Experimental Study of Biodegradation of Ethanol and Toluene Vapors

y=Ln[(S*-S)/(S*-S0)]
3.5
3
2.5
2
1.5
1
0.5
0
y = 0.0010t
R 2 = 0.9978
y = 0.00088t
R 2 = 0.99642
y = 0.00084t
R 2 = 0.99709
0 1000 2000 3000 4000
Time, sec
300 rpm
450 rpm
600 rpm
Figure 4-1 Determination of toluene mass transfer coefficients
Ethanol mass transfer results demonstrated that at inlet ethanol concentrations of
80.0 to 92.0 mg/L, air flow rates up to 3.8 L/min and mixing speeds of 135 to 600 RPM,
ethanol was completely removed from the air streams by the aqueous phase in the
reactor. Ethanol liquid concentrations can then be calculated from the material balance:
dS
dt
Q( C
g, in
− C
g,
out
= (4-3)
V
e
)
where S e is ethanol concentration in the liquid phase (g/L), t is time in minutes, V is the
working volume of the reactor (L), Q is the air flow rate (L/min), and C g,in (g/Lair) and
C g,out (g/Lair) are the ethanol concentrations in the inlet and outlet air streams,
respectively.
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