1.5. Concentration Changes and Steady State Assumptions

Try these first

1. 1.

   What is mass balance in pollutant concentration modeling?

   Hint

   Think about how substances enter and leave a system.

2. 2.

   Define steady state in your own words.

   Hint

   Consider what conditions might cause concentration to stay the same.

3. 3.

   What does mass balance involve in pollution modeling?

   • Rate in = Rate out
   • Accumulation = Rate + Reactions
   • Zero emissions

   Hint

   Think of it as a balance scale.

4. 4.

   True or False: Steady state conditions can still occur in unsteady environments.

   • True
   • False

   Hint

   Consider the meaning of 'steady' versus 'unsteady'.

5. 5.

   A factory releases a pollutant at a constant rate. Over time, how would you expect the concentration at a monitoring station to behave? Discuss conditions that would validate your steady state assumptions.

   Hint

   Reflect on what changes can influence pollutant transport.

6. 6.

   Given a pollutant's rate of flow, derive how the concentration will behave if the emissions suddenly increase by 50%. What does this imply about steady state?

   Hint

   Consider what happens to balance when sources increase suddenly.