scholarly journals Biosorption of Uranyl Ions from Aqueous Solution by Parachlorella sp. AA1

2021 ◽  
Vol 18 (7) ◽  
pp. 3641
Author(s):  
Ja-Young Yoon ◽  
In-Hyun Nam ◽  
Min-Ho Yoon
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Uranyl Ions ◽  
Batch Experiments ◽  
Edge Structure ◽  
Biosorption Capacity ◽  
X Ray ◽  
Optimum Ph ◽  
Treatment And Disposal ◽  
X Ray Absorption

In the present study we investigated the ability of the microalgal strain Parachlorella sp. AA1 to biologically uptake a radionuclide waste material. Batch experiments were conducted to investigate the biosorption of uranyl ions (U(VI)) in the 0.5–50.0 mg/L concentration range by strain AA1. The results showed that AA1 biomass could uptake U(VI). The highest removal efficiency and biosorption capacity (95.6%) occurred within 60 h at an initial U(VI) concentration of 20 mg/L. The optimum pH for biosorption was 9.0 at a temperature of 25 °C. X-ray absorption near edge structure analysis confirmed the presence of U(VI) in pellets of Parachlorella sp. AA1 cells. The biosorption methods investigated here may be useful in the treatment and disposal of nuclides and heavy metals in diverse wastewaters.

Nitrogen K-edge X-ray absorption near edge structure (XANES) spectra of purine-containing nucleotides in aqueous solution

2014 ◽  
Vol 141 (5) ◽  
pp. 055102 ◽  
Author(s):  
Hiroyuki Shimada ◽  
Taishi Fukao ◽  
Hirotake Minami ◽  
Masatoshi Ukai ◽  
Kentaro Fujii ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

A Xanes Study of Square Copper(II) Complexes

1991 ◽  
Vol 35 (B) ◽  
pp. 1115-1120
Author(s):  
Hisanobu Wakita ◽  
Toshio Yamaguchi ◽  
Hirohiko Adachi ◽  
Manabu Fujiwara ◽  
Seiichi Yamashita
Keyword(s):  
Aqueous Solution ◽  
Lower Energy ◽  
Molecular Orbital Calculations ◽  
Counter Anion ◽  
Edge Structure ◽  
X Ray ◽  
Square Planar ◽  
Tetraaza Macrocycles ◽  
X Ray Absorption ◽  
Back Donation

AbstractThe XANES (X-ray absorption near edge structure) spectra of copper(II) ions in solid state and in solution of the square-planar copper(II) complexes with tetraaza macrocycles were measured. The peaks in the measured XANES spectra shifted to lower energy side with increasing the electron density of central copper(II) ions. The molecular orbital calculations for the complexes were carried out by the DV-Xα method, and the theoretical XANES spectra were estimated. The clear chemical shift obtained by this XANES study is evaluated and leads to a new concept of π-back donation between the copper(II) complexes and counter anion in aqueous solution.

Structural changes of nucleic acid base in aqueous solution as observed in X-ray absorption near edge structure (XANES)

2014 ◽  
Vol 591 ◽  
pp. 137-141 ◽  
Author(s):  
Hiroyuki Shimada ◽  
Taishi Fukao ◽  
Hirotake Minami ◽  
Masatoshi Ukai ◽  
Kentaro Fujii ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Nucleic Acid ◽  
Structural Changes ◽  
Acid Base ◽  
Edge Structure ◽  
X Ray ◽  
Nucleic Acid Base ◽  
X Ray Absorption

Nitrogen K-edge x-ray absorption near edge structure of pyrimidine-containing nucleotides in aqueous solution

2015 ◽  
Vol 142 (17) ◽  
pp. 175102 ◽  
Author(s):  
Hiroyuki Shimada ◽  
Hirotake Minami ◽  
Naoto Okuizumi ◽  
Ichiro Sakuma ◽  
Masatoshi Ukai ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

scholarly journals An extended-X-ray-absorption-fine-structure study of bovine erythrocyte superoxide dismutase in aqueous solution. Direct evidence for three-co-ordinate Cu(I) in reduced enzyme

