Calculating Total Sewage Flow in a Sewer Line
Calculating Total Sewage Flow in a Sewer Line
A sewer line receives sewage from two contributing areas. One area is roughly 13.9 km2 in size and has a population density of only 80 persons per hectare. The average rate of sewage flow from this area is 135 litres per person per day. The second area has a population density of 10 persons per 100 m2, contributing sewage to the sewer pipe at a rate of 45 KL/ha/day. The total coverage of this area is 20.56 km2. If 20% is assigned to infiltration, determine the total sewage flow (m³/min) in the pipe. [20 Marks]
Final answer:
The total sewage flow in the pipe is approximately 0.104 m³/min.
Explanation:
To calculate the total sewage flow in the pipe, we need to calculate the sewage flow from each contributing area and then sum them up.
Let's start with the first area:
Calculate the total population in the first area:
Population = Area * Population Density
Population = 13.9 km2 * 80 persons/hectare
Population = 1112 persons
Calculate the total sewage flow from the first area:
Sewage Flow = Population * Sewage Flow Rate
Sewage Flow = 1112 persons * 135 litres/person/day
Sewage Flow = 150,120 litres/day
Now, let's move on to the second area:
Calculate the total population in the second area:
Population = Area * Population Density
Population = 20.56 km2 * (10 persons/100 m2)
Population = 2056 persons
Calculate the total sewage flow from the second area:
Sewage Flow = Population * Sewage Flow Rate
Sewage Flow = 2056 persons * (45 KL/ha/day)
Sewage Flow = 92,520 KL/day
Next, calculate the total sewage flow from both areas:
Total Sewage Flow = Sewage Flow from First Area + Sewage Flow from Second Area
Total Sewage Flow = 150,120 litres/day + 92,520 KL/day
Finally, calculate the total sewage flow in m³/min:
1 KL = 1000 m³
Total Sewage Flow (m³/min) = (150,120 litres/day + 92,520 KL/day) * (1 KL/1000 m³) * (1 day/1440 min)
Total Sewage Flow (m³/min) = 0.104 m³/min
Question:
How is the total sewage flow in a sewer line calculated?
Answer:
The total sewage flow in a sewer line is calculated by determining the sewage flow from each contributing area, summing them up, and converting the units to get the final flow rate in m³/min.