AFM As a Pre-treatment To RO,DM & EDI Plants

AFM As a Pre-treatment To RO,DM & EDI Plants – 

UF, RO membranes  & DM plant resins work best when they are new and clean. Fouling of the membranes by inorganic and organic contaminants as well as biofouling are some of the main issues effecting the performance and cost of running water treatment systems.

AFM is an activated mesoporous aluminosilcate with glass as a structural substrate.  The surface area is over 1,000,000m2 per tonne of filter media of a particle size 0.5 to 1.0mm. The very large surface area has a negative –ve charge for the adsorption of positive +ve particles that are too small to be mechanically removed from the water.  The pre-coagulation and flocculation stage will drag some chemicals out of solution to form small positive charge particles that are easy to remove by AFM.

AFM is used prior to UF and RO, however AFM filtration can actually out-perform UF filtration when combined with pre coagulation and flocculation via a ZPM static mixer prior to AFM filtration. AFM is a much lower cost than UF and can remove most particles down to 0.1 microns and many particles that are much smaller by adsorption reactions.  While UF will give absolute filtration down to 0.03 microns, AFM can give nominal filtration down to at least 0.1microns and sub 0.01 micron particles by electrical adsorption reactions. AFM will also remove many chemicals and pollutants from solution by selective molecular sieve adsorption. Indeed we can now activate AFM to remove specific dissolved priority substances from water.  AFM can therefore perform better than UF and is a more cost effective and efficient option as a pre-treatment prior to RO.

Regeneration of AFM is by a simple back-wash using filtered water, and the process is 100% sustainable, the media should last for the life of the filtration system.

You don’t need to use chlorine with AFM for cleaning, so no THM (trihalomethane) production with organic matter such as organic acids. In addition to dissolved natural organic matter TCP (trichlorophenol) can act as a precursor for the production TCA  trichloroanisole.  TCA has a terrible taste even at single-digit parts per trillion.


SDI Control In Membrane –

As a pre-treatment prior to RO or UF, the SDI after AFM will be at least 50% to 75% lower than the SDI from a sand filter. IFTS independent accredited laboratory have conducted a very detailed analysis of AFM in comparison to sand other media.  The results confirm the superior performance of AFM.


order Lyrica samples Performance comparison of AFM  with sand and UF AFM


UF at 0.03 microns

Remove dissolved silica

Yes Can add free silica to water No

Remove phosphate

Yes, when combined with NoPhos no No

Remove dissolved organics

Yes, especially when combined with APF precoagulation and flocculation using ZPM After 6 months sand filters will be increasing organic load through autotrophic bacteria No, UF cannot remove chemicals in solution.


No,  AFM does not biofoul Yes, 100% coverage of every grain of sand in 3 days Yes, membranes need to be regularly cleaned

Prevention of RO membrane biofouling

Yes, because it removes phosphate and dissolved nutrients required by bacteria No, sand is the perfect substrate to grow bacteria. Often solids load is higher on discharge than influent. Phosphate, and dissolved nutrients will react the RO membranes


No Yes, with carbonates, calcite, struvite, ferric etc Yes, with carbonates, calcite, struvite, ferric etc


Not required, AFM does not biofoul. So no chlorine reaction products such as THM`s, TCA, or hydrobromous acid Yes, sand filters need to be chlorinated continuously or as part of a regular cleaning schedule. May be required as part of the cleaning schedule

Filtration level

90% down to 0.1micron,  approx. 80% down to 0.01micron All sand filters will channel, so membranes are exposed to unfiltered water. 0.03 to 0.01 microns absolute, unless the membrane ruptures


100% sustainable, Circular Economy VIBES winner in the UK No sustainable, needs to be replaced at 1 to 10 year intervals Not sustainable, membranes need to be replaced at 1 to 10 year intervals

Operation costs

Can operate at 50% higher flow rates, so much lower capital cost than sand filtration Lower capital cost than AFM and  higher running, operation & maintenance costs Much higher capital cost than AFM. Much higher pressures and running costs. Lower area required for installation

Other AFM Application Areas

AFM as in potable water treatment
AFM in pressure sand filter
AFM in swimming pool

AFM® reduces the biological risk from bacteria and parasites as well as the chemical risk from water and air just above the surface. The result is a safer pool for children, a healthier work place for staff in public pools and a greatly improved swimming experience for everyone. Read More…

AFM in SWRO plants

SWRO – Sea water reverse osmosis has found a great importance today as a technology for the reclamation of brackish water or sea water and making it potable enough for human consumption or industrial applications.  Read More…

AFM for Arsenic Removal

Arsenic is often found in borehole / tube wells and ground water at varying concentrations depending upon the geology of the ground. In India western states along with certain locations in the south have fairly high contamination of Arsenic in the ground water. IN certain cases Arsenic is also found in the waste water effluent of certain industries. Read More…

AFM for Iron & Manganese removal

Iron and manganese are often found in borehole / tube wells and ground water at varying concentrations depending upon the geology of the ground. Read More…

AFM for Chromium 6 removal

Chromium is occasionally found in ground water in trace amount from 1 to 10 ug/l however the occurrence of chromium is usually associated with pollution from industries such a leather tanning, wood preservation and textiles. Polluted ground water may have much higher concentrations. Read More…