CN113003713A

CN113003713A - Leachate and kitchen wastewater MBR system and process

Info

Publication number: CN113003713A
Application number: CN202110327266.7A
Authority: CN
Inventors: 杨勇; 张鼎; 袁学文; 李华; 李成海; 朱元朝; 颜锡; 张席
Original assignee: Jiangsu Jiyang Environmental Technology Co ltd
Current assignee: Jiangsu Jiyang Environmental Technology Co ltd
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2021-06-22

Abstract

The invention discloses a leachate and kitchen wastewater MBR system and process, which comprises a water production system, a backwashing system and an aeration system, wherein the water production system comprises a membrane box, a membrane pool, a membrane cleaning water tank, a water production tank, an electric hoist and cleaning equipment. The invention optimally designs the combination mode of biochemistry and a membrane system, so that the MBR process is more integrated; and the curtain type membrane is directly arranged in the biochemical aeration tank, the aeration system performs oxygenation aeration on the biochemical tank and disturbance aeration on the curtain type membrane wire, and self-cleaning and dredging are performed on the surface of the curtain type membrane by utilizing the action of transverse water flow, so that equipment investment and operation energy consumption are saved.

Description

Leachate and kitchen wastewater MBR system and process

Technical Field

The invention relates to the field of garbage leachate and kitchen waste wastewater treatment, in particular to a leachate and kitchen waste MBR system and process.

Background

With the progress of cities and towns, China is greatly promoted in the field of domestic garbage treatment, and the projects of garbage classification and garbage incineration combined synergistic treatment are increasing day by day; in the process of treating the domestic garbage, particularly organic garbage, a large amount of waste water such as percolate, filtrate, fermentation liquor and the like is generated in the links of sorting, squeezing, fermentation and the like, and the waste water has high treatment difficulty and high operation cost due to high organic concentration, high oil content, high salt content and various impurities.

The conventional treatment process for percolate in a household garbage incineration power generation project comprises the following steps: pretreatment + anaerobism + AOMBR + membrane advanced treatment process, which has gradually gained market acceptance in recent applications; in the items such as kitchen, kitchen are remained, fruit vegetables of domestic waste incineration power generation project coprocessing, a large amount of organic waste press filtrate or zymotic fluid waste water that contain oil height, tiny impurity are many need original waste incineration power plant filtration liquid treatment station to carry out coprocessing, and the filtration liquid that this waste water and conventional waste incineration power plant produced has similar place also to have different places in nature, and simple direct hybrid processing has some unmatched places.

The biochemical MBR of the percolate treatment project of the traditional household garbage incineration project adopts more tubular ultrafiltration membranes, the tubular ultrafiltration membranes mainly adopt membrane channels with the diameter of 8mm or 5mm, and the membrane blockage is prevented by utilizing a high-flow-rate cross flow technology; however, this process has the following disadvantages: high membrane blocking frequency, high operation energy consumption and high equipment matching investment.

In the treatment of high-concentration organic wastewater such as garbage percolate, kitchen waste, fruit and vegetable, particularly high-concentration grease and short fibers contained in kitchen and kitchen waste filter pressing wastewater and biogas slurry wastewater, great trouble is brought to a normal biochemical and membrane filtration combined process; short and small fibers are enriched in wastewater, the conventional main flow pipe type ultrafiltration membrane is difficult to adapt, membrane pores are often blocked, the cleaning frequency is increased, the damage to a membrane filter layer is increased in the dredging process, the service life of the membrane is seriously reduced, and the production treatment capacity and the utilization efficiency are further influenced.

Disclosure of Invention

Aiming at the problems, the invention provides a leachate and kitchen wastewater MBR system and process, which are used for solving the problems.

The invention is realized by the following technical scheme:

the utility model provides a filtration liquid and meal kitchen waste water MBR system, is including producing water system, backwash system and exploding the gas system, it includes membrane case, membrane pond, membrane washing pond, produces water tank, electric block and cleaning equipment to produce the water tank, electric block and produce the water mouth to produce the water tank, backwash system through producing the water pipe connection to produce the water mouth to through wasing the pipe connection cleaning equipment, it is provided with the product water pump on the water pipe to produce, electric block connects the membrane case, the membrane case passes through electric block and removes between membrane pond and membrane washing pond, the membrane pond includes water inlet and sludge discharge port, outside biochemical pond is connected to the water inlet, sludge discharge port connects sludge backflow equipment.

