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Biosorption of neodymium (nd) from aqueous solutions using Spirulina platensis sp. strains

Lima, Eder Claudio; Pinto, Diana; Schadeck Netto, Matias; Simoes dos Reis, Glaydson; Silva Oliveira, Luis Felipe; Dotto, Guilherme Luiz (MDPI AGSwitzerland, 2022-10-28)

Rare earth elements such as neodymium (Nd) are important elements used mainly in developing new technologies. Although they are found in low concentrations in nature, they can be obtained by extracting solid samples such ...
Leaching of rare earth elements from phosphogypsum

Frantz Lütke, Sabrina; Silva Oliveira, Marcos Leandro; Waechter, Samuel Rodrigo; Silva Oliveira, Luis Felipe; Cadaval, Tito (Elsevier Ltd.United Kingdom, 2022)

High amounts of phosphogypsum (PG) are generated in the production of phosphoric acid. Previous literature demonstrates that obtaining rare earth elements (REE) from PG is a promising alternative to managing this waste. ...
Nanometric particles of high economic value in coal fire region: Opportunities for social improvement

Silva Oliveira, Luis Felipe; Crissien Borrero, Tito José; Schneider, Ismael L.; Blanco, Érika P.; Sampaio, Carlos H. (Universidad de la Costa, 2020-02-10)

Spontaneous coal combustion in the La Guajira coals was studied for the presence of carbon nanophases (e.g., carbon nanotubes), occurrence of rare earth elements (REEs) in them, and the probable mechanisms for concentration ...
Nickel-aluminium layered double hydroxide as an efficient adsorbent to selectively recover praseodymium and samarium from phosphogypsum leachate

dos Reis, Glaydson S.; Dotto, Guilherme Luiz; Vieillard, Julien; Silva Oliveira, Marcos Leandro; Frantz Lütke, Sabrina; Grimm, Alejandro; Silva Oliveira, Luis Felipe; Lima, Éder C.; Naushad, Mu.; Lassi, Ulla (Elsevier BVNetherlands, 2023-10-15)

This study aimed to synthesize a green powdered layered double hydroxide (LDH) based on nickel-aluminum (Ni–Al-LDH) to evaluate its efficiency in the removal of rare earth elements (REEs), Praseodymium (Pr3+) and Samarium ...
Occurrence of carbon nanotubes and implication for the siting of elements in selected anthracites

Silva Oliveira, Luis Felipe; Crissien Borrero, Tito José; Sampaio, Carlos H.; Hower, James; Daifg, Shifeng (Universidad de la Costa, 2020-03-01)

Petrographic, geochemical, and electron microbeam investigations of selected anthracites and anthracite-rank coaly shales were conducted. The Pennsylvania, Rhode Island, and KwaZu-Natal anthracites show an enrichment in ...
Rare earth elements study of cretaceous coals from benue trough basin, Nigeria: modes of occurrence for greater sustainability of mining

Akinyemi, Segun Ajayi; Nyakuma, Bemgba Bevan; Jauro, Aliyu; Olanipekun, Timileyin; Mudzielwana, Rabelani; Gitari, Wilson; Saikia, Binoy; Dotto, Guilherme Luiz; Hower, J. C; Silva, Luis F. O (Fuel, 2021-07-14)

The rare earth elements (REE) possess a beneficial combination of chemical and physical properties, making them valuable for most advanced branches of engineering and technology. Alternative sources of REE are desirable ...

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Biosorption of neodymium (nd) from aqueous solutions using Spirulina platensis sp. strains
...
Lima, Eder Claudio | 2022-10-28

Rare earth elements such as neodymium (Nd) are important elements used mainly in developing new technologies. Although they are found in low concentrations in nature, they can be obtained by extracting solid samples such as phosphogypsum. Among the techniques, adsorption has been used successfully with several adsorbent materials. In this work, two strains of Spirulina platensis (LEB-18 and LEB-52) were employed as biosorbents for efficiently removing the Nd element from the aqueous media. Biosorption tests were carried out in a batch system, and the results of the biosorption kinetics showed that for both materials, the biosorption of Nd was better described by the Avrami model. Moreover, it could be considered that 80 min would be necessary to attain the equilibrium of Nd(III) using both biosorbents. The result of the biosorption isotherms showed that for both strains, the best-fitted model was the Liu model, having a maximum biosorption capacity of 72.5 mg g−1 for LEB-18 and 48.2 mg g−1 for LEB-52 at a temperature of 298 K. Thermodynamics of adsorption showed that for both LEB-18 and LEB-52 the process was favorable (∆G° < 0) and exothermic (∆H° −23.2 for LEB-18 and ∆H° −19.9 for LEB-52). Finally, both strains were suitable to uptake Nd, and the better result of LEB-18 could be attributed to the high amount of P and S groups in this biomass. Based on the results, a mechanism of electrostatic attraction of Nd3+ and phosphate and sulfate groups of both strains of Spirulina platensis was proposed.

