Bauxite, Biotite, Glauconite and Olivine
Acid pre-treated minerals: Glauconite, Biotite, Bauxite
These four acid pre-treated natural available minerals will be tested by Ghent University during the NuReDrain project. These minerals are all rich in iron, alumina, magnesium and silica and can be dug up from deeper soil layers.
They all have a very high affinity for soluble forms of phosphorus (phosphates). In this way an insoluble, chemical bond between the metal cation (Fe and or Al) and the phosphorates will form on the surface of the filter materials.