Furthermore, the backwashing system comprises a backwashing water tank, a backwashing pump, a cartridge filter, a backwashing flow meter and a backwashing flow meter, wherein the backwashing water tank is connected with a water outlet through a water production pipeline, and the backwashing pump, the cartridge filter, the backwashing flow meter and the backwashing flow meter are sequentially arranged on the water production pipeline.

Further, the backwashing water tank and the production water tank are shared.

Further, the gas explosion system comprises a fan, a gas rotor flow meter and a manual valve, wherein the fan is connected with the gas inlet through a gas inlet pipeline, and the gas rotor flow meter and the manual valve are sequentially arranged on the gas inlet pipeline.

Furthermore, the cleaning equipment comprises an acid cleaning water pump, an alkali cleaning water pump, an acid security filter, an alkali security filter, an acid cleaning water tank and an alkali cleaning water tank, wherein the outlet of the acid cleaning water tank is connected with a cleaning pipeline through the acid security filter and the acid cleaning water pump; the outlet of the alkali cleaning water tank is connected with a cleaning pipeline through an alkali security filter and an alkali cleaning water pump.

Further, the cleaning pipeline comprises an in-situ cleaning pipeline and an ex-situ cleaning pipeline.

Further, a PTFE built-in MBR membrane is arranged in the membrane box.

The MBR process for leachate and kitchen wastewater comprises the following steps:

water is produced, a water producing pump pumps out membrane pool water from membrane filaments in the membrane box, and the produced water is conveyed to a water producing box through a water producing pipeline, an automatic valve and a water producing flow meter;

backwashing, namely injecting a backwashing water source into the membrane filaments by a backwashing pump through a cartridge filter, a backwashing flow meter and a backwashing automatic valve to perform backwashing scouring on the surface pollutants of the membrane filaments;

chemical cleaning, namely taking the membrane box out of the membrane pool, putting the membrane box into a membrane cleaning water pool, and cleaning the membrane box through a cleaning pipeline;

and (4) aerating, namely connecting the fan into an aeration pipeline inside the membrane box, and adjusting the aeration quantity through a manual valve.

Further, the chemical cleaning includes in-situ cleaning and ex-situ cleaning, and specifically includes:

in-situ cleaning, when the membrane box is cleaned in situ, the membrane pool is emptied, the membrane box is exposed in the air, cleaning liquid in the cleaning equipment enters the interior of the membrane wire through a water production port and infiltrates to the outer wall of the membrane wire, and an acid/alkali cleaning pump is used for alternately and chemically cleaning the membrane unit;

cleaning in different positions, namely lifting the membrane box to a membrane cleaning water tank for soaking and cleaning.

Further, the backwashing water source comprises a water source in the water production tank and an external water source.

The invention has the beneficial effects that:

(1) the invention optimally designs the combination mode of biochemistry and a membrane system, so that the MBR process is more integrated;

(2) the curtain type membrane is directly arranged in the biochemical aeration tank, the aeration system performs oxygenation aeration on the biochemical tank and disturbance aeration on the curtain type membrane wire, and self-cleaning and dredging are performed on the surface of the curtain type membrane by utilizing the action of transverse water flow, so that equipment investment and operation energy consumption are saved;

(3) according to the invention, the curtain film is formed to drive the water pressure by utilizing the liquid level difference potential energy in the biochemical tank body, so that the operation power of the produced water suction pump is reduced, and the energy consumption is further saved;

(4) the curtain type membrane unit is provided with the lifting device, the off-line cleaning device is arranged beside the biochemical pool, and the membrane is cleaned when the off-line cleaning is needed;

(5) the on-line cleaning device is arranged, the medicine feeding port is arranged on the self-membrane backwashing pipeline, the curtain-type membrane is cleaned by on-line high-concentration medicines, the cleaning effect is better, the medicine dosage for medicine cleaning is obviously reduced compared with soaking, and the environmental pollution equivalent is reduced;

(6) the invention sets pipeline optimization such as water production bypass, aeration pipeline bypass and the like, can produce water under the condition that the membrane system does not have any electric work, and achieves the aim of zero energy consumption water production.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic diagram of the system of the present invention;

in the figure, 1-membrane tank, 2-membrane tank, 3-membrane cleaning water tank, 4-water production tank, 5-electric hoist, 6-aeration system, 7-water production pump, 8-external biochemical tank, 9-sludge reflux equipment, 10-water production flowmeter, 11-acid cartridge filter, 12-acid cleaning water pump, 13-acid cleaning water tank, 14-alkali cartridge filter, 15-alkali cleaning water pump, 16-alkali cleaning water tank, 17-cleaning flowmeter and 18-sludge reflux pump.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

