This article presents studies on the precipitation of Pt, Pd, Rh, and Ru nanoparticles (NPs) from model and real multicomponent solutions using sodium borohydride, ascorbic acid, sodium formate, and formic acid as reducing agents and... more
This article presents studies on the precipitation of Pt, Pd, Rh, and Ru nanoparticles (NPs) from model and real multicomponent solutions using sodium borohydride, ascorbic acid, sodium formate, and formic acid as reducing agents and polyvinylpyrrolidone as a stabilizing agent. As was expected, apart from PGMs, non-precious metals were coprecipitated. The influence of the addition of non-precious metal ions into the feed solution on the precipitation yield and catalytic properties of the obtained precipitates was studied. A strong reducing agent, NaBH4 precipitates Pt, Pd, Rh, Fe and Cu NPs in most cases with an efficiency greater than 80% from three- and four-component model solutions. The morphology of the PGMs nanoparticles was analyzed via SEM-EDS and TEM. The size of a single nanoparticle of each precipitated metal was not larger than 5 nm. The catalytic properties of the obtained nanomaterials were confirmed via the reaction of the reduction of 4-nitrophenol (NPh) to 4-aminoph...
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This article presents studies on the recovery of cobalt from a spent cobalt oxide catalyst, left after the preparation of industrial catalysts. Apart from cobalt, the tested material contained iron, copper, zinc, and nickel. Leaching was... more
This article presents studies on the recovery of cobalt from a spent cobalt oxide catalyst, left after the preparation of industrial catalysts. Apart from cobalt, the tested material contained iron, copper, zinc, and nickel. Leaching was proposed as a simple and feasible operation to treat the spent cobalt oxide. The 0.1–8.0 M H2SO4 solutions were applied as leaching agents at an ambient temperature and at 70 °C. An 8.0 M H2SO4 solution at 70 °C leached two-fold more Co(II) than a 0.1 M H2SO4 solution at the same temperature. Similar to Co(II), regardless of the leaching temperature, the Fe ion was leached more efficiently with 4.0 or 8.0 M H2SO4 than with a 0.1 M acid. It should be emphasized that the Co(II) content in the solution after leaching was predominant at >90% (~4800 mg/dm3), compared to other metal ions. The ANOVA analysis indicated that both the sulfuric(VI) acid concentration and temperature had a significant effect on the leaching efficiency. An increase in acid co...
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The salt of formula [H2EDTA2+][HSO4−]2 (dihydrogen ethylenediaminetetraacetate di(hydrogen sulfate(VI)) was used to examine the physicochemical properties of the resulting Ni layer and evaluate the applicability of the salt as a new... more
The salt of formula [H2EDTA2+][HSO4−]2 (dihydrogen ethylenediaminetetraacetate di(hydrogen sulfate(VI)) was used to examine the physicochemical properties of the resulting Ni layer and evaluate the applicability of the salt as a new additive for Watts-type baths. The Ni coatings deposited from baths containing [H2EDTA2+][HSO4−]2 were compared with those obtained from other baths. The nucleation of nickel on the electrode was proven to occur the slowest in the bath that contained the mixture of [H2EDTA2+][HSO4−]2 and saccharin compared with other baths. The addition of [H2EDTA2+][HSO4−]2 alone (bath III) generated a coating with a morphology similar to that obtained from bath I (without additives). Despite the similar morphology and wettability of the Ni-coated surfaces plated from various baths (all Ni coatings were hydrophilic with contact angles in the range of 68 to 77°), some differences in electrochemical properties were noted. The corrosion resistance for the coatings plated f...
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This paper presents Cr(III) removal from nickel sulfate waste solutions as a pretreatment step for the modification of hydrogen storage alloys. Adsorption with two cation exchange resins, Dowex G26 (strongly acidic) and MAC-3 (weakly... more
This paper presents Cr(III) removal from nickel sulfate waste solutions as a pretreatment step for the modification of hydrogen storage alloys. Adsorption with two cation exchange resins, Dowex G26 (strongly acidic) and MAC-3 (weakly acidic), and precipitation with various solutions were chosen as simple operations for Cr(III) removal from waste solutions. The adsorption of Cr(III) was investigated for both model and real waste nickel solutions. Dowex G26 appeared to be more efficient in Cr(III) removal (RCr(III) from 43 to 80%) than MAC-3 (RCr(III) from 40 to 53%). However, the adsorption from multi-component solutions (presence of Co(II), Ni(II) and Cr(III)) showed no selectivity in Cr(III) adsorption in comparison to those of Co(II) and Ni(II). Cr(III), Ni(II) and Co(II) were removed at a comparable level (30–36%) from a three-component solution of 10 g/dm3 of each metal ion, and a 56–72% removal of these ions was achieved from the real solution. Therefore, the precipitation of C...
