A grit chamber is designed to treat an average wastewater flow of 1 m3/sec at an...

A grit chamber is designed to treat an average wastewater flow of 1 m³/sec at an overflow rate of 4752 m³/m² –d to capture sand with the following particle size distribution:

% by wt. Diameter (mm)

30 1.0

30 0.5

30 0.2

10 0.1

The design overflow rate is such that 100% removal of the 0.5 mm diameter particles will be achieved. The operating temperature is 20°C and the specific gravity of the sand particles is 2.65. Assume that the stickiness coefficient (k) for sand is 0.04 and the Darcy-Weisbach friction factor (f) is 0.03.

a. Determine the surface area and vertical cross-sectional area of the grit chamber if only the 0.1 mm diameter particles will be scoured away

b. Calculate the removal efficiency assuming that only the 0.1 mm diameter particles will be

scoured away.

c. If the ratio of peak to average flow is 1.4, calculate the overall removal efficiency at the peak flow.

Expert Solution

Ally Wells answered 11 months ago

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