The sorption and desorption behaviors of two perfluoroalkane sulfonates（PFSAs）, including perfluorohexane sulfonate（PFHx S） and perfluorooctane sulfonate（PFOS） on two humic acids（HAs） and humin（HM）, which we...The sorption and desorption behaviors of two perfluoroalkane sulfonates（PFSAs）, including perfluorohexane sulfonate（PFHx S） and perfluorooctane sulfonate（PFOS） on two humic acids（HAs） and humin（HM）, which were extracted from a peat soil, were investigated. The sorption kinetics and isotherms showed that the sorption of PFOS on the humic substances（HSs） was much higher than PFHx S. For the same PFSA compound, the sorption on HSs followed the order of HM 〉 HA2 〉 HA1. These suggest that hydrophobic interaction plays a key role in the sorption of PFSAs on HSs. The sorption capacities of PFSAs on HSs were significantly related to their aliphaticity, but negatively correlated to aromatic carbons,indicating the importance of aliphatic groups in the sorption of PFSAs. Compared to PFOS,PFHx S displayed distinct desorption hysteresis, probably due to irreversible pore deformation after sorption of PFHx S. The sorption of the two PFSAs on HSs decreased with an increase in p H in the solution. This is ascribed to the electrostatic interaction and hydrogen bonding at lower p H. Hydrophobic interaction might also be stronger at lower p H due to the aggregation of HSs.展开更多
Monodisperse graphene oxide （GO） microspheres were synthesized via microfluidics technology as a novel adsorbent for rapid （in 2 rain） and high efficiency （98%） removal of perfluorooctane sulfonate （PFOS） from...Monodisperse graphene oxide （GO） microspheres were synthesized via microfluidics technology as a novel adsorbent for rapid （in 2 rain） and high efficiency （98%） removal of perfluorooctane sulfonate （PFOS） from water. This novel material is a potential solution for treatment of bioaccumulative organic polluted water. To achieve improved performance, Mg2＋ was introduced into GO, and the metal composite exhibited significantly improved PFOS removal effidency owing to bridging and interaction between Mg~＋ and the PFOS molecules, which was supported by density functional theory and X-ray photoelectron spectroscopy （XPS）. This facile strategy may be extended to the synthesis of other spheres with unique structural features for application in water treatment.展开更多
Perfluorooctane sulfonate(PFOS),as a potential persistent organic pollutant,has been widely detected in water environments,and has become a great concern in recent years.PFOS is very stable and difficult to decompose ...Perfluorooctane sulfonate(PFOS),as a potential persistent organic pollutant,has been widely detected in water environments,and has become a great concern in recent years.PFOS is very stable and difficult to decompose using conventional techniques.Sorption may be an attractive method to remove it from water.In this study,the molecularly imprinted polymer(MIP)adsorbents were prepared through the polymerization of 4-vinylpyridine under different preparation conditions in order to remove perfluorooctane sulfonate(PFOS)from water.The MIP adsorbents using perfluorooctanoic acid(PFOA)as the template had good imprinting effects and could selectively remove PFOS from aqueous solution.The sorption behaviors including sorption kinetics,isotherms,and effect of pH,salt,and competitive anions were investigated.Experimental results showed that the sorption of PFOS on the MIP adsorbents was very fast,pHdependent,and highly selective.The achieved fast sorption equilibrium within 1 h was attributed to the surface sorption on the fine adsorbents.The sorption isotherms showed that the sorption selectivity of PFOS on the MIP adsorbents decreased at high PFOS concentrations,which may be due to the double-layer sorption and the formation of PFOS micelles on the sorbent surface.The sorption of PFOS on the MIP adsorbents was mainly dominated by the electrostatic interaction between the protonated vinylpyridine on the adsorbent surface and the anionic PFOS.The prepared MIP adsorbents can potentially be applied in water and wastewater treatment for selective removal of PFOS.展开更多
