Levels and occurrence of legacy and emerging poly-and perfluoroalkyl substances in ship sewage and ballast water
In order to study the effects of Per-and polyfluoroalkyl substances(PFASs)and their emerging alternatives in ballast water and domestic wastewater of ships on the pollution of PFASs in the marine environment,systematically collected 56samples of black water,grey water,black and grey mixed water,and ballast water from 46ships in 16 ports and analyzed 17 traditional PFASs and 2 novel alternatives in these samples.The concentration of ∑PFASs in the ballast water of the ships ranged from 45.6~97.4ng/L;the concentration of ∑PFASs in the domestic sewage of ships ranged from 24~14681ng/L,and the highest concentration of ∑PFASs appeared in grey water samples.There was no significant difference in the content and assignment of PFASs between different types of ships.Among the traditional PFASs,perfluorooctanoic acid(PFOA)and perfluorobutane sulfonic acid(PFBS)were the compounds with higher percentages in most of the samples;and among the newer alternatives,the concentration of sodium perfluorononenoyloxy benzene sulfonate(OBS)was relatively high,the frequency of 6∶2 chlorinated polyfluorinated ether sulfonate(6∶2Cl-PFESA)was less frequently detected.The higher concentration of EPFASs in the treated marine sewage than in the untreated was attributed to the conversion of precursors to PFASs in the treatment process of sewage of ships.