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Leaching of rare earth elements from phosphogypsum
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Frantz Lütke, Sabrina | 2022

High amounts of phosphogypsum (PG) are generated in the production of phosphoric acid. Previous literature demonstrates that obtaining rare earth elements (REE) from PG is a promising alternative to managing this waste. However, the reported leaching efficiencies are low in most cases, or drastic leaching conditions are required. Therefore, this work aimed to study the leaching conditions of REE from PG to obtain high leaching efficiency values. Initially, a 24 factorial experimental design investigated the factors that affect the conventional acid leaching of REE from PG (leaching acid (citric and sulfuric acid), solid/liquid ratio, acid concentration, and temperature). Better leaching efficiency values of the sum of all REE (62.0% and 89.7% for citric and sulfuric acid, respectively) were obtained using an acid concentration of 3 mol L−1, solid/liquid ratio of 1/20 g mL−1, and temperature of 80 °C. Subsequently, the experiments optimization, performed through a central composite rotational design, indicated that the maximum leaching efficiency was achieved using a sulfuric acid concentration of 2.9 mol L−1, solid/liquid ratio of 1.7/20 g mL−1, and 55 °C. Under these conditions, the leaching efficiency of the sum of all REE was 90.0%. Leaching kinetics results showed that the equilibrium was reached in about 20 min for most REE. The mechanism investigation suggested that surface chemical reaction and diffusion through the boundary layer controlled the leaching.

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Nanometric particles of high economic value in coal fire region: Opportunities for social improvement
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Silva Oliveira, Luis Felipe | 2020-02-10

Spontaneous coal combustion in the La Guajira coals was studied for the presence of carbon nanophases (e.g., carbon nanotubes), occurrence of rare earth elements (REEs) in them, and the probable mechanisms for concentration of these rare compounds. For this purpose, various techniques such as scanning electron microscopy (SEM), Field-emission SEM, transmission electron microscopy (TEM), high-resolution TEM, and focused ion beam (FIB) were used. The development and alteration of the nanoparticles by geo-processes during the early modification periods of coal combustion were explored. Certain types of carbon nanophases and REE compounds may constitute nanominerals and ultra-fine particles accumulated in the coal peat. Assemblages of these nanophases (crystalline and amorphous compounds), predominantly the clay-monazite relationship and its connection to tonsteins in the coal combustion zones in the east region of the coal mines studied in this work, indicate that the coal area was subjected to REE concentration. The carbon nanophases contained several potential hazardous elements (PHEs), including, arsenic, bromine, cadmium, chlorine, fluorine, mercury, and other PHEs. While carbon nanotubes have been known to be produced from spontaneous combustion of coal of varying ranks, the present work is the first report on the naturally occurring REEs and carbon nanophases in the Colombian coal mining area.

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Nickel-aluminium layered double hydroxide as an efficient adsorbent to selectively recover praseodymium and samarium from phosphogypsum leachate
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dos Reis, Glaydson S. | 2023-10-15

This study aimed to synthesize a green powdered layered double hydroxide (LDH) based on nickel-aluminum (Ni–Al-LDH) to evaluate its efficiency in the removal of rare earth elements (REEs), Praseodymium (Pr3+) and Samarium (Sm3+), from synthetic effluents and real leachate using phosphogypsum as a secondary source of REEs. Several characterization techniques were employed to evaluate the physicochemical properties of Ni-Al-LDH adsorbent, such as specific surface area and porosity, functional surface groups and phases, and point of zero charge. The characterization results indicated that Ni-Al-LDH exhibited a typical layered structure confirming the successful synthesis. The effect of key adsorption variables, such as pH, contact time, initial concentration, and temperature, on the REEs adsorption was extensively studied in single-factor experiments separately. The kinetic and equilibrium adsorption data agreeably fitted the Avrami and Sips models, respectively. The maximum adsorption capacities for Pr3+ and Sm3+ adsorption were 18.13 and 15.68 mg g−1 at 298 K, respectively. The thermodynamic parameters (ΔH0, ΔS0, ΔG0) indicated that the adsorption was spontaneous, favorable, and exothermic for both Pr3+ and Sm3+. The interactions between Pr3+ and Sm3+ onto Ni-Al-LDH suggest that multiple adsorption mechanisms are involved, such as ion exchange, precipitation, chelation, and pore filling. Finally, the Ni-Al-LDH could selectively recover REEs, specially Pr3+ and Sm3+, from the real phosphogypsum leachate. It has been demonstrated that Ni-Al-LDH is a promising adsorbent material that could be used as an adsorbent for the recovery of REEs from synthetic and real effluents.

