Industry Overview
The water treatment industry is one of the most important application areas for PVDF membrane materials. As global water scarcity intensifies and environmental discharge standards become more stringent, membrane-based water treatment technology has developed rapidly due to its advantages of high efficiency, energy savings, and small footprint. PVDF hollow fiber ultrafiltration and microfiltration membranes, with their excellent chemical resistance (especially chlorine resistance), high strength, and long service life, have become the mainstream membrane materials for municipal water supply, industrial wastewater treatment, and seawater desalination pretreatment.
FUERTAI provides a full range of water treatment membrane material solutions, from membrane-grade PVDF resins to water membrane powders, from pipes and fittings to valves and pump components, covering the core material needs of water treatment systems.
Core Material Solutions
Hollow Fiber Ultrafiltration Membranes: PVDF DY-3 water treatment membrane-grade resin and PVDF water membrane powder are ideal materials for manufacturing hollow fiber ultrafiltration membranes. Hollow fiber membrane strands have an outer diameter of 0.8-1.5mm, wall thickness of 0.15-0.4mm, and pore size of 0.01-0.1μm, efficiently retaining suspended solids, colloids, bacteria, and viruses. PVDF membrane strands offer excellent chlorine resistance (free chlorine tolerance ≥5,000 ppm·h), withstanding routine chlorine disinfection cleaning — an advantage unmatched by other membrane materials such as PS and PES.
Flat-Sheet Microfiltration Membranes: PVDF water membrane powder can be used to manufacture flat-sheet microfiltration membranes with uniform pore distribution and high flux. Flat-sheet membranes are produced using Non-solvent Induced Phase Separation (NIPS) or Thermally Induced Phase Separation (TIPS) processes. TIPS-produced PVDF membranes have narrower pore size distribution and higher strength, suitable for demanding applications like MBR (Membrane Bioreactor). Flat-sheet membrane thickness is 0.5-1.0mm, with large effective membrane area and convenient cleaning.
Piping Systems: PVDF pipes and fittings offer excellent chemical resistance for water treatment chemical transport piping, including acid/alkali dosing lines, sodium hypochlorite delivery pipes, and RO concentrate discharge pipes. PVDF piping systems operate at pressures up to PN16, service temperatures from -40°C to 140°C, with connection methods including butt fusion, socket fusion, and flanged connections.
Valves and Pump Components: PVDF injection pellets are used to manufacture valves and pump components resistant to various water treatment chemicals, including sodium hypochlorite, sulfuric acid, and sodium hydroxide. PVDF injection-molded parts offer excellent dimensional stability and creep resistance for long-term service under pressure and temperature cycling conditions. Compared to metal valves, PVDF valves are lightweight, scale-free, and maintenance-free.
Technical Highlights
| Membrane Type | Pore Size Range | Flux Range | Chlorine Resistance | Application |
|---|---|---|---|---|
| UF Membrane | 0.01~0.1μm | 50~150 LMH | ≥5,000ppm·h | Water purification/Reuse |
| MF Membrane | 0.1~0.5μm | 100~300 LMH | ≥5,000ppm·h | MBR/Pretreatment |
Key technical considerations for water treatment membrane materials:
- Membrane Process Selection: NIPS offers lower cost but wider pore size distribution; TIPS costs more but delivers superior membrane performance — choose based on application requirements and budget
- Membrane Strand Strength: Hollow fiber membranes require sufficient tensile strength (≥3MPa) and burst pressure (≥0.4MPa); PVDF strands are stronger than PS and PES
- Chlorine Resistance: Water treatment membranes require periodic chlorine disinfection cleaning; PVDF's chlorine resistance far exceeds PS/PES/PA membrane materials, making it the best choice for chlorine-containing environments
- Hydrophilic Modification: PVDF membrane surfaces are hydrophobic and require hydrophilicity improvement through blending modification or surface grafting to reduce fouling rates
Application Cases
Municipal Water UF: A municipal water plant's 100,000 ton/day ultrafiltration system using PVDF hollow fiber UF membranes, pore size 0.03μm, design flux 60 LMH, product water turbidity ≤0.1 NTU, bacteria removal >99.99%, membrane service life exceeding 5 years.
Industrial Wastewater MBR: A textile wastewater treatment project using PVDF flat-sheet membrane MBR process, pore size 0.2μm, design flux 15 LMH, COD removal >90%, color removal >95%, membrane cleaning interval exceeding 3 months.
Seawater Desalination Pretreatment: A seawater desalination plant pretreatment system using PVDF UF membranes, product water SDI<3, providing reliable feed water for the RO system, membrane service life exceeding 7 years.
Selection Recommendations
FUERTAI recommends following the ’Water Quality Driven’ principle for water treatment membrane material selection: First, determine membrane type (UF/MF) and pore size range based on feed water quality; then select the appropriate PVDF resin grade based on membrane manufacturing process (NIPS uses water membrane powder, TIPS uses membrane-grade resin); finally, confirm piping and valve materials based on system chemical environment. FUERTAI provides membrane material selection consulting, membrane process recommendations, and volume supply services.
