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
Electron beam(EB) degradation of perfluorooctanoic acid(PFOA) and perfluorooctane sulfonate(PFOS) in aqueous solutions was studied. It suggested that PFOA and PFOS degradation followed the pseudo-firstorder kinetics, ...Electron beam(EB) degradation of perfluorooctanoic acid(PFOA) and perfluorooctane sulfonate(PFOS) in aqueous solutions was studied. It suggested that PFOA and PFOS degradation followed the pseudo-firstorder kinetics, and degradation rates increased with increasing initial p H. Radical scavengers' experiments indicated that hydrated electron and hydrogen radical were important in the electron beam degradation of PFOA and PFOS, especially hydrated electron. The decomposition efficiencies were 95.7% for PFOA and 85.9% for PFOS, by EB irradiation in an anoxic alkaline solution(p H = 13).The potential degradation pathways of PFOA and PFOS by electron beam irradiation through defluorination and the removal of CH_2 unit were proposed.展开更多
Perfluorooctane sulfonate （PFOS） has emerged as one of the most concerning contaminants in recent years. This study aimed to investigate the acute toxicity effect of PFOS on sperm viability, kinematics and fertiliza...Perfluorooctane sulfonate （PFOS） has emerged as one of the most concerning contaminants in recent years. This study aimed to investigate the acute toxicity effect of PFOS on sperm viability, kinematics and fertilization success in zebrafish （Danio rerio）. Sperm were activated in aqueous media containing a range of PFOS concentrations （0, 0.09, 0.9 and 9 mg/L）. Viabilities and kinematics of the sperm exposed to different PFOS treatments were assessed via computer-assisted sperm analysis （CASA） at 20, 40, 60, and 80 s after activation. PFOS exposure decreased the percentage of motile sperm, the curvilinear velocity （VCL）, and the mean angular displacement （MAD） of spermatozoa, but showed no influence on the straight- line velocity （VSL） or the angular path velocity （VAP）. Furthermore, a significant decrease in fertilization success was observed in spermatozoa that were exposed to 0.9 mg/L PFOS or more. These findings indicate that PFOS pollution in natural aquatic environment may be a potential threaten to successful reproduction of fish.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
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 Natural Science Foundation of China(Nos.11675098,41430644,41473090,41373098)Program for Changjiang Scholars and Innovative Research Team in University(No.IRT13078)
文摘Electron beam(EB) degradation of perfluorooctanoic acid(PFOA) and perfluorooctane sulfonate(PFOS) in aqueous solutions was studied. It suggested that PFOA and PFOS degradation followed the pseudo-firstorder kinetics, and degradation rates increased with increasing initial p H. Radical scavengers' experiments indicated that hydrated electron and hydrogen radical were important in the electron beam degradation of PFOA and PFOS, especially hydrated electron. The decomposition efficiencies were 95.7% for PFOA and 85.9% for PFOS, by EB irradiation in an anoxic alkaline solution(p H = 13).The potential degradation pathways of PFOA and PFOS by electron beam irradiation through defluorination and the removal of CH_2 unit were proposed.
基金Supported by the National Natural Science Foundation of China(Nos.40632009,31300340)the Natural Science Foundation Project of Chongqing(No.cstc2015jcyjA20016)the Youth Top-notch Talent Cultivation Program of Chongqing Normal University(No.14CSBJ08)
文摘Perfluorooctane sulfonate （PFOS） has emerged as one of the most concerning contaminants in recent years. This study aimed to investigate the acute toxicity effect of PFOS on sperm viability, kinematics and fertilization success in zebrafish （Danio rerio）. Sperm were activated in aqueous media containing a range of PFOS concentrations （0, 0.09, 0.9 and 9 mg/L）. Viabilities and kinematics of the sperm exposed to different PFOS treatments were assessed via computer-assisted sperm analysis （CASA） at 20, 40, 60, and 80 s after activation. PFOS exposure decreased the percentage of motile sperm, the curvilinear velocity （VCL）, and the mean angular displacement （MAD） of spermatozoa, but showed no influence on the straight- line velocity （VSL） or the angular path velocity （VAP）. Furthermore, a significant decrease in fertilization success was observed in spermatozoa that were exposed to 0.9 mg/L PFOS or more. These findings indicate that PFOS pollution in natural aquatic environment may be a potential threaten to successful reproduction of fish.
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.
