Reduction of aromatic hydrocarbons by zero-valent iron and palladium catalyst

Permeable reactive barrier (PRB) is one of the most popular innovative technologies for remediation of contaminated groundwater and soils. Pd catalysts and zero-valent iron were simultaneously tested to remove aromatic compounds in batch reactors. A few chlorinated aromatics, chlorophenols, and some non-chlorinated aromatics such as benzene, naphthalene, and phenanthrene were evaluated. Benzene was reduced to cyclohexane, indicating that the Fe/Pd catalysis system reduces the aromatic ring. Iron could supply electrons onto palladium surface through direct contact or produce hydrogen even if iron is not chemically bonded with palladium as Pd/Fe. Pd/Fe and Fe/Pd catalysts could dechlorinate and reduce the aromatic rings, implying that they could be an excellent alternative material for PRB, which treats halogenated compounds and recalcitrant contaminants.