Sorption and desorption of perfluorooctane sulfonate (PFOS) on humic acid at different temperatures were studied. It was found that the sorption process could be modeled with power kinetic equation very well, sugges...Sorption and desorption of perfluorooctane sulfonate (PFOS) on humic acid at different temperatures were studied. It was found that the sorption process could be modeled with power kinetic equation very well, suggesting that diflusion predominated the sorption of PFOS on the humic acid. The sorption capacity was doubled when the temperature increased from 5 to 35°C, and thermodynamics parameters △G0 was calculated to be –7.11 to –5.04 kJ/mol, △H0 was 14.2 kJ/mol, and △S 0 was 69.5 J/(mol·K), indicating that the sorption was a spontaneous, endothermic, and entropy driven process. Desorption hysteresis occurred at all studied temperatures which suggested that humic acid may be an important sink of PFOS in the environment.展开更多
In order to study toxicological effects of perfluorononanoic acid (PFNA), perfluorooctane sulfonate (PFOS), and their mixtures (PFNA/ PFOS) on Daphnia magna (D. magna), a suite of comprehensive toxicity tests ...In order to study toxicological effects of perfluorononanoic acid (PFNA), perfluorooctane sulfonate (PFOS), and their mixtures (PFNA/ PFOS) on Daphnia magna (D. magna), a suite of comprehensive toxicity tests were conducted, including a 48-h acute toxicity test, a 21-day chronic test, a feeding experiment, and a biomarker assay. D. magna were exposed to aqueous solutions of PFNA and PFOS (alone and in combination) at concentrations ranging from 0.008 to 5 mg/L. The survival, growth, and reproduction of D. magna were monitored over a 21- day life cycle. The biomarkers, including acetylcholinesterase (ACHE), superoxide dismutase (SOD), and catalase (CAT) activities, were determined after seven days of exposure. PFOS was more toxic than PFNA based on the results of the acute toxicity test. Perfluorinated compounds (PFCs) inhibited both growth and reproduction of D. magna during the testing period. The ingestion rates and the biomarkers, including ACHE, SOD, and CAT activities, were significantly inhibited by PFCs in most cases. Moreover, the combined effects related to the growth and reproduction showed the antagonistic effects of PFCs.展开更多
AIM: To investigate changes in the rabbit retina after shortterm and small amounts tamponade of perfluorooctane(PFO).METHODS: New Zealand rabbits were used, and 48 eyes were randomly and evenly assigned into four diff...AIM: To investigate changes in the rabbit retina after shortterm and small amounts tamponade of perfluorooctane(PFO).METHODS: New Zealand rabbits were used, and 48 eyes were randomly and evenly assigned into four different groups. The PFO groups received a residue of 0.1 mL of PFO for ophthalmic surgery or 0.1 mL of F-Octane at the end of surgery; eyes from the pars plana vitrectomy(PPV) group were filled with balanced salt solution and those having not received surgical intervention served as controls. Eyes were collected at 1, 4 and 12 wk and studied.RESULTS: Under a microscope, nuclear counts of the inner nuclear layer(INL) and outer nuclear layer(ONL) did not differ among the four groups at all time points; however, slight disarrangement of the ONL and occasional vacuolization of the INL were found in the inferior retina only at 12 wk in two PFO groups. Four of the groups had similar results of Caspase-3 and TNF-α staining at all time points. Alternatively, IL-8 was increased in PFOa and PPV control groups at 4 wk and in all three PPV groups at 12 wk; also, the apoptotic index(%) was similarly increased in all three PPV groups at 4 and 12 wk.CONCLUSION: Both PFOs are well tolerated in rabbit eyes for up to 12 wk, which suggests that they can be used safely as intraoperative tools or for short-term and small amounts tamponade after surgery.展开更多
Perfluorooctane sulfonate (PFOS) is a class of stable organic compounds with wide industrial,commercial, and consumer applications, such as in textiles, paper, pesticides, and shampoos;. It is readily absorbed, but ...Perfluorooctane sulfonate (PFOS) is a class of stable organic compounds with wide industrial,commercial, and consumer applications, such as in textiles, paper, pesticides, and shampoos;. It is readily absorbed, but poorly eliminated, with the elimination half-life of approximately 5 years;.Hence, there have been concerns regarding its potential damage to human health. Some studies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