Perfluorooctane sulfonate（PFOS） had wide applications,such as in the electroplating industry,but its use was restricted in 2009 by the Stockholm Convention,due to its environmental persistence and potential hazards....Perfluorooctane sulfonate（PFOS） had wide applications,such as in the electroplating industry,but its use was restricted in 2009 by the Stockholm Convention,due to its environmental persistence and potential hazards.As the most common PFOS alternative,lH,lH,2H,2H-perfluorooctane sulfonic acid（6：2FTS） and its salts have been increasingly used.However,little is known about its photochemical decomposition.This paper reports the ferric ion-induced efficient decomposition and defluorination of 6：2FTS under 254 nm ultraviolet（UV） irradiation;the underlying mechanisms were also investigated.In the presence of 100 ｜imol/L ferric ion and at pH 3.0,the first-order decomposition rate constant of 6：2FTS（10 mg/L） was 1.59/hr,which was 6 times higher than for direct UV photolysis.The effects of the ferric ion concentration and the solution pH on the 6：2FTS photodecomposition were investigated and the optimal reaction conditions were determined.In addition to fluoride and sulfate ions,shorter-chain PFCAs（C2-C7） were detected as major intermediates.The addition of hydrogen peroxide or oxalic acid accelerated the decomposition of 6：2FTS under UV irradiation,but not its defluorination,indicating that hydroxyl radicals can directly react with 6：2FTS but not with the shorter-chain PFCAs.Accordingly,a mechanism for 6：2FTS photochemical decomposition in the presence of ferric ion was proposed,which comprises two reaction pathways.First,hydroxyl radicals can directly attack 6：2FTS,leading to C- C bond cleavage.Alternatively,6：2FTS coordinates with ferric ion to form Fe（III）-6：2FTS complexes,which can undergo ligand-to-metal charge transfer under UV irradiation,causing C-S bond cleavage.展开更多
Environmental contamination resulting from the production or release of harmful chemicals can lead to negative consequences for wildlife and human health. Perfluorinated alkyl acids（PFAAs） were historically produced...Environmental contamination resulting from the production or release of harmful chemicals can lead to negative consequences for wildlife and human health. Perfluorinated alkyl acids（PFAAs） were historically produced as protective coatings for many household items and currently persist in the environment, wildlife, and humans. PFAAs have been linked to immune suppression, endocrine disruption, and developmental toxicity in wildlife and laboratory studies. This study examines the American alligator, Alligator mississippiensis,as an important indicator of ecosystem contamination and a potential pathway for PFAA exposure in humans. Alligator meat harvested in the 2015 South Carolina（SC） public hunt season and prepared for human consumption was collected and analyzed for PFAAs to determine meat concentrations and relationships with animal body size（total length）, sex, and location of harvest. Of the 15 PFAAs analyzed, perfluorooctane sulfonate（PFOS） was found in all alligator meat samples and at the highest concentrations（median 6.73 ng/g）. No relationship was found between PFAA concentrations and total length or sex.Concentrations of one or all compounds varied significantly across sampling locations, with alligators harvested in the Middle Coastal hunt unit having the highest PFOS concentrations（median 16.0 ng/g; p = 0.0001）. Alligators harvested specifically from Berkley County, SC（located in the Middle Coastal hunt unit） had the highest PFOS concentrations and the greatest number of PFAAs detected（p 〈 0.0001）. The site-specific nature of PFAA concentrations in alligator meat observed in this study suggests a source of PFAA contamination in Berkley County, SC.展开更多
The distribution of polyfluoroalkyl compounds(PFCs)in the dissolved and particulate phase and their discharge from the river Elbe into the North Sea were studied.The PFCs quantified included C_(4)-C_(8) perfluorinated...The distribution of polyfluoroalkyl compounds(PFCs)in the dissolved and particulate phase and their discharge from the river Elbe into the North Sea were studied.The PFCs quantified included C_(4)-C_(8) perfluorinated sulfonates(PFSAs),6∶2 fluorotelomer sulfonate(6∶2 FTS),C_(6) and C_(8) perfluorinated sulfinates(PFSiAs),C_(4)-C_(12) perfluorinated carboxylic acids(PFCAs),perfluoro-3,7-dimethyl-octanoic acid(3,7m_(2)-PFOA),perfluorooctane sulfonamide(FOSA),and n-ethyl perfluroctane sulfonamidoethanol(EtFOSE).PFCs were mostly distributed in the dissolved phase,where perfluorooctanoic acid(PFOA)dominated with 2.9–12.5 ng/L.In the suspended particulate matter FOSA and perfluorooctane sulfonate(PFOS)showed the highest concentrations(4.0 ng/L and 2.3 ng/L,respectively).The total flux ofΣPFCs from the river Elbe was estimated to be 802 kg/year for the dissolved phase and 152 kg/year for the particulate phase.This indicates that the river Elbe acts as a source of PFCs into the North Sea.However,the concentrations of perfluorobutane sulfonate(PFBS)and perfluorobutanoic acid(PFBA)in the North Sea were higher than that in the river Elbe,thus an alternative source must exist for these compounds.展开更多
