Surface aerators

Surface aerators "AKEA"

Introduction

A crucial aspect of a waste water treatment plant with an aerobic step is to bring in contact the organic pollutants with the microorganisms, the alimentary substances (mainly nitrogen and phosphorus) and oxygen. The former action is achieved via the aeration system “AKEA”. The “AKEA” surface aeration system has a fan located on the surface of the tank which rotates and sucks in atmospheric air and the latter is then transferred to the aeration tank.

The shape of the fan is like an inverted cone and in the perimeter are incorporated a series of smaller fans. The fan rotation serves a dual purpose. Firstly a centrifugal force is produced, the movement becomes turbulent and huge amounts of air are captured between the series of fans. Secondly the activated sludge is kept in suspension, inhibiting the formation of solid aggregates. Finally air is transferred in the form of spray into the aeration tank.

The “AKEA” surface aeration system is able to work twenty four hours per day and is not affected by climatic conditions. It is installed on bases on the surface of the aeration tank or on a pontoon bridge. Typical yield values in terms of air supply are more than 80% and it shows excellent stability over time.

For the choice of the correct aeration system several parameters have to be considered, for instance the yield of oxygen transfer, the required power etc.