Kinetic Study of n-Hexane Biodegradation by an Isolated Fungal Consortium from a Biofilter

The kinetic study of a pollutant biodegradation is considered as one of the main steps in characterization of a biofilter performance. In this research, an unidentified fungal consortium which previously had been isolated from a compost biofilter treating n-Hexane and Toluene vapors, was used to remove n-hexane in a batch system. To specify the ability of the isolated fungi, the effect of temperature and hexane concentration were studied. The hexane concentration in liquid phase varied in the range of 5-25 mg/l and operating temperature altered between 25- 45°C in a central composite design (CCD) analysis. The optimum conditions for hexane biodegradation obtained at 36.5°C and 8.6 mg/L. The kinetic investigations at 25 and 40°C presented that a Haldane, Webb and Yano models could predict the biodegradation well with R2 value of more than 0.98. In addition, the affinity of fungal consortium to degrade hexane at 40°C was higher than degradation at 25°C. The kinetic parameters of Haldane model at 40°C were νmax= 3.57 (mg/gBiomass.h); KS=9.57(mg/L); KI=20.48(mg/L).