In this In Focus segment we explore the hollow fibre membrane technology behind T-safe Water Filtration, including the filter media, mode of operation and the wide range of opportunistic waterborne pathogens it effectively retains.
- T-safe Filtration Technology
- How T-safe Water Filters are constructed,
- How T-safe Water Filters work,
- Which bacteria do T-Safe Water Filters retain?
T-safe Filtration Technology
T-safe utilises sophisticated hollow fibre membrane (HFM) technology, to remove harmful pathogenic micro-organisms from the water flow and provide clean sterile water at the point of use. HFMs are synthetic membranes with a semi-permeable barrier in the form of hollow fibre straws. Originally developed in the late 1960s, HFMs are the major choice for a wide range of applications including water treatment, desalination pre-treatment and dialysis1.
The HFM technology used in T-safe Water Filters has many advantages over other forms of filter media used in point of use filter applications, such as pleated sheet membranes. HFMs have a greater surface-to-volume ratio which increases filtration capacity and extends the usable life cycle by reducing the rate at which a T-safe filter clogs by a factor of 3 in the case of point-of-use filters, in other sectors even by a factor of 172. HFM are also self-supporting and therefore do not require stabilisation, whilst their construction facilitates the integration of technologies to prevent air-locking that is commonly seen in pleated sheet membrane filters.
T-safe Filter construction
A T-safe filter cartridge consists of many hollow fibre filter straws that are manufactured from Polysulfone – a synthetic polymer. Each individual hollow fibre filter straw is precision engineered with a maximum pore diameter of 0.1µm, and a wall thickness of 90µm consisting of a ‘labyrinth’ like complex sponge structure. These hollow fibre filter straws are bundled together in a ‘U Shape’ configuration within the cartridge, to form a complex high-capacity filter matrix.
How T-safe filters work
T-safe Water Filters remove pathogenic micro-organisms from the water flow, via the mechanism of size exclusion. A combination of the 0.1µm absolute rated pore size, complex sponge structure and hollow fibre wall thickness, provides an impenetrable barrier to the passage of waterborne bacteria which are much larger in size. Watch our short video that showcases T-safe hollow fibre membrane technology in operation. Remember to adjust your device volume to hear the audio description.
Bacteria retained by T-safe Water Filters
The T-safe Medical and Pro Water Filtration range has been validated and certified as a sterilizing grade membrane filter for liquid filtration, as it has proven filtration efficacy in accordance with ASTM F838-15a3. T-safe therefore provides an effective barrier to the release of all clinical opportunistic waterborne pathogens including;
|Microorganism||Dimension (Diameter x Length)||Maximum T-safe Pore Size*||Retained by T-safe|
|Legionella Pneumophila||0.4 X 2.25µm||0.1µm||Yes|
|Pseudomonas aeruginosa||0.65 X 2.25µm||0.1µm||Yes|
|Stenotrophomonas Maltophilia||0.5 X 1.5µm||0.1µm||Yes|
|Escherichia coli||0.9 X 3µm||0.1µm||Yes|
|Staphylococcus aureus||0.75 X 0.75µm||0.1µm||Yes|
- 1. Baker RW. Membrane technology and applications. 3rd ed. Chichester, UK: Jon Wiley & Sons, Oct. 2016.
- 2. Yang X, Wang R, Fane AG, Tang CY, Wenten IG. Membrane module design and dynamic shear-induced techniques to enhance liquid separation by hollow fiber modules: a review. Desalin Water Treat, 51 (16-18) 2013, pp. 3604-3627.
- 3. ASTM F838-15a – Standard Test Method for Determining Bacterial Retention of Membrane Filters Utilized for Liquid Water treatment. Test standard, Oct 2015.