301. Iron-mediated reactions of polychlorinated biphenyls in electrochemical peroxidation process (ECP)
- Author
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Ronald J. Scrudato, Benjamin Connor, Lauren Falanga, Michele Arienzo, James J. Pagano, Jeffrey R. Chiarenzelli, Arienzo, Michele, Chiarenzelli, Jeffrey, Scrudato, Ronald, Pagano, Jame, Falanga, Lauren, and Connor, Ben
- Subjects
Environmental Engineering ,Iron filings ,Health, Toxicology and Mutagenesis ,Iron ,Inorganic chemistry ,Electrochemistry ,Iron powder ,chemistry.chemical_compound ,Adsorption ,Oxidizing agent ,Environmental Chemistry ,Electrodes ,Biphenyl ,Zerovalent iron ,Aqueous solution ,Chemistry ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Hydrogen Peroxide ,Oxidants ,Pollution ,Polychlorinated Biphenyls ,Environmental Pollutants ,Oxidation-Reduction - Abstract
A study was conducted to explore some of the basic processes of polychlorinated biphenyl (PCB) destruction by a new technology termed electrochemical peroxidation process (ECP). ECP represents an enhancement of the classic Fenton reaction (H 2 O 2 +Fe 2+ ) in which iron is electrochemically generated by steel electrodes. Focus was on the extent of adsorption of a mixture of Aroclor 1248 on steel electrodes in comparison to iron filings. Commercially available zero-valent iron filings rapidly adsorbed PCBs from an aqueous solution of Aroclor 1248. Within 4 h, all the PCBs were adsorbed at 1%, 5%, and 10% Fe 0 (w/v) concentrations. Little difference in adsorption was found between acidic (2.3) and unamended solutions (pH 5.5), even though significant differences in iron oxidation state and Fe 2+ concentrations were measured in solution. PCB adsorption also occurs on steel electrodes regardless of the pH or electric current applied (AC or DC), suggesting the combination of oxidizing (free radical-mediated reactions) and reducing (dechlorination reactions) iron-mediated degradation pathways may be possible. Extraction of the iron powder after 48 h of contact time yielded the progressive recovery of biphenyl with increasing Fe mass(from 0.4% to 3.5%) and changes of the PCB congener-specific pattern as a consequence of dechlorination. A variety of daughter congeners similar to those accumulated during anaerobic microbial dechlorination of Aroclor 1248 in contaminated sediments indicate preferential removal of meta - and para -chlorines.
- Published
- 2001