Composite Sorbents of Ammonia

2020 ◽  
pp. 169-195
Author(s):  
Yu. I. Aristov
Keyword(s):  
Composite Sorbents

scholarly journals Synthesis of a New Phosphonate-Based Sorbent and Characterization of Its Interactions with Lanthanum (III) and Terbium (III)

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1513
Author(s):  
Yuezhou Wei ◽  
Khalid A. M. Salih ◽  
Mohammed F. Hamza ◽  
Toyohisa Fujita ◽  
Enrique Rodríguez-Castellón ◽  
...  
Keyword(s):  
High Tech ◽  
Low Grade ◽  
Acid Solutions ◽  
Hydrogel Beads ◽  
Secondary Sources ◽  
Composite Sorbents ◽  
Synthesis Procedure ◽  
New Generation ◽  
Mild Acid

High-tech applications require increasing amounts of rare earth elements (REE). Their recovery from low-grade minerals and their recycling from secondary sources (as waste materials) are of critical importance. There is increasing attention paid to the development of new sorbents for REE recovery from dilute solutions. A new generation of composite sorbents based on brown algal biomass (alginate) and polyethylenimine (PEI) was recently developed (ALPEI hydrogel beads). The phosphorylation of the beads strongly improves the affinity of the sorbents for REEs (such as La and Tb): by 4.5 to 6.9 times compared with raw beads. The synthesis procedure (epicholorhydrin-activation, phosphorylation and de-esterification) is investigated by XPS and FTIR for characterizing the grafting route but also for interpreting the binding mechanism (contribution of N-bearing from PEI, O-bearing from alginate and P-bearing groups). Metal ions can be readily eluted using an acidic calcium chloride solution, which regenerates the sorbent: the FTIR spectra are hardly changed after five successive cycles of sorption and desorption. The materials are also characterized by elemental, textural and thermogravimetric analyses. The phosphorylation of ALPEI beads by this new method opens promising perspectives for the recovery of these strategic metals from mild acid solutions (i.e., pH ~ 4).

scholarly journals Experimental Comparison of Innovative Composite Sorbents for Space Heating and Domestic Hot Water Storage

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 476
Author(s):  
Vincenza Brancato ◽  
Larisa G. Gordeeva ◽  
Angela Caprì ◽  
Alexandra D. Grekova ◽  
Andrea Frazzica
Keyword(s):  
Silica Gel ◽  
Xrd Analysis ◽  
Complete Characterization ◽  
Operating Conditions ◽  
Hot Water ◽  
Experimental Comparison ◽  
Space Heating ◽  
Calorimetric Analysis ◽  
Domestic Hot Water ◽  
Composite Sorbents

In this study, the development and comparative characterization of different composite sorbents for thermal energy storage applications is reported. Two different applications were targeted, namely, low-temperature space heating (SH) and domestic hot water (DHW) provision. From a literature analysis, the most promising hygroscopic salts were selected for these conditions, being LiCl for SH and LiBr for DHW. Furthermore, two mesoporous silica gel matrixes and a macroporous vermiculite were acquired to prepare the composites. A complete characterization was performed by investigating the porous structure of the composites before and after impregnation, through N2 physisorption, as well as checking the phase composition of the composites at different temperatures through X-ray powder diffraction (XRD) analysis. Furthermore, sorption equilibrium curves were measured in water vapor atmosphere to evaluate the adsorption capacity of the samples and a detailed calorimetric analysis was carried out to evaluate the reaction evolution under real operating conditions as well as the sorption heat of each sample. The results demonstrated a slower reaction kinetic in the vermiculite-based composites, due to the larger size of salt grains embedded in the pores, while promising volumetric storage densities of 0.7 GJ/m3 and 0.4 GJ/m3 in silica gel-based composites were achieved for SH and DHW applications, respectively.

