Approximate analytical equations for rate curves in the case of biporous sorbents and linear sorption isotherms

1979 ◽  
Vol 28 (8) ◽  
pp. 1769-1770
Author(s):  
V. I. Ulin ◽  
P. P. Zolotarev ◽  
S. N. Efremov
Keyword(s):  
Sorption Isotherms ◽  
Linear Sorption

Sorption of magnesium–picolinate complexes on a macroporous styrene–divinylbenzene copolymer containing immobilized 8-hydroxyquinoline and on the copolymer itself

1992 ◽  
Vol 70 (3) ◽  
pp. 926-930 ◽  
Author(s):  
Gocool Persaud ◽  
Frederick F. Cantwell
Keyword(s):  
Picolinic Acid ◽  
Sorption Isotherms ◽  
Magnesium Ion ◽  
Ligand Complex ◽  
Solution Ph ◽  
Complex Species ◽  
Linear Sorption ◽  
Atomic Absorption Technique ◽  
Styrene Divinylbenzene ◽  
Absorption Technique

The sorbent XAD-OXINE was prepared by covalently binding 8-hydroxyquinoline onto the surface of the macroporous copolymer Amberlite XAD-2 to give about 20% surface coverage. Sorption, onto both XAD-2 and XAD-OXINE, of the magnesium-containing species that are present in solutions of magnesium ion and picolinic acid was studied by the column equilibration/atomic absorption technique at solution pH of 6.00 and 7.50 and ionic strength of 0.25. By using solutions containing various amounts of added magnesium and picolinic acid, in which the ratio of the two metal–ligand complex species, MgP+/MgP2, varied greatly (P− is the ligand picolinate), it was shown that neither the species Mg2+ nor the species MgP+ sorb to an appreciable extent onto the parent polymer XAD-2, but the neutral species MgP2 sorbs strongly and exhibits a linear isotherm. Then, by measuring the sorption isotherm of the species Mg2+ on XAD-OXINE in the absence of picolinic acid, by measuring the overall sorption of magnesium-containing species on XAD-OXINE in the presence of picolinic acid, and by assuming that the sorption of the species MgP2 onto XAD-OXINE was about the same as it was on XAD-2, it was possible to show that the species MgP+ sorbs strongly onto XAD-OXINE, and exhibits linear sorption isotherms. Thus, XAD-OXINE sorbs all three species Mg2+, MgP+, and MgP2. Keywords: Amberlite XAD-2, immobilized oxine, magnesium ion.

Mechanisms of cesium sorption onto magnetite

2006 ◽  
Vol 94 (9-11) ◽  
Author(s):  
Noelia Granizo ◽  
T. Missana
Keyword(s):  
Sorption Isotherms ◽  
Radionuclide Migration ◽  
Trace Impurities ◽  
Linear Sorption ◽  
Geological Repository ◽  
Maximum Sorption ◽  
Precipitation Phenomena ◽  
Co Precipitation ◽  
High Level ◽  
Oxide Electrolyte

One of the current options for the final disposal of high level radioactive wastes is the deep geological repository (DGR). The metal canisters represent the first physical barrier to radionuclide migration towards the geosphere and their corrosion products may play a significant role in sequestering radionuclides by sorption and/or (co)precipitation phenomena.In this work, the sorption ofSorption was negligible up to pH 8.5 and maximum sorption values were reached around pH 12. A significant increase in Cs sorption was observed when decreasing the ionic strength. Linear sorption isotherms were observed within the range of Cs concentration used (up to 10As expected, Cs showed very small sorption onto the oxide, but the whole experimental results could be satisfactorily fit with a simple model. In addition, the model developed in the oxide-electrolyte system was able to reproduce fairly well the sorption of Cs onto magnetite in two more complex waters (synthetic bentonite and cement porewaters).All the possible effects on sorption that could increase the uncertainties on the (small) sorption values were analysed in depth. In addition, the possible influence of mineral trace impurities on the sorption (for example silicates from experimental vessels), already discussed in the literature, was avoided.

scholarly journals Sorption and transformation of the reactive tracers resazurin and resorufin in natural river sediments

