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a b s t r a c tFe 3 O 4 magnetic nanoparticles (MNPs) with diameters about 10 nm were synthesized successfully and used to remove phenol and aniline from aqueous solution. The results showed that phenol and aniline could be eliminated easily from solution under acidic and neutral conditions in the presence of MNPs and H 2 O 2 . When the concentrations of Fe 3 O 4 MNPs and H 2 O 2 were 5 g L −1 and 1.2 M, respectively, phenol and aniline could be removed completely after 6 h of reaction at 308 K, and the total organic carbon (TOC) abatement efficiency for phenol and aniline were 42.79% and 40.38%. Some intermediates such as formic acid, acetic acid, fumaric acid and hydroquinone were detected during reaction. Fe 3 O 4 MNPs exhibited good stability and reusability, also showed excellent catalysis ability to eliminate some substituted phenolic and aniline compounds from solution. Fe 3 O 4 MNPs had good superparamagnetism and was readily separated from solution by applying an external magnetic field. Finally we proposed that phenol and aniline might be degraded by the hydroxyl free radicals (·OH) released from H 2 O 2 in the presence of Fe 3 O 4 MNPs as catalysts.

ABSTRACT:The incomplete mass-balance of organic fluorine in human serum indicates the existence of unknown per-and polyfluoroalkyl substances (PFASs) with persistent and bioaccumulative properties. Here we characterized human exposure and elimination kinetics of chlorinated polyfluoroalkyl ether sulfonic acids (Cl-PFESAs) in metal plating workers (n = 19), high fish consumers (n = 45), and background controls (n = 8). Cl-PFESAs were detected in >98% of the sampled individuals with serum concentrations ranging <0.019−5040 ng/mL. Statistically higher median serum levels were observed in high fish consumers (93.7 ng/mL) and metal plating workers (51.5 ng/mL) compared to the background control group (4.78 ng/mL) (Kruskal−Wallis rank sum test, p < 0.01). Cl-PFESAs could account for 0.269 to 93.3% of ∑PFASs in human serum indicating that this compound class may explain a substantial fraction of previously unidentified organic fluorine in the Chinese population. Estimated half-lives for renal clearance (median 280 years; range 7.1−4230 years) and total elimination (median 15.3 years; range 10.1−56.4 years) for the eight carbon Cl-PFESA suggest that this is the most biopersistent PFAS in humans reported to date. The apparent ubiquitous distribution and slow elimination kinetics in humans underscore the need for more research and regulatory actions on Cl-PFESAs and PFAS alternatives with similar chemical structures.