Laboratory investigation of PCB bake-out from tertiary contaminated concrete for remediation of buildings. (July 2017)

• Record Type: Journal Article
• Authors: Kolarik, Barbara; Andersen, Helle Vibeke; Frederiksen, Marie; Gunnarsen, Lars
• Is Part Of: Chemosphere. Volume 179(2017)
• Page Start: 101
• Page End: 111
• Publication Date: 2017-07
• Subjects: Polychlorinated biphenyls -- Mitigation -- Thermal stripping -- Indoor air -- Building materials -- Tertiary sources; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2017.03.094
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Polychlorinated biphenyls (PCBs) have been used in flexible construction products from the 1950s to the 1970s. Despite a relatively low vapour pressure, PCBs have over the years emitted to the indoor air and adsorbed to other surfaces, creating tertiary sources. While necessary to protect the environment and health of building occupants, remediation of the contaminated buildings is an expensive and difficult process. The aim of this study was to investigate the effect of bake-out as a method for removing PCB from contaminated indoor surfaces. Four painted and four sandblasted samples of concrete wall were kept at 50 or 65 °C for 10 or 20 days in small scale chambers, which were ventilated with clean air at area specific rates comparable to full scale rooms. The air concentrations were measured several times during the bake-out. Concentrations of PCB in paint, plaster and concrete were measured before and after the experiment. For the painted samples, PCB28 and PCB52 followed by PCB138 and PCB153 were the predominant congeners measured in air. A significant reduction of the PCB concentration was only found for more volatile congeners in paint, while no significant effects were observed in the plaster or concrete. For the most effective setting (65 °C, 20 days), the concentration of PCB∑7 in the paint was reduced by 40%. For the sandblasted samples, the less volatile congeners PCB138 and PCB153 were predominant in the air during bake-out. No effect was observed on the initially low concentrations of the sandblasted samples, possibly due to analytical limitations. Highlights: Painted and sandblasted samples of PCB contaminated concrete either exposed to 65 °C or 50 °C for 20 or 10 days. Significant impact of temperature and duration on PCB removal based on air results. Significant decrease of PCB concentration only in the paint fraction. No significant effect of bake-out on fractions of the sandblasted samples. Different types of the same material might behave differently under bake-out.