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The study reported in this article has shown for the first time that strongly acidic solutions (pH < 0.5) obtained after hydrometallurgical treatment of spent automotive converters (SAC) may be valuable secondary sources of platinum... more
The study reported in this article has shown for the first time that strongly acidic solutions (pH < 0.5) obtained after hydrometallurgical treatment of spent automotive converters (SAC) may be valuable secondary sources of platinum group metal (PGM) nanoparticles (NPs). The PGM precipitation strongly depended on the solution pH; the yield of the precipitated PGM NPs increased considerably from 40% to almost 100% when the pH was adjusted to 7–8. To improve the NPs stability, commercial TiO2 was used as support to obtain efficient recyclable PGM@TiO2 catalysts. The size of the PGM NPs was smaller than 5 nm, while the diameter of the supported particles varied from 10 to 50 nm. The size and dispersion of PGM NPs on the support strongly depended on the pH of the medium: at pH < 0.5, the Pt and Pd NPs were significantly smaller than the NPs obtained at pH 7–8. Also, in the case of Pt@TiO2 and Rh@TiO2, the NPs were well dispersed on the support in contrast to the large agglomerates...
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The review presents advances in the removal of Cr(III) from the industrial effluents published in the last ten years. Although Cr(III) has low solubility and is less dangerous for the aquatic environment than Cr(VI), it cannot be released... more
The review presents advances in the removal of Cr(III) from the industrial effluents published in the last ten years. Although Cr(III) has low solubility and is less dangerous for the aquatic environment than Cr(VI), it cannot be released into the aquatic environment without limitations and its content in water should be restricted. The development of efficient techniques for the removal of Cr(III) is also a response to the problem of chromium wastewater containing Cr(VI) ions. Very often the first step in dealing with such wastewater is the reduction in chromium content. In some cases, removal of Cr(III) from wastewaters is an important step for pretreatment of solutions to prepare them for subsequent recovery of other metals. In the review, hydrometallurgical operations for Cr(III) removal are presented, including examples of Cr(III) recovery from real industrial effluents with precipitation, adsorption, ion exchange, extraction, membrane techniques, microbial-enhanced techniques,...
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The chapter presents some aspects of metal leaching from e-waste. It focuses on new leaching systems containing ionic liquids (ILs) for recovery of copper (mainly) from waste printed circuit boards (PCBs). It is reported that the most... more
The chapter presents some aspects of metal leaching from e-waste. It focuses on new leaching systems containing ionic liquids (ILs) for recovery of copper (mainly) from waste printed circuit boards (PCBs). It is reported that the most efficient are acidic ILs with bisulfate anion, and they perform even better than sulfuric acid. However, the results of the leaching show that IL agent should be supported by the presence of some oxidants (e.g. H2O2) to increase the process efficiency. Nonetheless, the use of ILs seems to be a perspective option to make the leaching more intensive and effective, a lot of basic research is necessary to investigate the mechanism of the Cu leaching, and to find optimum process conditions.
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This paper presents an application of three phosphonium ionic liquids for removal of Pd(II) ions from aqueous chloride solutions with liquid-liquid extraction and transport across polymer inclusion membranes (PIM).... more
This paper presents an application of three phosphonium ionic liquids for removal of Pd(II) ions from aqueous chloride solutions with liquid-liquid extraction and transport across polymer inclusion membranes (PIM). Trihexyl(tetradecyl)phosphonium chloride and bromide (Cyphos IL 101 and 102) and bis-(2,4,4-trimethylpentyl)phosphinate (Cyphos IL 104) were investigated as carriers of Pd(II) from aqueous chloride media. Extraction of Pd(II) with Cyphos IL 102 has not been previously described in the literature. Cyphos IL 102 used for the first time as metal ion carrier, efficiently extracts palladium(II) ions both with liquid-liquid extraction and PIM. NaCl concentration does not affect Pd(II) extraction with Cyphos IL 102, while increasing HCl content in the feed aqueous phase causes decrease in extraction efficiency. Stripping of Pd(II) with 0.5 M NH4OH is efficient (84 to 90%) and the organic phase after stripping could be reused for extraction. For PIM transport the highest values o...
