Process and device for the aeration of waste water

摘要

Waste water containing suspended biologically active sludge and circulating in an endless path in a vessel is aerated by withdrawing a stream of the water and recycling it to the vessel in the form of a plurality of downwardly directed jets which penetrate the water surface and thereby entrain air in the water. The jets are directed onto the water surface at an angle of less than 60 DEG and the horizontal component of the motion of the jets is substantially parallel to the recirculation path of the main body of water at the point of impact. The jets are divided regularly over the water surface of the vessel and the energy being imparted to the total number of water jets being at least 2 W per m3 of water contained in the vessel.