Trimeric uranyl(vi)–citrate forms Na+, Ca2+, and La3+ sandwich complexes in aqueous solution

2020 ◽  
Vol 56 (86) ◽  
pp. 13133-13136
Author(s):  
Jerome Kretzschmar ◽  
Satoru Tsushima ◽  
Björn Drobot ◽  
Robin Steudtner ◽  
Katja Schmeide ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
Sandwich Complexes ◽  
Oxygen Atoms

Under the uranyl citrate umbrella: metal ions are extremely shielded from water upon coordination by six uranyl(vi) oxygen atoms.

Complexes of carbohydrates with metal cations. III. Conformations of alditols in aqueous solution

1974 ◽  
Vol 27 (7) ◽  
pp. 1447 ◽  
Author(s):  
SJ Angyal ◽  
D Greeves ◽  
JA Mills
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Metal Ions ◽  
Chloroform Solution ◽  
Metal Cations ◽  
Carbon Carbon Bonds ◽  
Carbon Bonds ◽  
Oxygen Atoms

Complex formation of alditols with metal ions in aqueous solution has been investigated by electrophoresis and by the study of the N.M.R. spectra in the presence of europium ions. Complexing occurs at three consecutive oxygen atoms which are in a gauche-gauche arrangement; the energy required to form this arrangement (by rotation around carbon-carbon bonds) determines the extent of complex formation. It appears that the alditols in aqueous solution are essentially in the same conformations as are their acetates in chloroform solution.

Structure of the Solvated Strontium and Barium Ions in Aqueous, Dimethyl Sulfoxide and Pyridine Solution, and Crystal Structure of Strontium and Barium Hydroxide Octahydrate

1995 ◽  
Vol 50 (1) ◽  
pp. 21-37 ◽  
Author(s):  
Ingmar Persson ◽  
Magnus Sandström ◽  
Haruhiko Yokoyama
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Metal Ions ◽  
Dimethyl Sulfoxide ◽  
Metal Ion ◽  
Water Molecules ◽  
Barium Ions ◽  
X Ray ◽  
Pyridine Solution ◽  
Oxygen Atoms

Single crystal X-ray data, collected at 298 K, are used to redetermine the crystal structure of the non-isomorphic compounds [Sr(H2O)8](OH)2 and [Ba(H2O)8](OH)2. The eight water oxygen atoms form distorted Archimedean antiprisms around the octahydrated metal ions with mean metal ion-oxygen distances 2.62 and 2.79 Å for strontium and barium, respectively. A second coordination shell of 24 hydrogen-bonded oxygen atoms with mean metal ion-oxygen distances M…OII 4.76 and 4.80 Å, respectively, is observed. The hydroxide ions in both structures have an unusual hydrogen bond arrangement with 5 bonds accepted and one donated.The structure of the solvated strontium and barium ions in aqueous, dimethyl sulfoxide and pyridine solutions has been studied by means of large angle X-ray scattering and extended X-ray absorption fine structure spectroscopy techniques. In aqueous solution independent determinations of the first-sphere metal-oxygen coordination by the two techniques resulted in the bond lengths Sr-O 2.63 (2) and Ba-O 2.81 (3) Å, and for both metal ions a hydration number of 8.1 (3). The second coordination spheres are very diffuse with only about 13 water molecules at similar M…OII distances as in the crystal structures and 2-3 water molecules closer to the metal ions. In dimethyl sulfoxide solution both ions were found to coordinate 6.0 (5) solvent molecules with the distances Sr-O 2.54(1), Sr…S 3.77(1) Å, and Ba-O 2.76(1), Ba…S 3.99(1) Å. For the solvated ions in pyridine solution EXAFS measurements yielded the distances Sr-N 2.57 (2) and Ba-N 2.78 (3) Å, with a probable solvation number of 6.Correlations of hydration enthalpies and partial molar volumes with experimental M-O bond distances in aqueous solution are used to discuss hydration numbers and bond character for all of the alkaline earth metal ions.

