CHE 313
__________________
LAST NAME, FIRST
Problem set #3
1-8 Copy the program Mass3.exe from the class distribution folder to your flash or H drive. You
can also download the program from the website:
https://www.csupomona.edu/~tknguyen/che313/homework.htm.
Run the program and solve all 8 problems in any order. Solve the problem with the data provided
by the program, copy the problem statement to Word. The program will check your answer and
provide an answer code when you click on “Check”. Copy the answer code and paste them after
the problem statement or next to the answer.
Your work must follow the format given in assignment #1 to receive full credit:
You will not receive full credit if you do not provide every step in the calculation even if
you use a Matlab program.
9) A biofilm consists of living cells immobilized in a gelatinous matrix. A toxic organic solute
(species A) diffuses into the biofilm and is degraded to harmless products by the cells within the
biofilm. We want to treat 0.1 m3 per hour of wastewater containing 0.1 mole/m3 of the toxic
substance phenol using a system consisting of biofilms on rotating disk as shown below.
Waste water
feed stream
biofilm
CA0
CA(z)
Inert
solid
surface
CA0
Well-mixed contactor
biofilm
Treated
z=0
waste water
The biofilm thickness is 2 mm and the phenol concentration in the outlet stream is 0.02 mole/m 3.
The rate of disappearance of phenol (species A) within the biofilm is described by the following
equation
rA = − k1cA where k1 = 0.019 s-1
The diffusivity of phenol in the biofilm at the process temperature of 25oC is 2.0×10-10 m2/s.
Phenol is equally soluble in both water and the biofilm. Write your own Matlab program to plot
(a) the molar flux (mol/sm2) of phenol as a function of distance into the biofilm and (b) the
concentration (mole/m3) of phenol as a function of distance into the biofilm. Use the Title
command to label your name on the graph.
(Ref. Fundamentals of Momentum, Heat, and Mass Transfer by Welty, Wicks, and Wilson, 4th Edition, 2001, pg.
496.)