SBIR Phase I: A Transformational Method to Extract Polychlorinated Biphenyls (PCBs) from Building Masonry

The broader impact of this Small Business Innovation Research (SBIR) Phase 1 project is solving the legacy polychlorinated biphenyls (PCBs) problem impacting our aging schools and infrastructure. The U.S. Environmental Protection Agency (EPA) estimates as many as 55,000 schools and 800,000 government and non-government buildings may have been constructed with PCB-laden paints, caulks, mastics and adhesives before the 1979 PCBs ban.

Simply removing the PCB-laden source in hopes it will eliminate the hazard has proven futile as a growing body of data is revealing PCBs from weathered caulk can leach as deep as 6-inches into adjacent porous masonry (e.g., concrete, brick, and mortar). Currently, total demolition and select removal (i.e., partial demolition) are the only EPA-approved PCB removal options and both are quickly filling up the handful of landfills willing to take it.

The proposed technical innovation will transform a dormant government patent that extracts PCBs in paint, into a non-destructive treatment method that penetrates and extracts PCBs absorbed in building masonry. Such an innovation will have a direct and beneficial impact on the government agencies and school renovation commissions who cannot afford to demolish the old and rebuild new.

This SBIR Phase 1 project proposes to demonstrate the feasibility of two proprietary solvent-paste formulations at extracting PCBs from different masonry types after the source (e.g., caulk) has been removed. The solvent-paste is applied directly to the contaminated masonry surface and scraped off after a pre-determined treatment period. Once applied, the lipophilic alcohol in the solvent-paste penetrates the masonry’s open pore spaces, and solubilizes the PCB molecules it encounters along the way.

The process of desorbing the PCBs from the inorganic masonry particles and into the applied paste is aided – via capillary action – by the lipophilic alcohol drawing the hydrophobic PCBs toward the paste. Technical challenges include desorbing the stickier spectrum of hydrophobic Aroclors (e.g., 1248, 1254, 1260) added to paints, caulks and adhesives in seasonally cool (< 50°F), wet weather.

Since successful commercialization of an alternative PCB treatment technology requires approval from EPA in accordance with the PCB regulations (40 CFR 761), the performance of both solvent-pastes will be evaluated against the regulation’s stringent 1 ppm high occupancy cleanup criterion.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.