Introduction: The Challenge of Muddy Water
After heavy storms, rivers turn rust-brown with surging sediment, colloids, and microorganisms (turbidity >300 NTU). Traditional sand filters require multi-stage pretreatment and fail to block bacteria/viruses. PVDF ultrafiltration (UF) membranes, with 0.01-micron physical screening, revolutionize high-turbidity water treatment—directly producing potable water (<0.1 NTU).
1. Three Breakthroughs of PVDF UF Membranes Against Muddy Water
1. Anti-Fouling Structural Design
- Outside-In Crossflow Filtration: Water permeates from the outside of membrane fibers inward, trapping sediment on the surface (not inside), increasing dirt holding capacity by 5× (withstands 300μm particle impact).
- Air-Water Dual Backwash: Initiates air scouring (12 Nm³/h airflow) every 30 minutes. Fiber vibration dislodges sludge, achieving >95% flux recovery.
2. Extreme Environment Resistance
- Mechanical Strength: PVDF material tensile strength reaches 4 MPa, enduring 6.25 bar water pressure (equivalent to a 60m water column).
- Chemical Stability: Resists pH 2-11 cleaning agents and 2,000 ppm sodium hypochlorite, eliminating biofilm growth.
2. Performance Comparison: PVDF vs. Traditional Processes
| Parameter | PVDF UF Membrane | Sand Filter + Activated Carbon |
|---|---|---|
| Turbidity Removal | >99.9% (Output ≤0.1 NTU) | 85%-90% (Residual >1 NTU) |
| Bacteria Rejection | 100% (Pore size < bacteria) | 40%-60% |
| Energy Consumption | 0.1 kW·h/ton (water pressure only) | 0.8 kW·h/ton (pump required) |
| High-Turbidity Shock | Handles 300 NTU feed directly | Requires pre-sedimentation (<50 NTU) |
3. Real-World Applications
1. Household Water Supply
PVDF UF systems directly filter 200 NTU water. Unit capacity varies based on consumption needs.
2. Commercial/Industrial Use
High-flow systems with auto backwash (select models by turbidity), reducing manual cleaning.
4. Advantages of Cleanable PVDF UF Membranes
PVDF hollow-fiber UF membranes feature:
- Outside-in filtration (0.01μm precision)
- SS304 housing (waterproof/corrosion-resistant)
- Clamp connections for easy disassembly/cleaning
- Tear-resistant fibers surviving aggressive cleaning
- 3-5 year service life
