Five common problems with MBR membrane components

Question 1:

What are the precautions for the preservation of membrane components?

• Do not remove the protective film of the membrane module package.

• When storing, it must be placed in a ventilated, dry place without corrosive gases.

• The suitable storage environment temperature range is 5~40℃.

• Membrane modules should not be exposed to the sun, otherwise it will easily cause the membrane surface to stick.

• Membrane modules should not be exposed to rain, alternating wet and dry conditions will affect performance.

• Before entering the pool, welding and other constructions that are likely to produce small and sharp solid substances are not allowed around the components, otherwise they need to be covered to prevent burns from welding slag.

Operation and maintenance case: 100 tons of landfill leachate treatment project in Guizhou

Project problem: Just after the membrane module was installed, the effluent water was turbid.

Check situation: Our operation and maintenance personnel rushed to the site for maintenance, disassembled the components, and inspected the outer water collection main pipe, branch pipe, diaphragm, etc., and finally found that the diaphragm was welded, resulting in turbid water.

Guidance results: Our operation and maintenance personnel adopt the method of replacing the diaphragm with large weld damage, and use AB glue to repair the diaphragm with small weld damage. Finally, after re-entering the water, the project runs normally and the water is clear .

Question 2:

How to choose membrane cleaning agent?

• Organic matter: use sodium hypochlorite with a concentration of 0.5% to 1%

• Inorganic substances: use 5‰-10‰ oxalic acid, 1%-3% citric acid or hydrochloric acid with pH=2～3

• Membrane fouling is mostly organic fouling, which can be cleaned with sodium hypochlorite.

• If there are many substances that are prone to scaling such as calcium, magnesium, and iron, use oxalic acid, citric acid, or hydrochloric acid for cleaning.

Operation and maintenance case: a 1,000-ton chemical wastewater treatment project in Shaoxing

Project problem: The customer reported that the water output of the membrane module that has been in operation for about two years is small.

Troubleshooting situation: Our technical staff first communicated with the phone and temporarily stopped using it, and then rushed to the project site for maintenance. After the liquid level dropped, it was found that calcium carbonate scale was attached to the surface of the pipe and diaphragm, resulting in a small water output.

Guidance results: Pickling with hydrochloric acid with a pH of 3, soaking time is three hours, after soaking, turn on the fan for one hour to blow off the calcium carbonate scale on the membrane surface, finally solve the problem, and run normally to discharge water.

Question 3:

What is the reason for the foam in the aeration tank after adding medicine to wash the membrane?

Reason: The environment of the membrane pool is slightly damaged after washing the membrane, and the microorganisms attached to the membrane surface are killed and become pollutants in the pool. These changes will cause the membrane pool to be aerated within a short period of time after washing the membrane. More foam, the environment in the pool will return to normal after running for a period of time, and the situation with more foam will automatically recover.

Solution:

1.Before the components are air-exposed, turn on the self-priming pump to discharge water in a small amount to discharge the cleaning solution.

2. Spray with water to suppress the foam.

3. Add defoamer, pay attention to add non-silicon defoamer!

Question 4:

How to control the uniformity of aeration during the operation of MBR membrane modules?

Aeration intensity is one of the important parameters in MBR operation. It reflects the amount of aeration and is positively related to the shear force on the membrane surface.

When the aeration intensity is low, the hydraulic shear force generated by aeration is not enough to remove the pollutants on the surface of the membrane; excessive aeration will cause the sludge flocs to break up and produce a large number of small particles of colloid and dissolved substances, resulting in pollution. Blocking.

Control measures:

1.Ensure that the air volume and pressure meet the design requirements

2. Operation and maintenance regularly vent the valve, clear the aeration hole, and ensure the smooth flow of the aeration pipeline.

3. Pay attention to the sediment at the bottom of the membrane tank and discharge it regularly.

Question 5:

Will the main ribs and auxiliary ribs on the diaphragm fall off?

The membrane surface and the support plate are welded by ultrasonic or hot-melt machine, and there are main ribs and auxiliary ribs. The main rib is located on the inner side, and whether it falls off determines whether the diaphragm leaks; the auxiliary rib is located on the outer side, and falling off will only affect the appearance and will not cause water leakage.

Operation and maintenance case: Shanxi 7500 tons municipal sewage treatment project

Project situation: The flat membrane module of this project has been in continuous operation for more than 6 years. In response to the needs of municipal sewage plants, our company will replace the membrane module and provide the owner with guidance on the installation and commissioning of the membrane module.

Processing results: Under the guidance of our operation and maintenance technicians, the overall installation and commissioning of the project was completed within 10 days of the planned construction period, and the actual water discharge index was better than the quasi-four-category limit.

As a core module research and manufacture of membrane bioreactor (MBR), Nanjing JX purification,Co., Ltd. has standard MBR series products, mature water treatment process, professional operation and maintenance management team and complete after-sales service system .

Up to now, enterprise service projects have covered 32 provinces and cities, with more than 2,000 successful cases.

Therefore, in the face of MBR process operation and maintenance debugging problems, we can be prepared to judge, respond quickly and solve efficiently, helping major enterprises to complete water treatment tasks.