REMOVAL OF HEAVY METAL Cr (II), Ni (II), Cu (II), Zn (II), Cd (II), Pb (II) IONS FROM AQUEOUS SOLUTION BY MENTHA PIPERITA EXTRACT

2020 ◽  
pp. 15-20
Author(s):  
Ersin Yucel ◽  
Mine Yucel
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
High Efficiency ◽  
Correlation Coefficients ◽  
Langmuir Model ◽  
Mentha Piperita ◽  
Freundlich Model ◽  
Biosorption Capacity ◽  
Peppermint Extract ◽  
The Stability

In this study, the usage of the peppermint (Mentha piperita) for extracting the metal ions [Mg (II), Cr (II), Ni (II), Cu (II), Zn (II), Cd (II), Pb (II)] that exist at water was investigated. In order to analyze the stability properties, Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms were used at removing the metal ions and the highest correlation coefficients (R2) were obtained at Langmuir isotherm. Therefore, it is seen that the Langmuir model is more proper than the Freundlich model. However, it was found that the correlation coefficients of removing Ni and Cd is higher at Freundlich model than Langmuir and low at Dubinin-Radushkevich isotherm. It is established that the biosorption amount increase depends on the increase of biosorbent and it can be achieved high efficiency (95%) even with small amount (0.6 mg, peppermint extract) at lead ions. It is also determined that the peppermint extracted that is used at this study shows high biosorption capacity for metal ions and can be used for immobilization of metals from polluted areas.

Comparative Bio-sorption of Cadmium and Nickel Ions from Aqueous Solution onto Fibers of Date Palm using Fluidized Bed Column

2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Heavy Metal Ions ◽  
Date Palm ◽  
Operating Conditions ◽  
Initial Concentration ◽  
Bed Height

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).

Stabilization of Hazardous Materials into Ferrites

1991 ◽  
Vol 23 (1-3) ◽  
pp. 399-404 ◽  
Author(s):  
Y. Tamaura ◽  
P. Q. Tu ◽  
S. Rojarayanont ◽  
H. Abe
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Present Method ◽  
Hazardous Materials ◽  
Precipitation Process ◽  
Waste Waters ◽  
Formation Reaction ◽  
Coating Method ◽  
Hazardous Metal

Stabilization of the hazardous materials by the Fe3O4-coating method was studied. In the ferrite-formation reaction in the aqueous solution, the adsorption of the metal ions and the oxidation of the adsorbed Fe(II) ions are repeated on the surface of the ferrite particles. This reaction was adopted to the coating of the hazardous materials with the Fe3O4(or ferrite). By repeating the two steps of l)the addition of the Fe(II) aqueous solution into the suspension of the hazardous materials, and 2)the oxidation by passing air through the reaction suspension, with the Fe3O4 layer, we could coat the surfaces of the hazardous materials, such as the heavy metal sludge from the neutralization-precipitation process, the CaF2 precipitates in the treatment of the waste waters containing fluoride ion along with hazardous metal ions, and the soils containing Cd(II) ion. These Fe3O4-coated hazardous materials are very stable and no heavy metal ions are leached under the normal environmental conditions. The ferrite sludges formed in the “Ferrite Process” were highly stabilized by the present method, and by the heat-treatment.

scholarly journals Evaluation of N-Alkyl-bis-o-aminobenzamide Receptors for the Determination and Separation of Metal Ions by Fluorescence, UV-Visible Spectrometry and Zeta Potential

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1737 ◽  
Author(s):  
Marisela Martinez-Quiroz ◽  
Xiomara E. Aguilar-Martinez ◽  
Mercedes T. Oropeza-Guzman ◽  
Ricardo Valdez ◽  
Eduardo A. Lopez-Maldonado
Keyword(s):  
Aqueous Solution ◽  
Zeta Potential ◽  
Metal Ions ◽  
Environmental Concern ◽  
Separation Of Metal Ions ◽  
Complexing Capacity ◽  
Alkyl Groups ◽  
Molecular Fluorescence ◽  
Uv Visible ◽  
Phase Sensor

This paper presents the synthesis and evaluation of physicochemical behavior of a new series of N-alkyl-bis-o-aminobenzamides (BOABs) in aqueous solution. The study was targeted to the complexing capacity of five metal ions (Fe2+, Cu2+, Cd2+, Hg2+ and Pb2+) of environmental concern as the medullar principle of a liquid phase sensor for its application in the determination of these metal ions due to its versatility of use. Molecular fluorescence, UV-visible and Zeta potential were measured for five BOABs and the effect of alkyl groups with different central chain length (n = 3, 4, 6, 8 and 10) on physicochemical performance determined. The results have shown that these derivatives present higher sensibility and selectivity for Cu2+ even in the presence of the other metal ions. An additional application test was done adding a pectin (0.1 wt %) solution to the BOAB-Cu+2 complex to obtain a precipitate (flocs) as a potential selective separation process of Cu from aqueous solution. The solid was then lyophilized and analyzed by SEM-EDS, the images showed spheric forms containing Cu+2 with diameter of approximately of 8 μm and 30 wt %.

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