Integrated Chemical-Biological Remediation for Polycyclic Aromatic Hydrocarbons Contaminated Soil

Abstract

An integrated slurry-phase remedial system was developed for cleanup of polycyclic aromatic hydrocarbon (PAH) contaminated soil in Singapore. The bench-scale remedial system consisted of a chemical treatment to initiate the degradation of PAHs followed by a biological treatment. The 20% (weight/volume) slurry of PAH contaminated soil was mixed continuously at 180 rpm in the 1 L bioreactor. PAH contaminated soil was synthesized by spiking naphthalene, phenanthrene, and pyrene onto uncontaminated model soil. Fenton’s reagent was added during chemical treatment to initiate degradation of PAHs. The removal efficiency of chemical treatment was 76%. The active PAH-degrading strain of bacteria was isolated from a slurry-phase reactor, where garden soil was used as a source of indigenous microorganisms. The sequencing of 16S rDNA showed that this bacterial strain was close to