Patent ID: 8029673

Claim:
A vertical-horizontal filter unit for the biological purification of polluted water, comprising: an upper filter zone ( 3 ) having feeds ( 1 ) for the polluted water, a lower filter zone ( 5 ), situated beneath it, a barrier layer ( 4 ) having opening(s), wherein the barrier layer ( 4 ) is situated between the upper and lower filter zones ( 3 , 5 ), and at least one removal location ( 7 ), the polluted water permeating the lower filter zone ( 5 ) after permeating the upper filter zone ( 3 ) and the filter unit having a seal ( 8 ) in relation to the soil on its sides and/or its floor, wherein the filter unit comprises a device ( 6 ) for introducing a medium, which contains organic carbon, into the lower filter zone ( 5 ), or for introducing microorganisms and/or substances, which cause or support metabolism of the materials contained in the polluted water, into the lower filter zone ( 5 ), the upper filter zone ( 3 ) is an aerobic filter zone, in which a nitrification of the polluted water occurs, the lower filter zone ( 5 ) is an anaerobic filter zone, having denitrifying microorganisms, in which mixing and denitrification of the nitrified polluted water, which was treated in the upper filter zone ( 3 ), with a medium, which contains organic carbon, occurs, wherein the barrier layer ( 4 ) having opening(s) is situated between the upper and lower filter zones ( 3 , 5 ), the lower filter zone ( 3 ) and the upper filter zone ( 5 ) are homogeneous.