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Lewatit® FO 36

Lewatit® FO 36 is a macroporous, monodispersed, polystyrene-based resin for the selective adsorption of oxoanions, such as arsenate or arsenite ions. It is a weakly basic ion exchange resin which is doped with a nano-scaled film of iron oxide covering the inner surfaces of the pores of the polymer bead. Oxoanions are bond by a specific, reversible reaction involving hydroxy-groups on the iron oxide surface.

Business Unit
Ion Exchange Resins

Properties and benefits
Lewatit® FO 36 is especially suitable for use in the following applications:

  • arsenic removal from drinking water
  • arsenic removal from ground water (ground water remediation)
  • arsenic removal from process solutions even in presence of high contents of neutral salts

In the purification of potable water arsenic can be removed down to rest concentrations significantly lower than 10 µ  g/l which is the maximum contaminant level set in several countries.

Besides of arsenic containing oxyanions such as arsenate and arsenite    Lewatit®FO 36    is capable of adsorbing other species as there are HPO42-, HSbO42-, SCN-etc. Also it has to be considered that the weakly basic anion exchange group in the resin is still active and can react in the specific way basically known for this kind of functional group.

Lewatit® FO 36 should never be exposed to solutions with pH lower than 4. Otherwise iron oxide will be dissolved and washed out and the resin will lose its functionality.

Advantages of polymer resin based ironoxide doped adsorbers compared to a basically inorganic adsorber are:

  • regenerability
  • no bleeding of fine iron oxide particles
  • high mechanical strength and therefore easy to backwash or to pump in suspension
  • no blocking of the resin bed due to build up of fines
  • fast kinetics due to optimised pore structure

When using Lewatit® FO 36 to treat potable water special care should be given to the start up of the new resin. Please refer to the recommended start-up-conditions contained in this data sheet.