6-2 Fluorotelomer alcohol aerobic biodegradation in soil and mixed bacterial culture
2009; Elsevier BV; Volume: 78; Issue: 4 Linguagem: Inglês
10.1016/j.chemosphere.2009.10.044
ISSN1879-1298
AutoresJinxia Liu, Ning Wang, Bogdan Szostek, Robert C. Buck, Patricia K. Panciroli, Patrick W. Folsom, Lisa M. Sulecki, Cheryl A. Bellin,
Tópico(s)Effects and risks of endocrine disrupting chemicals
ResumoThe first studies to explore 6-2 fluorotelomer alcohol [6-2 FTOH, F(CF(2))(6)CH(2)CH(2)OH] aerobic biodegradation are described. Biodegradation yields and metabolite concentrations were determined in mixed bacterial culture (90d) and aerobic soil (180d). 6-2 FTOH primary degradation half-life was less than 2d in both. The overall mass balance in mixed bacterial culture (day 90) was approximately 60%. At day 90, the molar yield was 6% for 6-2 FTA [F(CF(2))(6)CH(2)COOH], 23% for 6-2 FTUA [F(CF(2))(5)CFCHCOOH], 16% for 5-2 sFTOH [F(CF(2))(5)CHOHCH(3)], 6% for 5-3 acid [F(CF(2))(5)CH(2)CH(2)COOH], and 5% for PFHxA [F(CF(2))(5)COOH]. The overall mass balance in aerobic soil was approximately 67% (day 180). At day 180, the major terminal metabolites were PFPeA, [F(CF(2))(4)COOH, 30%], PFHxA (8%), PFBA [F(CF(2))(3)COOH, 2%], and 5-3 acid (15%). A new metabolite 4-3 acid [F(CF(2))(4)CH(2)CH(2)COOH] accounted for 1%, 6-2 FTOH for 3%, and 5-2 sFTOH for 7%. Based on 8-2 FTOH aerobic biodegradation pathways, PFHxA was expected in greatest yield from 6-2 FTOH degradation. However, PFPeA was observed in greatest yield in soil, suggesting a preference for alternate degradation pathways. Selected metabolites were also studied in aerobic soil. 5-3 Acid degraded to only 4-3 acid with a molar yield of 2.3%. 5-2 sFTOH degraded to PFPeA and PFHxA, and 5-2 FT Ketone [F(CF(2))(5)COCH(3)] degraded to 5-2 sFTOH, suggesting that 5-2 sFTOH is the direct precursor to PFPeA and PFHxA. Another new metabolite, 5-3 ketone aldehyde [F(CF(2))(5)COCH(2)CHO] was also identified in mixed bacterial culture. The formation of PFBA, PFPeA, and 4-3 acid indicates that multiple -CF(2)- groups in 6-2 FTOH were removed during microbial biodegradation.
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