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Abstract This paper presents sustainable hydrometallurgical recovery of Co(II) from wastewater, achieved by application of two ionic liquids (Cyphos IL 101 or 104) and an acidic extractant (Cyanex 272). The separation of Co(II) is carried... more
Abstract This paper presents sustainable hydrometallurgical recovery of Co(II) from wastewater, achieved by application of two ionic liquids (Cyphos IL 101 or 104) and an acidic extractant (Cyanex 272). The separation of Co(II) is carried out from model aqueous chloride and sulfate solutions, as well as from a real waste sulfate solution containing also Ni(II). The extractants were investigated both as single carriers and as synergic mixtures, the latter giving no positive synergistic effect. Cyanex 272 does not allow Co(II) to be transferred from chloride solutions effectively, while extraction from sulfate mixtures reaches totally up to 100% after two stages. Cyphos IL 101 does not give satisfactory results of Co(II) recovery from sulfate solutions, while both Co(II) and Ni(II) are transferred efficiently from chloride ones. Stripping of Co(II) from the loaded organic phases with 1 M H2SO4 is very efficient (95–100%), regardless of the type of extractant (Cyanex 272 or Cyphos IL 104) and its concentration. Application of 1 M H2SO4 allows Co(II) to be recovered from the loaded organic phase (up to 100%) in one stage of stripping and to be enriched even three-to fivefold relative to that in the feed. It also allows the organic phase to be reused for further extractions. Theoretical considerations of economic feasibility of the process proposed indicated that the value of cobalt in solutions after proposed steps increases from 0.32 USD/dm3 (after two stages of extraction) to 1.42 USD/dm3 after stripping. The major novelty of this work is the design of hydrometallurgical recovery of Co(II) from real sulfate wastewater in the presence of Ni(II), which permits sustainable processing of waste, recycling and recovery of critical element and also regeneration and reuse of organic chemicals applied for extraction.
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E-waste amount is growing at about 4% annually, and has become the fastest growing waste stream in the industrialized world. Over 50 million tons of e-waste are produced globally each year, and some of them end up in landfills causing... more
E-waste amount is growing at about 4% annually, and has become the fastest growing waste stream in the industrialized world. Over 50 million tons of e-waste are produced globally each year, and some of them end up in landfills causing danger of toxic chemicals leakage over time. E-waste is also sent to developing countries where informal processing of waste electrical and electronic equipment (WEEE) causes serious health and pollution problems. A huge interest in recovery of valuable metals from WEEE is clearly visible in a great number of scientific, popular scientific publications or government and industrial reports.
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Research Interests: Engineering, Chemistry, Metallurgy, Water Purification, Wastewater Treatment, and 14 moreMedicine, Solvent Extraction, Steel, Legislation, Hazardous Materials, Solutions, Industrial Waste, Conservation of Natural Resources, Ion Exchange, Membrane Distillation, Economic Benefit, Pickling, Sulfuric Acid, and Best available techniques
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The paper presents basic studies on the precipitation of platinum, palladium, rhodium, and ruthenium nanoparticles from model acidic solutions using sodium borohydride, ascorbic acid, and sodium formate as reducing agents and... more
The paper presents basic studies on the precipitation of platinum, palladium, rhodium, and ruthenium nanoparticles from model acidic solutions using sodium borohydride, ascorbic acid, and sodium formate as reducing agents and polyvinylpyrrolidone as a stabilizing agent. The size of the obtained PGM particles after precipitation with NaBH4 solution does not exceed 55 nm. NaBH4 is an efficient reducer; the precipitation yields for Pt, Pd, Ru, Rh are 75, 90, 65 and 85%, respectively. By precipitation with ascorbic acid, it is possible to efficiently separate Pt, Rh, and Ru from Pd from the two-component mixtures. The obtained Pt, Pd, and Rh precipitates have the catalytic ability of the catalytic reaction of p-nitrophenol to p-aminophenol. The morphological characteristic of the PGM precipitates was analyzed by AFM, SEM-EDS, and TEM.
