The ultrafiltration is a pressure-driven membrane process used to separate particles, colloids and macromolecules from liquids. It plays a central role in industrial water and wastewater treatment and is used for both pre-treatment and direct water treatment.
Table of contents
Technical basics
Ultrafiltration membranes have a pore size of around 0.01 to 0.1 micrometers and are therefore able to filter out particles such as:
- Bacteria,
- Viruses,
- Colloids,
- Proteins and
- Effectively retain macromolecules
.
In contrast to microfiltration or nanofiltration, ultrafiltration aims to remove suspended solids and dissolved organic substances, but without retaining salts or dissolved ions
Photo: ALMA Mem UF ultrafiltration module in stainless steel design, installed in the ALMA Modul technical room container
Structure and materials
UF membranes are made of polymer materials such as polyethersulfone (PES), polyvinylidene fluoride (PVDF) or ceramic. These materials are chemically and mechanically stable, which makes them suitable for various industrial applications. The membranes are available in the form of hollow fibers, flat membranes or spiral elements.
Operation
The process takes place under an operating pressure of 1 to 10 bar. The water is pressed through the membrane, leaving the impurities behind. The filtration process generates two streams:
- Permeate: The purified water.
- Retentate: The concentrate with the retained substances.
Areas of application
Drinking water treatment
- Removal of suspended solids, bacteria and viruses from raw water sources.
Industrial process water treatment
- Provision of high-quality water for production processes in the food, beverage and chemical industries.
Waste water treatment
- Pre-treatment or post-treatment of wastewater streams to comply with legal limits.
Recycling of production wastewater
- Returning treated water to the production cycle, especially in water-intensive industries such as the textile or paper industry.
Pharmaceutical and biotechnology industry
- Separation of proteins and biopolymers in biotechnological processes.
Photo: Individual ALMA MEM UF ultrafiltration systems for industrial water treatment
Advantages of ultrafiltration
- High filtration efficiency: removal of particles and microorganisms down to a size of 0.01 µm.
- Low chemical requirement: Compared to conventional chemical treatment processes.
- Compact system design: Low space requirement thanks to modular design.
- Robustness and durability: Suitable for varying water qualities.
- Energy efficiency: Low operating pressure leads to reduced energy consumption.
Challenges and maintenance
Fouling and scaling are typical problems in ultrafiltration. These deposits on the membrane surface reduce the filtration performance and increase the pressure loss. The following measures are required to minimize these effects:
- Regular chemical cleaning (CIP): To remove deposits.
- Use of antifouling agents: To prevent the formation of deposits.
- Optimization of pre-treatment: removal of coarse impurities before the UF stage.
ALMAWATECH solutions
ALMAWATECH offers comprehensive ultrafiltration solutions for a wide range of industries. Our UF systems are characterized by high efficiency, durability and individual adaptation to specific customer requirements. They are equipped with state-of-the-art control systems that ensure continuous monitoring and automatic cleaning. With our pilot plants, we test on site to find the optimal solution for your water or wastewater flow.
Conclusion
Ultrafiltration is a versatile and effective technology for water and wastewater treatment. Its ability to reliably remove microorganisms and particles makes it an indispensable component of modern water treatment systems. Thanks to its modularity and efficiency, it is suitable for a wide range of industrial applications and supports the sustainable use of water resources.
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