Influence of synthetic packing materials on the gas dispersion and biodegradation kinetics in fungal air biofilters
Issue date
2008Author
Prenafeta-Boldú, Francesc Xavier
Groenestijn, Johan W. van
Flotats i Ripoll, Xavier
Suggested citation
Prenafeta-Boldú, Francesc Xavier;
Illa i Alibés, Josep;
Groenestijn, Johan W. van;
Flotats i Ripoll, Xavier;
.
(2008)
.
Influence of synthetic packing materials on the gas dispersion and biodegradation kinetics in fungal air biofilters.
Applied Microbiology and Biotechnology, 2008, vol. 79, p. 319-327.
https://doi.org/10.1007/s00253-008-1433-2.
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Show full item recordAbstract
The biodegradation of toluene was studied in two
lab-scale air biofilters operated in parallel, packed respec-
tively with perlite granules (PEG) and polyurethane foam
cubes (PUC) and inoculated with the same toluene-
degrading fungus. Differences on the material pore size,
from micrometres in PEG to millimetres in PUC, were
responsible for distinct biomass growth patterns. A compact
biofilm was formed around PEG, being the interstitial
spaces progressively filled with biomass. Microbial growth
concentrated at the core of PUC and the excess of biomass
was washed-off, remaining the gas pressure drop compar-
atively low. Air dispersion in the bed was characterised by
tracer studies and modelled as a series of completely stirred
tanks (CSTR). The obtained number of CSTR (
n
) in the
PEG packing increased from 33 to 86 along with the
applied gas flow (equivalent to empty bed retention times
from 48 to 12 s) and with operation time (up to 6 months).
In the PUC bed,
n
varied between 9 and 13, indicating that
a stronger and steadier gas dispersion was achieved.
Michaelis
–
Menten half saturation constant (
k
m
) estimates
ranged 71
–
113 mg m
−
3
, depending on the experimental
conditions, but such differences were not significant at a
95% confidence interval. The maximum volumetric elim-
ination rate (
r
m
)variedfrom23to50gm
−
3
h
−
1
.
Comparison between volumetric and biomass specific
biodegradation activities indicated that toluene mass trans-
fer was slower with PEG than with PUC as a consequence
of a smaller biofilm surface and to the presence of larger
zones of stagnant air.