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Ultrafiltration/Membrane Filtration (UF/MF) System Survey: Lessons Learned (Atassi et al., 2007)
TABLE 9.4
Root Cause of Problem
Primary Membrane System Problems
Utility No.
• Lower achievable flux than projected.
• Unable to meet design
1.
• Higher than anticipated downtime.
• Unable to meet design
6.
• Manufacturer missed to include
• More membrane capacity needed to
integrity tests.
be installed.
• Failures in membrane potting.
• Excessive system downtime.
8.
• System not handling water pressure/
• Insufficient system training for staff.
• Difficult system operation.
9.
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9. MEMBRANE FILTRATION
Lessons Learned
address extreme WQ conditions.
• Ancillary support systems can be a
• Undersized membrane ancillary
• Unable to meet design
significant bottleneck if undersized.
by membrane supplier.
of previous data by suppliers.
scaling pilot testing results.
• Pilot test during extreme water quality
(WQ) conditions.
• Pilot testing did not address extreme
capacity
• Use conservative safety factor when up-scaling pilot testing results.
WQ conditions.
• Pilot test during extreme WQ conditions.
• Excessive membrane fouling.
• High clean-in-place
2.
• Additional pretreatment may be needed to
• Pilot testing did not address extreme
WQ conditions.
• Excessive downtime and
• Additional pretreatment may be needed to
• Lower than projected membrane life.
support systems.
capacity.
obtain the useful membrane life indicated
• Potential membrane fouling and lack
• Lack of experience with use of membranes
• Excessive fiber breakage.
• Excessive downtime and
5.
for given WQ may require change in
• Fouling or WQ putting higher stress
maintenance.
membrane chemistry and durability
on the fibers than expected.
• Lower than projected WQ.
capacity.
under worst case operations scenario.
valve opening/closing time for
• Pilot test during extreme WQ conditions.
• More frequent chemical cleaning
• Higher than expected O&M
7.
• Use conservative safety factor when up-
needed than initially projected.
costs.
• Never use membrane that has components
or materials that have never been tested
minimum offered by the manufacturer.
previously.
• Make sure that replacement of failed
• Frequently failing membrane
• Excessive downtime.
10.
caskets, valves, and seals is included in the
• Complete thorough review of the downtime for all MF/UF system operational steps
• Plan for additional staff training beyond the
previously!
potting materials not tested
manufacturer membrane system warrantee.
• Air leaking form gaskets and valves.
integrity testing.
• Failure to meet product WQ
targets.
frequencies;
operation and maintenance
(O&M) costs.
• Higher membrane
replacement costs.
3.
4.