An Aerated Grit Chamber offers a low-cost, mechanically simple way to remove grit from a wastewater stream. Air is introduced into an eductor tube which is located near the bottom of a grit chamber thereby creating a toroidal flow pattern. The continuous rising flow deflects off an energy-recovery baffle at the liquid surface. This flow pattern causes the grit to settle to the bottom of the chamber while keeping lighter organic material in suspension to be processed further downstream. Since the driving force is a blower, this type of grit removal has no moving parts below the surface which means that maintenance is significantly reduced. Once the grit has settled, either a recessed-impeller grit pump or, more commonly, an air-lift pump is used to remove the grit slurry and send it on for dewatering. The air-lift pump option is particularly advantageous since the air supply needed for operation of the aerated grit chamber is already in place.

ADVANTAGES
• Extremely simple mechanical design
• No moving parts below the water surface
• Can use the blower air for air-lift pumping as well
• Possible septic conditions of the plant influent may be alleviated through pre-preparation
   in the grit chamber