Persistent perfluorinated organic compounds, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are used in a variety of industrial applications. They are very stable in the environment, distribute...Persistent perfluorinated organic compounds, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are used in a variety of industrial applications. They are very stable in the environment, distribute widely in the global environment and in wild life, and are detected in human sera. Our searches have detected ppt levels of PFOS and PFOA in the surface water of Japan and China; their levels are generally more than ten times higher in city areas. Neither PFOS nor PFOA is removed by the purification process of city water. Both PFOS and PFOA are detected in sera of all the people of Japan and China (about 1000 times as high as those in surface water), and their concentrations are increasing in both countries, especially in China. PFOS and PFOA primarily distribute to the liver and cause the liver toxicity. They also cause developmental toxicity. PFOS which is not genotoxic in a variety of assay system including our in vivo comet assay, induced tumors of the liver, thyroid and mammary gland of rats. PFOA which is weakly carcinogenic is not mutagenic in many studies including our in vivo comet assay.展开更多
Because the widely used perfluorooctane sulfonate(PFOS) is harmful to both environment and human health, it is of great significance and urgency to develop sensitive and selective sensors for the detection of trace PF...Because the widely used perfluorooctane sulfonate(PFOS) is harmful to both environment and human health, it is of great significance and urgency to develop sensitive and selective sensors for the detection of trace PFOS in water. In this study, a tetraphenylethylene-derived macrocycle Bowtie Cyclophane has been developed as a fluorescent sensor based on aggregation-induced emission enhancement and fluorochromism. Sensitive detection of PFOS has been achieved with a limit of detection(LOD) of47.3 ± 2.0 nmol/L(25.4 ± 1.1 μg/L) accompanied by visual fluorescence color changes.展开更多
Per-and polyfluoroalkyl substances(PFASs)can be taken up and bioaccumulated in plants,but the toxic mechanisms of PFASs on wetland plants are still unclear.In present study,the toxic influences of perfluorooctane sulf...Per-and polyfluoroalkyl substances(PFASs)can be taken up and bioaccumulated in plants,but the toxic mechanisms of PFASs on wetland plants are still unclear.In present study,the toxic influences of perfluorooctane sulfonate(PFOS)on Eichhornia crassipes(E.crassipes)and Cy perus alternifolius(C.alternifolius)in a vertical-sub surface-flow constructed wetland were evaluated.The results showed that E.crassipes was more tolerant to PFOS stress than C.alternifolius,and the growth and chlorophyll synthesis of the two plants were promoted by low concentration(<0.1 mg/L)of PFOS,and the chlorophyll synthesis was inhibited by high concentration(10 mg/L)of PFOS but the growth did not change obviously.The catalase activity and malondialdehyde content in the leaves of the two plants increased,peroxidase activity decreased under exposure to high concentrations of PFOS,and superoxide dismutase activity did not change.Under PFOS stress,the membrane of plant leaves and the cell structure of the two wetland plants were destroyed,and the mitochondrial contour of root cells became incomplete.Tanscriptomic analysis showed that the expression levels of genes related to cell wall formation,the cell apoptosis pathway,material synthesis,and metabolism in the plants were changed by PFOS.Analysis in fluorogenic quantitative real time polymerase chain reaction(RT-qPCR)also confirmed that the photosynthesis system of E.crassipes was inhibited,while that of C.alternifolius was promoted.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
