Abstract: It is necessary in sewage-treatment devices to remove from the waste waters to be cleaned besides the sediment mixtures also impurities which are on the surface of the waste water. This floating matter is according to the invention continuously conveyed into an intermediate container by means of a worm conveyor sweeping over the waste water, from which intermediate container the conveyed matter is discontinuously pumped off.

Abstract: Conveyor-band filter apparatuses, so-called Paternoster filter rakes, which serve primarily for the mechanical cleansing of flowing sewage, are to be made capable by the invention of removing not only the normal filtered material, but also coarser fragments, from the conduit through which the sewage flows, without the usually steep conveying angle having to be varied; for this purpose, filter elements of the endless filter band are arranged in each case on the chain links and are designed on their end faces in such a way that only a small gap remains even in the state in which they are mutually pivoted relative to one another. Furthermore, attached to the filter elements are filter rakes forming a horizontal lifting face which extends transversely through the conduit and which can nevertheless be kept clean by corresponding stripping devices.