Background and purpose: Polycyclic aromatic hydrocarbons (PAHs) are a group of environmental pollutants in soils and sediments that causes concern because of their toxic, mutagenic and carcinogenic effects. The purpose of this study was to determine the feasibility of utilizing poultry manure as a co-substrate to enhance the bioremediation of phenanthrene and anthracene in contaminated soil.

Materials and methods: The soil samples were homogenized and filtered using a 2.0 mm sieve. The soil samples were added into nine aluminum buckets. Then, phenanthrene and anthracene solution were added into buckets. Finally the inoculum was mixed with buckets’ contents. The treatment was performed with or without poultry manure. In all treatments, tap water was added during the bioremediation to adjust the moisture content (15 - 20%) according to the recommended values for the bioremediation process. All of the bioremediation experiments were carried out in duplicate during 45 days of incubation.

Results: The biodegradation data of anthracene and phenanthrene indicates about 92.65% and 95.62% (samples without co-substrate), 96.07% and 95.91% (samples contain co- substrate) degradation at the concentration of 12.5 mg/kg. Also, the experimental data revealed that the PAHs removal percentage increases due to increase in incubation time. Moreover, the results of the changes COD showed that highest rate COD removal in sample containing co-substrate occurred.

Conclusion: According to this result, the presence of poultry manure as a co-substrate can enhance the anthracene and phenanthrene removal comparing to the control sample and the sample contain co-substrate.