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The extraction of zinc(II), iron(III) and iron(II) with TBP from hydrochloric acid solutions containing high zinc(II) concentration is studied. Two technological approaches for the separation are considered. Firstly, the selective... more
The extraction of zinc(II), iron(III) and iron(II) with TBP from hydrochloric acid solutions containing high zinc(II) concentration is studied. Two technological approaches for the separation are considered. Firstly, the selective extraction of iron(III) (iron(II) is oxidized to iron(III)) over zinc(II) with TBP deficiency. Secondly, iron(III) reduction to iron(II) followed by zinc(II) selective extraction with an excess of TBP. The total removal of iron(III) needs several successive extractions with fresh TBP portions. Such a process is not technologically reasonable. Stripping both of zinc(II) and iron(III) can be effectively accomplished with water but is not selective. Prior stripping, the organic phase can be washed with small amounts of water. Scrubbing of TBP solutions containing iron(III) contaminated with zinc(II) gives always a mixture of zinc(II) and iron(III) which must be recycled to the extraction step in continuous process. Scrubbing of TBP solutions containing zinc(I...
Investigations on trihexyl(tetradecyl)phosphonium cas selective carrier to remove zinc(II) from HCl solution in bul k liquid membrane system were carried out. The use of trihexyl(tetradecyl)phospho nium chloride as a selective carrier of... more
Investigations on trihexyl(tetradecyl)phosphonium cas selective carrier to remove zinc(II) from HCl solution in bul k liquid membrane system were carried out. The use of trihexyl(tetradecyl)phospho nium chloride as a selective carrier of zinc(II) in the membrane process is disa dvantageous. Zinc(II) and the carrier form strong bounded ionic pair that makes z inc stripping very difficult. And the obtained zinc(II) concentration in the strippin g phase is small, what disqualifies the use of the system on a larger scal e .
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The extraction of zinc(II), iron(III) and iron(II) with TBP from hydrochloric acid solutions containing high zinc(II) concentration is studied. Two technological approaches for the separation are considered. Firstly, the selective... more
The extraction of zinc(II), iron(III) and iron(II) with TBP from hydrochloric acid solutions containing high zinc(II) concentration is studied. Two technological approaches for the separation are considered. Firstly, the selective extraction of iron(III) (iron(II) is oxidized to iron(III)) over zinc(II) with TBP deficiency. Secondly, iron(III) reduction to iron(II) followed by zinc(II) selective extraction with an excess of TBP. The total removal of iron(III) needs several successive extractions with fresh TBP portions. Such a process is not technologically reasonable. Stripping both of zinc(II) and iron(III) can be effectively accomplished with water but is not selective. Prior stripping, the organic phase can be washed with small amounts of water. Scrubbing of TBP solutions containing iron(III) contaminated with zinc(II) gives always a mixture of zinc(II) and iron(III) which must be recycled to the extraction step in continuous process. Scrubbing of TBP solutions containing zinc(I...
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The extraction of zinc(II), iron(III) and iron(II) with TBP and its binary mixtures with DEHPA and CYANEX 302 from hydrochloric acid solutions was studied. It was found that the extraction ability of zinc(II) chlorocomplexes from... more
The extraction of zinc(II), iron(III) and iron(II) with TBP and its binary mixtures with DEHPA and CYANEX 302 from hydrochloric acid solutions was studied. It was found that the extraction ability of zinc(II) chlorocomplexes from hydrochloric acid solutions decreased in the order: TBP > TBP:HL=3:1 vol/vol > TBP:HL=1:1 vol/vol. Iron(III) was strongly extracted by TBP and its binary mixtures with DEHPA and CYANEX 302, and the extraction fell in the order: binary mixtures with DEHPA or CYANEX 302> TBP> DEHPA >> CYANEX 302. Iron(II) was not extracted by the considered extractants. Zinc(II) could not be selectively extracted in the presence of iron(III). Contrary, iron(III) could be selectively extracted, especially with the binary 1:1 vol/vol mixtures of TBP with DEHPA or CYANEX 302. The stripping of zinc(II) could be accomplished in three successive stages using water and 0.1 M H 2SO4. Iron(III) could be stripped in three stages with 0.1 M H2SO4.
