Experimental Study of Biodegradation of Ethanol and Toluene Vapors

Substrate and biomass
concentrations, g/L
1.4
2
1.2
1
1.5
0.8
0.6
1
0.4
0.5
0.2
0
0
95 105 115 125
Toluene gas outlet, mg/L
Time, h
ethanol benzyl alcohol biomass
acetic acid
toluene Cgout, mg/L
Figure 4-16. Continuous removal of toluene-ethanol mixture from a polluted air stream
at a dilution rate of 0.1 h -1 and ethanol inlet concentration of 15.9 mg/L
with toluene inlet concentration of 5.8 mg/L
4.4.4 Toluene-benzyl alcohol Bioremediation
Prior to continuous bioremediation of benzyl alcohol and toluene, cultures were
started in batch mode with an initial benzyl alcohol concentration of 1.0 g/L to obtain an
initial high population of biomass for the continuous bioremediation studies.
The medium was added to the reactor at 150 mL/h (dilution rate of 0.1 h -1 ),
benzyl alcohol was added at a feed rate of 0.12 g/h using a syringe pump, and the air
flow rate was set at 0.4 L/min. When the benzyl alcohol feed rate was 0.12 g/h and
toluene inlet concentrations were 4.5 and 5.7 mg/L (toluene loadings of 72 and 91
mg/L-h, total loadings of 152 and 171 mg/L-h), conditions reached steady state and the
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