Apparatus for aerating and mixing waste water

Apparatus for aerating waste water in a basin, said apparatus comprising:

• a main supply pipe for receiving the air under pressure;
• a plurality of branch pipes each communicating with said main supply pipe to receive air therefrom, each branch pipe extending generally along the bottom of the basin and each branch pipe being a plastic pipe subject to longitudinal expansion and contraction in response to temperature changes in the waste water;
• a plurality of aerators for each branch pipe, each aerator and being adapted to release a plurality of fine air bubbles when air is supplied to the aerator and each aerator being provided with ballast to hold the aerator down on the bottom of the basin;
• a flexible conduit connecting each aerator with the corresponding branch line to provide communication between the branch lines and the corresponding aerators, thereby applying air to the aerators for release of air bubbles therefrom to effect aeration of the waste water, wherein each flexible conduit has a length at least as great as the distance between the corresponding branch pipe and the surface of the waste water to permit each aerator to be raised to the surface of the waste water while the corresponding branch pipe remains on the bottom of the basin and connected to the flexible conduit;
• a flexible line for each aerator connected therewith at one end and having an opposite end disposed at the surface of the waste water;
• a float for each line connected with said opposite end thereof, said floats floating on the surface of the waste water to maintain said lines accessible from the surface for lifting of the aerators to the surface of the waste water;
• and
• at least one hold down bracket for each branch pipe provided with ballast to hold the bracket down on the bottom of the basin, said bracket having means for holding down the branch pipe while permitting the branch pipe to longitudinally expand and contract, whereby said brackets accommodate thermally induced expansion and contraction of the branch pipes and said flexible conduits allow the aerators to remain stationary as the branch pipes expand and contract.