4.1. Factors Affecting Diffusion and Convection

Try these first

1. 1.

   Define diffusion in the context of contaminant transport.

   Hint

   Think about the movement of particles in a fluid.

2. 2.

   What is convection?

   Hint

   Remember the term 'bulk movement'.

3. 3.

   What is the primary driver of diffusion?

   • Temperature
   • Concentration Gradient
   • Pressure

   Hint

   Think about how particles naturally spread.

4. 4.

   True or False: Convection always enhances contaminant transport.

   • True
   • False

   Hint

   Consider what convection means as a process.

5. 5.

   Consider a contaminated lake with an initial concentration of 200 mg/L of a contaminant. If the flux is initially at its highest level due to high concentration, describe how you would model the change in concentration at different times.

   Hint

   Think of how the relationship between concentration and flux can change with time.

6. 6.

   Given the interplay between diffusion and convection in a sediment-water system, outline a monitoring strategy to assess the contaminant transport process effectively.

   Hint

   Consider factors that can influence both diffusion and convection, such as weather events.