Example 1

As shown in fig. 1, this embodiment provides a leachate and kitchen wastewater MBR system, including producing water system, backwash system and exploding gas system 6, it includes membrane case 1, membrane pond 2, membrane cleaning water tank 3, produces water tank 4, electric block 5 and cleaning equipment to produce the water system, membrane case 1 includes the air inlet and produces the water mouth, the air inlet is connected and is exploded gas system 6, produce the mouth of a river and connect through producing water pipeline and produce water tank 4, backwash system to connect cleaning equipment through wasing the pipeline, it is provided with product water pump 7 on the water pipeline to produce, electric block 5 connects membrane case 1, membrane case 1 moves between membrane pond 2 and membrane cleaning water tank 3 through electric block 5, membrane pond 2 includes water inlet and sludge discharge port, outside biochemical pond 8 is connected to the water inlet, sludge discharge port connects sludge backflow equipment 9.

Further, the backwash water tank is shared with the production water tank 4.

Further, the gas explosion system 6 comprises a fan, a gas rotor flow meter and a manual valve, wherein the fan is connected with the gas inlet through a gas inlet pipeline, and the gas rotor flow meter and the manual valve are sequentially arranged on the gas inlet pipeline.

Further, the cleaning equipment comprises an acid cleaning water pump 12, an alkali cleaning water pump 15, an acid cartridge filter 11, an alkali cartridge filter 14, an acid cleaning water tank 13 and an alkali cleaning water tank 16, wherein an outlet of the acid cleaning water tank 13 is connected with a cleaning pipeline through the acid cartridge filter 11 and the acid cleaning water pump 12; the outlet of the alkali cleaning water tank 16 is connected with a cleaning pipeline through an alkali cartridge filter 14 and an alkali cleaning water pump 15.

Further, a PTFE built-in MBR membrane is arranged in the membrane box 1.

water is produced, the water pump 7 pumps the water in the membrane pool 2 out of the membrane wires in the membrane box 1, and the produced water is conveyed to the water production box 4 through a water production pipeline, an automatic valve and a water production flow meter 10;

chemical cleaning, namely taking the membrane box 1 out of the membrane pool 2, putting the membrane box into a membrane cleaning water pool 3, and cleaning the membrane box through a cleaning pipeline;

and (4) aerating, namely connecting the fan into an aeration pipeline inside the membrane box 1, and adjusting the aeration quantity through a manual valve.

in-situ cleaning, when the membrane box 1 is subjected to in-situ cleaning, emptying the membrane pool 2, exposing the membrane box 1 in the air, allowing cleaning liquid in cleaning equipment to enter the interior of the membrane filaments through a water production port and infiltrate to the outer walls of the membrane filaments, and alternately performing chemical cleaning on the membrane units by using an acid/alkali cleaning pump;

cleaning in different positions, namely lifting the membrane box 1 to a membrane cleaning water tank 3 for soaking and cleaning.

Further, the backwashing water source comprises a water source in the water production tank 4 and an external water source.

Further, a cleaning flow meter 17 is further arranged on the cleaning pipeline.

The specific principle of the embodiment is as follows:

built-in MBR membrane of PTFE:

the membrane of the hollow fiber membrane biochemical reactor is immersed in the bioreactor, after raw water enters the membrane bioreactor, most pollutants in the raw water are decomposed by activated sludge in the mixed liquid, and water is filtered by the membrane under the action of a suction pump or a water head difference. The built-in MBR realizes the cross flow effect on the membrane surface by utilizing the upward shearing force of gas and liquid during aeration, and reduces the pollution to the membrane. The greatest advantage of internal MBRs is low power consumption compared to external MBRs. The PTFE membrane has the filtration precision as high as 0.1 mu m, has higher removal rate on pollutants such as virus, bacteria, colloid and the like in water, and has the effluent turbidity below 1NTU and good effluent quality stability. The operation mode of the membrane system is intermittent operation, the membrane system continuously operates for 9min, and then periodic backwashing is carried out, wherein the backwashing time is 1 min. The flow of the water producing pump 7 can be controlled by frequency conversion, and the actual water yield is related to the water inflow.

The operation process comprises the following steps:

(1) preparation before operation

a. Before starting up the machine each time, checking whether each water pump and the automatic valve are normal;

b. checking the liquid level of the MBR membrane tank 2;

c. before a power switch of the lift pump is started, the switching conditions of each manual valve are checked;

d. and checking aeration quantity of the MBR system.

(2) Water production program

And opening a water production valve of the MBR system, starting a water production pump 7, enabling the system to enter an operating state, and enabling the water production mode of the system to be stopped for 1 minute every 9 minutes, and sequentially and circularly operating.

