CN107986433A - A kind of porous aggregate cladded type MBR devices and sewage water treatment method - Google Patents

Abstract

The invention discloses a porous filler-coated MBR device and a sewage treatment method. The device is covered with a porous sponge filler on a ceramic membrane module. The sponge filler can rotate around the ceramic membrane module, and the ceramic membrane is cleaned by physical friction of the porous polyurethane sponge filler. The module alleviates the membrane fouling problem of MBR, reduces the frequency of backwashing, and the MBR system can still operate normally during the surface friction cleaning process without affecting the water outlet effect. The porous polyurethane sponge filler enriches the biofilm, hardly produces excess sludge, the filler can be replaced, and can be reused after being washed with alkaline solution. Combining the MBR biochemical reaction pool with the moving bed reactor increases the biomass and ensures the quality of the effluent.

Description

A porous filler-coated MBR device and sewage treatment method

technical field

The invention relates to a porous filler-coated MBR device and a sewage treatment method, which are used for treating sewage.

Background technique

As a new sewage treatment process that combines membrane separation and biotechnology, membrane bioreactor (Membrane Bioreactor, MBR) has excellent and stable effluent quality, small device footprint, and convenient operation and management. It is used in urban sewage, industrial wastewater treatment and Reclaimed water reuse has strong competitiveness and is highly valued globally. It is regarded as "best available technology" and has a very broad application prospect.

However, the problem of membrane fouling has always plagued MBR operation. For sewage with high organic content such as domestic sewage, the surface of the membrane module in the MBR is prone to biofouling or even a gel layer. If the sludge load of the MBR membrane is too high, not only the removal rate of pollutants cannot be guaranteed, but on the contrary, it will promote and aggravate the membrane fouling, so the membrane must be cleaned in time. Commonly used cleaning techniques, whether physical cleaning, external immersion chemical cleaning or chemical cleaning, are not only time-consuming and labor-intensive, but also increase operating costs. Incomplete cleaning of membrane modules, and repeated shutdown and startup of equipment will reduce its service life. Therefore, the MBR process is more suitable as an advanced treatment process for sewage with a low concentration of organic pollutants, such as slightly polluted water whose water quality index only exceeds the standard for Class III water bodies, etc.

In recent years, relevant experts and engineers at home and abroad have continuously improved the operation mode and effect of MBR, trying to reduce membrane fouling under the premise of ensuring the removal efficiency of pollutants. For example, co-dosing suspended fillers, activated carbon, etc. in the MBR, combining the advantages of the MBR and the moving bed reactor, on the one hand increases the active biomass, improves the removal effect of pollutants, especially ammonia nitrogen, and on the other hand reduces the suspended active pollution. The mud content should be adjusted to make the attached biofilm work as much as possible and reduce membrane fouling. However, the actual effect of membrane fouling control is not obvious, and cleaning is frequent during MBR operation. In fact, there are various forms of fillers, such as suspended, fixed, spherical, ring-packed, and fibrous, and the materials are also different, all of which have good hydrophilic effects and can increase the microbial content inside the reactor. However, although there are a few studies on the utilization of suspended packings to reduce membrane fouling by utilizing hydraulic conditions, little success has been achieved.

Contents of the invention

Aiming at the defects of the prior art, the present invention provides a porous filler-coated MBR device and a sewage treatment method to solve the problems of easy pollution of existing MBR biofilm reactors and high cost of replacing membrane components.

In order to solve the above technical problems, the technical solution adopted in the present invention is: a porous filler-coated MBR device, including a reaction tank, more than one set of ceramic membrane modules arranged in the reaction tank and a water inlet pipe arranged at the upper end of the reaction tank, The water inlet pipe is provided with an inlet pump, and each set of ceramic membrane modules is covered with a sponge packing, which is connected to a drive assembly that drives it to rotate around the ceramic membrane module; the lower end of each set of ceramic membrane modules is sealed, and the upper end is connected to a collection pipe , the collection pipes of each group of ceramic membrane modules are collected into the collection main pipe, and the collection main pipe is equipped with an outlet pump and connected to the outlet tank; the outlet tank is also connected with a backwash pipe, and the backwash pipe is provided with a backwash pump and connected to each The collection pipes of the ceramic membrane modules are connected; it also includes an aeration system. The aeration system includes an air compressor, an aeration pipe and an aeration head. The aeration pipe extends from the air compressor to the bottom of the reaction tank. pipe on.

The porous filler-coated MBR device of the present invention, the drive assembly includes a rotating cap, a rotating shaft, a rotating disk and a motor, the rotating cap is placed on the top of the sponge filler, the rotating shaft is fixedly connected between the rotating disk and the rotating cap, and the rotating disk and The motor is connected.

