BIOTECHNOLOGY LETTERS
Volume 15 No.7 (July 1993) pp.737-742
Received as revised 2nd June
ENRICHMENT OF FUNGI AND DEGRADATION OF STYRENE IN BIOFILTERS
Huub H.J. Cox*, Jos~ H.M. Houtman, Hans J. Doddema, and Wim Harder
J
TNO Institute of Environmental Sciences, PO Box 6011, 2600 JA Delft, The
Netherlands
SUMMARY
Experiments were set up in order to enrich styrene-degrading fungi in
biofilters under conditions representative for industrial off-gas treat-
ment. From the support materials tested, polyurethane and perlite proved
to be most suitable for enrichment of styrene-degrading fungi. The bio-
filter with perlite completely degraded styrene when amounts ranging
between 290 and 675 mg/m = in the influent gas were present. An elimina-
tion capacity of at least 70 g styrene per m 3 filter bed per hour was
calculated.
INTRODUCTION
Styrene is a volatile environmental pollutant, emitted by styrene/-
polystyrene manufacturing plants and the reinforced plastics industry.
The styrene concentration in industrial waste gases is generally low (0-I
g/m 3 (Tossavainen, 1978)) and microbial purification of these gases may
be economically feasible compared to chemical and physical treatment
methods. Various methods
developed, i.e. compost
(Ottengraf, 1986). Here,
for microbial waste gas treatment have been
filters, bioscrubbers and trickle-bed filters
a new concept in biofi!tration is presented,
which is based on the application of fungi for the degradation of waste
gas compounds in biofilters containing inert support materials for the
immobilization of the fungi. In principle the application of fungi in
biofilters may offer two advantages:
i. Stringent control of the water activity and/or pH in the filter bed
is less important, since fungi are generally tolerant to low water
activity and low pH.
2. Reduction of the water activity in the filter bed may improve the mass
transfer of poorly water soluble waste gas compounds like styrene.
The number of reported styrene-degrading fungi is low; sty