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8305224 
Meetings & Symposia 
Biodegradation of hexane vapors by a fungal consortium 
Arriaga, SL; Revah, S 
2004 
Proceedings - Air & Waste Management Association. Meeting
ISSN: 1052-6102 
Indianapolis, IN 
Proceedings of the A and WMA's 97th Annual Conference and Exhibition; Sustainable Development: Gearing Up for the Challenge 
1493-1502 
English 
The limiting step for biofiltration processes of Hydrophobic compounds is generally the transfer of pollutants from the gas to the liquid biotic phase, where biodegradation occurs. It has recently been shown, for hydrophobic compounds, the use of fungi may improve removal efficiency. For this study, a mixed consortium acclimated to pH 4 with hexane vapors for 30 days was used to inoculate a 2.4 L biofilter using perlite as an inert support. After 2 weeks, a significant fungal growth was observed in the reactor. For an hexane inlet load of around 140 g.m-3.h-1, average elimination capacities (EC) of 100 g.m 3.h-1 were attained with the predominantly fungal system. The biofilter reduced its activity within few days, from 100 to 70 g.m-3.h-1 when no mineral medium was added. Increasing the hexane inlet load and regularly providing mineral medium allowed to reach a maximum elimination capacity of 150 g.m-3.h-1, which is greater than those reported elsewhere for bacterial systems. The addition of an antibacterial inhibitor during 15 days confirmed that around 95% of hexane degradation was due to fungal activity. The biomass in the filter was 354 mg.g-1dry perlite without important pressure drop (10 mm of water). The greater efficiency obtained with fungal biofilters can be possibly related to the existence of hydrophobic hyphae. Two fungi were isolated from the consortia and were identified as Cladosporium and Fusarium spp. The hexane biodegradation activity of these fungal strains was demonstrated in two short time experiments performed in lab-scale biofilters (0.230 L). In these experiments, EC of 40 and 50 g.m-3.h-1 were obtained for Cladosporium and Fusarium spp. respectively, with a biomass content of only 38 mg.g-1dry perlite, showing the potential of the strains.