Karolina Wieszczycka

Adsorption of Ni(II) from model solutions using co-precipitated inorganic oxides

The aim of this work was to obtain an inorganic oxide system containing silica and magnesium oxide, and characterized by specific physicochemical properties, in particular well-defined adsorption parameters. The preparation process was carried out according to a co-precipitation method using solutions of sodium silicate and selected inorganic magnesium salt. The oxide system obtained (MgO·SiO2) was used as a support (adsorbent) of nickel(II) ions, whose precursors were model solutions of nitrates. The effectiveness of the adsorption process was evaluated using many different analytical techniques, including atomic absorption spectroscopy, energy dispersive X-ray spectroscopy and equivalent point titration. Moreover the stability of adsorbent/adsorbate bonding was estimated. The oxide systems—adsorbents—used in the process were also analyzed according to their physicochemical properties, especially changes in adsorption parameters. The last part of the study involved evaluation of the kinetics of the adsorption process depending on time and the pH of the reaction system.

Removal of Copper(II) from Chloride Solutions using Hydrophobic Pyridyl Ketone Oximes

Abstract: The model oximes of 1‐(2‐pyridyl)undecane‐1‐one (2PC10), 1‐(2‐pyridyl)tridecane‐1‐one (2PC12) and 1‐(4‐pyridyl)tridecane‐1‐one (4PC12) were synthesized and used for copper(II) extraction from chloride solutions. The behavior of these ligands towards copper(II) extraction was investigated for different experimental conditions with a particular emphasis on the influence of the concentrations of copper ions, chloride ions, and ligand. The obtained results indicated the ability of pyridylketoximes to extract copper(II) from chloride solutions. 2‐Pyridyl ketone oximes are stronger extractants of copper than 4‐pyridyl ketone oximes. Copper can be effectively stripped by water or diluted sulfuric acid.

Solvent Extraction of Iron(III) From Chloride Solutions in the Presence of Copper(II) and Zinc(II) Using Hydrophobic Pyridyl Ketoximes

In this work, oximes of 1-(2-pyridyl)tridekane-1-one and 1-(4-pyridyl)tridecane-1-one were used as model hydrophobic extractants for iron(III) from a chloride media. Both studied pyridyl ketoximes have the ability to extract iron(III) from chloride solutions. The highest degree of iron(III) extraction was observed for 1-(2-pyridyl)tridecane-1-one oxime. During extraction with 4-pyridyl ketoxime, a precipitated complex was observed, which has a disadvantageous effect for the extraction process. Iron(III) could be effectively stripped by 1% HCl from organic solution after extraction. Selectivity extractions from multielemental aqueous solutions containing iron(III) using 2- and 4-pyridyl ketoximes were also studied. The highest extraction percentage and good selectivity was observed for Cu2+ from a solution containing 1.0 M Cl− with 1-(2-pyridyl)tridecane-1-one oxime. A scheme of separation of particular metal ions from mulielemental aqueous solutions was also proposed. The separation of metal ions is possible in three stages of extraction.

Removal of Cadmium(II) Ions from Chloride Solutions by Cyanex 301 and Cyanex 302

The main goal of this work was to study and compare the extraction of cadmium(II) ions by the two organophosphorous extractants: Cyanex 301 and Cyanex 302. The effect of different variables influencing the extraction of cadmium(II) ions such as the concentration of acid or metal ion and type of extractant has been investigated. Obtained results from the extraction process were compared with the FT-IR spectra. Results of spectrophotometric analysis confirm the observations of the extraction process, for example, the negative effect of hydrochloric acid on cadmium extraction by Cyanex 302.

Zinc(II) Ions Removal from Chloride Solutions by Hydrophobic Alkyl-Pyridyl Ketoximes

The aim of this work was to examine the influence of the concentration of chloride, nitrate, perchlorate, and zinc(II) ions in the extraction process using synthesized hydrophobic 2-pyridyl ketoximes. Results indicated that oximes could extract zinc(II) ions from chloride solutions and that the extraction depended on ligand and chloride ion concentrations. A maximum extraction was observed at 1.0–1.5 M Cl- and at higher chloride solutions the complex-forming power of 2-pyridyl ketoximes slowly decreased. Zinc(II) ions were effectively stripped from the loaded organic phase with water or ammonia solutions in two stages. The regenerated oximes could yet be used again in the extraction of zinc(II) ions and the reagents could be able to extract solutions with similar results as before. The current study shows that 2-pyridyl ketoximes can be used to extract zinc(II) ions from concentrated chloride solutions and that the separation of copper(II) ions from multielemental solutions is possible.

