R5 AM Perflourochemical Biodegradation, Fate, and Transport
Thursday, 17 November 2005: 8:00 AM - 11:40 AM in 321-323

(BER-1117-855591) Biodegradation studies of fluorotelomer-based polymers in activated sludge, soil, and sediment.

Berti, William¹, Szostek, Bodan², Schaefer, Edward³, Van Hoven, Raymond³, Wang, Ning¹, Gannon, John¹, Buck, Robert⁴, ¹ DuPont Central Research and Development, Newark, DE, USA² DuPont Haskell Laboratory for Health and Environmental Sciences, Newark, DE, USA³ Wildlife International, Ltd., Easton, MD, USA⁴ DuPont Chemical Solutions Enterprise, Wilmington, DE, USA

ABSTRACT- Biodegradation of fluorotelomer-based polymers in the environment is of interest to determine whether they may be a potential source of perfluorinated carboxylic acids (PFCAs). Studies to determine whether the fluorotelomer moieties covalently bonded in these polymers can be liberated and transformed to PFCAs are underway. The biodegradation studies are being conducted in aerobic sludge and under aerobic and anaerobic conditions in soils and sediments. Treatments for the soil studies include an untreated control soil, live (non-sterilize) soil containing the test substance (i.e., commercially-sold polymer product emulsion) added at 200 mg polymer kg^-1 soil (soil dry wt.), sterilized soil containing the test substance, and sterilized soil containing 8-2 Telomer B Alcohol (8-2 TBA), two telomer acids, and 8, 9, 10, and 11 carbon-containing PFCAs to assess recoveries over the year-long experiment. The test vessels are incubated statically at 20°C. Anaerobic conditions are imposed by flushing the test vessels with anaerobic mixed gas and then sealing them. Treatments and methods for the sediment studies are similar to those of the soil studies. Sediment and water are added to each test vessel so the resulting water:sediment volume ratio is between 3:1 and 4:1 and the minimum sediment layer is approximately 2 cm. In addition to headspace and sediment extract samples, separate aqueous samples are collected and analyzed for the sediment studies. Analyses of the test systems from the activated sludge and soil studies indicate that ppb levels of 8-2 TBA, two telomer acids, and 8 to 11 carbon-containing PFCAs extracted from soils are accounted for by transformation of residual fluorotelomer raw materials present in the polymer products.

Key words: fluorotelomer, biodegradation, perfluorinated carboxylic acids