A vertical-flow constructed wetland(VFCW)was used to treat simulated domestic sewage containing perfluorooctane sulfonate(PFOS).The removal rate of PFOS in the domestic sewage was 93%–98%,through soil adsorption and ...A vertical-flow constructed wetland(VFCW)was used to treat simulated domestic sewage containing perfluorooctane sulfonate(PFOS).The removal rate of PFOS in the domestic sewage was 93%–98%,through soil adsorption and plant uptake,suggesting that VFCWs can remove PFOS efficiently from wastewater.The removal of PFOS in the VFCW was dependent on soil adsorption and plant uptake;moreover,the percentage of soil adsorption was 61%–89%,and was higher than that of the plants uptake(5%–31%).The absorption capacity of Eichhornia crassipes(E.crassipes)(1186.71 mg/kg)was higher than that of Cyperus alternifolius(C.alternifolius)(162.77 mg/kg)under 10 mg/L PFOS,and the transfer factor of PFOS in E.crassipes and C.alternifolius was 0.04 and 0.58,respectively,indicating that PFOS is not easily translocated to leaves from roots of wetland plants;moreover,uptake of PFOS by E.crassipes was more than that of C.alternifolius because the biomass of E.crassipes was more than that of C.alternifolius and the roots of E.crassipes can take up PFOS directly from wastewater while C.alternifolius needs to do so via its roots in the soil.The concentration of 10 mg/L PFOS had an obvious inhibitory effect on the removal rate of total nitrogen,total phosphorus,chemical oxygen demand,and ammonia nitrogen in the VFCW,which decreased by 15%,10%,10%and 12%,respectively.Dosing with PFOS in the wastewater reduced the bacterial richness but increased the diversity in soil because PFOS stimulated the growth of PFOS-tolerant strains.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
Per-and polyfluoroalkyl substances(PFAS)are found to have multiple adverse outcomes on human health.Recently,epidemiological and toxicological studies showed that exposure to PFAS had adverse impacts on pancreas and s...Per-and polyfluoroalkyl substances(PFAS)are found to have multiple adverse outcomes on human health.Recently,epidemiological and toxicological studies showed that exposure to PFAS had adverse impacts on pancreas and showed association with insulin abnormalities.To explore how PFAS may contribute to diabetes,we studied impacts of perfluorooctane sul-fonate(PFOS)on cell viability and insulin release capacity of pancreatic β cells by using in vivo and in vitro methods.We found that 28-day administration with PFOS(10 mg/(kg body weight·day))caused reductions of pancreas weight and islet size in male mice.PFOS admin-istration also led to lower serum insulin level both in fasting state and after glucose infusion among male mice.For cell-based in vitro bioassay,we used mouse β-TC-6 cancer cells and found 48-hr exposure to PFOS decreased the cell viability at 50 μmol/L.By measuring insulin content in supernatant,48-hr pretreatment of PFOS(100 μmol/L)decreased the insulin re-lease capacity of β-TC-6 cells after glucose stimulation.Although these concentrations were higher than the environmental concentration of PFOS,it might be reasonable for high con-centration of PFOS to exert observable toxic effects in mice considering mice had a faster removal efficiency of PFOS than human.PFOS exposure(50 μmol/L)to β-TC-6 cells induced intracellular accumulation of reactive oxidative specie(ROS).Excessive ROS induced the re-active toxicity of cells,which eventually invoke apoptosis and necrosis.Results in this study provide evidence for the possible causal link of exposure to PFOS and diabetes risk.展开更多
Perfluorooctane sulfonate(PFOS)is a persistent organic pollutant(POP)and emergent contaminant that are widespread in the environment.Understanding the mechanisms controlling the distribution of PFOS and its isomers be...Perfluorooctane sulfonate(PFOS)is a persistent organic pollutant(POP)and emergent contaminant that are widespread in the environment.Understanding the mechanisms controlling the distribution of PFOS and its isomers between hydrargillite and the water phase is important in order to study their redistribution and mobility in the environment.This study investigated the effects of pH,humic acid,fulvic acid and Na_(2)SO_(4) on sorption of PFOS isomers to hydrargillite.A mixture of PFOS isomers was spiked into water and hydrargillite was added to the system and shaken for one day;the system was tested with different aqueous composition.Concentrations of PFOS isomers in the aqueous phase were quantified using an ultra-performance liquid chromatograph coupled to a triple quadrupole mass spectrometer.Our results showed that the distribution coefficients of PFOS isomers were found to be 0.76,0.71,0.93 and 0.90 at pH 6.5,for 3-/4-/5-PFOS,6-/2-PFOS,L-PFOS and total PFOS respectively.The distribution coefficients increased at lower pH and decreased at alkaline conditions.The presence of humic substances(HS)increased the sorption slightly at the environmental pH of 6.5,although a competition effect was observed during acidic conditions.A tendency of PFOS distribution to hydrargillite in the presence of Na_(2)SO_(4) was like its behavior in the presence of HS although the mechanisms behind the sorption were interpreted differently.This study revealed that L-PFOS was readily sorbed when no other chemicals were added or in 20 mg/L FA or 100 mg/L Na_(2)SO_(4).We suggest that an increase in PFOS sorption in the presence of HS may be due to hydrophobic mechanisms while Na_(2)SO_(4) contributed to increased sorption through ionic strength effects.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