1984 ◽  
Vol 219 (3) ◽  
pp. 985-990 ◽  
Author(s):  
N J Blackburn ◽  
S S Hasnain ◽  
N Binsted ◽  
G P Diakun ◽  
C D Garner ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Superoxide Dismutase ◽  
Structure Study ◽  
Reduced Form ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Fine ◽  
Copper Site ◽  
Erythrocyte Superoxide Dismutase ◽  
X Ray Absorption

Copper and zinc K-edge e.x.a.f.s. (extended X-ray-absorption fine structures) were measured for the metal sites of oxidized and reduced bovine superoxide dismutase in aqueous solution. Detailed analysis of the spectra indicates that the copper site of the enzyme changes on reduction and is most probably co-ordinated to three imidazole groups at a shorter distance Cu-N(alpha) = 0.194 nm (1.94 A) in the reduced form compared with a co-ordination of four imidazole groups at 0.199 nm (1.99 A) and an oxygen atom from solvent water at 0.224 nm (2.24 A) in the oxidized form. Examination of the edge, near-edge structure and e.x.a.f.s. of the zinc sites indicates that the stereochemical changes at copper that accompany reduction introduce minimal perturbation on the stereochemistry at zinc.

Studies of Cu(II) in soil by X-ray absorption spectroscopy

2001 ◽  
Vol 81 (3) ◽  
pp. 271-276 ◽  
Author(s):  
A I Frenkel ◽  
G V Korshin
Keyword(s):  
Heavy Metals ◽  
Fine Structure ◽  
Structural Parameters ◽  
Structural Data ◽  
Axial Direction ◽  
Careful Examination ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

Based on original data for copper, this paper evaluates the use and advantages of X-ray absorption fine structure (XAFS) in studies of heavy metals in soils. The structural parameters of the Cu2+ target were quantified for soil exposed to copper and the same soil eluted with 0.1 M HCl. Experimental data were obtained using synchrotron sources of second and third generations.X-ray absorption near edge structure (XANES) indicated that the copper in both samples is likely to be predominantly bound by oxygen-containing functional groups. Extended X-ray absorption fine structure (EXAFS) analysis showed that the equatorial Cu-O distances were similar to those seen for Cu2+-humic complexes in aqueous solutions, but the axial distances for both samples were longer than in water. In the axial direction, this may indicate a type of ligation dissimilar to that in solutions. The magnitude of the mean square deviation of the axial Cu-O distance in the 0.1 M HCl eluted sample indicated a stronger bond compared with that in the sample containing both extractable and tightly bound copper. The results indicate that careful examination of structural data for sequentially eluted soils in combination with the development of new radiation sources to improve the sensitivity and quality of the data are likely to improve insight into the nature of interactions between heavy metals and soil. Key words: Soil, copper, humic, speciation, extended X-ray absorption fine structure, X-ray absorption near edge structure

Chemical and orientational imaging of polymeric samples

1994 ◽  
Vol 52 ◽  
pp. 68-69
Author(s):  
H. Ade ◽  
B. Hsiao ◽  
G. Mitchell ◽  
E. Rightor ◽  
A. P. Smith ◽  
...  
Keyword(s):  
Ethylene Terephthalate ◽  
National Laboratory ◽  
Brookhaven National Laboratory ◽  
Carbonyl Groups ◽  
Aromatic Rings ◽  
Edge Structure ◽  
X Ray ◽  
Scanning Transmission ◽  
Polymeric Samples ◽  
X Ray Absorption

We have used the Scanning Transmission X-ray Microscope at beamline X1A (X1-STXM) at Brookhaven National Laboratory (BNL) to acquire high resolution, chemical and orientation sensitive images of polymeric samples as well as point spectra from 0.1 μm areas. This sensitivity is achieved by exploiting the X-ray Absorption Near Edge Structure (XANES) of the carbon K edge. One of the most illustrative example of the chemical sensitivity achievable is provided by images of a polycarbonate/pol(ethylene terephthalate) (70/30 PC/PET) blend. Contrast reversal at high overall contrast is observed between images acquired at 285.36 and 285.69 eV (Fig. 1). Contrast in these images is achieved by exploring subtle differences between resonances associated with the π bonds (sp hybridization) of the aromatic groups of each polymer. PET has a split peak associated with these aromatic groups, due to the proximity of its carbonyl groups to its aromatic rings, whereas PC has only a single peak.

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