How to operate and maintain ultrafiltration membrane

广州海纳滤膜科技有限公司
GUANGZHOU HINA MEMBRANE TECH.CO.,LTD
Specializing in water treatment processing and producing UF membrane /MBR membrane/RO
System/ UF plant/ MBR system for all kinds of sewage water treatment.
www.gzhina.com Contact :Don Lin E-mail:don@gzhina.com Tel :86-20-36455022 Fax:86-20-36000436
Operation&MaintainanceOperation&MaintainanceOperation&MaintainanceOperation&Maintainance InstrutionInstrutionInstrutionInstrution ofofofof UFUFUFUF ProductsProductsProductsProducts
1.

2. UltrafiltrationUltrafiltrationUltrafiltrationUltrafiltration membranemembranemembranemembrane modulemodulemodulemodule runningrunningrunningrunning instructionsinstructionsinstructionsinstructions
Hina ultrafiltration membrane module operates in four states: normal filtration,
backwash, , chemical cleaning, and integrity testing.
NormalNormalNormalNormal filtration:filtration:filtration:filtration:
In the state of the normal filtration, filtration can be full amount of filtering, and
may be cross-flow filtration. In the full amount of filtering, inlet into the the Hina
ultrafiltration membrane module is driven by transmembrane pressure through
the membrane to purify. A cross-flow will form concentrated water in the
running , this concentrate all velocity along the membrane surface.
Concentrated water outflow of water from the concentrated water-side of the
ultrafiltration membrane module, it takes away part of intercepting matter.
Usually when raw water turbidity of less than 20NTU, COD is less than 5, we
strongly recommend that adopt full amount of filtering. Backwashing interval
can be designed for 30 minutes, during which, every 10 minutes positive flow
10 seconds according to the change in turbidity so that the intercepted
material is discharged before it has not entrapped to form a hard scale on the
membrane surface and resulted in highly contaminated, this facilitates the
stability of the membrane flux. In the operation of ultrafiltration membrane
module, colloids, suspended solids, bacteria and others in the raw water are
intercepted by membrane surface; these substances will accumulate in the
membrane surface and pollute the membrane. In
order to maintain the performance of the membrane, especially keep the
membrane permeable rate stable relatively, filtered water clean or backwash
the membrane for a short time are required. Generally it requires the system
go for 1-3 minutes ultrafiltration membrane backwash to run every 30-60
minutes.
Manual or automatic control program to perform are also available in
backwashing.
GeneralGeneralGeneralGeneral backwashingbackwashingbackwashingbackwashing steps:steps:steps:steps:
● positive flow: drained concentrated water of ultrafiltration membrane inner
hole;
●backwashing: flush loose or peeling of the membrane surface contaminants;
●equal-pressure flushing: loose or peeling off from the membrane surface
retentate out of the membrane module. Regular backwashing can maintain a
relatively stable membrane performance, but can not make the backwash flux
reached 100% recovery.

ChemicalChemicalChemicalChemical cleaningcleaningcleaningcleaning ::::
With the membrane module working time extension, membrane fouling will
continue to increase. As the membrane permeable rate will decline, to restore
the membrane flux, regular chemical cleaning of membrane module. Chemical
cleaning should select the appropriate chemical according to impurities in raw
water quality. Usually first with pickling, and then caustic wash: the pickling
solution is generally in 2% citric acid (pH = 2), the alkali eluent is 0.5% NaOH /
200ppmNaClO (pH = 12).
When to chemical cleaning system is determined by the operational conditions
of the system. When the system transmembrane pressure reaches
0.8-0.12MPa, the system should be chemical cleaning. Adjust frequency of
positive flow and backwashing and its running time.
IntegrityIntegrityIntegrityIntegrity Testing:Testing:Testing:Testing:
The hollow fiber of membrane module ruptures occasionally (broken filaments)
in the process of operation of the system, thus destroying the integrity of the
membrane module. The impurity in raw water will enter into the produced
water through the broken places; so it is crucial to find broken wire timely and
isolate it to keep the system integrity, especially when the system is used for
drinking water treatment. To inspect single membrane module integrity,the
pressure bubble test can be used to identify the integrity of the hollow fiber.
Epoxy glue blocked at both ends of the broken fiber is available to make the
system permanent isolation when found to have broken fiber. Repaired
membrane module must carry on flushing, as far as possible will enter the
clean water production impurities; avoid to cause for other membrane pollution.
Repaired membrane module should be flushed, try to clean up impurities into
the water production end to avoid contamination of other membrane.
TheTheTheThe methodmethodmethodmethod totototo testtesttesttest thethethethe integrityintegrityintegrityintegrity ofofofof membranemembranemembranemembrane module:module:module:module:
The inner hole of the filaments of the first film filled with water, drained of air in
the inner bore of the silk membrane is then added to the purification of
compressed air from the product outlet, the gas pressure of 0.04-0.06MPa to
observe the membrane module of the membrane fiber end face, when there is
a large continuous bubbles emerge from the internal bore of the membrane
fiber, can be determined this root membrane rupture, well marked in its tip, and
then use the same method to find the other end of the head of the silk
membrane. A head at both ends of the silk membrane simple drying process,
with an epoxy glue to block both ends of the pores of the membrane, with the
system completely isolated. (If the device is not being used for a

long period of poor equipment maintenance of membrane dehydration film
wire 0.04-0.06MPa, the compressed air through the membrane cause film
damaged the illusion, not particularly serious dehydration membrane silk can
be alcohol soaked recovery part of the flux). Cleaning, transmembrane
pressure range of the system design, the system's water production should
reach the original design requirements, otherwise it should continue to carry
out cleaning and chemical cleaning or shortenthe chemical cleaning
3.3.3.3. PhysicalPhysicalPhysicalPhysical cleaningcleaningcleaningcleaning andandandand chemicalchemicalchemicalchemical cleaningcleaningcleaningcleaning systemsystemsystemsystem
The cleaning system is mainly composed of medicine tank, treated water tank,
circulating pump. Gas mixed with water cleaning also includes air compressor.
General physicalphysicalphysicalphysical cleaningcleaningcleaningcleaning can be divided into pressure flushing and
backwashing.close the treated water valve and open the concentrated water
valve to make raw water with faster than normal state flush the membrane
surface to remove dirt. Backwashing is to close raw water valve and use
circulating pump, inject the treated water tank of water from the outlet water
into the membrane module (a 100μm security filter must be installed before the
backwashing water enter the outlet water port to prevent pipes or water
purification large particles from entering the membrane
module in the tank to cause damage or contamination of the membrane).
Make the treated water according to opposite direction of the normal filtered
through the membrane, wash away the surface of the membrane pollutants,
and make them discharge from the concentrated water outlet and the inlet side.
After backwashing, the immediate pressure flushing can make the trapped
pollutants discharged more effectively.
ChemicalChemicalChemicalChemical cleaningcleaningcleaningcleaning systemsystemsystemsystem with a circulating pump the dispensing tank
cleaning fluid into the ultrafiltration system cleaning cycle and soak, rely on the
role of chemicals to remove the dirt of the surface of the membrane, in order to
restore the
membrane of water production capacity, to maintain the design flow
requirements .

How to operate and maintain ultrafiltration membrane

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How to operate and maintain ultrafiltration membrane