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Occurrence of carbon nanotubes and implication for the siting of elements in selected anthracites
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Silva Oliveira, Luis Felipe | 2020-03-01

Petrographic, geochemical, and electron microbeam investigations of selected anthracites and anthracite-rank coaly shales were conducted. The Pennsylvania, Rhode Island, and KwaZu-Natal anthracites show an enrichment in the middle to heavy rare earths (REE) while the Virginia semi-anthracite exhibited a decreasing trend through the light REE, a peak in Gd, and a depletion in the heavy REE. Substitution of As, Hg, and Se in pyrite was most apparent in the Virginia coal. The Pennsylvania, Rhode Island, and KwaZu-Natal anthracites contained spherical carbon nanotube (CNT) structures. The CNTs contained several elements, including Hg, Cd, F, Cl, and Br. While CNTs are known to be produced from coals of varying ranks, this seems to be the first report of naturally occurring CNTs.

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Rare earth elements study of cretaceous coals from benue trough basin, Nigeria: modes of occurrence for greater sustainability of mining
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Akinyemi, Segun Ajayi | 2021-07-14

The rare earth elements (REE) possess a beneficial combination of chemical and physical properties, making them valuable for most advanced branches of engineering and technology. Alternative sources of REE are desirable due to limited reserves of conventional REE containing minerals over the world combined with disproportionate supply over demand in the commodity markets. This study investigated the occurrence of REE and carbon nanotubes (CNTs) in Cretaceous Nigerian coals for prospective industrial applications. Results show that the coals’ crystalline mineral matter comprises quartz, kaolinite, and illite with minor quantities of feldspar, hematite, magnetite, calcite, dolomite, which indicate detrital mineral origins. Elemental relationships (such as Al2O3/TiO2, Cr/Th vs. Sc/Th, and Co/Th vs. La/Sc) suggest sediment-source regions with mafic, intermediate or felsic compositions. REE are either strongly fractionated or characterized by light-enrichment along with outlook coefficient (Coutl) values that suggest the coals are prospective substitute sources for REE and yttrium (REY) recovery. Several minerals including jarosite, goethite, epsomite, ferrohexahydrite, natrojarosite, rozenite, and gypsum were detected in trace amounts. REE mineral phases were not identified but only amorphous phases containing Ce, La, Nd, Th, Pr, Sm, Gd, Tb, Dy, Ho, and Hf. Maceral composition (high vitrinite), presence of iron-containing minerals (hematite and magnetite), high carbon contents, reduced volatile matter and low ash content favoured the formation of naturally occurring multi-walled carbon nanotube (MWCNTs) structures in Maiganga (MGA) coal. Hence, the present study is the first scientific report on the naturally occurring REEs and MWC nanophases in Cretaceous coals from the Benue Trough. © 2021

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Browsing by Subject "Rare earth elements"

Biosorption of neodymium (nd) from aqueous solutions using Spirulina platensis sp. strains ﻿

Leaching of rare earth elements from phosphogypsum ﻿

Nanometric particles of high economic value in coal fire region: Opportunities for social improvement ﻿

Nickel-aluminium layered double hydroxide as an efficient adsorbent to selectively recover praseodymium and samarium from phosphogypsum leachate ﻿

Occurrence of carbon nanotubes and implication for the siting of elements in selected anthracites ﻿

Rare earth elements study of cretaceous coals from benue trough basin, Nigeria: modes of occurrence for greater sustainability of mining ﻿

Envíos recientes

Biosorption of neodymium (nd) from aqueous solutions using Spirulina platensis sp. strains

Leaching of rare earth elements from phosphogypsum

Nanometric particles of high economic value in coal fire region: Opportunities for social improvement

Nickel-aluminium layered double hydroxide as an efficient adsorbent to selectively recover praseodymium and samarium from phosphogypsum leachate

Occurrence of carbon nanotubes and implication for the siting of elements in selected anthracites

Rare earth elements study of cretaceous coals from benue trough basin, Nigeria: modes of occurrence for greater sustainability of mining

Biosorption of neodymium (nd) from aqueous solutions using Spirulina platensis sp. strains

Leaching of rare earth elements from phosphogypsum

Nanometric particles of high economic value in coal fire region: Opportunities for social improvement

Nickel-aluminium layered double hydroxide as an efficient adsorbent to selectively recover praseodymium and samarium from phosphogypsum leachate

Occurrence of carbon nanotubes and implication for the siting of elements in selected anthracites

Rare earth elements study of cretaceous coals from benue trough basin, Nigeria: modes of occurrence for greater sustainability of mining