(3) Backwash procedure

The MBR system operates for 10min once circulation (operates for 9min and stops for 1min), after 12 times of circulation, the system performs backwashing, namely within 1min after 12 th circulation and stopping, the water production pump 7 is firstly closed, then the water production valve is closed, the backwashing valve is opened, the backwashing pump is started, after 40-60 s, backwashing is finished, the backwashing water pump is closed again, the backwashing valve is closed, the water production valve is opened, the water production pump 7 is started, and the system enters into circulation operation again.

(4) Shutdown procedure

And after the machine is selected to be stopped, the water producing pump 7 is stopped, the water producing valve is closed, and the machine is stopped.

MBR system linkage mode:

the MBR membrane pool 2 liquid level meter is interlocked with the water production pump 7, the sludge reflux pump 18 and the water production valve, when the liquid level of the membrane pool 2 is low, the water production pump 7 and the sludge reflux pump 18 automatically stop running, the water production valve is closed, the MBR system is stopped, and the water production valve is automatically opened, the water production pump 7 and the sludge reflux pump 18 are started after the liquid level of the membrane pool 2 is restored to the running liquid level. (the opening and closing of each valve must be performed after the previous operation is completed); when 2 high liquid levels in MBR membrane cisterna, stop 2 water intake pumps in MBR membrane cisterna, wait 2 liquid levels in membrane cisterna and resume to the operation liquid level and then start the water intake pump.

MBR system daily inspection

Stabilization of aeration conditions and biological treatment is particularly important for stable operation of the membrane system. Please perform the daily examination described below.

(1) Checking the stability of the transmembrane pressure Difference

The change in the transmembrane pressure difference may be due to the following reasons:

1. under the condition of operating according to the designed water yield, if the transmembrane pressure difference suddenly rises, the occurrence of membrane pollution is indicated;

2. the water yield is increased, namely the operation flux is increased, and the transmembrane pressure difference is increased;

3. abnormal aeration state or increased sludge concentration, resulting in rapid increase of transmembrane pressure difference;

4. the turbidity of produced water is increased, and transmembrane pressure difference is reduced, possibly due to loosening and breakage of a flange at a port of a membrane element or breakage and leakage of a pipeline;

5. filter paper assay, > 15mL (5 min).

(2) Aeration state

Checking whether the aeration air quantity is the designed quantity and whether the aeration is uniform. When the abnormal aeration air quantity and obvious uneven aeration are found, the necessary measures are taken: such as cleaning and dredging the aeration pipeline and the aeration box, checking whether the aeration pipeline is misplaced, checking the running state of a fan, adjusting the aeration air quantity and the like.

(3) Sludge concentration (MLSS)

It is recommended that MLSS be controlled to 5000-25000 mg/L, and the predetermined performance may not be achieved when the condition is not satisfied, so please properly adjust the concentration range of MLSS: when the MLSS is too low, measures such as throwing seed sludge or stopping sludge discharge and the like can be adopted; when the MLSS is too high, measures such as increasing the sludge discharge amount can be taken.

(4) Temperature of water

It is recommended to control the water temperature of the membrane tank 2 to 15 to 40 ℃, and in the case where this condition is not satisfied, since there is a possibility that a predetermined performance cannot be achieved, it is necessary to take necessary measures such as cooling and heat retention (a decrease in the water temperature causes a decrease in the membrane flux).

(5) Water level

Please check if the water level of the membrane bioreactor is within the normal range. The liquid level is preferably 1300-500 mm higher than the membrane box and is not lower than the membrane box 1. If the abnormality occurs, please check the level meter and the control program for the abnormality.

Matters of attention

(1) Before the water production system is started, the aeration system must be started, and the fan is started after each valve of the aeration pipeline is opened to ensure that the membrane yarn is completely shaken and the designed air volume is achieved;

(2) when water is produced for the first time, the situation of discontinuous water production may exist, the reason is that air exists in the pipeline, and the vacuum state cannot be completely realized in the pipeline, the MBR backwashing system is recommended to be started, a water production valve is opened, the whole pipeline and membrane filaments are filled with backwashing water, then the MBR backwashing system is closed, and the water production pipeline, the valve and the pump are checked to normally start the water production system. (this step is required after off-line MBR cleaning);

(3) after the MBR system is started to operate, parameters such as aeration air quantity, water yield, backwashing quantity, concentration and period of an on-line cleaning agent and the like are ensured to be executed strictly according to design requirements;

(4) the normal service life of the filter bag arranged in the cartridge filter is 2-3 weeks (the weekly check is recommended to prevent the filter bag from being perforated). After the filter works for a period of time, because impurities on the surface of the filter bag are accumulated continuously, when the pressure gauge at the upper end of the cartridge filter is increased to be more than 0.2 MPa, the filter bag is required to be replaced in time, otherwise the normal operation of the system is influenced (the replaced filter bag can be reused after being treated by acid washing and alkali washing);

(5) if the system needs on-line maintenance chemical cleaning and the system is shut down temporarily, the aeration system does not need to be closed; if the system needs off-line recovery chemical cleaning, the aeration system is closed after the shutdown procedure is finished, and the blower and each valve of the aeration pipeline are closed in sequence.

