Abstract: The present invention provides novel apparatus for aerating a body of liquid. The apparatus includes a diffuser shell in the form of a substantially tubular, elongate body of a relatively rigid, gas permeable material such as fine pore polyethylene. The diffuser is closed at one end by a first end cap and at the other end by a combination second end cap and gas inlet assembly. The latter is adapted for connection to a source of pressurized gas. Disposed within the hollow interior of the diffuser shell is an elongate housing for containing a suitable ballast. The diffuser shell and ballast housing are dimensioned so that there is an interspace between the external periphery of the ballast housing and the inside of the diffuser shell. The ballast housing is supported at one end by the first end cap, and at the other end by the second end cap and inlet assembly so as to maintain the interspace between the ballast housing and the diffuser shell.

Abstract: Apparatus for agitating and aerating sewage and industrial waste comprising a plurality of flexible, inflatable cells disposed in the bottom of a liquid waste holder and means for supplying and withdrawing air to and from the cells so as to cause them to periodically inflate and deflate, whereby the liquid is agitated by the varying water displacement of the cells. Aeration is accomplished by providing the cells with gas-escape orifices that permit air to escape from the cells into the surrounding liquid at controlled rates in the form of small bubbles that rise in the liquid and make intimate contact with suspended solids.