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Grit Chambers in SewageTreatment

Primary Sewage Treatment.

Grit includes sand and other heavy matter such as seeds and coffee grounds that settle from sewage waste water, when the velocity of flow is reduced. if not removed in Waste Water preliminary  Treatment ( Sewage Treatment – Preliminary Treatment ). Grit chamber may cause abrasive wear and cause serious operation difficulties in primary sewage water treatment ( Waste Water Treatment ), as mechanical wear and clogging of pipes by deposition and accumulate in sludge holding tank sand digestives.


Grit chambers are designed to remove particles equivalent to a fine size as 0.2mm diameter with a specific gravity 2.7 with minimum of organic material included.

A variety of systems are employed depending on the quantity of grit in the waste water.

The grit chamber consisted of two or more long narrow channels constructed in parallel with space for grit storage. While one is in service the idle channel could  be cleaned.


A proportional were placed at the discharge end  control the flow such that the horizontal velocity was maintained at about 0.3m/s independent of the quantity of flow. This allow the grit to settle while providing a scouring velocity to flush  through organic suspended solids