scholarly journals Adsorption of Rare Earth Elements from Aqueous Solutions Using Geopolymers

Proceedings ◽  
2018 ◽  
Vol 2 (10) ◽  
pp. 567 ◽  
Author(s):  
Željka Fiket ◽  
Ana Galović ◽  
Gordana Medunić ◽  
Martina Furdek Turk ◽  
Maja Ivanić ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Aqueous Solutions ◽  
High Efficiency ◽  
Low Cost ◽  
Coal Ash ◽  
Industrial Sector ◽  
Efficient Removal ◽  
Model Solutions ◽  
Technology Applications

Rare earth elements, i.e., lanthanides, are important components of many recently developed technology applications. However, their increasing use in the industrial sector, medicine, and agriculture over the last few decades has provided them with the title of “new pollutants”. Different methods are now applied for the removal of various pollutants from wastewaters, whereby the emphasis is placed on adsorption due to its simplicity, high efficiency, and low cost. In the present study, geopolymers prepared from coal ash were examined regarding their capacity for the adsorption of lanthanides from model solutions. The obtained results indicate the efficient removal of lanthanides by prepared geopolymers, depicting them as effective adsorbents for this group of elements.

scholarly journals Adsorption of Uranium, Mercury, and Rare Earth Elements from Aqueous Solutions onto Magnetic Chitosan Adsorbents: A Review

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3137
Author(s):  
Georgia Michailidou ◽  
Ioanna Koumentakou ◽  
Efstathios V. Liakos ◽  
Maria Lazaridou ◽  
Dimitra A. Lambropoulou ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Aqueous Solutions ◽  
Low Cost ◽  
Kinetic Equations ◽  
Value Added ◽  
Hydroxyl Groups ◽  
Adsorption Mechanisms ◽  
Natural Polysaccharide ◽  
Effects Of Ph

The compound of chitin is the second most important and abundant natural biopolymer in the world. The main extraction and exploitation sources of this natural polysaccharide polymer are mainly crustaceans species, such as shrimps and crabs. Chitosan (CS) (poly-β-(1 → 4)-2-amino-2-deoxy-d-glucose) can be derived from chitin and can be mentioned as a compound that has high value-added applications due to its wide variety of uses, including pharmaceutical, biomedical, and cosmetics applications, food etc. Furthermore, chitosan is a biopolymer that can be used for adsorption applications because it contains amino and hydroxyl groups in its chemical structure (molecules), resulting in possible interactions of adsorption between chitosan and pollutants (uranium, mercury, rare earth elements (REEs), phenols, etc.). However, adsorption is a very effective, fast, simple, and low-cost process. This review article places emphasis on recent demonstrated research papers (2014–2020) where the chemical modifications of CS are explained briefly (grafting, cross-linking etc.) for the uptake of uranium, mercury, and REEs in synthesized aqueous solutions. Finally, figures and tables from selected synthetic routes of CS are presented and the effects of pH and the best mathematical fitting of isotherm and kinetic equations are discussed. In addition, the adsorption mechanisms are discussed.

Techno-economic analysis of supercritical extraction of rare earth elements from coal ash

2018 ◽  
Vol 189 ◽  
pp. 539-551 ◽  
Author(s):  
Saptarshi Das ◽  
Gabrielle Gaustad ◽  
Ashok Sekar ◽  
Eric Williams
Keyword(s):  
Rare Earth ◽  
Economic Analysis ◽  
Rare Earth Elements ◽  
Coal Ash ◽  
Supercritical Extraction

Determining rare-earth elements in aqueous solutions using PGNAA technology

2022 ◽  
Author(s):  
Yongsheng Ling ◽  
Jianwen Chen ◽  
Pingkun Cai ◽  
Wenbao Jia ◽  
Daqian Hei ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Aqueous Solutions

scholarly journals Substantial thermal conductivity reduction in mischmetal skutterudites MmxCo4Sb12 prepared under high-pressure conditions, due to uneven distribution of the rare-earth elements

