An Aerated Grit Chamber removes grit from wastewater streams.
Airflow is generated by a blower and is introduced into the Aerated Grit Chamber via a tube which is located near the bottom of the chamber, thereby creating a circular or toroidal flow pattern in the wastewater. 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. 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.
- Extremely simple mechanical design
- No moving parts below the water surface
- Can use blower air for air-lift pumping as well
- Maintenance is significantly reduced
- Consistent grit removal efficiency over a wide flow range
- Possible septic conditions of the plant influent may be alleviated through pre-preparation in the grit chamber
- Performance of downstream units may be improved by using pre-aeration to reduce septic conditions in incoming wastewater
- Aerated grit chambers are versatile, allowing for chemical addition, mixing, pre-aeration and flocculation