Bioremediation of Sediment in Persian Gulf Coast (RESEARCH NOTE)

The amount of petroleum hydrocarbon and heavy metals in sediment of Persian Gulf’s shore at 8 selected stations were determined and showed the maximum of 143.6 and 58.6 mg/kg sediment, respectively. The above maximum amounts were related to Emam Hassan zone which is located at 50 kilometers to west Boushehr port. Bioremediation of contaminated sediment were studied in slurry and solid state fermentation. 8 bacteria types were isolated. Four species Em2, SH, GN1 and GN3 presented maximum PAH (Poly Aromatic Hydrocarbons) removal efficiency. Biodegradation efficiency under slurry conditions was observed after about 45 days which during this period, naphthalene and phenanthrene showed 73 and 66% removal efficiency, respectively. Under solid-state conditions, microbial activity of mixed and pure culture was studied. The results presented that the mixed culture due to strength and tolerance of different strains for growth, showed higher degradability compared to pure strains, but due to insufficient mixing under solid state conditions, mass transfer rate of nutrient reduced which caused to reduce cell activity, therefore removal efficiency under slurry conditions was higher.