AQUADYN® FZ50 Series Hollow Fiber Module | OPERATION MANUAL
MICRODYN-NADIR | REVISION: B | DATE: 01/08/2020
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6
Offline Treatment
When operation is stoped for a long period of time, it is necessary to fill the module with a preservative solution to avoid
drying of the membrane or bacteria growth. If the sodium hypochlorite is used as a biocide, the effective chlorine may be
quickly consumed by soiled material remaining in the system. Measure the free chlorine concentration after a brief interval of
filling and check that the effective chlorine is not consumed completely. After this, the module may be stored.
6.1
SHORT-TERM STORAGE (2 DAYS OR LESS)
Backwash the module immediately before stopping operation. The backwash water (free chlorine concentration of 3-5 mg/L)
needs to remain in the module. Be sure that liquid does not leak or evaporate during storage.
6.2
SHORT-TERM STORAGE (3-7 DAYS)
Store the module after filling with a sodium hypochlorite water solution (free chlorine concentration between 10-20 mg/L).
This can be achieved by backwashing until the chlorine concentration in the discharge water has reached this concentration.
6.3
LONG-TERM STORAGE (LONGER THAN 7 DAYS)
For long-term storage, it is recommended to use the preservative solution (500 mg/L sodium benzoic acid water solution or
formalin 2 wt% sodium sulfate, 0.2 wt% water solution).
If storing the modules for 3 months or longer, please contact MICRODYN-NADIR.