With quantitative conversion to volatile derivatives,substance such as perfluorooctane sulfonate(PFOS)that is difficult to analyze can be separated by conventional techniques and then be characterized.In this paper,th...With quantitative conversion to volatile derivatives,substance such as perfluorooctane sulfonate(PFOS)that is difficult to analyze can be separated by conventional techniques and then be characterized.In this paper,the methods and procedures in which perfluorooctane sulfonic acids were converted to corresponding sulfonic ester by reaction with triethylorthoacetate(TEOA)in the presence of solvent were described,and then PFOS was analyzed as ethyl ester derivatives.Mass spectra(MS)were generated using electron ionization(EI)mode.And the EI spectra of the volatile derivatives show ions characteristic of both the fluorinated hydrocarbon and the sulfonic ester portion of the molecules.展开更多
Improving the technical performance of related industrial products is an efficient strategy to reducing the application quantities and environmental burden for toxic chemicals.A novel polyfluoroalkyl surfactant potass...Improving the technical performance of related industrial products is an efficient strategy to reducing the application quantities and environmental burden for toxic chemicals.A novel polyfluoroalkyl surfactant potassium 1,1,2,2,3,3,4,4-octafluoro-4-(perfluorobutoxy)butane-1-sulfonate(F404)was synthesized by a commercializable route.It had a surface tension(γ)of 18.2 mN/m at the critical micelle concentration(CMC,1.04 g/L),significantly lower than that of perfluorooctane sulfonate(PFOS,ca.33.0 mN/m,0.72 g/L),and exhibited remarkable suppression of chromium-fog at a dose half that of PFOS.The half maximal inhibitory concentration(IC_(50))values in HepG2 cells and the lethal concentration of 50%(LC_(50))in zebrafish embryos after 72 hpf indicated a lower toxicity for F404 in comparison to PFOS.In a UV/sulphite system,89.3%of F404 were decomposed after 3 h,representing a defluorination efficiency of 43%.The cleavage of the ether C—O bond during the decomposition would be expected to form a short chain·C_(4)F_(9) as the position of the ether C—O in the F404 fluorocarbon chains is C4—O5.The ether unit is introduced in the perfluoroalkyl chain to improve water solubility,biocompatibility and degradation,thereby minimizing the environmental burden.展开更多
基金support of Chinese Natural Science Foundation(No.21277077,21325730)Ministry of Education(No.20130031130005)+1 种基金Ministry of Science and Technology(No.2012ZX07529-003)Ministry of Education Innovation Team(IRT 13024)
文摘The sorption and desorption behaviors of two perfluoroalkane sulfonates（PFSAs）, including perfluorohexane sulfonate（PFHx S） and perfluorooctane sulfonate（PFOS） on two humic acids（HAs） and humin（HM）, which were extracted from a peat soil, were investigated. The sorption kinetics and isotherms showed that the sorption of PFOS on the humic substances（HSs） was much higher than PFHx S. For the same PFSA compound, the sorption on HSs followed the order of HM 〉 HA2 〉 HA1. These suggest that hydrophobic interaction plays a key role in the sorption of PFSAs on HSs. The sorption capacities of PFSAs on HSs were significantly related to their aliphaticity, but negatively correlated to aromatic carbons,indicating the importance of aliphatic groups in the sorption of PFSAs. Compared to PFOS,PFHx S displayed distinct desorption hysteresis, probably due to irreversible pore deformation after sorption of PFHx S. The sorption of the two PFSAs on HSs decreased with an increase in p H in the solution. This is ascribed to the electrostatic interaction and hydrogen bonding at lower p H. Hydrophobic interaction might also be stronger at lower p H due to the aggregation of HSs.
文摘Monodisperse graphene oxide （GO） microspheres were synthesized via microfluidics technology as a novel adsorbent for rapid （in 2 rain） and high efficiency （98%） removal of perfluorooctane sulfonate （PFOS） from water. This novel material is a potential solution for treatment of bioaccumulative organic polluted water. To achieve improved performance, Mg2＋ was introduced into GO, and the metal composite exhibited significantly improved PFOS removal effidency owing to bridging and interaction between Mg~＋ and the PFOS molecules, which was supported by density functional theory and X-ray photoelectron spectroscopy （XPS）. This facile strategy may be extended to the synthesis of other spheres with unique structural features for application in water treatment.