Liquid-liquid extraction(LLE)using ionic liquids(ILs)-based methods to remove perfluoroalkyl chemicals(PFACs),such as perfluorooctanoic acid(PFOA)and perfluorooctane sulfonic acid(PFOS),from wastewater,is an important...Liquid-liquid extraction(LLE)using ionic liquids(ILs)-based methods to remove perfluoroalkyl chemicals(PFACs),such as perfluorooctanoic acid(PFOA)and perfluorooctane sulfonic acid(PFOS),from wastewater,is an important strategy.However,the lack of physicochemical and LLE data limits the selection of the most suitable ILs for the extraction of PFACs.In this work,1763 ILs for PFACs extraction from water were systematically screened using COSMOtherm to estimate the infinite dilution activity coefficient(lnγ^(∞))of PFOA and PFOS in water and ILs.To evaluate the accuracy of COSMOtherm,8 ILs with various lnγ^(∞)values were selected,and their extraction efficiency(E)and distribution coefficient(D_(exp))were measured experimentally.The results showed that the predicted lnγ^(∞)decreased as the increase of experimental extraction efficiency of PFOA or PFOS,while the tendency of predicted distribution coefficient(D_(pre))was consistent with the experimental(D_(exp))results.This work provides an efficient basis for selecting ILs for the extraction of PFACs from wastewater.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
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
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
Co-existing organic compounds may affect the adsorption of perfluorinated compounds (PFCs) and carbon nanotubes in aquatic environments. Adsorption of perfluorooctane sulfonate (PFOS), perfluorooctane acid (PFOA...Co-existing organic compounds may affect the adsorption of perfluorinated compounds (PFCs) and carbon nanotubes in aquatic environments. Adsorption of perfluorooctane sulfonate (PFOS), perfluorooctane acid (PFOA), perfluorobutane sulfonate (PFBS), and perfluor- ohexane sulfonate (PFHxS) on the pristine multi-walled carbon nanotubes (MWCNTs-Pri), carboxyl functionalized MWCNTs (MWCTNs-COOH), and hydroxyl functiona- lized MWCNTs (MWCNTs-OH) in the presence of humic acid, 1-naphthol, phenol, and benzoic acid was studied. Adsorption kinetics of PFOS was described well by the pseudo-second-order model and the sorption equilibrium was almost reached within 24 h. The effect of co-existing organic compounds on PFOS adsorption followed the decreasing order of humic acid 〉 1-naphthol 〉 benzoic acid〉phenol. Adsorbed amounts of PFOS decreased significantly in the presence of co-existing or preloaded humic acid, and both adsorption energy and effective adsorption sites on the three MWCNTs decreased, resulting in the decrease of PFOS adsorption. With increasing pH, PFOS removal by three MWCNTs decreased in the presence of humic acid and phenol. The adsorbed amounts of different PFCs on the MWCNTs increased in the order ofPFBS 〈 PFHxS 〈 PFOA 〈 PFOS. The increase of both initial concentrations and the number of aromatic rings of co-existing organic compounds suppressed PFOS adsorption on the MWCNTs.展开更多
基金supported by the National Natural Science Foundation of China (No. 20477050, 20621703)
文摘Sorption and desorption of perfluorooctane sulfonate (PFOS) on humic acid at different temperatures were studied. It was found that the sorption process could be modeled with power kinetic equation very well, suggesting that diflusion predominated the sorption of PFOS on the humic acid. The sorption capacity was doubled when the temperature increased from 5 to 35°C, and thermodynamics parameters △G0 was calculated to be –7.11 to –5.04 kJ/mol, △H0 was 14.2 kJ/mol, and △S 0 was 69.5 J/(mol·K), indicating that the sorption was a spontaneous, endothermic, and entropy driven process. Desorption hysteresis occurred at all studied temperatures which suggested that humic acid may be an important sink of PFOS in the environment.
