Membrane Filtration (MF/UF/NF)
Mit Water supplies membrane filtration systems as pre-treatment for seawater reverse osmosis desalination plants. UF and MF membranes provide a robust physical barrier that consistently produces high-quality feed water regardless of raw seawater quality variations.
Working Principle
Seawater passes through hollow fibre or tubular UF/MF membranes under low pressure (0.5-2.5 bar). The membranes physically retain suspended solids, colloids, bacteria, algae and other particulate matter while allowing dissolved salts to pass through. This produces filtrate with turbidity below 0.1 NTU and SDI15 typically below 3, providing ideal feed water quality for SWRO membranes.
System Features
Our seawater UF/MF systems include skid-mounted membrane racks, feed and backwash pumps, air scour blowers, clean-in-place system, integrity testing equipment, and PLC control. Membranes are typically PVDF hollow fibre with high chemical resistance for seawater service. Systems are designed with redundancy to allow online cleaning of individual racks while maintaining production.
Membrane filtration is the preferred pre-treatment for SWRO plants:
- Open-intake seawater desalination pre-treatment
- Challenging seawater with high turbidity or algal blooms
- Beach well seawater filtration
- Brackish water desalination pre-treatment
- Wastewater reclamation pre-treatment
- Cooling water filtration for coastal power plants
Technical Parameters
| Flow Rate | 50 to 5,000 m3/h per unit |
| Membrane Type | PVDF hollow fibre UF or MF |
| Pore Size | 0.02 to 0.1 um (UF); 0.1 to 0.4 um (MF) |
| Operating Pressure | 0.5 to 2.5 bar |
| Filtrate Turbidity | Below 0.1 NTU |
| Filtrate SDI15 | Below 3 |
| Recovery Rate | 90% to 95% |
| Cleaning System | Automatic backwash, air scour, CEB, CIP |