Biodegradation of phenanthrene in an anaerobic batch reactor: Growth kinetics

Abstract

The purpose of present research was to demonstrate the ability of mixed consortia of microorganisms to degrade high concentrations of phenanthrene (PHE) as the sole carbon source. Batch experiments were carried out by induction of mineral salt medium containing PHE to the seed culture and monitoring PHE biodegradation. The microbial propagation was conducted using PHE concentrations in the range of 20 to 100 mg/l. The microbial growth on PHE was defined based on Monod and modified Logistic rate models. The kinetic studies revealed that maximum specific growth rates (?m) for PHE concentrations of 20, 50 and100 mg/l were 0.12, 0.23 and 0.035 h-1, respectively. The doubling times for microbial population in PHE concentrations of 20, 50 and100 mg/l were 13, 15 and 17.5h, respectively. Also, maximum cell dry weight (xm) of 54.23 mg/l was achieved, while the inhibition coefficient was 0.023 h-1. It was observed that the experimental data were well represented by the proposed models. It was also found that the biodegradation of PHE was successfully performed by the isolated strains.