基金supported by the National Natural Science Foundation of China(Grant No.51279061)the Qing Lan Project of Jiangsu Province
文摘In order to study toxicological effects of perfluorononanoic acid (PFNA), perfluorooctane sulfonate (PFOS), and their mixtures (PFNA/ PFOS) on Daphnia magna (D. magna), a suite of comprehensive toxicity tests were conducted, including a 48-h acute toxicity test, a 21-day chronic test, a feeding experiment, and a biomarker assay. D. magna were exposed to aqueous solutions of PFNA and PFOS (alone and in combination) at concentrations ranging from 0.008 to 5 mg/L. The survival, growth, and reproduction of D. magna were monitored over a 21- day life cycle. The biomarkers, including acetylcholinesterase (ACHE), superoxide dismutase (SOD), and catalase (CAT) activities, were determined after seven days of exposure. PFOS was more toxic than PFNA based on the results of the acute toxicity test. Perfluorinated compounds (PFCs) inhibited both growth and reproduction of D. magna during the testing period. The ingestion rates and the biomarkers, including ACHE, SOD, and CAT activities, were significantly inhibited by PFCs in most cases. Moreover, the combined effects related to the growth and reproduction showed the antagonistic effects of PFCs.
基金Supported by the National Key Research&Development Plan(No.2017YFC0108200)the Shanghai Committee of Science and Technology(No.16140901000+1 种基金 No.13430710500 No.15DZ1942204)
文摘AIM: To investigate changes in the rabbit retina after shortterm and small amounts tamponade of perfluorooctane(PFO).METHODS: New Zealand rabbits were used, and 48 eyes were randomly and evenly assigned into four different groups. The PFO groups received a residue of 0.1 mL of PFO for ophthalmic surgery or 0.1 mL of F-Octane at the end of surgery; eyes from the pars plana vitrectomy(PPV) group were filled with balanced salt solution and those having not received surgical intervention served as controls. Eyes were collected at 1, 4 and 12 wk and studied.RESULTS: Under a microscope, nuclear counts of the inner nuclear layer(INL) and outer nuclear layer(ONL) did not differ among the four groups at all time points; however, slight disarrangement of the ONL and occasional vacuolization of the INL were found in the inferior retina only at 12 wk in two PFO groups. Four of the groups had similar results of Caspase-3 and TNF-α staining at all time points. Alternatively, IL-8 was increased in PFOa and PPV control groups at 4 wk and in all three PPV groups at 12 wk; also, the apoptotic index(%) was similarly increased in all three PPV groups at 4 and 12 wk.CONCLUSION: Both PFOs are well tolerated in rabbit eyes for up to 12 wk, which suggests that they can be used safely as intraoperative tools or for short-term and small amounts tamponade after surgery.