In the porous filler-coated MBR device of the present invention, the rotating cap, the rotating shaft, and the rotating disk are provided with through holes, and the collecting pipe is connected to the ceramic membrane module through the holes.

In the porous filler-coated MBR device of the present invention, the sponge filler is a porous polyurethane sponge filler, and the sponge filler is filled with biofilm.

In the porous filler-coated MBR device of the present invention, the bottom of the reaction pool is connected with a vent pipe, and the vent pipe is provided with a vent pipe valve.

In the porous filler-coated MBR device of the present invention, activated sludge is also arranged in the reaction tank.

In the porous filler-coated MBR device of the present invention, valves are provided on the water collection pipes, collection main pipes and backwash pipes of each group of ceramic components.

In the porous filler-coated MBR device of the present invention, the ceramic membrane module is a tubular microfiltration membrane with a pore size of 0.10-0.2 μm, a working pressure of 0.05-0.15 Mpa, and a working temperature of 5-40°C.

The present invention also discloses a sewage treatment method, which is based on the porous filler-coated MBR device described in claim 1, comprising the following steps: S01), slightly polluted water enters the reaction through the water inlet pipe under the suction of the water inlet pump Under the action of the aeration system, ceramic membrane modules and sponge packing, the pollutants in the slightly polluted water are degraded and metabolized, and the water quality is purified. Under the action of suction, it enters the collection pipe, and the water in the collection pipe is collected and enters the outlet tank after the main collection pipe; S02). When the membrane flux decreases by 30% or the membrane pressure is higher than 0.15Mpa and lower than 0.4Mpa, the driving component drives the sponge The filler rotates, and the sponge filler rotates and scrapes on the surface of the ceramic membrane module to scrape off a part of the biofilm attached to the surface of the ceramic membrane module; S03). When the membrane pressure is higher than 0.4Mpa, the inlet pump and outlet pump stop working, and the reverse The flushing pump starts to work, and the water in the outlet tank enters the interior of the ceramic membrane module through the collection main pipe and the collection pipe under the suction of the backwash pump, and finally seeps out from the micropores of the membrane and enters the reaction tank. The pump stops working, at the same time, the water inlet pump and the water outlet pump are turned on, and re-enter the operation stage to degrade and metabolize the slightly polluted water.

Beneficial effects of the present invention: the present invention covers the ceramic membrane assembly with a porous sponge filler, the sponge filler can rotate around the ceramic membrane assembly, and utilizes the physical friction of the porous polyurethane sponge filler to clean the ceramic membrane assembly, thereby alleviating the membrane fouling problem of the MBR and reducing the When the frequency of backwashing is reduced, the MBR system can still operate normally during the surface friction cleaning process without affecting the water outlet effect. The porous polyurethane sponge filler enriches the biofilm, hardly produces excess sludge, the filler can be replaced, and can be reused after being washed with alkaline solution. Combining the MBR biochemical reaction pool with the moving bed reactor increases the biomass and ensures the quality of the effluent. The rotating disc and rotating cap are buckled on the porous packing, which is convenient for disassembly and assembly, and provides convenience for later replacement and maintenance. The invention has the advantages of simple structure, fast membrane fouling cleaning speed and good effect, reduced sewage treatment cost, characteristic, saved infrastructure cost, and realizes further treatment of slightly polluted water on the whole, so that the effluent water quality index is better than the standard of Class II water body.

Description of drawings

Fig. 1 is the structural representation of the porous filler coating type MBR device of the present invention;

In the figure: 1. Water inlet pump, 2. Water outlet pump, 3. Backwash pump, 4. Air compressor, 5. Water outlet tank, 6. Water inlet pipe, 7. Aeration system, 7-1, Aeration head, 8 , backwash pipe, 9, collecting main pipe, 10, rotating disk, 11, rotating shaft, 12, rotating cap, 13, porous polyurethane sponge packing, 14, biofilm, 15, reaction tank, 16, ceramic membrane module, 17, effluent Main pipe, 18, vent pipe, 19, vent pipe valve, 20, collection pipe, 21, membrane module control valve, 22, activated sludge, 23, motor, 24, outlet valve, 25, backwash valve.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in FIG. 1 , a porous filler-coated MBR device includes a reaction tank 15 , a ceramic membrane module 16 , a porous polyurethane sponge filler 13 , an aeration system 7 , an outlet pump 2 , a backwash pump 3 and an outlet tank 5 . The ceramic membrane module 16 , the porous polyurethane sponge packing 13 and the aeration system 7 are inside the reaction tank 15 . The water outlet pump 2, the backwash water pump 3 and the water outlet tank 5 are located outside the reactor.

