Species dependent accumulation and transformation of 8:2 polyfluoroalkyl phosphate esters in sediment by three benthic organisms

Sediment is a major sink for 8:2 polyfluoroalkyl phosphate diester (8:2 diPAP) in the environment. In the present study, three representative benthic organisms, including carp (Cyrinus carpio), loach (Misgurnus anguillicaudatus) and worm (Limnodrilus hoffmeisteri), were exposed to 8:2 diPAP spiked sediment at 300 ng g(-1). 8:2 diPAP in the sediment was bioavailable to carp, loach and worm even though the biota-sediment accumulation factors (BSAFs) (0.137, 0.0273, 0.413 g g(-1), respectively) were relatively low due to its large molecular weight and high log K-OW value. The worm displayed the greatest enrichment ability among the three species, implying the utility of using worm as a bio-indicator of 8:2 diPAP pollution in sediment. The biotransformation products (e.g. 8:2 FTUCA and 7:3 FTCA) were detected in all the three species, suggesting that they had the ability to transform 8:2 diPAP. Loach displayed the strongest metabolism capacity while worm displayed the weakest. Transformation of 8:2 diPAP also took place in the sediment by microorganisms. Notably, the concentration ratio of 7:3 FTCA and 8:2 FTUCA in the sediment was much lower than that in benthic organisms, suggesting that the aquatic benthic organisms and microorganisms had different transformation activities and mechanisms.