Cesium Sorption on Tonalite and Mica Gneiss

1999 ◽  
Vol 556 ◽  
Author(s):  
M. Siitari-Kauppi ◽  
P. Hölttä ◽  
S. Pinnioja ◽  
A. Lindberg
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Mass Distribution ◽  
Distribution Ratio ◽  
Crushed Rock ◽  
Cesium Sorption ◽  
Surface Areas ◽  
Alteration Minerals ◽  
Specific Surface Areas ◽  
Sorption Time

AbstractDifferent approaches for measuring the interaction between radionuclides and rock matrix are needed to test the compatibility of transport models and retardation experiments. In this work sorption of cesium (134Cs) was studied on unaltered mica gneiss, and on unaltered, moderately altered and strongly altered tonalite. The crushed rock samples were sieved into seven fractions from 0. 1 mm to 3.15 mm. The mass distribution ratio values for each fraction was determined using the static batch method. Cesium sorption onto different minerals was demonstrated using digital image analysis in order to interpret thin section autoradiographs. The autoradiographic method based on irradiation-induced luminescence properties in feldspars was applied in order to estimate the alteration of tonalites.Cesium sorption on moderately altered and strongly altered tonalite was stronger than on unaltered rocks owing to larger specific surface areas and the composition of alteration minerals. Strongest sorption was found on biotite. Mass distribution ratio, Rd, values of 0.3–1.1 m3·kg−1 for unaltered rocks and 0.9–3.4 m3·kg−1 for altered rocks were determined. Moderate dependence on surface area was found for mica gneiss after I and 3 days sorption time. For strongly altered tonalite only slight dependence on surface area was found. Research-articled -values increased as a function of sorption time due to diffusion into the particles. Higher increase in values for larger diameter particles indicated the availability of internal specific surface areas.

The Effect of Specific Surface Area on Radionuclide Sorption on Crushed Crystalline Rock

1996 ◽  
Vol 465 ◽  
Author(s):  
P. Hölttä ◽  
M. Siitari-Kauppi ◽  
P. Huihuri ◽  
A. Lindberg ◽  
A. Hautojärvt
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Mass Distribution ◽  
Specific Surface Area ◽  
Crystalline Rock ◽  
Crushed Rock ◽  
Surface Irregularity ◽  
Adsorption Method ◽  
Thin Sections ◽  
Surface Areas

ABSTRACTThe sorption of sodium (22Na), calcium (45Ca) and strontium (85Sr) was studied on mica gneiss, unaltered, moderately altered and strongly altered tonalite samples taken from hole SY-KR7 drilled in the Syyry area in Sievi, Western Finland. The crushed rock samples were sieved into six fractions from 71 μm to 1250 μm. A proportional mineral composition for the different fractions were estimated by X-ray diffraction. The specific fraction surface areas were determined by the BET nitrogen adsorption method. The fractal method was applied to characterize rocks and to describe quantitatively surface irregularity. The mass distribution ratio values for each fraction were determined using the static batch method. The sorption of tracers onto different minerals was observed using rock thin sections. Kd-values calculated from thin section Ka-values and Kd revalues obtained from batch experiments were in good agreement. Mass distribution ratios for different size fractions are given, and the effect of the specific surface area is discussed. Owing to larger specific surface areas considerably higher sorption on smaller fractions was found for altered tonalites.

Behavior of Cs in Grimsel granodiorite: sorption on main minerals and crushed rock

2016 ◽  
Vol 0 (0) ◽  
Author(s):  
Eveliina Muuri ◽  
Jussi Ikonen ◽  
Minja Matara-aho ◽  
Antero Lindberg ◽  
Stellan Holgersson ◽  
...  
Keyword(s):  
Specific Surface ◽  
Test Site ◽  
Potassium Feldspar ◽  
Distribution Coefficients ◽  
Crushed Rock ◽  
Surface Areas ◽  
Bet Method ◽  
Grimsel Test Site ◽  
Specific Surface Areas ◽  
Phreeqc Modelling

