retain this advantage without incurring excessive increases in capital investment.

Secondly, the equipment investment of the process is high, particularly the investment of the membrane component and the matched equipment is high, the equipment for improving the system is reduced, and the investment is correspondingly reduced.

Thirdly, the biological phosphorus removal effect of the process biochemical system is poor (about 50 percent) and is lower than that of the conventional A ² O non-MBR process (60-70%). A large amount of phosphorus removal agent needs to be added. The improved system can fully exert the biochemical phosphorus removal capability and reduce the medicament consumption.

The energy consumption of the process comprises medicament, power consumption, equipment, materials, manpower and the like, wherein the MBR membrane separation system runs in a sludge environment, so that the pollution and blockage are serious, and the flux is low, so that the energy consumption for membrane scrubbing and membrane medicament cleaning is huge. In addition, the membrane module also needs to be replaced for 5 to 8 years. The improved aims are as follows: reduce the number of die assemblies, reduce the scrubbing strength and reduce the consumption of film cleaning agents. The improvement direction can effectively improve the short plate of the technology, expand the application field and have high practical value.

Disclosure of Invention

Dephosphorization improvement MBR system is reinforceed to low energy consumption, its characterized in that includes: the device comprises an SBR tank 1, a coagulating sedimentation tank 2, an immersed ultrafiltration tank 3, an aeration fan 4, a dosing device 5, a membrane scrubbing fan 6, a suction pump 7, an SBR water inlet pipe 8, an SBR water outlet pipe 9, a coagulating sedimentation tank water outlet pipe 10, an immersed ultrafiltration suction pipe 11, a water production pipe 12, a decanter 13, an aerator 14, a stirrer 15, a mixing stirrer 16, a flocculation stirrer 17 and a membrane component 19.

The SBR tank 1 is provided with a decanter 13, an aerator 14, a stirrer 15 and an aeration fan 4 which are connected with the aerator, and then the SBR tank is connected with the coagulating sedimentation tank 2.

The coagulating sedimentation tank 2 is divided into 3 parts of mixing, flocculation and sedimentation, the mixing part is provided with a dosing device 5 and a mixing stirrer 16, the flocculation is provided with a flocculation stirrer 17, and the connecting coagulating sedimentation tank 2 is connected with the immersed ultrafiltration tank 3 through a coagulating sedimentation tank water outlet pipe 10.

The immersed ultrafiltration tank is provided with a membrane scrubbing fan and a membrane component. The immersed ultrafiltration tank is connected with a suction pump 7 through an immersed ultrafiltration suction pipe 11; the suction pump 7 is also connected to a water production pipe 12.

Furthermore, the sedimentation part of the coagulating sedimentation tank 2 is provided with an inclined tube, and the inclined tube 18 is a three-dimensional structure formed by combining a plurality of hexagonal tubes which are closely arranged in parallel and is in a single row or a plurality of rows.

(1) SBR process replaces A2O process

Unlike the A2O + MBR process, the SBR process is used instead of the A2O process.

SBR is a short for a sequencing batch activated sludge process, and is an activated sludge sewage treatment technology which operates according to an intermittent aeration mode.

The SBR process is flexible in operation mode and operation, can obtain good effects of denitrification and dephosphorization through process control, and can be periodically operated according to six stages of water inlet, aeration aerobic reaction, aeration anoxic reaction stopping, sedimentation, water discharge and idling. The SBR water inlet period is only stirred to manufacture an anaerobic environment, the mixed liquor is ensured to be in an anaerobic state, and after water inlet is finished, oxygenation aeration is carried out to complete carbon oxidation, ammonia nitrogen nitration and phosphorus absorption, and the aerobic reaction period is formed. And stopping aeration in the anoxic reaction period, keeping stirring and mixing, and preparing an anoxic environment to achieve the aim of denitrification. And performing sludge-water separation on the mixed solution in the precipitation period, and draining and leaving the mixed solution idle after the precipitation is finished. The period design is usually 4, 6 and 8h, the integral period is completed every day, and the operation period can be flexibly adjusted through automation. The single tank body runs intermittently, and 4 tank bodies can realize continuous water inlet and continuous water outlet. In order to ensure the denitrification and dephosphorization effect of a biochemical system and accurately control dissolved oxygen, the anaerobic section is between 0mg/L and 0.2mg/L, the anoxic section is between 0.2mg/L and 0.5mg/L, and the aerobic section is between 1.5mg/L and 3 mg/L.

The SBR process aeration tank and the sedimentation tank are integrated, and a secondary sedimentation tank does not need to be built. Not only can replace the A2O process, but also can save land and reduce the civil engineering investment. Because the biological phosphorus removal capability of SBR can be fully utilized, and a phosphorus removal agent does not need to be added into the biological tank, the drug effect is prevented from being reduced and the adverse effect on sludge is avoided, and the method is superior to A ² And (4) O + MBR process.

