scholarly journals Extraction properties of β-aminophosphine oxides towards lanthanides and alkaline earth metals

2012 ◽  
Vol 10 (6) ◽  
pp. 1933-1941 ◽  
Author(s):  
Ekaterina Matveeva ◽  
Elena Sharova ◽  
Alexander Turanov ◽  
Vasilii Karandashev ◽  
Irina Odinets
Keyword(s):  
Ionic Liquid ◽  
Metal Ions ◽  
Phosphine Oxide ◽  
Separation Factor ◽  
Alkaline Earth ◽  
Extraction Efficiency ◽  
Alkaline Earth Metals ◽  
Neutral Media ◽  
Extraction Properties

AbstractThe investigation of the extraction properties of a series of polyoligodentate β-aminophosphine oxides 1–8 bearing from one to six phosphine oxide groups in a molecule towards Ln(III) and alkaline earth metals ions from neutral media has revealed that, using common diluents, the extraction efficiency increases with an increase of a number of P=O functions in a ligand. The addition of ionic liquid, namely 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([bmim][NTf2]), significantly increasing the extraction efficiency and application of IL concentration of 0.05 M (in 1,2-dichloroethane) providing the maximum recovery of metal ions with Lu/La separation factor reaching up to 91. Hexapodal tris[bis(2-diphenylphosphorylethyl)aminoethyl]amine 8 demonstrates the highest extraction under all conditions applied and the separation factor for U and Eu of this compound exceeded 103.

Zeta potential of clay minerals and quartz contaminated by heavy metals

2005 ◽  
Vol 42 (5) ◽  
pp. 1280-1289 ◽  
Author(s):  
A Kaya ◽  
Y Yukselen
Keyword(s):  
Heavy Metals ◽  
Zeta Potential ◽  
Metal Ions ◽  
Alkaline Earth ◽  
Alkaline Earth Metals ◽  
Ion Concentration ◽  
Test Results ◽  
Ζ Potential ◽  
Pore Fluid Chemistry ◽  
Electrokinetic Decontamination

Laboratory and in situ test results show that electrokinetic decontamination is a promising subsurface decontamination method. However, it has also been reported that several problems arise, such as reverse flow and pH gradient across the anode and the cathode during the electrokinetic decontamination process. Variation in pH alters the zeta (ζ) potential of soils, which is one of the factors affecting the efficiency of contaminant removal by the electrokinetic method. The magnitude of the ζ potential controls the fluid flow rate, whereas its sign controls the flow direction. However, research on how the ζ potential of soils changes under various chemical conditions is limited. In this paper, the effect of pore-fluid chemistry on the ζ potential of kaolinite, montmorillonite, and quartz powder is determined with NaCl, LiCl, CaCl2·2H2O, MgCl2·6H2O, CuCl2, CoCl2, ZnCl2, AlCl3, and Pb(NO3)2. The test results reveal that the ζ potential of the minerals with alkali and alkaline-earth metals changes according to the diffuse electrical double-layer theory. The hydrolyzable metal ions produce two points of zero charge (PZCs), one of which is that of the soil; and the other, that of hydrolyzable oxide. The ζ potential of minerals with hydrolyzable metal ions becomes increasingly positive and reaches its maximum value at neutral pH. It then decreases and again reaches very negative values at alkaline pH values (pH ∼ 10), depending on ion concentration and the bulk precipitation pH of hydrolyzable metals as hydrolyzable oxides. On the basis of the results of this study, it is recommended that the ζ potential of the soils be determined before electrokinetic decontamination.Key words: alkaline-earth metals, electrokinetic decontamination, heavy metals, zeta potential.

Simultaneous Removal of Heavy-Metal Ions by MnO2 Loaded D301 Resin

2011 ◽  
Vol 255-260 ◽  
pp. 2791-2796 ◽  
Author(s):  
Hong Mei Ma ◽  
Zhi Liang Zhu ◽  
Yong Qian Cheng
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Alkaline Earth ◽  
Removal Rate ◽  
Alkaline Earth Metals ◽  
Simultaneous Removal ◽  
High Concentration ◽  
Solution Ph

MnO2-loaded D301 weak basic anion exchange resin was used as adsorbent to simultaneously remove Co2+, Ni2+, Cd2+, Zn2+ andCu2+ from aqueous solution contained high concentration of alkali and alkaline-earth metals ions. The effects of solution pH and coexistent ions on the adsorption were investigated. The results indicated that Co2+, Ni2+, Cd2+, Zn2+ andCu2+ can be simultaneously removed in the wide pH range of 3 to 8. The coexistence of PO43− decreased the heavy metal ions removal rate, but for other high concentrations coexistence cations and anions such as Na+, K+, Cl−, NO3−, SO42− and HCO3−, there is no significant impact on removal rate of heavy metals. The adsorption isotherm can be well described by Langmuir isotherm. The adsorption processes followed the pseudo first-order kinetics model. High adsorption capacity makes it a good promising candidate material for simultaneous removal of Co2+, Ni2+, Cd2+, Zn2+ andCu2+ from aqueous solution with the co-existence of high concentration of alkali and alkaline-earth metals ions.