The reaction pool 15 is a square container without a cover made of plexiglass. The water inlet pipe 6 is connected to the upper part of the reaction tank 15, and the water inlet pipe 6 is provided with a water inlet pump 1. The aeration system 7 is located at the bottom of the reaction tank 15, the air in the aeration system 7 is supplied by the air compressor 4 outside the reaction tank 15, and released into the reaction tank 15 through the aeration head 7-1. Suspended activated sludge 22 grows in the reaction tank 15 .

The vent pipe 18 is arranged at the bottom of the reaction pool 13, and a vent pipe valve 19 is arranged on the vent pipe 18.

The several groups of tubular ceramic membrane modules 16 are fixed and submerged below the water level of the reactor, the lower end of the tubular membrane modules is blocked, and the upper end is an outlet water collection pipe 20 , which is provided with a membrane module control valve 21 . The collection pipes of all the membrane modules are collected into the collection main pipe 9, and finally pumped to the outlet tank 5 by the outlet pump 2. The front end of the water outlet pump is provided with a water outlet valve 24 . The outside of the water outlet tank is provided with a water outlet main pipe 17 .

The porous polyurethane sponge filler 13 is relatively hard and is tightly wrapped around the outer periphery of the ceramic membrane module 16 . Biofilms 14 grow on the surface and inside of the polyurethane sponge filler 13 . The outer periphery of the upper part of the porous polyurethane sponge packing 13 is wrapped by the rotating cap 12, and the upper part of the rotating cap 12 is connected with the rotating shaft 11. The rotating shaft 11 is a hollowed-out hollow cylinder and is wrapped around the outside of the collecting tube 20 . The rotating shaft 11 is connected with the rotating disk 10, and the rotating disk 10 is located above the water level and below the membrane module control valve 21. The rotating disk 10 is connected with an external motor 23, and the motor 23 drives the rotating disk 10 to rotate.

One end of the backwash pipe 8 is connected to the outlet water tank 5 and the other end is connected to the collection main pipe 9 . A backwash pump 3 is arranged on the backwash pipe 8 , and a backwash electric valve 25 is arranged between the backwash pump 3 and the intersection point of the backwash pipe 8 and the collection main pipe 9 .

In this embodiment, the ceramic membrane module is a tubular microfiltration membrane with a pore size of 0.10-0.2 μm, the working pressure of the filtration membrane is 0.05-0.15 MPa, and the working temperature is 5-40° C.

In this embodiment, the porous polyurethane sponge filler 13 is a hard hydrophilic biological filler. On the one hand, it can realize the attachment and growth of biofilm and increase the biomass in the reactor. Rotated under the driving force, the biofilm attached to the tubular ceramic membrane module 16 is scraped off to reduce membrane pollution.

In this embodiment, when the biofilm is thick during long-term operation, the ceramic membrane module and the sponge filler can be taken out of the reaction tank for cleaning.

The invention integrates the advantages of both MBR (realized by ceramic membrane components) and biological contact oxidation process (realized by sponge fillers), and uses the characteristics of the filler itself to solve the problems of easy pollution of existing MBR biofilm reactors and high cost of replacing membrane components To solve the problem, a porous filler-coated MBR device system and a wastewater treatment method for treating slightly polluted water are provided.

The working principle of the porous filler-coated MBR device described in this embodiment is that the treatment of the polluted water by the porous filler-coated MBR device includes a biodegradation process and a physical separation process. First, the slightly polluted water is lifted by the water inlet pump 1 and discharged into the MBR reaction tank 15 through the water inlet pipe 6 . The aeration system increases the dissolved oxygen in the water and plays a certain stirring role. Under the action of the activated sludge 22 and the biofilm 14 on the porous polyurethane sponge filler 13, the oxygen generated by the aeration is used to degrade and transform the pollutants in the influent water . Under the action of the outlet pump 2, the treated water passes through the packing gap and flows into the interior of the ceramic membrane module 16 through the filter holes of the ceramic membrane module, and then passes through the collecting pipe 20, and the water collecting main pipe 2 is collected to the water outlet tank 5. With the decrease of membrane flux and the increase of transmembrane pressure difference, membrane cleaning is realized through two processes: membrane surface friction cleaning and backwashing. Membrane surface friction cleaning is to use rough porous sponge-like polyester porous filler to clean the outer surface of ceramic membrane under the rotation of rotating disk and rotating cap; The particles in the pores of the MBR membrane are washed out, and the deep cleaning of the microfiltration pores is carried out. In summary, by controlling the specific operating conditions of the MBR reaction tank, such as sludge concentration, dissolved oxygen, membrane surface friction cleaning frequency, backwashing intensity and other parameter settings and operating methods, the removal of organic matter can be achieved, and the micro-polluted water can be generally realized. in-depth processing.

