27
Version: 20221219
I.
Storage of membranes
The membrane should never be allowed to dry out. Keep the system filled with water
between batches. For longer periods it is recommended to add a suitable solution to keep the
membranes wetted, and to prevent bacterial growth during storage. The storage solution
should be selected in accordance with the chemical compatibility of the specific membrane
material. Some examples of storage solutions are:
•
0.1 N NaOH
•
20% ethanol
•
20% isopropanol
Always seek the applicable safety information for the selected checmicals used as storage
solution (e.g. handling and storage and conduct in emergency situations). For long term
storage it is recommended to replace the storage solution at regular intervals, for instance
every 3-6 months.
When preparing the membrane module for storage it is important to evacuate the permeate
compartment from air. This is best done by recirculating the storage solution at a pressure
suitable for the given membrane until air does not appear in the permeate outlet. Once the
membrane module is evacuated from air all valves should be closed off.