2013 ◽  
Vol 10 (10) ◽  
pp. 12187-12216 ◽  
Author(s):  
D. Lemke ◽  
R. González-Pinzón ◽  
Z. Liao ◽  
T. Wöhling ◽  
K. Osenbrück ◽  
...  
Keyword(s):  
River Sediments ◽  
Tracer Tests ◽  
Sorption Isotherms ◽  
Hyporheic Exchange ◽  
Batch Experiments ◽  
Linear Sorption ◽  
Alkaline Conditions ◽  
Kinetic Sorption ◽  
Reactive Tracers ◽  
Transient Tracer

Abstract. Resazurin (Raz) and its reaction product resorufin (Rru) have increasingly been used as reactive tracers to quantify metabolic activity and hyporheic exchange in streams. Previous works have indicated that these compounds undergo sorption in stream sediments. We present a series of laboratory column and batch experiments on Raz and Rru transport, sorption, and transformation within sediments with different physicochemical properties under neutral and alkaline conditions. The data of the column experiments were fitted by a model accounting for physical transport, equilibrium and kinetic sorption, and three first-order reactions. The most likely parameters and their uncertainty were determined by a Markov-Chain Monte Carlo approach. Linear and non-linear sorption isotherms of both compounds were obtained by batch experiments. We found that kinetic sorption dominates sorption of both Raz and Rru, with characteristic timescales of sorption in the order of > 80 min. The linear sorption models for both Raz and Rru appeared adequate for concentrations that are typically applied in field-tracer tests. The supposed two-site sorption model helps interpreting transient tracer tests using the Raz–Rru system.

The Influence of Disintegration of Hard Coal Varieties of Different Metamorphism Grade on the Amount of Sorbed Ethane / Wpływ rozdrobnienia odmian węgla kamiennego o różnym stopniu metamorfizmu na ilości sorbowanego etanu

2013 ◽  
Vol 58 (2) ◽  
pp. 449-463 ◽  
Author(s):  
Mieczysław Żyła ◽  
Agnieszka Dudzińska ◽  
Janusz Cygankiewicz
Keyword(s):  
Sorption Isotherms ◽  
Electron Donors ◽  
Hard Coal ◽  
Coal Surface ◽  
Compact Layer ◽  
Compact Structure ◽  
Small Surface ◽  
Mining Works ◽  
The Impact ◽  
Content Of Oxygen

Ethane constitutes an explosive gas. It most often accompanies methane realizing during exploitation and mining works. In this paper the results of ethane sorption have been discussed on three grain classes of six selected hard coal samples collected from active Polish coalmines. On the basis of obtained results, it has been stated that the tested hard coals prove differentiated sorption power with reference to ethane. Te extreme amount of ethane is sorbed by low carbonized hard coal from “Jaworzno” coalmine. This sort of coal shows great porosity, and great content of oxygen and moisture. The least amount of ethane is sorbed by hard coal from “Sośnica” coalmine. This sort of coal possesses relatively a great deal of ash contents. Together with the process of coal disintegration, the amount of sorbed ethane increases for all tested coal samples. Between tested coals there are three medium carbonized samples collected from “Pniówek”, “Chwałowice” “Zofiówka” coalmines which are characterized by small surface values counted according to model BET from nitrogen sorption isotherms determined at the temperature of 77.5 K. The samples of these three coals prove the highest, from between tested coals, increase of ethane sorption occurring together with their disintegration. These samples disintegrated to 0,063-0,075 mm grain class sorb ethane in the amount corresponding with the sorption quantity of low carbonized coal from “Jaworzno” coalmine in 0.5-0.7 mm grain class. It should be marked that the low carbonized samples collected from “Jaworzno” and Wesoła” coalmines possess large specific surface and great porosity and belong to coal group of “loose” spatial structure. Regarding profusion of sorbed ethane on disintegrated medium carbonized samples from “Pniówek”, “Zofiówka”, “Chwałowice” coalmines it can be supposed that in the process of coal disintegration, breaking their “compact’ structure occurs. Loosened structure of medium carbonized coals results in increasing accessibility of ethane particles to sorption centres both electron donors and electron acceptors which are present on hard coal surface. The surface sorption centre increase may result in formation a compact layer of ethane particles on coal surface. In the formed layer, not only the strengths of vertical binding of ethane particles with the coal surface appear but also the impact of horizontal strengths appears which forms a compact layer of sorbed ethane particles. The surface layer of ethane particles may lead to explosion.

