Cleaning of lined reinforced polyvinylidene fluoride hollow fiber curtain membrane modules (MBR membranes )
lined reinforced polyvinylidene fluoride hollow fiber curtain membrane modules (MBR membranes ) are divided into online cleaning and offline cleaning according to the position of the lined reinforced polyvinylidene fluoride hollow fiber curtain membrane modules (MBR membranes ) during cleaning, and can be divided into physical cleaning and chemical cleaning according to the properties of the cleaning fluid .
Cleaning method
Membrane Cleaning Parameter Table
| Classification | Cleaning Method | Cleaning Equipment | Cleaning Frequency | Cleaning Fluid Formula |
|---|
| Physical Cleaning | Online Air Cleaning | Blower | 24 hours continuous | Wind (continuous aeration) |
| Physical Cleaning | Online Water Backwash | Backwash Pump | 1 time/day | MBR outlet water / tap water |
| Chemical Cleaning | Online Chemical Cleaning | Dosing Pump | 1 time/3 months | 1000 mg/L Sodium Hypochlorite |
| Chemical Cleaning | Offline Chemical Cleaning (Recommended) | Chemical Cleaning Pool | 1 time/3 - 12 months | Formula 1, Formula 2, Formula 3
(Note: Specific components of the three formulas are to be supplemented) |
For "Offline Chemical Cleaning", the frequency "1 time/March-December" is interpreted as "1 time every 3 to 12 months" (i.e., 1 to 4 times a year) based on common industrial cleaning conventions; if it refers to a specific period (e.g., once between March and December annually), it is recommended to confirm with the equipment manufacturer.
The three formulas for offline chemical cleaning are only labeled as "Formula 1/2/3" since specific component information (e.g., chemical type, concentration) is not provided. It is necessary to supplement the detailed formula content according to actual cleaning requirements (e.g., for organic pollution, inorganic pollution, or biological pollution).
Cleaning fluid formula
| Recipe | Drug Type and Concentration | Cleaning Objects | pH |
|---|
| Recipe 1 | - 0.5% - 1.0% citric acid / oxalic acid
- Or 0.2% - 0.4% hydrochloric acid | Inorganic matter (Metal oxides, scale) | ≈ 1 |
| Recipe 2 | 1000 ppm sodium hypochlorite | Organic matter (organisms, bacteria) | Depends on the environment, generally weakly alkaline |
| Recipe 3 | - 1000 - 3000 ppm sodium hypochlorite
- 0.1% - 0.3% sodium hydroxide | Organic matter (organics, proteins, bacterial remains) | 13 - 14 |
The conditions in the table are standard conditions, which can be adjusted appropriately according to the quality of the wastewater to be treated. For details, please contact relevant personnel of our company.
In the table:
Online air cleaning
Online air cleaning refers to a cleaning method in which a blower is used to supply air to the inner and outer aeration pipes of the MBR membrane box (MBR membrane box ) when the MBR membrane box is in operation. The large bubbles generated by the inner and outer aeration pipes are used to purge and clean the membrane wire surface of the MBR membrane box (MBR membrane ), thereby delaying the fouling of the MBR membrane box (MBR membrane ) and restoring the membrane flux. Online air cleaning is generally designed to operate continuously for 24 hours.
Online water backwash
Online water backwashing refers to the process when the reinforced polyvinylidene fluoride hollow fiber curtain membrane module (MBR membrane) with inner lining is shut down ( the suction pump is shut down at this time,The blower does not stop running), the effluent or tap water of the membrane bioreactor (MBR) is sucked by the backwash pump, and the lining-enhanced polyvinylidene fluoride hollow fiber curtain membrane module (MBR membrane ) is backwashed to delay the fouling of the lining-enhanced polyvinylidene fluoride hollow fiber curtain membrane module (MBR membrane ) and restore the membrane flux.
Online water backwashing is generally designed to be performed once every 24 hours ,for5 minuteseachtime. Online water backwashing operation steps:
（1）Stop the suction pump while keeping the blower running;
（2）Close the water outlet valve, open the backwash valve, and start the backwash pump;
（3）Stop the backwash pump after 5 minutes;
（4）Close the backwash valve, open the outlet valve, start the suction pump, and switch to normal operation.
