Iron Coated Sand from Balen and from Grobbendonk
Iron Coated sand from Balen and Grobbendonk (by-products of drinking water purification)
Ghent University will test two types of iron coated sand (coming from two different regions: Balen and Grobbendonk). Both types of Iron coated sand are the by-product of drinking water companies. The four natural available minerals are all rich in iron, alumina, magnesium and silica and can be dug up from deeper soil layers.
This type of sand has 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.