ABS Self-aspirating submersible aerators for wastewater and water treatment in municipal and industrial plants. Main areas of application are mixing and equalisation tanks, activated sludge tanks, SBR-reactors and sludge storage tanks at a water depth between 2 and 8 m. The aerator is free standing on the bottom of the basin and hence can be installed without emptying the basin. The aerator is characterised by a very low noise level and no aerosol formation. The aeration produces fine bubbles and the oxygen transfer factor is high.