Schmutzedecke

Schmutzedecke is a complex biological layer formed on the surface of slow sand filters. The composition of any Schmutzedecke varies but will typically consiste of a gelatinous matrix of bacteria, fungi, protozoa, rotifera and a range of aquatic insect larvae. As a Schmutzedecke ages more algae tend to develop and larger aquatic organisms may be present including some Endoprocta, Snails and Annelid worms. The Schmutzedecke is the layer that provides the effective purification in potbale water treatment, the underlying sand providing the support medium for this biological treatment layer