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The paper reviews application of various liquid membranes (LM), particularly of emulsion and supported liquid membranes, for metal separation from model and industrial wastewaters. A variety of carriers and separation systems is shown.... more
The paper reviews application of various liquid membranes (LM), particularly of emulsion and supported liquid membranes, for metal separation from model and industrial wastewaters. A variety of carriers and separation systems is shown. Not only model solutions on a laboratory scale are presented but also some examples of real wastewater separation with LM are reported.
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Abstract The recovery of metals from waste is profitable not only from an economic but also from an ecological point of view. The natural resources of metals (especially platinum group metals – PGM) are limited, while the amount of waste... more
Abstract The recovery of metals from waste is profitable not only from an economic but also from an ecological point of view. The natural resources of metals (especially platinum group metals – PGM) are limited, while the amount of waste containing the desired metals is still growing. The purpose of the work is the use of quaternary phosphonium salts, i.e. Cyphos IL 101 (trihexyl(tetradecyl)phosphonium chloride), Cyphos IL 102 (trihexyl(tetradecyl)phosphonium bromide) and Cyphos IL 104 (trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate), for the separation of palladium(II), platinum(IV), rhodium(III) and ruthenium(III) from their multi-component model mixtures of composition based on real solutions after leaching of PGM-containing wastes (e.g. automobile catalytic converters). Though, Pd(II) could not be separated from Pt(IV) by one-stage extraction, separation of Pd(II) from Pt(IV) was possible by stripping with 0.1 M thiourea in 0.5 M HCl. The extraction of Rh(III) from the four-component solution practically did not occur (Rh(III) stayed in raffinate), therefore Pt(IV) and Pd(II) could be selectively separated from Rh(III). As a result of the work, a separation procedure of successful separatation of Pd(II), Pt(IV), Ru(III) Rh(III) from four-component solutions has been developed based on two stages of extraction with ionic liquid solution (trihexyl(tetradecyl)phosphonium chloride) and two stages of stripping.
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This paper presents an application of three phosphonium ionic liquids for removal of Pd(II) ions from aqueous chloride solutions with liquid-liquid extraction and transport across polymer inclusion membranes (PIM).... more
This paper presents an application of three phosphonium ionic liquids for removal of Pd(II) ions from aqueous chloride solutions with liquid-liquid extraction and transport across polymer inclusion membranes (PIM). Trihexyl(tetradecyl)phosphonium chloride and bromide (Cyphos IL 101 and 102) and bis-(2,4,4-trimethylpentyl)phosphinate (Cyphos IL 104) were investigated as carriers of Pd(II) from aqueous chloride media. Extraction of Pd(II) with Cyphos IL 102 has not been previously described in the literature. Cyphos IL 102 used for the first time as metal ion carrier, efficiently extracts palladium(II) ions both with liquid-liquid extraction and PIM. NaCl concentration does not affect Pd(II) extraction with Cyphos IL 102, while increasing HCl content in the feed aqueous phase causes decrease in extraction efficiency. Stripping of Pd(II) with 0.5 M NH 4 OH is efficient (84 to 90%) and the organic phase after stripping could be reused for extraction. For PIM transport the highest values...
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Recovery of platinum group metals (PGM) from complex aqueous solutions generated as a result of leaching of various spent materials (e.g., spent automotive converters) is a vital issue in the context of the circular economy. In this study... more
Recovery of platinum group metals (PGM) from complex aqueous solutions generated as a result of leaching of various spent materials (e.g., spent automotive converters) is a vital issue in the context of the circular economy. In this study pyridinium derivatives containing an imidoamide or imine moiety (i.e., 3-[1-(2-ethylhexyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)ethane]-1-propylpyridinium chloride and 4-[1-amine(2-ethylhexyloxyimine)]-1-propylpyridinium chloride) are proposed as novel extractants for recovery of palladium(II) and platinum(IV) from model chloride aqueous solutions. The results of liquid-liquid extraction from one-component solutions of palladium(II) or platinum(IV) showed that quaternary pyridinium salts can be used as effective extractants for platinum metal ions. Moreover, PGM extraction from a two-component mixture proved no evident selectivity in the transfer of one of the met...