Anthraquinone-2-sulfonate（AQS） was employed in humus substitutes to evaluate the effects and influencing factors of U（VI） reduction by Shewanella oneidensis MR-1（S. oneidensis MR-1） under anaerobic condition. Th...Anthraquinone-2-sulfonate（AQS） was employed in humus substitutes to evaluate the effects and influencing factors of U（VI） reduction by Shewanella oneidensis MR-1（S. oneidensis MR-1） under anaerobic condition. The removal rate of U（VI） at 30 °C reaches 99.0% afterd 96 h with the p H value of 7.0 and AQS concentration of 1.0 mmol/L. The effective concentrations of AQS as the accelerator for U（VI） bioreduction are approximately 0.5-1.0 mmol/L. The bioreduction of U（VI） is inhibited when the concentration of AQS exceeds 2.0 mmol/L. The coexistence of ions, such as Cu2＋, Cr6＋, Mn2＋, shows a remarkable negative effect on the U（VI） reduction, and Zn2＋ shows less influence on the process compared with other tested ions. The U（VI） reduction is remarkably inhibited when the concentration of nitrate ion exceeds 1.0 mmol/L. Otherwise, no difference is found when the nitrate ion concentration is less than 0.5 mmol/L. Sulfate ion（5.0 mmol/L） slightly promotes the U（VI） reduction. Zero-valent iron（ZVI） promotes the U（VI） reduction by S. oneidensis, and the reduction rate improves with increasing the amount of ZVI in the range of 0-2.0 g/L. The XPS result indicates that uranium deposits on the cell surface are in U（VI） and U（IV） forms, and the majority of uranium in the solution is stable UO2.展开更多
The photochemical reaction process of anthraquinone-2-sodium sulfonate （AQS） in the mixture of water （H2O） and N-butylpyridinium tetrafluoroborate （[BPy] [BF4]） was studied using the laser flash photolysis techn...The photochemical reaction process of anthraquinone-2-sodium sulfonate （AQS） in the mixture of water （H2O） and N-butylpyridinium tetrafluoroborate （[BPy] [BF4]） was studied using the laser flash photolysis technique. Experimental results show that the excited triplet of AQS （3AQS＊） could react rapidly with H2O and the transient absorption spectra greatly changed by increasing the volume fraction of the ionic liquid （VIL） in [BPy][BF4]/H2O mixtures. The absorbance at 510 nm increased gradually with increasing VIL when 0〈VIL〈0.1. By contrast, the absorbance decreased gradually when VIL〉0.1. Otherwise, the absorbance of the band near 380 nm steadily increased. The apparent kinetic parameters of transient species B and ^3AQS＊ are obtained approximately. 3AQS＊ abstracting hydrogen from [BPy]＋ was also explored. It was deduced that the 350-420 nm band was the superposition of the peaks of 3AQS＊ and AQSH＇. The two reactions of 3AQS＊ with [BPy][BF4] and H2O are a pair of competitive reactions. We also concluded that the entire reaction processes slow down in the case of high [BPy] [BF4] concentrations.展开更多
The electron transfer reaction between triplet anthraquinone-2-sulfonate with poly-guanylic acid (5) (poly[G]) in acetonitrile-H2O has been investigated by 248 nm laser flash photolysis. The transient absorption spect...The electron transfer reaction between triplet anthraquinone-2-sulfonate with poly-guanylic acid (5) (poly[G]) in acetonitrile-H2O has been investigated by 248 nm laser flash photolysis. The transient absorption spectra of radical cation of poly[G] and radical anion of anthraqunione-2-sulfonate (AQS) arising from electron transfer reaction has been observed simultaneously for the first time. The formation processes of radical cation of poly[G] and radical anion of anthraquinone-2-sulfonate as well as the decay processes of triplet anthraquinone-2-sulfonate have also been observed, the apparent rate constants for the formation and decay of transient species have been determined. The free energy changes in the process of the electron transfer was also calculated.展开更多
基金Projects(1117508111475080)supported by the National Natural Science Foundation of China+3 种基金project(13JJ3078)supported by the Natural Science Foundation of Hunan ProvinceChinaProject(14k083)supported by the Innovation Platform Open Fund Project of University in Hunan ProvinceChina
文摘Anthraquinone-2-sulfonate（AQS） was employed in humus substitutes to evaluate the effects and influencing factors of U（VI） reduction by Shewanella oneidensis MR-1（S. oneidensis MR-1） under anaerobic condition. The removal rate of U（VI） at 30 °C reaches 99.0% afterd 96 h with the p H value of 7.0 and AQS concentration of 1.0 mmol/L. The effective concentrations of AQS as the accelerator for U（VI） bioreduction are approximately 0.5-1.0 mmol/L. The bioreduction of U（VI） is inhibited when the concentration of AQS exceeds 2.0 mmol/L. The coexistence of ions, such as Cu2＋, Cr6＋, Mn2＋, shows a remarkable negative effect on the U（VI） reduction, and Zn2＋ shows less influence on the process compared with other tested ions. The U（VI） reduction is remarkably inhibited when the concentration of nitrate ion exceeds 1.0 mmol/L. Otherwise, no difference is found when the nitrate ion concentration is less than 0.5 mmol/L. Sulfate ion（5.0 mmol/L） slightly promotes the U（VI） reduction. Zero-valent iron（ZVI） promotes the U（VI） reduction by S. oneidensis, and the reduction rate improves with increasing the amount of ZVI in the range of 0-2.0 g/L. The XPS result indicates that uranium deposits on the cell surface are in U（VI） and U（IV） forms, and the majority of uranium in the solution is stable UO2.
基金This work was supported by the National Natural Science Foundation of China （No.21173002） and the Anhui Provincial Natural Science Foundation, China （No.1308085MB20）.
文摘The photochemical reaction process of anthraquinone-2-sodium sulfonate （AQS） in the mixture of water （H2O） and N-butylpyridinium tetrafluoroborate （[BPy] [BF4]） was studied using the laser flash photolysis technique. Experimental results show that the excited triplet of AQS （3AQS＊） could react rapidly with H2O and the transient absorption spectra greatly changed by increasing the volume fraction of the ionic liquid （VIL） in [BPy][BF4]/H2O mixtures. The absorbance at 510 nm increased gradually with increasing VIL when 0〈VIL〈0.1. By contrast, the absorbance decreased gradually when VIL〉0.1. Otherwise, the absorbance of the band near 380 nm steadily increased. The apparent kinetic parameters of transient species B and ^3AQS＊ are obtained approximately. 3AQS＊ abstracting hydrogen from [BPy]＋ was also explored. It was deduced that the 350-420 nm band was the superposition of the peaks of 3AQS＊ and AQSH＇. The two reactions of 3AQS＊ with [BPy][BF4] and H2O are a pair of competitive reactions. We also concluded that the entire reaction processes slow down in the case of high [BPy] [BF4] concentrations.
文摘The electron transfer reaction between triplet anthraquinone-2-sulfonate with poly-guanylic acid (5) (poly[G]) in acetonitrile-H2O has been investigated by 248 nm laser flash photolysis. The transient absorption spectra of radical cation of poly[G] and radical anion of anthraqunione-2-sulfonate (AQS) arising from electron transfer reaction has been observed simultaneously for the first time. The formation processes of radical cation of poly[G] and radical anion of anthraquinone-2-sulfonate as well as the decay processes of triplet anthraquinone-2-sulfonate have also been observed, the apparent rate constants for the formation and decay of transient species have been determined. The free energy changes in the process of the electron transfer was also calculated.