(2) Adding a coagulating sedimentation unit

A coagulating sedimentation unit is added after the SBR process, so that high-efficiency chemical phosphorus removal is realized, and the conventional process is avoided at A ² The adverse effect of the phosphorus removal agent added into the O biological tank on the biochemical reaction is reduced, and the agent consumption is reduced. After the coagulating sedimentation, the water quality is greatly improved, and the separation of the membrane component on pollutants is also facilitated.

The coagulating sedimentation can be replaced by processes such as a high-efficiency sedimentation tank, magnetic coagulation, air floatation and the like. Reduce hydraulic load and save land occupation.

(3) The sludge-water separation membrane tank is changed into an immersed ultrafiltration tank to discharge water

General A ² The membrane tank of the O + MBR process is used for separating mud-water mixture, and because the sludge concentration is high and exceeds 1%, the separation difficulty is high, the membrane module is seriously polluted and blocked, the flux is lower and lower along with the extension of the operation time, and the water yield is reduced. The membrane module has huge scrubbing energy consumption, frequent cleaning of the medicament and huge consumption, and sodium hypochlorite, citric acid and sodium hydroxide contained in the cleaning wastewater have great influence on the environment. After the process is optimized, the sewage after coagulating sedimentation is further separated, and the separation difficulty is largeGreatly reduced aeration quantity of the air scrubbing, greatly reduced medicament consumption, increased membrane flux by about 100 percent and reduced equipment investment by about 50 percent.

(4) The improved system is beneficial to sludge dewatering

A ² Sludge produced by the O + MBR process is difficult to dehydrate, has high water content and high transportation and disposal costs. The sludge of the improved system is convenient for dehydration, and the medicament consumption and the transportation and disposal cost are lower.

Drawings

FIG. 1 is a schematic diagram of the system

An SBR pool 1; a coagulating sedimentation tank 2; an immersed ultrafiltration tank 3; an aeration fan 4; a dosing device 5; a membrane scrubbing fan 6; a suction pump 7; SBR water inlet pipe 8; SBR water outlet pipe 9; a water outlet pipe 10 of the coagulating sedimentation tank; an immersed ultrafiltration suction tube 11; a water production pipe 12; a decanter 13; an aerator 14; a stirrer 15; a mixer-agitator 16; a flocculation stirrer 17; a chute 18; a membrane module 19.

Fig. 2 is a schematic view of a chute.

Detailed Description

1) Description of the System

The process comprises the following steps: the sewage sequentially enters the SBR tank 1 → the coagulating sedimentation tank 2 → the immersed ultrafiltration tank 3 for treatment, and the common wall construction is suitable for saving land and investment.

Water head requirement: the SBR tank 1 adopts a decanter 13 for drainage, so a water head of about 1.5m needs to be reserved, namely the liquid level of the SBR tank 1 is about 1.5m higher than the liquid level of the coagulating sedimentation tank 2; the liquid level of the coagulation sedimentation tank 2 is about 0.4m higher than the liquid level in the immersed ultrafiltration tank 3.

SBR pool 1: 4 grids are a group, 2 or more groups can be designed according to the water quantity, and the building is carried out on the same wall. The tank is internally provided with a decanter 13 for skimming water from the top of the liquid level in the tank when water is discharged, and the water level is higher than the liquid level when water is not discharged. The bottom of the tank is provided with an aerator 14, and an aeration blower 4 in a blower room is used for oxygenating the SBR tank 1 in an aeration stage. The stirrer 15 is arranged on the inner wall of the pool, the start-stop time is accurately controlled by a PLC, and the stirrer is used for fully stirring in an anaerobic section and an anoxic section to ensure that the biochemical reaction is full. The water inlet of the SBR tank is controlled by an automatic valve and enters one of 4 lattices, and different tanks of each group can be alternately in the stages of water inlet, reaction, sedimentation and water outlet, so that water can be continuously fed and continuously and uniformly discharged (see the table below for details, and the time can be flexibly adjusted).

TABLE 1SBR tank routine operation time sequence table

Step sequence	1h	1h	1h	1h
					1 pool	Inflow water	Reaction (aeration and anoxia)	Precipitation of	Decanting water
2 pool	Decanting water	Inflow water	Reaction (aeration and anoxia)	Precipitation of
					3 pool	Precipitation of	Decanting water	Inflow water	Reaction (aeration and anoxia)
4 pool	Reaction (A)Aeration and anoxia)	Precipitation of	Decanting water	Inflow water

The drained water of the decanter 13 enters the coagulating sedimentation tank 2 through an SBR water outlet pipe 9. The stirrer 15 is started in the water inlet anaerobic section, and the stirrer 15 is started in the anoxic section after aeration.

