Provided are an apparatus and a method for biological treatment of an organic wastewater where it is possible to efficiently remove organic matter under high load while reducing the amount of air used for aerobic biological treatment and substantially decreasing the amount of sludge generated. The apparatus is characterized by being provided with: a first biological treatment tank 3 which has a fixed-type immobilized biocarrier and an aeration means; a second biological treatment tank 4 to which a treated liquid from the first tank 3 is introduced so as to perform treatment using suspended microorganisms, and which has an aeration means; and a sedimentation tank 5 in which solid-liquid from the second tank 4 is separated said liquid into settled sludge and treated water, wherein the apparatus has an influent line through which an organic wastewater is introduced to the first tank 3 and the second tank 4, and a return line 6 through which part of settled sludge discharged from the tank 5 is returned to the tank 4.

A mixing chamber for use in a beverage carbonation system is provided. In one embodiment, the carbonation mixing chamber includes a housing, a fluid inlet pathway, a gas inlet pathway, and an outlet pathway. The housing may have an inner chamber, and the fluid inlet pathway can be configured to extend into the inner chamber of the housing and receive fluid from a fluid source. The gas inlet pathway can be configured to extend into the inner chamber of the housing and can be configured to receive gas from a gas source. The gas inlet pathway can include a plurality of nozzles positioned within the inner chamber and configured to direct gas in a plurality of directions that differ from one another. The outlet pathway can be configured to dispense a mixture of fluid and gas from the inner chamber.

A sparger assembly (700) for a bioprocessing system includes a base plate (710) and at least one aeration manifold (712, 714) removably connected to tire base plate. Each aeration manifold includes at least one inlet for receiving a gas and a plurality of gas outlet openings for delivering tire gas to a fluid within the bioprocessing system. An impeller assembly (740) fora bioprocessing system includes a hub and at least one blade (742) operatively connected to the hub. The at least one blade includes a first portion connected to the hub and extending generally vertically, and a second portion extending at an upward angle from tire first portion.