基金supported by awards from National Natural Science Foundation of China [No.81703260]the Education Department of Jiangsu Province [No.16KJB330010]+2 种基金the Science and Technology Department of Jiangsu Province [No.BK20160227]the China Postdoctoral Science Foundation funded project [No.2016M601892]the Priority Academic Program for the Development of Jiangsu Higher Education Institutions(PAPD)
文摘Perfluorooctane sulfonate (PFOS) is a class of stable organic compounds with wide industrial,commercial, and consumer applications, such as in textiles, paper, pesticides, and shampoos;. It is readily absorbed, but poorly eliminated, with the elimination half-life of approximately 5 years;.Hence, there have been concerns regarding its potential damage to human health. Some studies
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.
文摘Persistent perfluorinated organic compounds, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are used in a variety of industrial applications. They are very stable in the environment, distribute widely in the global environment and in wild life, and are detected in human sera. Our searches have detected ppt levels of PFOS and PFOA in the surface water of Japan and China; their levels are generally more than ten times higher in city areas. Neither PFOS nor PFOA is removed by the purification process of city water. Both PFOS and PFOA are detected in sera of all the people of Japan and China (about 1000 times as high as those in surface water), and their concentrations are increasing in both countries, especially in China. PFOS and PFOA primarily distribute to the liver and cause the liver toxicity. They also cause developmental toxicity. PFOS which is not genotoxic in a variety of assay system including our in vivo comet assay, induced tumors of the liver, thyroid and mammary gland of rats. PFOA which is weakly carcinogenic is not mutagenic in many studies including our in vivo comet assay.
基金Financial support from the National Natural Science Foundation of China (Nos. 21672227, 21922113, 22071257)the Strategic Priority Research Program of Chinese Academy of Sciences (No.XDB17000000)+2 种基金the National Key Research and Development Program of China (No. 2017YFA0206903)K.C.Wong Education Foundationthe TIPC Director’s Fund。
文摘Because the widely used perfluorooctane sulfonate(PFOS) is harmful to both environment and human health, it is of great significance and urgency to develop sensitive and selective sensors for the detection of trace PFOS in water. In this study, a tetraphenylethylene-derived macrocycle Bowtie Cyclophane has been developed as a fluorescent sensor based on aggregation-induced emission enhancement and fluorochromism. Sensitive detection of PFOS has been achieved with a limit of detection(LOD) of47.3 ± 2.0 nmol/L(25.4 ± 1.1 μg/L) accompanied by visual fluorescence color changes.
基金supported by the National Key Research and Development Program of China(No.2018YFC1803100)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Per-and polyfluoroalkyl substances(PFASs)can be taken up and bioaccumulated in plants,but the toxic mechanisms of PFASs on wetland plants are still unclear.In present study,the toxic influences of perfluorooctane sulfonate(PFOS)on Eichhornia crassipes(E.crassipes)and Cy perus alternifolius(C.alternifolius)in a vertical-sub surface-flow constructed wetland were evaluated.The results showed that E.crassipes was more tolerant to PFOS stress than C.alternifolius,and the growth and chlorophyll synthesis of the two plants were promoted by low concentration(<0.1 mg/L)of PFOS,and the chlorophyll synthesis was inhibited by high concentration(10 mg/L)of PFOS but the growth did not change obviously.The catalase activity and malondialdehyde content in the leaves of the two plants increased,peroxidase activity decreased under exposure to high concentrations of PFOS,and superoxide dismutase activity did not change.Under PFOS stress,the membrane of plant leaves and the cell structure of the two wetland plants were destroyed,and the mitochondrial contour of root cells became incomplete.Tanscriptomic analysis showed that the expression levels of genes related to cell wall formation,the cell apoptosis pathway,material synthesis,and metabolism in the plants were changed by PFOS.Analysis in fluorogenic quantitative real time polymerase chain reaction(RT-qPCR)also confirmed that the photosynthesis system of E.crassipes was inhibited,while that of C.alternifolius was promoted.