Example 2

This embodiment discloses a method for sewage treatment using the porous filler-coated MBR device described in Example 1, which includes the following steps:

1. Operation stage:

Incoming water (slightly polluted water) enters the reaction tank 15 through the water inlet pipe 6 under the suction of the water inlet pump 1. Under the condition that the air compressor 4, the aeration system 7 and the aeration head 7-1 work normally, the micropollution Pollutants in the water are degraded and metabolized by the activated sludge 22 and the biofilm 14 on the porous polyurethane sponge filler 13, and the water quality is purified. The MLSS of the activated sludge in the reaction tank 15 is 200mg/L, the dissolved oxygen concentration is 5mg/L-6mg/L, and the hydraulic retention time is 12-24h. The purified slightly polluted water passes through the internal holes on the porous polyurethane sponge filler 13, and is pumped through the ceramic membrane 16 to the collection main pipe 9 and the water outlet tank 5 under the suction of the water outlet pump 2.

2. Membrane surface friction cleaning stage:

When the membrane flux decreases by 30% or the membrane pressure is higher than 0.15Mpa (less than 0.4Mpa), the motor drives the rotating shaft 11, the rotating cap 12 and the rotating disk 10 to rotate under the control of the electric control cabinet, and finally the torque drives the porous polyurethane sponge The filler 13 rotates and scrapes the surface of the ceramic membrane 16 to scrape off a part of the biofilm attached to the surface of the ceramic membrane 16 .

3. Backwashing stage:

When the membrane pressure is higher than 0.4Mpa, the water inlet pump 1 and the water outlet pump 2 stop working, and the water outlet valve 24 is closed. The backwash electric valve 25 is opened, and the backwash water is the outlet water in the outlet water tank 5. Under the suction of the backwash pump 3, it enters the interior of the ceramic membrane 16 through the collection main pipe 9 and the collection pipe 20, and finally seeps out from the micropores of the membrane. , into the reaction tank 15. After 20 minutes, the backwashing is over, the backwashing pump 3 stops working, and at the same time the backwashing electric valve 25 is closed, the outlet valve 24, the inlet pump 1 and the outlet pump 2 are turned on, and the operation mode of the running stage is re-entered.

In this embodiment, the backwash pump 3 and the backwash electric valve 25 in Step 1 operate intermittently, and only one of the backwash electric valve 25 and the water outlet valve 24 can be opened.

Adopt following test to verify effect of the present invention:

Utilize the wastewater treatment method of the present invention to solve the problem of easy pollution of existing MBR membranes and the high cost of replacing membrane modules, proceed according to the following steps:

1. Operation stage:

COD is 50~60mg/L, BOD ₅ is 10~20mg/L, ammonia nitrogen is 5~8mg/L, total phosphorus is 0.2~0.5mg/L and pH value is 6.0~7.0. Under the suction of the water inlet pump 1, it enters the reaction tank 15 through the water inlet pipe 6. Under the normal working conditions of the air compressor 4, the aeration system 7 and the aeration head 7-1, the pollutants in the slightly polluted water are absorbed by the activated sludge. 22 and the biofilm 14 on the porous polyurethane sponge filler 13 are degraded and metabolized, and the water quality is purified. The MLSS of the activated sludge in the reaction tank 15 is 200mg/L, the dissolved oxygen concentration is 5mg/L-6mg/L, and the hydraulic retention time is 12-24h. The purified slightly polluted water passes through the internal holes on the porous polyurethane sponge filler 13, and is pumped through the ceramic membrane 16 to the collection main pipe 9 and the water outlet tank 5 under the suction of the water outlet pump 2.

2. Membrane surface friction cleaning stage:

When the membrane flux decreases by 30% or the membrane pressure is higher than 0.15Mpa (less than 0.4Mpa), the motor drives the rotating shaft 11, the rotating cap 12 and the rotating disk 10 to rotate under the control of the electric control cabinet, and finally the torque drives the porous polyurethane sponge The filler 13 rotates and scrapes the surface of the ceramic membrane 16 to scrape off a part of the biofilm attached to the surface of the ceramic membrane 16 .