基金This work was supported by the National Natural Science Foundation of China(Grant No.50608045)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution(Grant No.08Z04ESPCT)the National Outstanding Youth Foundation of China(Grant No.50625823).
文摘Perfluorooctane sulfonate(PFOS),as a potential persistent organic pollutant,has been widely detected in water environments,and has become a great concern in recent years.PFOS is very stable and difficult to decompose using conventional techniques.Sorption may be an attractive method to remove it from water.In this study,the molecularly imprinted polymer(MIP)adsorbents were prepared through the polymerization of 4-vinylpyridine under different preparation conditions in order to remove perfluorooctane sulfonate(PFOS)from water.The MIP adsorbents using perfluorooctanoic acid(PFOA)as the template had good imprinting effects and could selectively remove PFOS from aqueous solution.The sorption behaviors including sorption kinetics,isotherms,and effect of pH,salt,and competitive anions were investigated.Experimental results showed that the sorption of PFOS on the MIP adsorbents was very fast,pHdependent,and highly selective.The achieved fast sorption equilibrium within 1 h was attributed to the surface sorption on the fine adsorbents.The sorption isotherms showed that the sorption selectivity of PFOS on the MIP adsorbents decreased at high PFOS concentrations,which may be due to the double-layer sorption and the formation of PFOS micelles on the sorbent surface.The sorption of PFOS on the MIP adsorbents was mainly dominated by the electrostatic interaction between the protonated vinylpyridine on the adsorbent surface and the anionic PFOS.The prepared MIP adsorbents can potentially be applied in water and wastewater treatment for selective removal of PFOS.
基金supported by the National Natural Science Foundation of China(Nos.21221004,21177071)the National Basic Research Program of China(No.2013CB632403)the Collaborative Innovation Center for Regional Environmental Quality
文摘Perfluorooctane sulfonate（PFOS） had wide applications,such as in the electroplating industry,but its use was restricted in 2009 by the Stockholm Convention,due to its environmental persistence and potential hazards.As the most common PFOS alternative,lH,lH,2H,2H-perfluorooctane sulfonic acid（6：2FTS） and its salts have been increasingly used.However,little is known about its photochemical decomposition.This paper reports the ferric ion-induced efficient decomposition and defluorination of 6：2FTS under 254 nm ultraviolet（UV） irradiation;the underlying mechanisms were also investigated.In the presence of 100 ｜imol/L ferric ion and at pH 3.0,the first-order decomposition rate constant of 6：2FTS（10 mg/L） was 1.59/hr,which was 6 times higher than for direct UV photolysis.The effects of the ferric ion concentration and the solution pH on the 6：2FTS photodecomposition were investigated and the optimal reaction conditions were determined.In addition to fluoride and sulfate ions,shorter-chain PFCAs（C2-C7） were detected as major intermediates.The addition of hydrogen peroxide or oxalic acid accelerated the decomposition of 6：2FTS under UV irradiation,but not its defluorination,indicating that hydroxyl radicals can directly react with 6：2FTS but not with the shorter-chain PFCAs.Accordingly,a mechanism for 6：2FTS photochemical decomposition in the presence of ferric ion was proposed,which comprises two reaction pathways.First,hydroxyl radicals can directly attack 6：2FTS,leading to C- C bond cleavage.Alternatively,6：2FTS coordinates with ferric ion to form Fe（III）-6：2FTS complexes,which can undergo ligand-to-metal charge transfer under UV irradiation,causing C-S bond cleavage.
基金the Graduate School at the College of Charlestonrepresents Technical Contribution No.6542 of the Clemson University Experiment Station
文摘Environmental contamination resulting from the production or release of harmful chemicals can lead to negative consequences for wildlife and human health. Perfluorinated alkyl acids（PFAAs） were historically produced as protective coatings for many household items and currently persist in the environment, wildlife, and humans. PFAAs have been linked to immune suppression, endocrine disruption, and developmental toxicity in wildlife and laboratory studies. This study examines the American alligator, Alligator mississippiensis,as an important indicator of ecosystem contamination and a potential pathway for PFAA exposure in humans. Alligator meat harvested in the 2015 South Carolina（SC） public hunt season and prepared for human consumption was collected and analyzed for PFAAs to determine meat concentrations and relationships with animal body size（total length）, sex, and location of harvest. Of the 15 PFAAs analyzed, perfluorooctane sulfonate（PFOS） was found in all alligator meat samples and at the highest concentrations（median 6.73 ng/g）. No relationship was found between PFAA concentrations and total length or sex.Concentrations of one or all compounds varied significantly across sampling locations, with alligators harvested in the Middle Coastal hunt unit having the highest PFOS concentrations（median 16.0 ng/g; p = 0.0001）. Alligators harvested specifically from Berkley County, SC（located in the Middle Coastal hunt unit） had the highest PFOS concentrations and the greatest number of PFAAs detected（p 〈 0.0001）. The site-specific nature of PFAA concentrations in alligator meat observed in this study suggests a source of PFAA contamination in Berkley County, SC.