Polyfunctional Derivatives of Imidodiphosphoric Acid as Extractants

1997 ◽  
Vol 62 (4) ◽  
pp. 620-625 ◽  
Author(s):  
Oldřich Navrátil ◽  
Petr Sládek ◽  
Alena Tokárová ◽  
Eckhard Herrmann ◽  
Moein Nouaman
Keyword(s):  
Aqueous Phase ◽  
Distribution Ratio ◽  
Alkaline Earth ◽  
Functional Group ◽  
Extraction Efficiency ◽  
Ester Group ◽  
Alkaline Earth Metals ◽  
Strontium Barium ◽  
Extraction Constants ◽  
Derivatives Of

The distribution of calcium, strontium, barium and scandium between aqueous and organic phases was studied using 0.1 M HNO3 or 0.01 to 0.1 M HCl as the aqueous phase and solutions of selected derivatives of organophosphoric reagents containing the conventional =P(O)NHP(O)= bifunctional group or the analogous trifunctional or tetrafunctional group in various organic solvents as the organic phase. The effect of substitution of one ester group by an OH or NH2 group was examined. While for the alkaline earth metals the distribution ratio increases if the bifunctional group is replaced by a higher-functional group, the reverse is true for scandium. The extraction efficiency is improved by the presence of OH or NH2 substituent groups. The composition of the extracted species was inferred by logarithmic analysis and the corresponding extraction constants were calculated.

Extraction of nitrates of alkali and alkaline earth metals with crown ether into hydrophilic ionic liquid in the presence of salting out agent

2009 ◽  
Vol 64 (3) ◽  
pp. 130-133 ◽  
Author(s):  
D. I. Djigailo ◽  
S. V. Smirnova ◽  
I. I. Torocheshnikova ◽  
A. G. Vendilo ◽  
K. I. Popov ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Crown Ether ◽  
Alkaline Earth ◽  
Alkaline Earth Metals ◽  
Salting Out

Enhanced Resource Recovery by Beneficiation and Direct Acid Leaching of Fly Ash

1986 ◽  
Vol 86 ◽  
Author(s):  
E. E. Berry ◽  
R. T. Hemmings ◽  
D. M. Golden
Keyword(s):  
Alkaline Earth ◽  
Extraction Efficiency ◽  
Fine Fraction ◽  
Acid Leaching ◽  
Alkaline Earth Metals ◽  
Magnetic Fraction ◽  
Mineral Beneficiation ◽  
Si Content ◽  
Extractable Al ◽  
Soluble Components

ABSTRACTAn investigation was conducted into the use of beneficiated ash fractions as feed materials for direct acid leaching to recover Al and other metals. A low-Ca (1.4% CaO) ash was selected from which four fractions (classifier fines, classifier rejects, magnetic concentrate, and non-magnetics) were produced by mineral beneficiation methods. The raw ash and the four ash fractions were leached with 6 M HCl under reflux. Mass balance data were obtained to determine extraction efficiency for Si, Al, Fe, Ca, Mg, Na, K and Ti. It was found that size separation of the ash had a marked influence in enhancing extraction efficiency from the fine fraction for all of the elements studied except Fe. Extraction of Fe from the magnetic fraction was less efficient than from the non-magnetic fraction. Examination of the solid residue after leaching showed that, although most of the acid-soluble components were removed from the glassy phases of the ash, a significant part of the ash comprised non-reactive glass of high-Si content. A relationship between extractable Al in ash and leachable alkali and alkaline earth metals was identified and discussed in terms of glass modification theory.

Probing cationic selectivity of cardiac calsequestrin and its CPVT mutants

2011 ◽  
Vol 435 (2) ◽  
pp. 391-399 ◽  
Author(s):  
Naresh C. Bal ◽  
Nivedita Jena ◽  
Danesh Sopariwala ◽  
Tuniki Balaraju ◽  
Sana Shaikh ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Metal Ions ◽  
Alkaline Earth ◽  
Ionic Radius ◽  
Alkaline Earth Metals ◽  
Polymorphic Ventricular Tachycardia ◽  
Dependent Manner ◽  
Preferential Binding ◽  
Domain Iii ◽  
Order Structures

CASQ (calsequestrin) is a Ca2+-buffering protein localized in the muscle SR (sarcoplasmic reticulum); however, it is unknown whether Ca2+ binding to CASQ2 is due to its location inside the SR rich in Ca2+ or due to its preference for Ca2+ over other ions. Therefore a major aim of the present study was to determine how CASQ2 selects Ca2+ over other metal ions by studying monomer folding and subsequent aggregation upon exposure to alkali (monovalent), alkaline earth (divalent) and transition (polyvalent) metals. We additionally investigated how CPVT (catecholaminergic polymorphic ventricular tachycardia) mutations affect CASQ2 structure and its molecular behaviour when exposed to different metal ions. Our results show that alkali and alkaline earth metals can initiate similar molecular compaction (folding), but only Ca2+ can promote CASQ2 to aggregate, suggesting that CASQ2 has a preferential binding to Ca2+ over all other metals. We additionally found that transition metals (having higher co-ordinated bonding ability than Ca2+) can also initiate folding and promote aggregation of CASQ2. These studies led us to suggest that folding and formation of higher-order structures depends on cationic properties such as co-ordinate bonding ability and ionic radius. Among the CPVT mutants studied, the L167H mutation disrupts the Ca2+-dependent folding and, when folding is achieved by Mn2+, L167H can undergo aggregation in a Ca2+-dependent manner. Interestingly, domain III mutants (D307H and P308L) lost their selectivity to Ca2+ and could be aggregated in the presence of Mg2+. In conclusion, these studies suggest that CPVT mutations modify CASQ2 behaviour, including folding, aggregation/polymerization and selectivity towards Ca2+.

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