The biosorption mechanisms of uranium on an aerobic bacterial strain Streptomyces sporoverrucosus dwc-3,isolated from a potential disposal site for（ultra-）low uraniferous radioactive waste in Southwest China,were ev...The biosorption mechanisms of uranium on an aerobic bacterial strain Streptomyces sporoverrucosus dwc-3,isolated from a potential disposal site for（ultra-）low uraniferous radioactive waste in Southwest China,were evaluated by using transmission electron microscopy（TEM）,energy dispersive X-ray（EDX）analysis,Fourier transform infrared spectroscopy（FT-IR）,X-ray photoelectron spectroscopy（XPS）,proton induced X-ray emission（PIXE）and enhanced proton backscattering spectrometry（EPBS）.Approximately60% of total uranium at an initial concentration of 10 mg/L uranium nitrate solution could be absorbed on 100 mg S.sporoverrucosus dwc-3 with an adsorption capacity of more than3.0 mg/g（wet weight）after 12 hr at room temperature at p H 3.0.The dynamic biosorption process of S.sporoverrucosus dwc-3 for uranyl ions was well described by a pseudo second-order model.S.sporoverrucosus dwc-3 could accumulate uranium on cell walls and within the cell,as revealed by SEM and TEM analysis as well as EDX spectra.XPS and FT-IR analysis further suggested that the absorbed uranium was bound to amino,phosphate and carboxyl groups of the cells.Additionally,PIXE and EPBS results confirmed that ion exchange also contributed to the adsorption process of uranium.展开更多
基金financially supported by the China National Natural Science Foundation(Nos.21071102,91126013)Joint Funds of China National Natural Science Foundation and China Academy of Engineering Physics(NSAF,No.U1330125)+1 种基金the State 863 project of China(No.2012AA063503)the National Fund of China for Fostering Talents in Basic Science(No.J1210004)
文摘The biosorption mechanisms of uranium on an aerobic bacterial strain Streptomyces sporoverrucosus dwc-3,isolated from a potential disposal site for（ultra-）low uraniferous radioactive waste in Southwest China,were evaluated by using transmission electron microscopy（TEM）,energy dispersive X-ray（EDX）analysis,Fourier transform infrared spectroscopy（FT-IR）,X-ray photoelectron spectroscopy（XPS）,proton induced X-ray emission（PIXE）and enhanced proton backscattering spectrometry（EPBS）.Approximately60% of total uranium at an initial concentration of 10 mg/L uranium nitrate solution could be absorbed on 100 mg S.sporoverrucosus dwc-3 with an adsorption capacity of more than3.0 mg/g（wet weight）after 12 hr at room temperature at p H 3.0.The dynamic biosorption process of S.sporoverrucosus dwc-3 for uranyl ions was well described by a pseudo second-order model.S.sporoverrucosus dwc-3 could accumulate uranium on cell walls and within the cell,as revealed by SEM and TEM analysis as well as EDX spectra.XPS and FT-IR analysis further suggested that the absorbed uranium was bound to amino,phosphate and carboxyl groups of the cells.Additionally,PIXE and EPBS results confirmed that ion exchange also contributed to the adsorption process of uranium.
