Birm

General description

This filter medium is an aluminium silicate that is coated in manganese dioxide. If the conditions allow, air pockets are used instead of chemicals. In this case the filter medium just needs backwashing with water. The filter medium acts as a catalyst to enhance the reaction between dissolved oxygen and the iron compounds, changing the Fe²⁺  into Fe³⁺ and resulting in the formation of iron hydroxides. These iron hydroxides precipitate which makes them easy to filter.

Physical properties

Colour Black

Bulk density 0.56 – 0.64 kg/l

Particle size 0.4 – 2 mm

Application areas

The filter medium Birm can be used to remove the following substances:

• Sediment
• Iron
• Manganese