Grit and other solid debris are an expensive part of both process water and wastewater, because they clog the water or wastewater treatment plants, lower efficiency, and cause abrasive wear and damage, and need more frequent cleaning, maintenance, and replacement.
Let’s look at the function of grit chamber in WWTPs.
What is the function of grit chamber in wastewater treatment plants?
Sand, silt, and grit are removed from water or wastewater using the grit removal procedure. Wastewater treatment plants frequently have headworks for removing grit and sand.
Grit removal can also be used to remove sand from river water intakes, before treating them to produce potable water, to remove fine abrasives in industrial applications, and to remove grit embedded in sludge.
Function of grit chamber
A long, narrow, or round tank called a grit chamber is a component of the basic sewage/wastewater treatment plant. Its goal is to reduce sewage flow so that grit materials, such as sand, ash and clinkers, eggshells, bone chips, and many other inorganic components, can be removed.
The functioning principle of a grit chamber
- The grit chambers serves as a kind of sedimentation tank, and are designed to separate the lighter organic materials from the heavier inorganic materials, with a specific gravity of about 2.65, so that they can proceed to the next step.
- The chamber is built to sustain varying rates of scouring and sedimentation.
- This makes sure that the flow velocity is not too high, which would prevent the settling of the silt and grit found in the sewage, or too low, which would cause the settling of lighter organic waste.
- For the chamber to operate properly, both of these requirements must be satisfied.
- The critical velocity of flow, abbreviated as VC, beyond which particles of a particular size and density eventually settle, should never be exceeded by the scouring velocity of grit particles.
Schield's formula for calculating the critical velocity of scour is as follows:
V = 3.5 to 4.5 {g(Ss – 1)d)/0.5}
- The horizontal flow velocity is measured to be between 15 and 30 centimetres per second during peak flows.
- It is essential that this velocity be maintained constant regardless of any variations in flow, which may occur to ensure that only organic materials, and not the grit get scoured from the bottom.
Conclusion
Grit Chamber reduces the amount of money spent on maintenance and the number of times a digester needs to be cleaned due to an excessive build-up of grit, by preventing abnormal wear and abrasion on moving mechanical equipment’s.
Thus, a grit chamber is employed to prevent the build-up of substantial deposits in the pipelines and channels.
How can we assist?
Netsol Water is passionate about transforming the productivity, efficiency, and profitability of wastewater treatment plants, using decades of experience and knowledge.
Typically, grit is removed automatically, although some smaller factories may employ a manual process. Contact us for a free consultation with a wastewater specialist, to determine the ideal option for your wastewater treatment plant.
Contact us at +91 9650608473 or enquiry@netsolwater.com for expert advice.
