ULTRA FILTRATION (UF) WATER TREATMENT
WHAT IS ULTRA FILTRATION?
Ultrafiltration is a membrane-based separation process used in various industries, including water treatment, food and beverage processing, pharmaceuticals, and biotechnology. It is a type of membrane filtration that operates on the principle of size exclusion and is typically employed to separate and concentrate solutes and suspended particles from a liquid (usually water). Ultrafiltration is typically in two forms; (1) sheet / film (spiral wound) or more commonly hollow fiber which in straw/capillary form (inside bore and outside diameter) either in single bore straws/capillaries or multi-bore capillaries (EX: 7-bores in a single capillary) known as hollow fiber membrane technology.
Most common materials used for UF membranes is polyether-sulfone (PES) however, polypropylene, acetate, PVC and CPVC are suitable for many applications.
Hollow fiber membranes can filter “inside-out” or “outside-in” depending on the capillary design as well as the application and system design.
A key feature of hollow fiber UF is its inherent ability to flush/backwash (self-clean) through an automatic system or manual valving. Because of this feature it can be utilized as an optimum pretreatment or pre-filter for any post treatment including carbon, resin, RO, and Nano as well as disinfecting treatment such as ozone and UV.
HOW ULTRA FILTRATION WORKS
THE PRINCIPLE OF ULTRAFILTRATION:
UF can be used to concentrate valuable components from a liquid, which is particularly useful in the recovery of proteins, enzymes, and other valuable biomolecules. To concentrate components, UF can be employed to retain larger molecules and particles in the retentate while allowing smaller solutes and solvents to pass through the membrane.
Ultrafiltration membranes have specific but nominal pore sizes that allow them to selectively permit the passage of solvents (such as water) and solutes (such as dissolved ions, small molecules, and suspended particles) based on their size and molecular weight.
Particles or solutes larger than the membrane's pore size are retained on one side of the membrane (the "retentate"), while smaller molecules and solvents can pass through the membrane to the other side (the "permeate"). UF is a Physical / Mechanical barrier only.
KEY CHARACTERISTICS OF ULTRA FILTRATION
1. Pore Size
UF membranes typically have pore sizes in the range of 0.010 to 0.099 micrometers (μm). This range allows them to effectively remove suspended solids, macromolecules, colloids, and microorganisms from a liquid stream. Again, pore sizes are nominal and are verified through a measurement process determining “molecular weight cut-off” (MWCO) which correlates to a nominal pore size. UF has no effect on TDS reduction; only total suspended solids (TSS) are reduced.
2. Pressure-Driven Process
Ultrafiltration relies on hydraulic pressure to force the liquid through the membrane. The pressure differential between the feed side (retentate) and the permeate side drives the separation process. UF has mostly been identified as a low pressure / low flow technology in applications that do not require high pressure influent or effluent.
3. Selective Separation
UF is primarily used for the separation of particles and solutes based on size. It is not as fine a filtration as nanofiltration or reverse osmosis, which can remove even smaller molecules and ions.
ULTRA FILTRATION WATER TREATMENT APPLICATIONS
UF is used for the removal of suspended solids, bacteria, viruses, and certain organic compounds from water, making it suitable for producing high-quality drinking water and treating wastewater. As a sub-micron solution it is effective against mold spores, cryptosporidium and other water borne pathogens.
INDUSTRIAL PROCESSES THAT USE ULTRA FILTRATION
Ultrafiltration has become a “go-to” media in various industrial applications across a wide range of industries. It is used in applications to separate and concentrate desired components while excluding unwanted contaminants. UF is used to separate solids from liquids or gases, clarify liquids, and meet specific quality and regulatory requirements.
Here are some key applications of ultrafiltration in industrial processes:
ULTRA FILTRATION IN CHEMICAL MANUFACTURING
Ultrafiltration is employed to clarify chemical solutions and remove impurities, ensuring the purity and quality of chemical products. It is used in chemical processes to separate solids from liquid reaction mixtures.
PHARMACEUTICAL ULTRA FILTRATION APPLICATIONS
USP Pure Water is a critical component in pharmaceutical manufacturing and plays a significant role in ensuring the safety, efficacy, and quality of pharmaceutical products. Ultrafiltration is vital for sterilizing and clarifying pharmaceutical products, vaccines, and biologics. It is used to remove microorganisms, particulates, and endotoxins from drug formulations and bioprocessing streams. Pharmaceutical companies must adhere to strict quality standards and regulatory requirements to produce and use USP Water in compliance with the USP and NF standards.
ULTRA FILTRATION IN FOOD & BEVERAGE PROCESSES
The food and beverage industry is subject to strict regulatory requirements regarding water quality and safety. Compliance with regulations, such as those from the U.S. Food and Drug Administration (FDA) and other local authorities, is essential. Continuous monitoring and testing of water quality parameters such as pH, conductivity, microbial counts, and TOC (a measure of the total amount of carbon in organic compounds in pure water and aqueous systems) are critical to ensure the consistency and safety of food and beverage products.
Water treatment in the food and beverage industry is tailored to the specific needs of the products being processed and the applicable regulations. The goal is to ensure that the water used in production meets the required quality standards while maintaining product safety and quality. Filtration is used to clarify juices, wines, and beer by removing suspended solids, yeast, and other particles. It helps purify edible oils and separate solids from liquids in the production of food products.
UF is employed as a point of entry water treatment for many food service establishments. It is also used in dairy processing, juice clarification, and protein concentration in food and beverage manufacturing. It can be used as a self-cleaning pre filtration for RO systems as well as removing suspended solids in high turbidity water sources.
ULTRA FILTRATION CONSUMES LESS ENERGY
Compared to some other membrane processes like reverse osmosis, ultrafiltration generally consumes less energy because it operates at lower pressure and retains larger particles.
ULTRA FILTRATION MEMBRANE MAINTENANCE
UF membranes require periodic cleaning and maintenance to prevent fouling and maintain their efficiency. WaterWise UF systems are designed with an automatic flush of the membrane surface that simplifies and automates this maintenance process. It should be note that PES membranes or very chlorine and chloramine tolerant and can withstand periodic disinfectant concentrations up to 200 ppm for up to 30 minutes at a time and can continuously withstand levels up to 4 ppm without accelerated degradation.