AbstractIn this study the sorption of cesium was investigated on four different minerals; quartz, plagioclase, potassium feldspar and biotite as well as granodiorite obtained from the Grimsel test site in Switzerland. The experiments were conducted in the presence of the weakly saline Grimsel groundwater simulant by determining the distribution coefficients using batch sorption experiments and PHREEQC-modelling across a large concentration range. In addition, the purity of the minerals was measured by XRD and the specific surface areas by BET method using krypton. The distribution coefficients of cesium were largest on biotite (0.304 ± 0.005 m

A Comparison of Methods for Determining Surface Areas of Carbon Black

1973 ◽  
Vol 46 (1) ◽  
pp. 192-203 ◽  
Author(s):  
R. A. Klyne ◽  
B. D. Simpson ◽  
M. L. Studebaker
Keyword(s):  
Carbon Black ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Surface Areas ◽  
Furnace Black ◽  
Area Increase ◽  
Experimental Errors ◽  
Specific Surface Areas ◽  
Surface Area Increase

Abstract 1. The various tint tests correlate with each other—it does not make much difference which of the three procedures is used. The discrimination between similar blacks is comparable. Specific surface areas obtained by the three methods are comparable and differences appear to be due to experimental errors. (Compare Figures 5–7). 2. Surface areas larger than some 90 to 100 m2/g cannot be reliably determined from tint strength measurements alone. 3. Structure exerts a pronounced effect on tint strength of furnace blacks, especially above 90 to 100 m2/g. Porosity and/or composition are apparently also variables which affect tinting strength. 4. Densichron reflectance on the dry carbon black can be used to estimate specific surface areas up to about 140 m2/g; but, since theabsoluteerrorincreases as the specific surface area increases, this method loses some of its reliability at values above about 110 m2/g. The relative error in reflectance determinations does not vary greatly over the furnace-black range. Densichron reflectance is influenced by composition, evidently due to composition-related differences in optical properties of the carbons. 5. In CTAB adsorption measurements, titration errors and handling errors tend to be rather constant for blacks of different surface area. Hence, CTAB permits better discrimination among blacks of small particle size. 6. The errors in Densichron reflectance surface area increase with specific surface area. Hence, the deviations between CTAB and reflectance surface area which are due to experimental error increase with the surface area of the sample.

Effect of Different Silicate Supports on the Catalytic Performance of MoVTeO Mixed Oxides in Partial Oxidation of Isobutane

2014 ◽  
Vol 12 (1) ◽  
pp. 623-628
Author(s):  
Jing Hu ◽  
Zhifang Li ◽  
Xiaoyuan Yang ◽  
Wenli Ding ◽  
Jingqi Guan
Keyword(s):  
Catalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Partial Oxidation ◽  
Mixed Oxides ◽  
Supported Catalysts ◽  
Catalytic Performance ◽  
Surface Areas ◽  
Specific Surface Areas ◽  
Mcm 41

Abstract A series of 5% MoV0.3Te0.25 supported on different silicates (i.e. SiO2, HMS, MCM-41, and MCM-48) have been prepared, characterized, and tested as catalysts in the partial oxidation of isobutane to methacrolein. Characterization results showed that the supports almost kept intact structures after supporting 5 wt.% MoV0.3Te0.25 and the supported catalysts had large specific surface areas. Catalytic tests showed that the specific surface area played a key role in the catalytic activity for the supported catalysts.

scholarly journals Preparation and characterization of high specific surface area Mn3O4 from electrolytic manganese residue

2010 ◽  
Vol 8 (5) ◽  
pp. 1059-1068 ◽  
Author(s):  
Tiefeng Peng ◽  
Longjun Xu ◽  
Hongchong Chen
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Magnetic Measurements ◽  
High Specific Surface Area ◽  
Surface Areas ◽  
Electrolytic Manganese ◽  
Electrolytic Manganese Residue ◽  
Specific Surface Areas