3. Backwashing stage:

When the membrane pressure is higher than 0.4Mpa, the water inlet pump 1 and the water outlet pump 2 stop working, and the water outlet valve 24 is closed. The backwash electric valve 25 is opened, and the backwash water is the outlet water in the outlet water tank 5. Under the suction of the backwash pump 3, it enters the interior of the ceramic membrane 16 through the collection main pipe 9 and the collection pipe 20, and finally seeps out from the micropores of the membrane. , into the reaction tank 15. After 20 minutes, the backwashing is over, the backwashing pump 3 stops working, and at the same time the backwashing electric valve 25 is closed, the outlet valve 24, the inlet pump 1 and the outlet pump 2 are turned on, and the operation mode of the running stage is re-entered.

The national water quality inspection standard (GB 5749-2006) was used to detect the effluent indicators of this test: COD<15mg/L, BOD ₅ <3mg/L, ammonia nitrogen<0.5mg/L and total phosphorus<0.1mg/L, better than Class II water standards.

The above descriptions are only the basic principles and preferred embodiments of the present invention. Improvements and replacements made by those skilled in the art according to the present invention belong to the protection scope of the present invention.

Claims (9)

1. a kind of porous aggregate cladded type MBR devices, including reaction tank, more than one group of ceramic membrane group being arranged in reaction tank Part and the water inlet pipe for being arranged at reaction tank upper end, water inlet pipe are equipped with intake pump, it is characterised in that：Outside every group of ceramic film component Sponge filler is arranged with, sponge filler is connected with driving, and it surrounds the rotating drive component of ceramic film component；Every group of ceramic membrane The lower end sealing of component, upper end are communicated with collecting pipe, and the collecting pipe of every group of ceramic film component is collected to collection manifold, collects total Pipe is equipped with water outlet pump and is connected to water tank；Water tank is also communicated with backwash tube, and backwash tube is equipped with backwashing pump simultaneously It is connected with the collecting pipe of every group of ceramic film component；Aerating system is further included, aerating system includes air compressor machine, aeration tube and aeration Head, aeration tube extend to reaction tank bottom by air compressor machine, and aeration head is located on aeration tube.

2. porous aggregate cladded type MBR devices according to claim 1, it is characterised in that：The driving component includes rotation Turn cap, shaft, rotating disk and motor, turncap is sleeved on sponge filler top, shaft be fixedly connected on rotating disk and turncap it Between, rotating disk is connected with motor.

3. porous aggregate cladded type MBR devices according to claim 2, it is characterised in that：Turncap, shaft and rotating disk On be provided with the hole to connect, collecting pipe passes through the hole and connects ceramic film component.

4. porous aggregate cladded type MBR devices according to claim 1, it is characterised in that：The sponge filler is porous Polyurethane sponge filler, sponge filler is interior to be filled with biomembrane.

5. porous aggregate cladded type MBR devices according to claim 1, it is characterised in that：Reaction tank bottom, which is connected with, puts Blank pipe, blow-down pipe are equipped with emptying tube valve.

6. porous aggregate cladded type MBR devices according to claim 1, it is characterised in that：Activity is additionally provided with reaction tank Sludge.

7. porous aggregate cladded type MBR devices according to claim 1, it is characterised in that：Every group of ceramic component catchments Valve is equipped with pipe, collection manifold and backwash tube.

8. porous aggregate cladded type MBR devices according to claim 1, it is characterised in that：Ceramic film component is micro- for tubulose Filter membrane, aperture are 0.10~0.2 μm, and operating pressure is 0.05~0.15Mpa, and operating temperature is 5~40 DEG C.

A kind of 9. sewage water treatment method, it is characterised in that：This method is based on porous aggregate cladded type MBR described in claim 1 and fills Put, comprise the following steps：S01）, micro-polluted water reaction tank is entered by water inlet pipe under the swabbing action of intake pump, be aerated Under the action of system, ceramic film component and sponge filler, the pollutant in micro-polluted water is degraded and is metabolized, and water quality obtains only Change, purified micro-polluted water is entered collecting pipe under the swabbing action of water outlet pump, received by the inner void on sponge filler Water in collector enters water tank after being summarised in collection manifold；S02）, when membrane flux reduce by 30% when or membrane pressure be higher than 0.15Mpa, less than 0.4Mpa when, drive component drive sponge filler rotate, sponge filler ceramic film component surface rotation scrapes Wipe, the biomembrane that a part is attached on ceramic film component surface is struck off；S03）, when membrane pressure is higher than 0.4Mpa, intake pump And water outlet pump is stopped, backwashing pump is started to work, and the water in water tank passes through collection under the swabbing action of backwashing pump Manifold, collecting pipe enter inside ceramic film component, are finally oozed out from the micropore of film, and into reaction tank, backwash terminates, backwash Pump is stopped, and at the same time, intake pump and water outlet pump are opened, and reenters operation phase, degraded and metabolism micro-polluted water.