# Homework Help: Mass Transfer (Wetted Column)

1. Mar 9, 2014

### salih129

Dear all,

I am currently doing a lab question. I do not know how to solve a calculation question.

Question: Calculate the average flux of the oxygen through the gas-liquid interface in the wetted-wall column. Remember that a more accurate value of the average flux can be calculated by taking the the liquid film thickness into account.

BAckground: In this experiment, we have to take note of dissolved oxygen concentration at the inlet and outlet of a wetted column for changing air and water flow rates. Air will flow in from the bottom while de-oxygenated water will flow down from the top. Oxygen will diffuse into the water.

I would appreciate any help. Thanks.

2. Mar 10, 2014

### Staff: Mentor

Hi Salih129. Welcome to Physics Forums!!!
Where do you think the main resistance to oxygen mass transfer is going to reside (a) on the gas side of the interface or (b) on the liquid side of the interface?

Assume you have water moving down the wall with a laminar parabolic velocity profile, as determined by solving the hydrodynamic flow equation. How thick is the layer of water on the wall in your application? What is the downward velocity of the water at the interface, and how long is the column? How long does it take for the water at the interface travel down the length of the column?

Chet