Proper UF membrane storage and maintenance are essential to ensure membrane performance, operational stability, and service life. This article outlines best practices for membrane preservation during storage, startup procedures after prolonged shutdown, and routine maintenance protocols.
UF Membrane Storage Requirements
- Storage Solution: New membranes must be soaked in a 1% sodium bisulfite (NaHSO₃) solution or a 79:20:1 water/glycerol/sodium bisulfite mixture , thn vacuum-sealed in plastic bags.
- Storage Conditions: Unopened new membranes can be stored in their original packaging for up to 18 months, and avoiding direct sunlight and freezing.
Daily Maintenance During Shutdown
- Short-Term Shutdown (≤7 Days): Use 2 ppm effective chlorine (NaClO) for 30-60 minutes to inhibit microbial activity. And keep membrane modules wet during shutdown, with pH ≥5.
- Long-Term Shutdown (>7 Days): After thorough cleaning, inject a 0.5-1% sodium bisulfite solution. Dry storage is prohibited, as water loss leads to irreversible pore collapse and flux decline
Protection and Storage Solutions
| Storage Solution Type | Concentration | Application Scenario |
| Sodium Bisulfite | 0.5%-1% | Long-term shutdown in freshwater systems |
| Glycerol + Sodium Bisulfite | 79:20:1 | New membrane sealing and storage |
| Residual Chlorine Solution | 5 ppm effective chlorine | Short-term storage for submerged modules |
Risk Warnings and Prohibitions
- Prohibitions: Membrane dehydration reduces porosity by 50%, leading to irreversible flux loss.
- Temperature Limits: Storage temperature ≤40°C.
