Abstract: Known types of equipment for the biological denitrification of potable water require (back) washing of the reactors from time to time. These denitrification processes proceed therefore in a discontinuous manner. The invention proposes a continuously operating denitrification process with a simple equipment arrangement. This is achieved by sumberged drum reactors (12, 14) which rotate in a first, anoxic biological stage (10) and in a second, aerobic biological stage (13). The immersion bodies (immersion body segments 31) contained in these reactors are, due to the rotation, continuously washed during the treatment of the potable water. Moreover, the sumberged drum reactors (12, 14) of the two biological stages (10, 13) are arranged according to the invention on a common drive shaft (26) with a drive element (drive motor 27).

Abstract: Known types of equipment for the biological denitrification of potable water require (back) washing of the reactors from time to time. These denitrification processes proceed therefore in a discontinuous manner. The invention proposes a continuously operating denitrification process with a simple equipment arrangement. This is achieved by submerged drum reactors (12, 14) which rotate in a first, anoxic biological stage (10) and in a second, aerobic biological stage (13). The immersion bodies (immersion body segments 31) contained in these reactors are, due to the rotation, continuously washed during the treatment of the potable water. Moreover, the submerged drum reactors (12, 14) of the two biological stages (10, 13) are arranged according to the invention on a common drive shaft (26) with a drive element (drive motor 27).

Abstract: Filling material for percolating filters for the treatment of liquid and process for producing and assembling the material. Especially in biological sewage treatment, filling material must provide the best possible hold for the biological filter film necessary for the purpose and must have uniform wettability. The disadvantage of known apparatuses meeting these requirements is that they either tend to clog or are difficult to produce. The new filling material will work effectively and reliably, while being simple to produce and assemble. To provide ideal growth surfaces for the biological filter film, the filling material has a plurality of plastic strips (20) which are connected to one another by means of a single holding sheet (21). Furthermore, the strips (20) have a special shape, in particular corrugated edges and/or a structured neutral region. The filling material is especially suitable for biological treatment, particularly the denitrification of sewage or drinking water.

Abstract: Mutually mating cable contact members, on longitudinally aligned contact carriers, are surrounded by annular sealing portions of these carriers, which have annular sealing surfaces engaging each other. Said sealing portions consist of materials having different elasticities. A ring surrounds the sealing portion of greater elasticity and presses the sealing surface of this portion against the sealing portion of the other contact carrier. By the coaction of the ring with the sealing portions of different elasticities, the new connector remains water tight when submerged in deep water for extended periods of time.