And (3) coagulating sedimentation tank 2: is connected with the SBR pool 1 through a channel or a pipeline. The method is divided into 3 parts of mixing, flocculation and sedimentation, and aims to further remove phosphorus and reduce suspended matters after passing through the SBR tank 1. And a mixing stirrer 16 is arranged in the mixing reaction section, the hydraulic retention time is 1-2 min, and the velocity gradient is not less than 500. And a coagulant adding device 5 in the dosing room adds coagulants such as PAC, polyferric sulfate, ferric trichloride and the like into the mixing section to be fully mixed with the sewage. After the sewage and the medicament are fully mixed, a flocculation stirrer 17 is arranged at the center of the flocculation section, the motor is positioned at the top of the stirrer, a frame type paddle is adopted, the submerged stirring is carried out at a low speed, and suspended matters, phosphate and the coagulating medicament in the sewage react to form flocs, so that the sludge and water are conveniently separated in a sedimentation tank. The inclined tube 18 is arranged in the sedimentation tank, the conventional inclined tube 18 is in a hexagonal tube shape and is formed by welding corrugated plates, the inclined length is 1m, the angle is 60 degrees, the treatment capacity of the inclined tube 18 is 3-5 times that of a horizontal sedimentation tank, the separation efficiency can be improved, and the plane area of the tank body is reduced. After suspended matters and phosphate in the sedimentation tank are removed after sedimentation, the sewage after top separation enters the immersed ultrafiltration tank 3 through a water outlet pipe 10 of the coagulation sedimentation tank to provide inflow water with low suspended matters.

An immersed ultrafiltration tank 3: the membrane module 19 is arranged in the tank and can be fixed on the tank wall or supported on the tank bottom. Through a low porosity microfiltration membrane<MF>And ultrafiltration membranes<UF>The effluent of the coagulating sedimentation tank 2 is mostly filtered by a membrane component 19 with a membrane aperture of 0.1-0.4 mu m, and the flux is preferably controlled at 25-30L/m ² H, 15-20L/m higher than that of the A2O + MBR process ² H, the number of membrane modules is reduced by 50%. The pressure of the filtration is provided by a suction pump 7, and the effluent passes through the productThe water pipe 12 enters a subsequent disinfection process stage. In order to ensure the stable water production of the membrane component, the membrane scrubbing fan 6 in the blower room continuously aerates and scrubs the bottom of the membrane component 19, so that the pollution blockage rate of the surface is reduced. The gas-water ratio is controlled to be about 4 times, which is 8 times lower than that of the A2O + MBR process. The membrane module 19 is maintained once every 7 days, and is restored once in 3-6 months, and the frequency is lower than that of the conventional A2O + MBR process.

Parameter control

Firstly, the SBR process is controlled to continuously, stably and uniformly discharge water, and impact on subsequent units is avoided.

And the coagulating sedimentation can be replaced by a high-efficiency sedimentation tank with high hydraulic load, magnetic coagulation or air flotation technology, so that the occupied area and the civil engineering investment are reduced.

And thirdly, suspended filler can be added to reduce the volume of the SBR tank and reduce the civil engineering investment and the construction cost.

Fourthly, the sludge concentration of the SBR tank is preferably controlled within the range of 4500-5000 mg/L.

Controlling the surface load of the coagulation sedimentation tank to be 15-20 m ³ /m ² .h。

Sixthly, the flux of the immersed ultrafiltration membrane is preferably controlled to be 25-30L/m ² .h。

Claims

1. Dephosphorization improvement MBR system is reinforceed to low energy consumption, its characterized in that includes: the system comprises an SBR (sequencing batch reactor) pool (1), a coagulating sedimentation pool (2), an immersed super filter pool (3), an aeration fan (4), a dosing device (5), a membrane scrubbing fan (6), a suction pump (7), an SBR water inlet pipe (8), an SBR water outlet pipe (9), a coagulating sedimentation pool water outlet pipe (10), an immersed ultrafiltration suction pipe (11), a water production pipe (12), a decanter (13), an aerator (14), an agitator (15), a mixing stirrer (16), a flocculation stirrer (17) and a membrane component (19);

the SBR tank (1) is provided with a decanter (13), an aerator (14) and a stirrer (15), an aeration fan (4) is connected with the aerator, and then the SBR tank is connected with a coagulating sedimentation tank (2);

the coagulating sedimentation tank (2) is divided into 3 parts of mixing, flocculation and sedimentation, the mixing part is provided with a dosing device (5) and a mixing stirrer (16), the flocculation is provided with a flocculation stirrer (17), and the connecting coagulating sedimentation tank (2) is connected with the immersed super filter (3) through a water outlet pipe (10) of the coagulating sedimentation tank;

the immersed ultrafiltration tank is provided with a membrane scrubbing fan and a membrane component; the immersed ultrafiltration tank is connected with a suction pump (7) through an immersed ultrafiltration suction pipe (11); the suction pump (7) is also connected with a water production pipe (12).

2. The MBR system with low energy consumption and improved phosphorus removal according to claim 1, wherein the sedimentation part of the coagulation sedimentation tank (2) is provided with inclined tubes, and the inclined tubes (18) are in a three-dimensional structure formed by combining a plurality of hexagonal tubes which are closely arranged in parallel and are in a single row or multiple rows.