Heterogeneous reductive dehalogenation of PCB contaminated transformer oil and brominated diphenyl ethers with zero valent iron

► Reductive dehalogenation of PCBs and PBDEs at 350–600°C with ZVI in N2. ► Waste transformer oil acts as its own proton donor. ► Alkanes can serve as proton donors. ► NO halogenated organic products are observed; all halides remain on the iron. Reductive dechlorination and debromination of halogenated biphenyls (PCBs) and diphenyl ethers (PBDEs) occurs efficiently at moderately elevated temperatures (350–600°C) with zero valent iron (iron powder) in a nitrogen atmosphere. The proton donors tested were waste transformer oil, iso-octane, and n-decane. Observation of production of biphenyl and diphenyl ether and their condensation products indicates that the reaction is not simple pyrolysis, but a reduction. No halogenated organic products are observed.