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This research was financially supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘A vertical-flow constructed wetland(VFCW)was used to treat simulated domestic sewage containing perfluorooctane sulfonate(PFOS).The removal rate of PFOS in the domestic sewage was 93%–98%,through soil adsorption and plant uptake,suggesting that VFCWs can remove PFOS efficiently from wastewater.The removal of PFOS in the VFCW was dependent on soil adsorption and plant uptake;moreover,the percentage of soil adsorption was 61%–89%,and was higher than that of the plants uptake(5%–31%).The absorption capacity of Eichhornia crassipes(E.crassipes)(1186.71 mg/kg)was higher than that of Cyperus alternifolius(C.alternifolius)(162.77 mg/kg)under 10 mg/L PFOS,and the transfer factor of PFOS in E.crassipes and C.alternifolius was 0.04 and 0.58,respectively,indicating that PFOS is not easily translocated to leaves from roots of wetland plants;moreover,uptake of PFOS by E.crassipes was more than that of C.alternifolius because the biomass of E.crassipes was more than that of C.alternifolius and the roots of E.crassipes can take up PFOS directly from wastewater while C.alternifolius needs to do so via its roots in the soil.The concentration of 10 mg/L PFOS had an obvious inhibitory effect on the removal rate of total nitrogen,total phosphorus,chemical oxygen demand,and ammonia nitrogen in the VFCW,which decreased by 15%,10%,10%and 12%,respectively.Dosing with PFOS in the wastewater reduced the bacterial richness but increased the diversity in soil because PFOS stimulated the growth of PFOS-tolerant strains.
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(Nos.U20A20133,21777187)the Royal Society International Collaboration Award for Research Professors(No.IC160121).
文摘Per-and polyfluoroalkyl substances(PFAS)are found to have multiple adverse outcomes on human health.Recently,epidemiological and toxicological studies showed that exposure to PFAS had adverse impacts on pancreas and showed association with insulin abnormalities.To explore how PFAS may contribute to diabetes,we studied impacts of perfluorooctane sul-fonate(PFOS)on cell viability and insulin release capacity of pancreatic β cells by using in vivo and in vitro methods.We found that 28-day administration with PFOS(10 mg/(kg body weight·day))caused reductions of pancreas weight and islet size in male mice.PFOS admin-istration also led to lower serum insulin level both in fasting state and after glucose infusion among male mice.For cell-based in vitro bioassay,we used mouse β-TC-6 cancer cells and found 48-hr exposure to PFOS decreased the cell viability at 50 μmol/L.By measuring insulin content in supernatant,48-hr pretreatment of PFOS(100 μmol/L)decreased the insulin re-lease capacity of β-TC-6 cells after glucose stimulation.Although these concentrations were higher than the environmental concentration of PFOS,it might be reasonable for high con-centration of PFOS to exert observable toxic effects in mice considering mice had a faster removal efficiency of PFOS than human.PFOS exposure(50 μmol/L)to β-TC-6 cells induced intracellular accumulation of reactive oxidative specie(ROS).Excessive ROS induced the re-active toxicity of cells,which eventually invoke apoptosis and necrosis.Results in this study provide evidence for the possible causal link of exposure to PFOS and diabetes risk.