Online chemical cleaning (optional )
Online chemical cleaning refers to a cleaning method in which the cleaning liquid in the dosing tank is pumped into the membrane fibers of the MBR membrane assembly with an inner lining and enhanced polyvinylidene fluoride hollow fiber curtain membrane assembly (MBR membrane ) through a dosing pump when both the MBR membrane assembly with an inner lining and the blower are stopped , thereby delaying the fouling of the MBR membrane assembly with an inner lining and enhanced polyvinylidene fluoride hollow fiber curtain membrane assembly (MBR membrane ) and restoring the membrane flux. Online chemical cleaning is generally designed to be performed once every three months or when the vacuum pressure difference (current vacuum pressure gauge value minus initial vacuum pressure gauge value) exceeds0.02MPa (whichever indicator comes first), each time for 1-6 hours.
Online chemical cleaning operation steps:
（1）Shut down the suction pump and blower;
（2）Close the water outlet valve, open the backwash valve and dosing valve, and start the dosing pump;
（3）After 30 minutes, stop the dosing pump and close the dosing valve;
（4）Start the blower after standingfor2-5 hours;
（5）After 30 minutes, open the water outlet valve, start the suction pump, and switch to normal operation a negative impact on the normal use and service life of the reinforced hollow fiber curtain membrane module (MBR membrane ) with inner lining, It plays an extremely important role, so when you perform online chemical cleaning for the first time, please contact our company's relevant technical personnel for technical support.
Offline chemical cleaning
Offline chemical cleaning refers to a cleaning method in which when both the liner-reinforced polyvinylidene fluoride hollow fiber curtain membrane module (MBR membrane ) and the blower are stopped, the liner-reinforced polyvinylidene fluoride hollow fiber curtain membrane module (MBR membrane ) is removed from the membrane bioreactor (MBR) pool and placed in a chemical cleaning tank that has been prepared with cleaning fluid, in order to delay fouling of the liner-reinforced polyvinylidene fluoride hollow fiber curtain membrane module (MBR membrane ) and restore membrane flux .
Offline chemical cleaning is generally designed to beperformed once every 3-12 months or when the vacuum pressure difference (current vacuum pressure gauge value minus initial vacuum pressure gauge value) exceeds 0.02MPa (whichever indicator comes first), each time for 1-6 hours.
Offline chemical cleaning operation steps:
（1）Shut down the suction pump and blower;
（2）Close the outlet valve and disassemble the joints or flanges of the water collecting pipe, internal aeration main pipe and external aeration pipe on the reinforced polyvinylidene fluoride hollow fiber curtain membrane cassette (MBR cassette) in the membrane bioreactor (MBR) pool;
（3）Lift the reinforced polyvinylidene fluoride hollow fiber curtain membrane cassette (MBR cassette) with lining into the chemical cleaning tank that has been prepared with cleaning liquid, and seal the joints or flange interfaces of the water collecting pipe, internal aeration main pipe and external aeration pipe;
（4）standingfor2-5 hours, open the aeration valve at the bottom of the chemical cleaning pool;
（5）After 30 minutes, close the aeration valve at the bottom of the chemical cleaning pool, hoist the reinforced polyvinylidene fluoride hollow fiber curtain membrane box (MBR membrane box ) back into the membrane bioreactor (MBR) pool, and connect the water collection pipe, internal aeration main pipe and external aeration pipe on the reinforced polyvinylidene fluoride hollow fiber curtain membrane box (MBR membrane box );
（6）Turn on the blower and suction pump and switch to normal operation.
Note! (1) Offline chemical cleaning affects the normal use and service life of the reinforced hollow fiber curtain membrane module (MBR membrane ) with inner lining. It plays an extremely important role, so when you perform online chemical cleaning for the first time, please contact our company's relevant technicians for technical support.
Note! (2) For membrane bioreactor (MBR) systems without lifting devices, it is necessary to install reinforced polyvinylidene fluoride hollow fiber with inner lining. The curtain membrane assembly (MBR membrane)is removed from the liner-enhanced polyvinylidene fluoride hollow fiber curtain membrane box (MBR membranebox ) and then placed in a chemical cleaning tank for cleaning. Since this work is likely to cause damage to the liner-enhanced polyvinylidene fluoride hollow fiber curtain membrane assembly (MBR membrane ), please contact our company's relevant technical personnel for technical support.
Cleaning of aeration pipes
Aeration pipes are usually cleaned by opening the air discharge valve or starting and stopping the blower, usually every 3-7 days,for 2-5 minutes each time. Ifthe above cleaning methods are not effective, the aeration pipes can be removed and cleaned with a high-pressure water gun or brush.