Extraction of Copper(II) Ions from Chloride and Sulphate Solutions Using Hydrophobic Pyridyl Ketoximes

Hydrophobic pyridyl ketoximes: 1-(2-pyridyl)tridecan-1-one oxime, 1-(3-pyridyl)tridecan-1-one oxime and 1-(4-pyridyl)tridecan-1-one oxime have been synthesized and investigated as extractants of copper(II) ions. Removal of metal ions was conducted from chloride, sulphate, and sulphate/chloride solutions. The influence of pH of aqueous solutions, copper(II), chloride, and sulphate ions and ligand concentration for extraction process were studied. Copper(II) extraction by hydrophobic 2-, 3-, and 4-pyridyl ketoximes from sulphate solutions is not possible. However, addition of chloride ions to initial sulphate media enables metal removal. The oxime of 1-(2-pyridyl)tridecane-1-one was determined as the strongest extractant of the tested oximes, but metal stripping was impossible. For the rest of the studied extractants the stripping process could be done using water or diluted mineral acid.

Degradation of organothiophosphorous extractant Cyanex 301.

The resistance of extractants to light is important during industrial extraction processes. A photodegradation of the organothiophosphorous extractant Cyanex 301 in toluene and hexane as organic diluent and the identification of possible degradation products using FT-IR and GC-MS techniques were performed. The influence of copper(II) and cobalt(II) ions on the stability of the extractant under UV-vis light exposure was also studied. The changes in the percentage composition of individual components of the extractant depended on the types of organic diluents and copper or cobalt ions. During this process, copper complex irradiation precipitation of black powder and photooxidation of toluene were observed. Based on these results we proposed a hypothetical mechanism of photodegradation of extractant Cyanex 301.

Recovery of Nickel(II) Ions from Sulphate/Chloride Solutions Using Hydrophobic Pyridylketoximes

In this study, the extraction of nickel(II) ions from sulphate and sulphate/chloride solutions with 2-, 3-, and 4-pyridylketoximes was investigated. The effect of different variables influencing the extraction of nickel(II) ions such as the extractant structure and the concentration of hydrogen ion, sulphate, and chloride ions have been studied. The shaking time and temperature also influenced metal ion removal. It was found that the hydrophobic 2-pyridylketoximes are the most effective extractants for nickel ions from sulphate/chloride solutions. The discussion also includes the mechanism of nickel(II) complexation by the hydrophobic pyridylketoximes and the speciation of nickel(II) in the presence of chloride and sulphate ions.

Pyridylketoximes with Branched Alkyl Chain as Extractants of Copper(II) Ions from Chloride Solutions

The present work describes fundamental studies of extractive copper(II) ions removal from chloride media with 2-, 3-, and 4- pyridylketoximes containing 2-ethylhexyl chain. The effect of different variables on the extraction of copper(II) ions such as the concentration of chloride ions, hydrochloric acid, and ligand has been investigated. The results indicate that the extraction ability of the pyridineketoximes towards copper(II) ions depends significantly on the position of oxime group in the pyridine ring. The oxime of 3-ethyl-1-(2-pyridyl)heptan-1-one was determined as the strongest extractant of the tested oximes and metal stripping was possible by the sodium oxalate with 0.2% addition of sulfuric acid. However, the copper(II) complexes with 3-pyridylketxime reextrcation could be effectively done using water or ammonium hydroxides. The oxime of 3-ethyl-1-(4-pyridyl)heptan-1-one formed a stable emulsion during mixing with chloride solution.

Photodegradation of pyridylketoximes in methanolic solutions under UV–Vis radiation

Photodegradation of the oximes of alkyl-2-, -3-, and -4-pyridylketones and identification of possible degradation products using LC–MS/MS and GC–MS techniques were performed. The influence of copper(II) and iron(III) ions on the stability of the oxime under UV–Vis radiation exposure were also studied. It was found that the photodegradation of the pyridylketoximes resulted in the photoisomerization, photofragmentation and photosubstitution to a pyridine ring. Based on these results, a hypothetical mechanism of photodegradation of pyridylketoximes was proposed.