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BASE CATALYZED DECOMPOSITION (BCD) OF PCB AND DIOXIN CONTAMINATED CONDENSATE OIL FROM THE REMEDIATION OF THE WARREN COUNTY LANDFILL, NC
Citation:
LYONS, T. AND K. COOK. BASE CATALYZED DECOMPOSITION (BCD) OF PCB AND DIOXIN CONTAMINATED CONDENSATE OIL FROM THE REMEDIATION OF THE WARREN COUNTY LANDFILL, NC. Presented at Association for Environmental Health Sciences (AEHS), 17th Annual Meeting and West Coast Conference on Soils, Sediment, and Water, San Diego, CA, March 19 - 22, 2007.
Description:
In the late 1970s thousands of gallons of transformer fluid contaminated with PCBs were illegally sprayed along approximately 210 miles of North Carolina state roadways. Listed as a Superfund site, the contaminated roadway berms were excavated and disposed in an approved PCB landfill built in Warren County, NC. There was much original opposition to the landfill from the local community, starting the Environmental Justice movement. The Governor of North Carolina promised the citizens of Warren County the landfill was temporary and when a technology became available that would successfully treat the PCB contaminated soil the landfill would be removed.
The U.S. EPA SITE Demonstration Program provided supported for the State of North Carolina in remediating the PCB contaminated soil from the Warren County Landfill, using the U.S. EPA developed Base Catalyzed Decomposition (BCD) process.
The BCD process relies on catalytic hydrogenation. In this type of process, a hydrogen donor in the untreated material supplies hydrogen ions which replace chlorine atoms in the chlorinated contaminants. The chlorinated contaminants are reduced to less toxic unchlorinated compounds and the chlorine is displaced as a chloride ion.
During the first phase of the treatment the soil was thermally desorbed and the highly contaminated residual condensate oil was collected. The initial plan was to treat this condensate oil with the BCD process in a nonpressurized heated stirred tank reactor at 330'C combined with hydrogen donor oil, NaOH, and proprietary catalyst. The state opted to send the condensate oil off for incineration. ORD was able to collect a sufficient sample of the contaminated condensate oil and performed bench-scale testing to prove the effectiveness of the BCD technology.
Prior to treatment the condensate oil was analyzed and found to contain high levels of PCB (53,000 mg/kg Aroclor 1016 and 38,000 mg/kg Aroclor 1260) and dioxins (370 ng/kg 2,3,7,8 TCDD and 290,000 ng/kg 2,3,7,8 TCDF). Two separate bench-scale treatability studies were performed on the condensate oil. The results of both these test indicate BCD dechlorinated PCBs to less than detection limits of 5.0 mg/kg. Dioxins were reduced to less than detection limits of 27.0 and 18.0 ng/kg,respectively.