2.2. Retardation Factor

Try these first

1. 1.

   Define the Retardation Factor.

   Hint

   Think about how it relates to flow rates.

2. 2.

   What does a Retardation Factor of 1 indicate?

   Hint

   What happens when R is equal to 1?

3. 3.

   What does a Retardation Factor greater than 1 indicate?

   • Contaminant moves faster than water
   • Contaminant moves slower than water
   • Contaminant moves at the same speed

   Hint

   Think about the relationship between R and contaminant transport.

4. 4.

   True or False: A semi-infinite boundary condition assumes that changes in concentration occur at all distances from contamination.

   • True
   • False

   Hint

   Consider the definition of semi-infinite in modeling.

5. 5.

   A sediment contains a contaminant with a Retardation Factor of 3. Calculate the expected concentration in pore water if the concentration in sediments is 90 mg/kg.

   Hint

   Remember how we calculate pore water concentration from sediments.

6. 6.

   Explain the potential environmental implications of high Retardation Factors in sediments on aquatic ecosystems.

   Hint

   Consider how contaminants interact with the ecosystem over time.