Technology of Obtaining Composite Sorbents for Water Purification

2017 ◽  
Vol 08 (03) ◽  
Author(s):  
Politaeva Natalia Anatolievna ◽  
Taranovskaya Elena Aleksandrovna ◽  
Slugin Vladimir Valentinovich ◽  
Prokhorov Vladislav Vladimirovich
Keyword(s):  
Water Purification ◽  
Composite Sorbents

scholarly journals Shaped Silica-polyethyleneimine Composite Sorbents for CO2 Capture via Adsorption

2017 ◽  
Vol 114 ◽  
pp. 2219-2227 ◽  
Author(s):  
Gregory P. Knowles ◽  
Alan L. Chaffee
Keyword(s):  
Co2 Capture ◽  
Composite Sorbents

scholarly journals Synthesis and Sorption Properties towards Sr-90 of Composite Sorbents Based on Magnetite and Hematite

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1189 ◽  
Author(s):  
Andrei Egorin ◽  
Eduard Tokar ◽  
Anastasia Kalashnikova ◽  
Tatiana Sokolnitskaya ◽  
Ivan Tkachenko ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Iron Oxide ◽  
Polymer Matrix ◽  
Iron Content ◽  
Alkaline Media ◽  
Composite Sorbent ◽  
Dynamic Sorption ◽  
Composite Sorbents ◽  
Sorption Characteristics

The article describes the synthesis of composite sorbents by immobilizing iron oxide in a polymer matrix with subsequent hydrothermal treatment at a temperature of 175 °C. The sorbents based on magnetite and hematite were synthesized, their magnetic properties and phase composition were evaluated, and the iron content was determined. Sorption characteristics of the composites towards microconcentrations of Sr-90 radionuclide in solutions with different mineralization and pH were investigated. It was shown that the sorbent based on magnetite was the most efficient. In alkaline media with pH above 11, the composite sorbent based on magnetite exhibited increased selectivity towards Sr-90 and proved to be suitable for application under dynamic sorption conditions with subsequent desorption of the radionuclide with a solution of HNO3.

Adsorption of Cesium Radionuclides by the Composite Sorbents Carbon Fiber/Transition Metals Ferrocyanides

2011 ◽  
Author(s):  
Irina V. Sheveleva ◽  
Veniamin V. Zheleznov ◽  
Svetlana Yu. Bratskaya ◽  
Valery G. Kuryavyi ◽  
Valentin A. Avramenko
Keyword(s):  
Composite Materials ◽  
Carbon Fiber ◽  
Transition Metals ◽  
Crystal Size ◽  
Porous Matrix ◽  
Cesium Ions ◽  
Preparation Conditions ◽  
Composite Sorbents ◽  
Cesium Radionuclides ◽  
Carboxylic Groups

Among various methods of cesium removal from aqueous solutions, sorption using transition metals ferrocyanides is the most efficient method due to extremely high affinity of cesium ions to ferrocyanides. The efficiency of transition metals ferrocyanides application is known to depend on the crystal size being the highest for nanocrystals. Although nanocrystals are difficult to handle in direct application, they can be used in composite materials. In this case two main problems arise: how to control the crystal size of transition metals ferrocyanides and fix them reliably in the supporting matrix. Here we suggest a new route to preparation of composite materials selective to cesium ions using transition metals ferrocyanides stabilized by siloxane-acrylate latexes. The size of transition metals ferrocyanides is controlled by the size of latex particles and their stability is determined by ionization of polyacrylic acid carboxylic groups on the functionalized latex surface. These functionalized particles can be used as precursors in preparation of composite materials by sedimentation and polymerization of latexes on the solid surface of porous matrix, e.g. carbon fibers. Several routes of preparation of carbon fiber based composite materials using functionalized latexes and sorption properties of the obtained materials are discussed. The effect of preparation conditions (method used, carbon fiber polarization potential, concentration of latexes functionalized with transition metals ferrocyanides) on cesium uptake by composite sorbents from solutions of various salinity is reported.

Sign in / Sign up

Export Citation Format

Share Document