Combined steam distillation and electrochemical peroxidation (ECP) treatment of river sediment contaminated by PCBs.
A combined treatment process utilizing steam distillation followed by electrochemical peroxidation (ECP) has been utilized to remove >90% of the polychlorinated biphenyls (PCBs) in St. Lawrence River sediment and destroy 95% of the PCBs recovered in the condensate. 2 l of condensate were collected by boiling 500 grams of sediment containing approximately 4.3 mg PCBs. Most of the PCBs (82.3%) were recovered as a small volume (<1 ml) of yellow oil floating on the condensate and coating glassware surfaces. The aqueous phase PCBs (182 microg/l) were destroyed (95%) by three sequential ECP treatments at 16.8 degrees C and pH 5, utilizing 1 ml of H2O2 (3%) and periodically reversed current (0.75-1.0 A @ 10 volts). Oxidation is primarily mediated by hydroxyl radicals produced by the reaction of hydrogen peroxide with electrochemically generated ferrous iron (Fenton's reagent). This work suggests steam extraction, in combination with advanced oxidation technologies, provides an effective treatment strategy for contaminated solids.
Chiarenzelli
J R
JR
Environmental Research Center, Oswego, NY 13126, USA. chiarenz@oswego.edu
Scrudato
R J
RJ
Wunderlich
M L
ML
Pagano
J J
JJ
D004563:Electrochemistry; D004785:Environmental Pollutants / Q000032:analysis*; D004787:Environmental Pollution / Q000517:prevention & control*; D019015:Geologic Sediments / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D011078:Polychlorinated Biphenyls / Q000737:chemistry*
D004785:Environmental Pollutants; C045076:Fenton's reagent; D016877:Oxidants; D006861:Hydrogen Peroxide; D011078:Polychlorinated Biphenyls; D007501:Iron