基金the German Federal Environmental Foundation for sponsoring the project.
文摘The distribution of polyfluoroalkyl compounds(PFCs)in the dissolved and particulate phase and their discharge from the river Elbe into the North Sea were studied.The PFCs quantified included C_(4)-C_(8) perfluorinated sulfonates(PFSAs),6∶2 fluorotelomer sulfonate(6∶2 FTS),C_(6) and C_(8) perfluorinated sulfinates(PFSiAs),C_(4)-C_(12) perfluorinated carboxylic acids(PFCAs),perfluoro-3,7-dimethyl-octanoic acid(3,7m_(2)-PFOA),perfluorooctane sulfonamide(FOSA),and n-ethyl perfluroctane sulfonamidoethanol(EtFOSE).PFCs were mostly distributed in the dissolved phase,where perfluorooctanoic acid(PFOA)dominated with 2.9–12.5 ng/L.In the suspended particulate matter FOSA and perfluorooctane sulfonate(PFOS)showed the highest concentrations(4.0 ng/L and 2.3 ng/L,respectively).The total flux ofΣPFCs from the river Elbe was estimated to be 802 kg/year for the dissolved phase and 152 kg/year for the particulate phase.This indicates that the river Elbe acts as a source of PFCs into the North Sea.However,the concentrations of perfluorobutane sulfonate(PFBS)and perfluorobutanoic acid(PFBA)in the North Sea were higher than that in the river Elbe,thus an alternative source must exist for these compounds.
基金Shanghai Municipal Bureau of Quality and Technical Supervision,China(No.09TBT017)
文摘With quantitative conversion to volatile derivatives,substance such as perfluorooctane sulfonate(PFOS)that is difficult to analyze can be separated by conventional techniques and then be characterized.In this paper,the methods and procedures in which perfluorooctane sulfonic acids were converted to corresponding sulfonic ester by reaction with triethylorthoacetate(TEOA)in the presence of solvent were described,and then PFOS was analyzed as ethyl ester derivatives.Mass spectra(MS)were generated using electron ionization(EI)mode.And the EI spectra of the volatile derivatives show ions characteristic of both the fluorinated hydrocarbon and the sulfonic ester portion of the molecules.
基金supported by the National Natural Science Foundation of China(Nos.21707049,21507044,21806058,21906069,21477049)the China Postdoctoral Science Foundation(No.2019M660185).
文摘Improving the technical performance of related industrial products is an efficient strategy to reducing the application quantities and environmental burden for toxic chemicals.A novel polyfluoroalkyl surfactant potassium 1,1,2,2,3,3,4,4-octafluoro-4-(perfluorobutoxy)butane-1-sulfonate(F404)was synthesized by a commercializable route.It had a surface tension(γ)of 18.2 mN/m at the critical micelle concentration(CMC,1.04 g/L),significantly lower than that of perfluorooctane sulfonate(PFOS,ca.33.0 mN/m,0.72 g/L),and exhibited remarkable suppression of chromium-fog at a dose half that of PFOS.The half maximal inhibitory concentration(IC_(50))values in HepG2 cells and the lethal concentration of 50%(LC_(50))in zebrafish embryos after 72 hpf indicated a lower toxicity for F404 in comparison to PFOS.In a UV/sulphite system,89.3%of F404 were decomposed after 3 h,representing a defluorination efficiency of 43%.The cleavage of the ether C—O bond during the decomposition would be expected to form a short chain·C_(4)F_(9) as the position of the ether C—O in the F404 fluorocarbon chains is C4—O5.The ether unit is introduced in the perfluoroalkyl chain to improve water solubility,biocompatibility and degradation,thereby minimizing the environmental burden.
