Oil grease removal wastewater treatment plant in Coimbatore
Oil & Grit Removal Chamber
Oil and grit chamber is used to separate the oil, grit and grease present in the water. It is an extension of the bar screen chamber but the tank bottom is deeper.
- It consists of a baffle placed in the middle of the tank.
- The baffle is constructed a few feet above the bottom of the tank.
- Oil and grease accumulated above the water on the inlet side of the tank and are to be periodically removed.
- The grit accumulates as sediment at the bottom of the tank and is removed by a pump which feeds it into the filter press.
Screen Details
Baffle = 3ft above the bottom, extending to the top.
- Being an extension of the bar screen chamber the outlet pipe of the oil and grit chamber is placed at a suitable height to overflow into the equalization tank.
- All overflow pipes are connected via T-joints to ease the settling of solid particles at the bottom of the tank.

- The incoming liquid is released below surface through a T-joint so that the falling water does not disturb (break up) the floating film of fat and scum (3).
- The tank is always filled till this level.
- The fat and scum rise to the top and float on the liquid. This needs to be removed periodically; otherwise it will leach into the wastewater.
- The heavier grit and solids sink to the bottom of the tank (most of it lies below the inlet pipe, but some of the grit may be moved toward the outlet side due to the strong flow of the wastewater).
This mass also needs to be removed from the tank periodically. - The baffle plate prevents the floating fat and scum (3) from drifting towards the outlet (7).
- Wastewater reaching the outlet side is free of fat, scum, grit and solids
- The outlet is through a T-joint pipe, similar to the inlet (1). The upper part is capped off (opened only for maintenance).