Ultrafiltration – General

Ultrafiltration (“UF”) is a proven filtration process based on microporous membranes. Separation is achieved based on a process where a liquid is forced through a semipermeable membrane through the application of pressure. Suspended solids and solutes of high molecular weight are retained, while water and low molecular weight solutes pass through the membrane in the permeate or filtrate. UF membranes can typically filter out suspended solids, bacteria, viruses and many other contaminants. Like a sieve, the separation process is based on size exclusion.

UF has a wide application range across potable water generation, sewage and industrial waste water treatment as well as in beverage production. Furthermore, UF membranes are often used as a pre treatment to Reverse Osmosis, for example in desalination plants. The wide application range explains for the large commercial market size of Ultrafiltration.

As a physical separation process, membranes in general require the addition of a very limited amount of chemicals only for the cleaning. This makes membranes an environmentally friendly water treatment process.

UF membranes are defined by the so-called molecular weight cut-off (MWCO), which relates to the size of the particles which can be filtered with the particular membrane. They are used in either cross-flow or dead-end mode.

De.mem’s Ultrafiltration technology: Maximizing treatment performance and flux

De.mem has access to a range of commercial UF products which are based on different materials. The technologies show different characteristics and technical specifications such as for example the MWCO or pore size. This allows De.mem to vary the product in the interest of its customer, i.e. offer the best suited membrane for the specific application.

For example, De.mem has developed its own PES-based UF membrane. The membrane is characterized by strong rejection in terms of a relatively small pore size, at a high throughput or “flux”. The technical specifications of this technology can be found here: [link to Dememflyer_UF].

De.mem offers its UF membranes as industry-standard 8-inch or 4-inch modules, or turn-key as a complete Ultrafiltration system. The Company also supplies to the residential market for domestic point-of-use water filtration.

De.mem produces its hollow fibre UF membranes at its production facility in Singapore.