Objective: This project will demonstrate the efficacy of a Bimetallic Treatment System (BTS) to remove and rapidly degrade polychlorinated biphenyls (PCB) found in structural coatings. Variables to be addressed include the substrates on which the PCB coatings have been applied; age of the coatings; interactions of weather conditions during BTS application; adhesion, appearance, and repeat application of BTS; and substrate condition on removal of the BTS and PCB coating. Investigators seek to reach PCB surface concentrations below the Toxic Substances Control Act limit of 50 parts per million (ppm), or lower cleanup goals as stipulated by the various installations. A guidance manual and on-site safety protocols will be developed to assist Department of Defense (DoD) managers and practitioners in designing and implementing structure coatings remediation using BTS. Material safety data sheets for the major formulation categories of BTS also will be developed and evaluated at one of the field demonstration sites. Technology Description: The BTS technology, which consists of elemental magnesium (Mg) coated with a small amount of palladium (Pd) in a solvent solution capable of donating hydrogen atoms, has two functions: (1) to extract PCBs from weathered, decades-old coating material such as paint and (2) to rapidly degrade the extracted PCBs. Researchers from the National Aeronautics and Space Administration-Kennedy Space Center and the University of Central Florida previously demonstrated rapid and complete dechlorination in aqueous/solvent systems containing Aroclors 1254, 1260, and 1268 (specific PCB mixtures). Significant, if not complete, PCB extraction and degradation from paint chips with total PCBs as high as 11,000 ppm has been achieved with as little as 48 hours of exposure. The solvent in BTS is used to open but not destroy a paint's polymeric lattice structure, allowing pathways for PCB movement out of the paint and into the solvent. After the BTS is removed from the paint surface, the lattice structure returns to its original configuration, with no change in surface appearance, texture, or hardness. Because of the wide variety of structural properties associated with each specific PCB-laden coating, the choice of solvents incorporated into BTS is specific to the material being treated. Additional BTS formulation properties that must be addressed for each site-specific application include viscosity and stability. Expected Benefits: Recent demolition and disposal costs associated with a structure coated with PCB-laden materials have been approximately $40 per square foot. The BTS technology will provide DoD with a rapid, low-cost alternative method of treating PCBs that facilitates (1) economical, continued use or reuse of structures by reducing treatment costs and eliminating long-term environmental liability associated with PCB contamination and (2) potential preservation of structures that would have otherwise been slated for demolition due to PCBs. It will have wide-ranging application across the military services, including Air Force launch structures, Navy vessels, Army ordnance facilities, and other infrastructure with PCB-containing material. (Anticipated Project Completion - 2008) Principal Investigator: Dr. Nancy Ruiz Naval Facilities Engineering Service Center 1100 23rd Avenue, ESC411 Port Hueneme, CA 93043 Telephone: (805) 982-1155 Fax: (805) 982-4304 E-mail: nancy.ruiz@navy.mil |
