Abstract: In UASB-type biogas reactors, the biogas is separated from the rising waste water stream by collection hoods arranged in staggered fashion, in which a zero pressure level is maintained, at which the gas transition takes place. In cross-section shapes of existing collection hoods, the zero pressure surface is sharply reduced when the water level is high, and the conversion to gas is correspondingly sharply reduced. Therefore, in accordance with the invention, a rectangular section shape is employed in which the zero pressure surface remains unchanged. The topside of the collection hoods can be formed as a smooth sliding surface in the shape of a roof for the anaerobic sludge sediment.

Abstract: The waste water which is discharged from the anaerobic treatment stages of biological waste water treatment plants still contains highly volatile organic substances which, if not biodegraded, escape into the ambient air and lead to unwelcome odors. Also, the exhaust air of the anaerobic treatment stage may contain such highly volatile substances. An escape into the ambient air can be prevented if the waste water which is discharged from the anaerobic treatment stage is aerated with exhaust air sucked off from the anaerobic stage and if this exhaust air, after the aeration, is then fed to a spray washer and compost filter. The water for the spray washer is taken from the discharge of the anaerobic stage and returns there.

Abstract: A module for a UASB (upflow anaerobic sludge blanket) reactor for anaerobic waste water treatment comprises an overflow threshold for the treated waste water that determines the water level in the module. Several immersed collection domes are provided for the digester gas which are staggered over the entire module cross-section and possess a drain into a collection pipe and an upper evacuation line for the waste air collecting above the water level. All walls, covers and installation parts of the module are made of plastic, if necessary reinforced with steel profiles, and are welded to each other. Also, all drains end at a narrow side of the module where they are connected in a gas-tight manner with discharge ducts which have been installed there along several modules and which may be closed off in sections.