FAQs

POREFLON Microfiltration Membrane Module

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Below are some common questions.
If your question is not answered here, contact us through the link "For information on products and technologies."

Category: Operating Conditions
What aeration rate should I use for membrane scouring?
What is the upper limit of SS in raw water?
What is the upper limit for removing oil contained in raw water?
What chemical can I use for cleaning?
When does the membrane module require cleaning?
What quantity of cleaning chemical should I use?
Do I need to perform backwash?
 
 
Category: Maintenance/Storage
Are the hollow fibers likely to break during use?
How should I store the POREFLON Membrane Module?
How long will the membrane last?
 
 
Category: Service
Do you sell your products as bare membrane modules?
How should I design a membrane module unit?
What are the specific uses for pressurized and submerged membrane modules?
Can I use the membrane module to produce drinking water?
Category: Operating Conditions

What aeration rate should I use for membrane scouring?

For MBR applications, set your aeration rate to 50 to 80 L/min per membrane module.

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What is the upper limit of SS in raw water?

The limit depends on the type of SS. However, according to past filtration performance results, the maximum value is approximately 5,000 mg/L.

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What is the upper limit for removing oil contained in raw water?

We have confirmed that the removal rate is 99% or more for oil contained at a level of approximately 800 mg/L.

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What chemical can I use for cleaning?

An NaOH solution or a mixture of NaOH and NaOCl is effective for cleaning organic fouling.
Use an acid (sulfuric, hydrochloric, citric, etc.) for inorganic fouling. The POREFLON Membrane Module has excellent chemical resistance and can be used with solutions ranging widely from pH 1 to 14. We recommend you conduct preliminary tests to find the optimum type of chemical and its concentration.

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When does the membrane module require cleaning?

Clean your equipment when the transmembrane pressure difference starts to increase. Approximate measures are 80 kPa for pressurized membrane modules and 60 kPa for submerged membrane modules. Regular cleaning, whether the transmembrane pressure difference is high or not, is good practice and may ensure extended stable operation.

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What quantity of cleaning chemical should I use?

The amount depends on the cleaning frequency and the concentration of the chemical in use. However, the POREFLON Membrane Module exhibits a high recovery performance after cleaning with the use of a high-concentration chemical. Note that in this case more chemical may need to be used than with membranes made of other materials.

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Do I need to perform backwash?

In the case of pressurized membrane modules, we recommend you perform backwash on a regular basis. When submerged membrane modules are used in the MBR for municipal wastewater, the membrane modules operate without backwash.

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Category: Maintenance/Storage

Are the hollow fibers likely to break during use?

The hollow fiber membrane used in the POREFLON Membrane Module is exceptionally strong, and it will not break during normal operation.

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How should I store the POREFLON Membrane Module?

The POREFLON Membrane Module is semipermanently hydrophilic. You can store it dry before, during or after use.

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How long will the membrane last?

The mechanical service life of the membrane verified with in-house accelerated tests is more than 10 years. Note, however, that this figure has been arrived at in the test situation and is not guaranteed in actual operation.

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Category: Service

Do you sell your products as bare membrane modules?

We sell them basically as bare membrane modules. However, we may be able to respond to your request for membrane modules with unit frames. Please contact us.

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How should I design a membrane module unit?

You can develop a design to the size that meets your local conditions. You can also contact us and we will recommend a design.

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What are the specific uses for pressurized and submerged membrane modules?

In general, use one or other according to the turbidity of the raw water. The pressurized membrane module is suitable for low turbidity wastewater, while the submerged membrane module is intended for highly turbid wastewater.

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Can I use the membrane module to produce drinking water?

Yes, you can. The POREFLON Membrane Module has been authorized by the Association of Membrane Separation Technology of Japan (AMST) based on three specifications for waterworks membrane modules.

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