Answer:
Concentration = 10.33 kg/m³
Explanation:
We are given;
Mass of solids; 10,000 kg
Volume; V = 440,000 L = 440 m³
Rate at which water is pumped out = 40,000 liter/h
Thus, at the end of 5 hours we amount of water that has been replaced with fresh water is = 40,000 liter/h x 5 hours = 200,000 L = 200 m³
Now, since the tank is perfectly mixed, therefore we can calculate a ratio of fresh water to sewage water as;
200m³/440m³ = 5/11
Thus, the amount left will be calculated by multiplying that ratio by the amount of solids;
Thus,
Amount left; = 10000 x (5/11) = 4545 kg
The concentration would be calculated by:
Concentration = amount left/initial volume
Thus,
Concentration = 4545/440 = 10.3 kg/m³