基金the Knowledge Foundation(KKS)for funding the project within the Enforce Research Project(No.20160019)。
文摘Perfluorooctane sulfonate(PFOS)is a persistent organic pollutant(POP)and emergent contaminant that are widespread in the environment.Understanding the mechanisms controlling the distribution of PFOS and its isomers between hydrargillite and the water phase is important in order to study their redistribution and mobility in the environment.This study investigated the effects of pH,humic acid,fulvic acid and Na_(2)SO_(4) on sorption of PFOS isomers to hydrargillite.A mixture of PFOS isomers was spiked into water and hydrargillite was added to the system and shaken for one day;the system was tested with different aqueous composition.Concentrations of PFOS isomers in the aqueous phase were quantified using an ultra-performance liquid chromatograph coupled to a triple quadrupole mass spectrometer.Our results showed that the distribution coefficients of PFOS isomers were found to be 0.76,0.71,0.93 and 0.90 at pH 6.5,for 3-/4-/5-PFOS,6-/2-PFOS,L-PFOS and total PFOS respectively.The distribution coefficients increased at lower pH and decreased at alkaline conditions.The presence of humic substances(HS)increased the sorption slightly at the environmental pH of 6.5,although a competition effect was observed during acidic conditions.A tendency of PFOS distribution to hydrargillite in the presence of Na_(2)SO_(4) was like its behavior in the presence of HS although the mechanisms behind the sorption were interpreted differently.This study revealed that L-PFOS was readily sorbed when no other chemicals were added or in 20 mg/L FA or 100 mg/L Na_(2)SO_(4).We suggest that an increase in PFOS sorption in the presence of HS may be due to hydrophobic mechanisms while Na_(2)SO_(4) contributed to increased sorption through ionic strength effects.
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support from the Brook Byers Institute for Sustainable Systems,Hightower Chair,and Georgia Research Alliance at the Georgia Institute of Technology.
文摘Liquid-liquid extraction(LLE)using ionic liquids(ILs)-based methods to remove perfluoroalkyl chemicals(PFACs),such as perfluorooctanoic acid(PFOA)and perfluorooctane sulfonic acid(PFOS),from wastewater,is an important strategy.However,the lack of physicochemical and LLE data limits the selection of the most suitable ILs for the extraction of PFACs.In this work,1763 ILs for PFACs extraction from water were systematically screened using COSMOtherm to estimate the infinite dilution activity coefficient(lnγ^(∞))of PFOA and PFOS in water and ILs.To evaluate the accuracy of COSMOtherm,8 ILs with various lnγ^(∞)values were selected,and their extraction efficiency(E)and distribution coefficient(D_(exp))were measured experimentally.The results showed that the predicted lnγ^(∞)decreased as the increase of experimental extraction efficiency of PFOA or PFOS,while the tendency of predicted distribution coefficient(D_(pre))was consistent with the experimental(D_(exp))results.This work provides an efficient basis for selecting ILs for the extraction of PFACs from wastewater.
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.
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.
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We thank the National Nature Science Foundation of China (Grant No. 21177070), Tsinghua University Initiative Scientific Research Program (Nos. 20141081174 and 20131089251), and Collaborative Innovation Center for Regional Environmental Quality for financial support.
文摘Co-existing organic compounds may affect the adsorption of perfluorinated compounds (PFCs) and carbon nanotubes in aquatic environments. Adsorption of perfluorooctane sulfonate (PFOS), perfluorooctane acid (PFOA), perfluorobutane sulfonate (PFBS), and perfluor- ohexane sulfonate (PFHxS) on the pristine multi-walled carbon nanotubes (MWCNTs-Pri), carboxyl functionalized MWCNTs (MWCTNs-COOH), and hydroxyl functiona- lized MWCNTs (MWCNTs-OH) in the presence of humic acid, 1-naphthol, phenol, and benzoic acid was studied. Adsorption kinetics of PFOS was described well by the pseudo-second-order model and the sorption equilibrium was almost reached within 24 h. The effect of co-existing organic compounds on PFOS adsorption followed the decreasing order of humic acid 〉 1-naphthol 〉 benzoic acid〉phenol. Adsorbed amounts of PFOS decreased significantly in the presence of co-existing or preloaded humic acid, and both adsorption energy and effective adsorption sites on the three MWCNTs decreased, resulting in the decrease of PFOS adsorption. With increasing pH, PFOS removal by three MWCNTs decreased in the presence of humic acid and phenol. The adsorbed amounts of different PFCs on the MWCNTs increased in the order ofPFBS 〈 PFHxS 〈 PFOA 〈 PFOS. The increase of both initial concentrations and the number of aromatic rings of co-existing organic compounds suppressed PFOS adsorption on the MWCNTs.