The Influences of the Rank of Coal on Methane Sorption Capacity in Coals/Wpływ Rzędu Węgla Na Pojemność Sorpcyjną Metanu W Węglach

2014 ◽  
Vol 59 (2) ◽  
pp. 509-516
Author(s):  
Andrzej Olajossy
Keyword(s):  
Sorption Capacity ◽  
Coalbed Methane ◽  
Vitrinite Reflectance ◽  
Sorption Isotherms ◽  
Volatile Matter ◽  
Low Rank ◽  
Hard Coal ◽  
Petrographic Composition ◽  
Methane Sorption ◽  
Indian Coals

Abstract Methane sorption capacity is of significance in the issues of coalbed methane (CBM) and depends on various parameters, including mainly, on rank of coal and the maceral content in coals. However, in some of the World coals basins the influences of those parameters on methane sorption capacity is various and sometimes complicated. Usually the rank of coal is expressed by its vitrinite reflectance Ro. Moreover, in coals for which there is a high correlation between vitrinite reflectance and volatile matter Vdaf the rank of coal may also be represented by Vdaf. The influence of the rank of coal on methane sorption capacity for Polish coals is not well understood, hence the examination in the presented paper was undertaken. For the purpose of analysis there were chosen fourteen samples of hard coal originating from the Upper Silesian Basin and Lower Silesian Basin. The scope of the sorption capacity is: 15-42 cm3/g and the scope of vitrinite reflectance: 0,6-2,2%. Majority of those coals were of low rank, high volatile matter (HV), some were of middle rank, middle volatile matter (MV) and among them there was a small number of high rank, low volatile matter (LV) coals. The analysis was conducted on the basis of available from the literature results of research of petrographic composition and methane sorption isotherms. Some of those samples were in the form (shape) of grains and others - as cut out plates of coal. The high pressure isotherms previously obtained in the cited studies were analyzed here for the purpose of establishing their sorption capacity on the basis of Langmuire equation. As a result of this paper, it turned out that for low rank, HV coals the Langmuire volume VL slightly decreases with the increase of rank, reaching its minimum for the middle rank (MV) coal and then increases with the rise of the rank (LV). From the graphic illustrations presented with respect to this relation follows the similarity to the Indian coals and partially to the Australian coals.

scholarly journals Modelling Sorption Thermodynamics and Mass Transport of n-Hexane in a Propylene-Ethylene Elastomer

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1157
Author(s):  
Daniele Tammaro ◽  
Lorenzo Lombardi ◽  
Giuseppe Scherillo ◽  
Ernesto Di Maio ◽  
Navanshu Ahuja ◽  
...  
Keyword(s):  
Mass Transport ◽  
Interaction Parameter ◽  
Sorption Isotherms ◽  
Binary Interaction ◽  
Binary Interaction Parameter ◽  
Theoretical Interpretation ◽  
Sorption Behavior ◽  
Solvent Mixtures ◽  
Random Lattice ◽  
Hexane Vapor

Optimization of post polymerization processes of polyolefin elastomers (POE) involving solvents is of considerable industrial interest. To this aim, experimental determination and theoretical interpretation of the thermodynamics and mass transport properties of POE-solvent mixtures is relevant. Sorption behavior of n-hexane vapor in a commercial propylene-ethylene elastomer (V8880 VistamaxxTM from ExxonMobil, Machelen, Belgium) is addressed here, determining experimentally the sorption isotherms at temperatures ranging from 115 to 140 °C and pressure values of n-hexane vapor up to 1 atm. Sorption isotherms have been interpreted using a Non Random Lattice Fluid (NRLF) Equation of State model retrieving, from data fitting, the value of the binary interaction parameter for the n-hexane/V8880 system. Both the cases of temperature-independent and of temperature-dependent binary interaction parameter have been considered. Sorption kinetics was also investigated at different pressures and has been interpreted using a Fick’s model determining values of the mutual diffusivity as a function of temperature and of n-hexane/V8880 mixture composition. From these values, n-hexane intra-diffusion coefficient has been calculated interpreting its dependence on mixture concentration and temperature by a semi-empiric model based on free volume arguments.

