Sorption of stable and radioactive Cs(I), Sr(II), Co(II) ions on Ti–Ca–Mg phosphates

Journal of Radioanalytical and Nuclear Chemistry - In this paper, we studied the features of stable and radioactive Cs(I), Sr(II) and Co(II) ions sorption on Ti–Ca–Mg phosphates. The...     

Sorption Characteristics of Pillared Ferruginous Montmorillonite Modified with Cetylpyridinium Bromide

The sorption capacity of pillared ferruginous montmorillonite modified with cetylpyridinium bromide for iodine, methylene blue, and phenol was studied. Procedures for preparing a modified sorbent with the optimal sorption power for phenol were developed.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005, pp. 901–904.Original Russian Text Copyright © 2005 by Panasyugin, Kitikova, Bondareva, Sivak.     

Synthesis and Properties of Modified Fillers Based on Calcium and Magnesium Carbonates

A possibility of modifying natural carbonate fillers for paint and varnish industry by solutions of salts of some nonferrous metals was studied. Reactions of carbonates with metal ions and physicotechnical properties of the resulting materials were considered.     

Extraction of Co(II) ions from aqueous solutions with thermally activated dolomite

It was found that thermal activation of dolomite at 700–900°C may increase the sorption capacity of the samples up to 520 mg g^?1. It was shown that the most effective sorbent for Co²⁺ ions may be obtained by calcination of dolomite at 800°C, which allows under dynamic conditions (20 m h^?1) purifi cation of 500 column volumes of an aqueous solution with a Co(II) concentration of 10 mg L^?1 to the maximum allowable concentration.     

Study of the interaction of mono-, di-, and trisubstituted sodium orthophosphates with thermally activated dolomite

Interaction of dolomite thermally treated at 800°C with solutions of mono-, di-, and trisubstituted sodium phosphate was studied. It was shown that thermally treated dolomite binds 0.75 to 3.0 mmol g^–1 of phosphorus, depending on the nature of a phosphating reagent, and the interaction mostly occurs with magnesium oxide, which enables use of this kind of dolomite as a sorbent of phosphate ions. It was found that the nature of the phosphating reagent affects the chemical and phase composition of the materials obtained, as well as their sorption properties with respect to heavy metal ions. The products formed in acid-free phosphation of dolomite have high sorption capacity, from 1.5 to 6.8 mmol g^–1 for Pb²⁺, Zn²⁺, Cu²⁺, Cd²⁺, Ni²⁺, Sr²⁺, and Co²⁺ ions, which enables their use as effective sorbents for heavy metal ions.urning.     

Chemisorption properties of calcium hydrogen phosphate with respect to Cu(II) and Zn(II) ions in mono- and bicomponent solutions

Chemisorption properties of calcium hydrogen phosphate dihydrate CaHPO₄·2H₂O with respect to Cu(II) and Zn(II) ions in Me(NO₃)₂ mono- and bicomponent solutions were considered.     

Adsorption and Structural Properties of Montmorillonite Pillared with Hydroxocomplexes of Iron and Rare-Earth Metals

The sorption and structural parameters and the thermal stability are studied for montmorillonite pillared with Fe(III) polyhydroxocomplexes and mixed Fe(III)–Me(III) hydroxocomplexes, where Me = Ce, La, Y, or Ln. The dependence of the first basal reflection value d ₀₀₁ on the Fe/Me ratio is found. The d ₀₀₁ value is shown to be determined by the nature of the metal.     

Phase formation in the reaction of aluminosilicate ceramics with a phosphate binder

The effect of phase formation at the interface between macroscopic agglomerates constituting a porous aliminosilicate ceramic on its properties was studied by physicochemical methods, with an aluminophosphorous binder used as a modifying agent.     

Synthesis of Calcium and Magnesium Phosphates from Natural Carbonates and Study of Their Activity in Reactions with Lead(II) Ions

Chemical and thermal methods for obtaining calcium and magnesium phosphates from natural carbonate raw materials were studied. The activity of these compounds in uptake of lead(II) ions from solution was evaluated.     

Removal of heavy metal ions from aqueous solutions by alkaline-earth metal phosphates

The possibility of utilization of calcium or magnesium phosphates of various composition for heavy and non-ferrous metal extraction from aqueous solutions has been studied. The efficiency of the phosphates in removal of Pb(II), Cr(III) and Fe(III) ions has been shown to decrease in the following sequence: Mg₃(PO₄)₂>MgNH₄PO₄>Ca₃(PO₄)₂>CaHPO₄>Ca₁₀(PO₄)₆(OH)₂ which is inverse to their hydrolytic stability series. It has been established that phosphates of non-apatite structure are capable of binding up to 12 mmol g⁻¹ of the named heavy metals by a chemical interaction. Hydroxyapatite interacts with the polyvalent metal ions via either the above mentioned or ion-exchange mechanism, depending on preparation method used for the apatite and the nature of metal.