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Lime neutralization is widely used to precipitate heavy metals including copper and cobalt from wastewater. Limestone (calcium carbonate: CaCO3) is too stable to be used directly for this purpose. Grinding of CaCO3in the solutions of copper and cobalt sulphate was conducted to raise its reactivity. During the mechanochemical activation, CaCO3reacted with copper sulphate but not significantly with cobalt sulphate and this phenomenon allowed an easy separation of copper from cobalt. The residual of Cu(II) ions in solution could be controlled at less than 0.1%, meanwhile more than 90% of the Co(II) ions remained in aqueous solution. [ABSTRACT FROM AUTHOR]

Separation of nickel(II) and cadmium(II) ions with use of ion-exchange resins—Amberlyst 15 and Lewatit OC 1026—supported liquid membranes (SLM), polymer inclusion membranes (PIM) and ion-exchange membranes (IM) from sulphate solution has been studied. Di(2-ethylhexyl) phosphoric acid (D2EHPA) was used as the ion-carrier in PIM and SLM separation. It was shown that use of SLM or PIM membranes enables separation of Ni(II)/Cd(II) ions. Experimental results data show that the highest recovery factor values were obtained for supported liquid membranes. The SEM surface and cross-sectional images of SLM support, polymer inclusion membrane and ion-exchange membrane have been also prepared. [ABSTRACT FROM PUBLISHER]

Extraction and separation of divalent Mn and Zn ions from acidic sulfate solutions containing 0.05 M of each metal ion have been carried out using 0.04 M Na-CYANEX 272 in kerosene. The influences of the following parameters were studied: shaking time, equilibrium pH, extractant concentration, diluents type, and temperature. The extraction percentage of both metal ions increased with increasing equilibrium pH in the range 2.0–4.0 and 2.75–6.0 for Zn(II) and Mn(II), respectively. The separation factor, S(Zn/Mn), increases with the increase in pH to reach a maximum value of about 24 × 103at pH 4.0. Extraction of both metal ions increased with increasing extractant concentration. Aliphatic diluents were preferred compared to aromatic diluents. The thermodynamic parameters (ΔH, ΔS, and ΔG) for Mn(II) and Zn(II) were calculated. The extraction mechanism of both metals by Na-CYANEX 272, stripping from loaded extractant and recycling of extractant used in the extraction process were also investigated. [ABSTRACT FROM PUBLISHER]

Separation of nickel(II) and cadmium(II) ions from sulphate solution has been studied. The solutions of Ni(II) and Cd(II) have been treated with different exchange resins: Lewatit OC-1026, Lewatit TP-207, and Lewatit MonoPlus SP 112. Data obtained from the ion-exchange process was compared with data from the supported liquid membrane experiment. It was shown that the use of the supported liquid membrane process enables separation of investigated ions. In this process the highest recovery factor was obtained. The best separation of metal ions was obtained for the ion-exchange process with Lewatit OC 1026. [ABSTRACT FROM PUBLISHER]