scholarly journals Theoretical and experimental studies on uranium(vi) adsorption using phosphine oxide-coated magnetic nanoadsorbent

RSC Advances ◽  
2021 ◽  
Vol 11 (62) ◽  
pp. 39233-39244
Author(s):  
Zeinab F. Akl
Keyword(s):  
Aqueous Solutions ◽  
Phosphine Oxide ◽  
Experimental Studies ◽  
Cyanex 923

A Fe3O4@Cyanex-923 nanoadsorbent was prepared and applied as an efficient candidate for uranium(vi) removal from aqueous solutions.

Removal of aspirin from aqueous solutions using graphitic carbon nitride nanosheet: Theoretical and experimental studies

2020 ◽  
Vol 101 ◽  
pp. 107621 ◽  
Author(s):  
Mahdieh Chegeni ◽  
Zahra Mousavi ◽  
Mousa Soleymani ◽  
Sara Dehdashtian
Keyword(s):  
Aqueous Solutions ◽  
Carbon Nitride ◽  
Experimental Studies ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride

The extraction of mineral acids by the phosphine oxide Cyanex 923

1996 ◽  
Vol 42 (2) ◽  
pp. 245-255 ◽  
Author(s):  
F.J. Alguacil ◽  
F.A. López
Keyword(s):  
Phosphine Oxide ◽  
Mineral Acids ◽  
Cyanex 923

Chemistry of rhenium as an analogue of technetium: Experimental studies of the dissolution of rhenium oxides in aqueous solutions

2003 ◽  
Vol 91 (4) ◽  
Author(s):  
E. Kim ◽  
J. Boulègue
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Data ◽  
Experimental Studies ◽  
Experimental Results ◽  
Radioactive Element ◽  
Oxidation States ◽  
Dissolution Behavior ◽  
High Concentration ◽  
Very High ◽  
Chemical Analogue

SummaryThe migration of fissiogenic Tc into the environment can be predicted by studying the dissolution behavior of Re, a chemical analogue of Tc, avoiding the use of a radioactive element at high concentration. We developed a series of experimental studies of the solubility of Re oxides under various oxidation states (+VII, +IV, and +III), in oxidizing and anoxic media, so as to verify the validity of the available thermodynamic data concerning Re. The experimental results confirm that the predictable solubility of Re, under the conditions found in radioactive wastes storage, is very high when in the form of {ReO

Effect of the structure of calix[4]arenes, containing phosphine oxide and phosphoryl groups and impregnated on silica gel, on the efficiency of Eu3+ extraction from aqueous solutions

2013 ◽  
Vol 49 (3) ◽  
pp. 199-203 ◽  
Author(s):  
M. S. Lukashova ◽  
K. N. Belikov ◽  
K. Y. Bryleva ◽  
A. V. Verbytska ◽  
V. I. Kal’chenko
Keyword(s):  
Aqueous Solutions ◽  
Silica Gel ◽  
Phosphine Oxide ◽  
Phosphoryl Groups

scholarly journals The Influence of Aqueous Se(IV) on the Stability of Different CaCO3 Polymorphs Precipitated under Ambient Conditions

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1238
Author(s):  
Angeles Fernandez-Gonzalez ◽  
Alba Lozano-Letellier ◽  
Begoña Fernandez
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Aging Process ◽  
Experimental Studies ◽  
Atomic Ratio ◽  
Ambient Conditions ◽  
Calcium Carbonates ◽  
Cell Parameters ◽  
The Stability

Selenium is an essential bio-element, but because of its bioaccumulation potential, it can become toxic and is an important pollutant. The ubiquitous mineral calcite (CaCO3) has the ability to immobilize anions as SeO32− by different sorption or coprecipitation processes. Experimental studies have found that SeO32− can incorporate in the crystal structure of calcite by substituting CO32−. The presence of foreign ions in aqueous solution strongly affects CaCO3 precipitation, helping stabilize less stable polymorphs such as vaterite and aragonite or hydrated phases. In this work, we studied the aging process of calcium carbonates precipitated from aqueous solutions highly supersaturated with respect to CaCO3 and slightly supersaturated with respect to CaSeO3·H2O under ambient conditions, for times up to 30 days in which solids were kept in the remaining aqueous solution. Under these conditions, CaCO3 precipitated mainly as low crystallinity vaterite aggregates that hosted up to 16% atomic ratio Se:C. Vaterite purified and increased its crystallinity with aging time, but the vaterite–calcite transformation was strongly inhibited. The incorporation of Se(IV) in vaterite did not significantly affect the cell parameters or the external morphology of the aggregates. The precipitation of selenite as CaSeO3·H2O was conditioned by the availability of free Ca2+ and SeO32− that was not previously incorporated into precipitated carbonates.