scholarly journals Sorption and Desorption of Vanadate, Arsenate and Chromate by Two Volcanic Soils of Equatorial Africa

Soil Systems ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 22
Author(s):  
Sara Gonzalez-Rodriguez ◽  
Maria Luisa Fernandez-Marcos
Keyword(s):  
Laboratory Experiments ◽  
Sorption Isotherms ◽  
Soil Samples ◽  
Mineral Surfaces ◽  
Volcanic Soils ◽  
Iron Species ◽  
Freundlich Model ◽  
Equatorial Africa ◽  
Relevant Role ◽  
Icp Mass Spectrometry

Sorption of oxyanions by soils and mineral surfaces is of interest due to their role as nutrients or pollutants. Volcanic soils are variable charge soils, rich in active forms of aluminum and iron, and capable of sorbing anions. Sorption and desorption of vanadate, arsenate, and chromate by two African andosols was studied in laboratory experiments. Sorption isotherms were determined by equilibrating at 293 K soil samples with oxyanion solutions of concentrations between 0 and 100 mg L−1 V, As, or Cr, equivalent to 0−2.0 mmol V L−1, 0−1.3 mmol As L−1, and 0−1.9 mmol Cr L−1, in NaNO3; V, As, or Cr were determined by ICP-mass spectrometry in the equilibrium solution. After sorption, the soil samples were equilibrated with 0.02 M NaNO3 to study desorption. The isotherms were adjusted to mathematical models. After desorption with NaNO3, desorption experiments were carried out with a 1 mM phosphate. The sorption of vanadate and arsenate was greater than 90% of the amount added, while the chromate sorption was much lower (19–97%). The sorption by the Silandic Andosol is attributed to non-crystalline Fe and Al, while in the Vitric Andosol, crystalline iron species play a relevant role. The V and Cr sorption isotherms fitted to the Freundlich model, while the As sorption isotherms conformed to the Temkin model. For the highest concentrations of oxyanions in the equilibrating solution, the sorbed concentrations were 37–38 mmol V kg−1, 25 mmol As kg−1, and 7.2–8.8 mmol Cr kg−1. The desorption was low for V and As and high for Cr. The comparison of the sorption and desorption isotherms reveals a pronounced hysteresis for V in both andosols and for Cr in the Silandic Andosol. Phosphate induced almost no V desorption, moderate As desorption, and considerable Cr desorption.

scholarly journals ᶫ-Leucine Loading and Release in MIL-100 Nanoparticles

2020 ◽  
Vol 21 (24) ◽  
pp. 9758
Author(s):  
Ivan E. Gorban ◽  
Mikhail A. Soldatov ◽  
Vera V. Butova ◽  
Pavel V. Medvedev ◽  
Olga A. Burachevskaya ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydrothermal Synthesis ◽  
Cell Model ◽  
Metal Organic Framework ◽  
Acetic Acid Solution ◽  
Sorption Isotherms ◽  
Microwave Assisted Synthesis ◽  
High Porosity ◽  
Cytotoxicity Studies ◽  
Vis Spectroscopy

Synthesis of the MIL-100 metal-organic framework particles was carried out by hydrothermal (HT) and microwave (MW)-assisted methods. Transmission electron microscopy showed formation of microparticles in the course of hydrothermal synthesis and nanoparticles for microwave-assisted synthesis. Powder X-ray diffraction confirmed formation of larger crystallites for hydrothermal synthesis. Particle aggregation in aqueous solution was observed by dynamic light scattering. However, the stability of both samples could be improved in acetic acid solution. Nitrogen sorption isotherms showed high porosity of the particles. ᶫ-leucine molecule was used as a model molecule for loading in the porous micro- and nanoparticles. Loading was estimated by FTIR spectroscopy and thermogravimetric analysis. UV-VIS spectroscopy quantified ᶫ-leucine release from the particles in aqueous solution. Cytotoxicity studies using the HeLa cell model showed that the original particles were somewhat toxic, but ᶫ-leucine loading ameliorated the toxic effects, likely due to signaling properties of the amino acid.

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