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. a leachate and kitchen waste water MBR system, is characterized in that, comprises water production system, backwash system and gas explosion system, and described water production system comprises membrane box, membrane tank, membrane cleaning pool, water production tank, electric Hoist and cleaning equipment, the membrane box includes an air inlet and a water production port, the air inlet is connected to the gas explosion system, the water production port is connected to the water production tank and the backwash system through the water production pipeline, and is connected to the cleaning system through the cleaning pipeline Equipment, the water production pipeline is provided with a production pump, the electric hoist is connected to the membrane box, the membrane box is moved between the membrane tank and the membrane cleaning tank by the electric hoist, and the membrane tank includes a water inlet and a sludge discharge port , the water inlet is connected to an external biochemical tank, and the sludge discharge port is connected to a sludge return device.

2. a kind of leachate and kitchen waste water MBR system according to claim 1, is characterized in that, described backwash system comprises backwash tank, backwash pump, security filter, backwash flowmeter and backwash flow The backwash water tank is connected to the water production port through the water production pipeline, and the backwash pump, the security filter, the backwash flowmeter and the backwash flowmeter are sequentially arranged on the water production pipeline.

3. A kind of leachate and kitchen waste water MBR system according to claim 2, is characterized in that, described backwash water tank and water production tank are shared.

4. a kind of leachate and kitchen waste water MBR system according to claim 1, is characterized in that, described gas explosion system comprises blower fan, gas rotameter and manual valve, and described blower fan is connected by air inlet pipeline into inlet. The gas port, the gas rotameter and the manual valve are sequentially arranged on the air inlet pipeline.

5. a kind of leachate and kitchen waste water MBR system according to claim 1, is characterized in that, described cleaning equipment comprises acid cleaning water pump, alkali cleaning water pump, acid security filter, alkali security filter, acid cleaning water tank and alkali cleaning water tank, the outlet of the acid cleaning water tank is connected to the cleaning pipeline through the acid security filter and the acid cleaning water pump; the outlet of the alkali cleaning water tank is connected to the cleaning pipeline through the alkali security filter and the alkali cleaning water pump.

6. The Leachate and Kitchen Wastewater MBR system according to claim 1 or 5, wherein the cleaning pipeline comprises an in-situ cleaning pipeline and an off-site cleaning pipeline.

7. A kind of leachate and kitchen waste water MBR system according to claim 1, is characterized in that, in described membrane box is PTFE built-in MBR membrane.

8. a leachate and kitchen waste water MBR process, is characterized in that, comprises:

For water production, the water production pump pulls the water from the membrane tank from the membrane wire inside the membrane box, and transports the produced water to the water production tank through the water production pipeline, automatic valve, and water production flowmeter;

Backwashing, the backwashing pump injects the backwashing water source into the membrane wire through the security filter, the backwashing flowmeter and the backwashing automatic valve, and backwashes the pollutants on the surface of the membrane wire;

For chemical cleaning, take out the membrane box from the membrane tank, put it into the membrane cleaning tank, and clean it through the cleaning pipeline;

Explosion, connect the fan to the aeration pipeline inside the membrane box, and adjust the aeration volume through the manual valve.

9. a kind of leachate and kitchen wastewater MBR process according to claim 8, is characterized in that, described chemical cleaning comprises in-situ cleaning and ex-situ cleaning, specifically comprises:

In-situ cleaning, when the membrane box is cleaned in-situ, the membrane tank is emptied, the membrane box is exposed to the air, and the cleaning liquid in the cleaning equipment enters the membrane silk through the water outlet and infiltrates the outer wall of the membrane silk. The process of using acid/alkali The washing pump performs chemical cleaning on the membrane unit alternately;

For off-site cleaning, lift the membrane box to the membrane cleaning pool for soaking and cleaning.

10 . The MBR process for leachate and kitchen wastewater according to claim 8 , wherein the backwash water source includes an internal water source and an external water source in a water production tank. 11 .