A Mathematical Analysis of Directional Solidification of Aqueous Solutions

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Gideon Ukpai ◽  
Boris Rubinsky
Keyword(s):  
Mathematical Model ◽  
Aqueous Solutions ◽  
Mathematical Models ◽  
Directional Solidification ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Design Parameters ◽  
Fundamental Study ◽  
Biological Matter ◽  
Intent To Use

Abstract Horizontal directional solidification techniques have been broadly utilized for the freezing of biological matter under conditions in which the freezing rate during solidification must be controlled and known. Directional solidification is used for diverse applications such as fundamental research on freezing of biological materials, cryopreservation of biological matter, and tissue engineering. This study is motivated by our intent to use directional solidification as a simplified model for the study of three-dimensional (3D) cryoprinting. In evaluating directional solidification in the context of 3D cryoprinting, we realized that current mathematical models of directional solidification are not adequately representative for this purpose, because they are simplified and one-dimensional (1D). Here, we introduce an experimentally verified and more representative two-dimensional (2D) mathematical model of directional solidification that can aid in the fundamental study of freezing of biological matter, in particular during 3D cryoprinting. The mathematical model was used to develop correlations between the freezing rates that a layer of an aqueous solution experiences during directional solidification and the various design parameters such as thickness of the sample and temperature gradients in the substrate. Results show that the freezing rates can be higher than those suggested by the previously used simplified 1D mathematical models. The results can be used for developing simplified models of 3D cryoprinting. In addition, the results suggest that many experimental studies on directional solidification of aqueous solutions and biological matter may require readjustment of analysis, in view of these findings.

STUDIES ON DICYANOTRIAZOLE: I. THE CONDUCTANCE OF DILUTE AQUEOUS SOLUTIONS OF DICYANOTRIAZOLE AT 25 °C.

1942 ◽  
Vol 20b (8) ◽  
pp. 161-167 ◽  
Author(s):  
E. G. Taylor
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Dissociation Constant ◽  
Experimental Studies ◽  
Equivalent Conductance ◽  
A Value ◽  
Dilute Aqueous Solution ◽  
Dilute Aqueous Solutions

Previous experimental studies of dicyanotriazole have resulted in statements that the compound is an acid comparable in strength with the strong mineral acids.In the present work, measurements of the equivalent conductance of dicyanotriazole in dilute aqueous solution give the dissociation constant of the acid as 3.378 × 10−2 at 25 °C., thus showing it to be an acid possessing about the same strength as dichloracetic acid.The limiting equivalent conductance of dicyanotriazole at 25 °C. is 384.9. The earlier work gave a value of 397.44.

scholarly journals Fixed - bed Column Adsorption Studies Using Synthetic Hydroxyapatite for Pb(II) Removal from Aqueous Solutions

2019 ◽  
Vol 70 (5) ◽  
pp. 1758-1764
Author(s):  
Claudia Maria Simonescu ◽  
Iuliana-Raluca Tanase ◽  
Irina Nicoleta Purcaru ◽  
Christu Tardei ◽  
Virgil Marinescu
Keyword(s):  
Aqueous Solutions ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Design Parameters ◽  
Fixed Bed Column ◽  
Column Adsorption ◽  
Porous Beads ◽  
Synthetic Hydroxyapatite ◽  
Column Design ◽  
Critical Bed Depth

In the present paper, the adsorptive Pb(II) removal from synthetic aqueous solutions using a 2 cm diameter hydroxyapatite column has been studied through column adsorption experiments by varying column depths (1, 2, 3, 4 cm) and flow rate (10, 15, 22.5 mL/min). Different types of synthetic hydroxiapatites have been involved in experiments. Column design parameters such as critical bed depth and adsorption capacity have been determined from experimental studies. The results revealed the effectiveness of synthetic hydroxyapatite porous beads in Pb(II) removal from aqueous synthetic solutions.

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