Questions about kinetic equation of chemical oxygen demand

Hello!
There are two questions about kinetic equation of chemical oxygen demand. The equation is showed in the following figure.

  1. What does “ΔZ” mean in the equation?
  2. I want to know the references for this equation.

Hi yunyingli,

  1. In the kinetic equation of COD, the “ΔZ” term stands for the thickness of the bottom layer where the exchange of COD from sediment flux and water column take place.
  2. The Water Quality model in EFDC+ code was derived from the CE-QUAL-ICM water quality model. For the reference of equations, you can have:

Thank you for your reply!