Wastewater from a small town is treated in a trickling filter which is preceded by a screen, sand-removal and primary clarification. The maximum hydraulic capacity, or peak flow, of the treatment plant is 1,500 m³/h. The dry weather flow (Qdwf) amounts 7,500 m³/day, with a BOD concentration of 300 mg/l.
The maximum scouring velocity or slip velocity is 0.3 m/s and the maximum surface load or Hazen velocity is 40 m/h.
Calculate the liquid velocity during Qdwf (in m/s) in the channel.
Urgent!
To calculate the liquid velocity during dry weather flow (Qdwf) in the channel, we need to first determine the volumetric flow rate during Qdwf.
Given:
Qdwf = 7,500 m³/day
To convert the flow rate from m³/day to m³/h, we can multiply it by a factor of 1/24 (since there are 24 hours in a day):
Qdwf = 7,500 m³/day x (1/24 day/hour) = 312.5 m³/h
Now that we have the volumetric flow rate during Qdwf, we can calculate the liquid velocity in the channel using the formula:
V = Q/A
Where:
V is the liquid velocity (in m/s)
Q is the volumetric flow rate (in m³/h)
A is the cross-sectional area of the channel (in m²)
To find the cross-sectional area of the channel, we need to know the dimensions of the channel. Assuming the channel is rectangular, we can use the formula for the area of a rectangle:
A = width x depth
Since the width and depth of the channel are not provided in the question, we are unable to calculate the exact liquid velocity during Qdwf. However, if you have the dimensions of the channel, you can substitute the values into the formula to find the liquid velocity.