Author/Authors :
Nasrollahzadeh، H. S نويسنده School of Biological Sciences, University Sains Malaysia, 11800, Penang, Malaysia , , Najafpour، G.D نويسنده Department of Chemical Engineering, University of Mazandaran, Babol, Iran , , Aghamohammadi، N نويسنده School of Civil Engineering, University Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Seberang Perai Selatan, Penang, Malaysia ,
Abstract :
Biodegradation of Phenanthrene (PHE) was studied in aqueous culture to demonstrate
the potential of the mixed culture in degrading high concentration of PHE. The experiments were
conducted to monitor biodegradation of Phenanthrene for duration of 6 days. Biodegradation of
PHE was successfully achieved in low and middle concentration by the isolated mixed culture. A full
factorial Central Composite Design of experiments was used to construct response surfaces with
the removal, the extent of PHE degradation and the specific growth rate as responses. The initial
Phenanthrene concentration (X1) and the reaction time (X2) were used as design factors. The result
was shown that experimental data fitted with the polynomial model. Analysis of variance showed a
high coefficient of determination value in the range of 0.936–0.999. The maximum biodegradation of
PHE in terms of the removal of PHE (Y1) was found to be 0.100 mg/mg (degraded PHE/initial PHE).
The maximum extent of biodegradation relative to initial PHE concentration and biomass (Y2) was
0.171 mg/mg/mg (degraded PHE/initial PHE/biomass). This maximum biodegradation correspond to
the factors combination of middle level of PHE content (X1= 19.06 mg/L) and the highest level of
reaction time (X2 = 132.00 hours). The removal efficiency of PHE biodegradation was achieved
100%. Polynomial model was found useful to predict PHE degradation under the experimental studied.
It was observed that optimum biodegradation of PHE can be successfully predicted by RSM
