Sewage treatment by the activated sludge process crucially depends on achieving effective oxygenation of the wastewater. Typically, this part of the treatment can consume more than 50% of the energy used in the overall process because of the poor solubility of air in water.

GRAVITOX brings together the principles established for other oxygenation techniques:

•        Extended contact time at high pressure increases oxygen transfer – using a deep moving water column

•        Low energy formation of air bubbles – using a surface agitator and bubble entrainment in a water stream

Conventional aeration techniques achieve efficiencies of 1.05 - 2.5 kg O2/kWh. The extended contact process enables efficiencies of up to 8 kg O2/kWh to be achieved. Using aeration with this level of energy efficiency will produce up 75% reduction in the energy use for sewage treatment. 

A schematic diagram of the GRAVITOX aerator