2019 ◽  
Vol 7 (14) ◽  
pp. 4124-4131 ◽  
Author(s):  
J. Gainza ◽  
F. Serrano-Sánchez ◽  
J. Prado-Gonjal ◽  
N. M. Nemes ◽  
N. Biskup ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Pressure ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Lattice Thermal Conductivity ◽  
Low Cost ◽  
Uneven Distribution ◽  
Filling Fraction ◽  
The Rare Earth

Low-cost n-type Mischmetal-filled CoSb3 skutterudites with elemental filling-fraction separation, prepared at high pressure, exhibit markedly low lattice thermal conductivity.

scholarly journals Environmentally friendly comprehensive hydrometallurgical method development for neodymium recovery from mixed rare earth aqueous solutions using organo-phosphorus derivatives

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Verónica Cristina Arellano Ruiz ◽  
Rambabu Kuchi ◽  
Pankaj Kumar Parhi ◽  
Jin-Young Lee ◽  
Rajesh Kumar Jyothi
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Method Development ◽  
Neodymium Oxide ◽  
Selective Extraction ◽  
Extractant Concentration ◽  
Cyanex 272 ◽  
Extraction Behavior ◽  
Technology Applications ◽  
Hydrometallurgical Method

Abstract Rare earth elements (REEs) have obtained a greatest significant in human lives owing to their important roles in various high technology applications. The present method development was deal technology important REEs such as neodymium, terbium and dysprosium, selective extraction with possible separation and recovery studies, successfully. The chloride mediated mixed aqueous solution containing 1500 mg/L each of REEs such as Nd, Tb and Dy was subjected at selective separation of Nd from other associated REEs. Three organo-phosphorous based commercial extracting agents such as Cyanex 272, PC 88A and D2EHPA, were employed for the extraction, possible separation and recovery of rare earth elements. A comparative extraction behavior of all these three extractants as function of time, pH influence, extractant concentration, temperature and diluents were systematically investigated. The extraction tendency of organo-phosphorus reagents towards the extraction of either of the REEs follows of the sequence as: D2EHPA > PC 88A > Cyanex 272. The thermodynamic behavior of either of the extractants on liquid–liquid extraction processing of REEs was investigated and thermodynamic calculations were calculated and presented. Substantial recovery of neodymium oxalate followed by its calcined product as neodymium oxide was ascertained from XRD study and SEM–EDS analysis.

scholarly journals Magnetic Fe3O4@Chitosan Carbon Microbeads: Removal of Doxycycline from Aqueous Solutions through a Fixed Bed via Sequential Adsorption and Heterogeneous Fenton-Like Regeneration

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Bo Bai ◽  
Xiaohui Xu ◽  
Changchuan Li ◽  
Jianyu Xing ◽  
Honglun Wang ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
High Efficiency ◽  
Low Cost ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Chitosan Hydrogel ◽  
Fixed Bed Column ◽  
Adsorptive Removal ◽  
Sequential Adsorption ◽  
Cracking Process

The adsorptive removal of antibiotics from aqueous solutions is recognized as the most suitable approach due to its easy operation, low cost, nontoxic properties, and high efficiency. However, the conventional regeneration of saturated adsorbents is an expensive and time-consuming process in practical wastewater treatment. Herein, a scalable adsorbent of magnetic Fe3O4@chitosan carbon microbeads (MCM) was successfully prepared by embedding Fe3O4 nanoparticles into chitosan hydrogel via an alkali gelation-thermal cracking process. The application of MCM composites for the adsorptive removal of doxycycline (DC) was evaluated using a fixed-bed column. The results showed that pH, initial concentration, flow rate, and bed depth are found to be important factors to control the adsorption capacity of DC. The Thomas and Yoon-Nelson models showed a good agreement with the experimental data and could be applied for the prediction of the fixed-bed column properties and breakthrough curves. More importantly, the saturated fixed bed can be easily recycled by H2O2 which shows excellent reusability for the removal of doxycycline. Thus, the combination of the adsorption advantage of chitosan carbon with catalytic properties of magnetic Fe3O4 nanoparticles might provide a new tool for addressing water treatment challenges.

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