AbstractMn3O4 powders have been produced from Electrolytic Manganese Residue (EMR). After leaching of EMR in sulfuric acid, MnSO4 solution containing various ions was obtained. Purifying the solution obtained and then adding aqueous alkali to the purified MnSO4 solution, Mn(OH)2 was prepared. Two methods were employed to produce Mn3O4. One way was oxidation of Mn(OH)2 in aqueous phase under atmosphere pressure to obtain Mn3O4. The other way was roasting Mn(OH)2 precursors in the range of 500°C to 700°C. The prepared samples were investigated by using several techniques including X-ray powder diffraction (XRD), Fourier Transformation Infra-Red (FTIR) spectra, and Brunauer-Emmett-Teller (BET) specific surface area instrument. Particle distribution and magnetic measurements were carried out on laser particle size analyzer, vibrating sample magnetometer (VSM). Through XRD, FTIR and determination of total Mn content (TMC), the products prepared were confirmed to be a single phase Mn3O4. BET specific surface areas can reach to 32 m2 g−1. The results indicated that products synthesized by aqueous solution oxidation method had higher specific surface areas and smaller particle size than those prepared by means of roasting. However the products prepared using the above two methods showed no obvious differences in magnetic property.

scholarly journals Adsorption of water vapour and the specific surface area of arctic zone soils (Spitsbergen)

2018 ◽  
Vol 32 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Jolanta Cieśla ◽  
Zofia Sokołowska ◽  
Barbara Witkowska-Walczak ◽  
Kamil Skic
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Water Vapour ◽  
Specific Surface Area ◽  
Nitrogen Adsorption ◽  
Total Carbon ◽  
Arctic Zone ◽  
Surface Areas ◽  
Arctic Soils ◽  
Specific Surface Areas

AbstractWater vapour/nitrogen adsorption were investigated and calculated the specific surface areas of arctic-zone soil samples (Turbic Cryosols) originating from different micro-relief forms (mud boils, cell forms and sorted circles) and from different depths. For the characterisation of the isotherms obtained for arctic soils, the Brunauer-Emmet-Teller model was then compared with the two other models (Aranovich-Donohue and Guggenheim-Anderson-de Boer) which were developed from Brunauer-Emmet-Teller. Specific surface area was calculated using the Brunauer-Emmet-Teller model at p p0−1range of 0.05-0.35 for the water vapour desorption and nitrogen adsorption isotherms. The values of total specific surface area were the highest in Cryosols on mud boils, lower on cell forms, and the lowest on sorted circles. Such tendency was observed for the results obtained by both the water vapour and nitrogen adsorption. The differences in the values of specific surface area at two investigated layers were small. High determination coefficients were obtained for relationships between the specific surface areas and contents of clay and silt fraction in Cryosols. No statistically significant correlation between the total carbon amount and the values of specific surface area in Cryosols has been found.

scholarly journals The Effects of Various Parameters of the Microwave-Assisted Solvothermal Synthesis on the Specific Surface Area and Catalytic Performance of MgF2 Nanoparticles

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3566
Author(s):  
Yawen Wang ◽  
Zahra Gohari Bajestani ◽  
Jérôme Lhoste ◽  
Sandy Auguste ◽  
Annie Hémon-Ribaud ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Solvothermal Synthesis ◽  
Catalytic Performance ◽  
High Specific Surface Area ◽  
Microwave Assisted ◽  
Surface Areas ◽  
Specific Surface Areas ◽  
Nanoparticle Sizes

High-specific-surface-area MgF2 was prepared by microwave-assisted solvothermal synthesis. The influences of the solvent and the magnesium precursors, and the calcination atmospheres, on the nanoparticle sizes and specific surface areas, estimated by X-Ray Powder Diffraction, N2 sorption and TEM analyses, were investigated. Nanocrystallized (~7 nm) magnesium partially hydroxylated fluorides (MgF2−x(OH)x) with significant specific surface areas between 290 and 330 m2∙g−1 were obtained. After activation under gaseous HF, MgF2−x(OH)x catalysts underwent a large decrease of both their surface area and their hydroxide, rates as shown by their 19F and 1H solid-state NMR spectra. Expect for MgF2 prepared from the acetate precursor, an activity of 30–32 mmol/h∙g was obtained which was about 40% higher compared with that of MgF2 prepared using Trifluoroacetate method (21.6 mmol/h∙g).

scholarly journals Inhibition of tetrachloroethene and trichloroethene on methanogenesis in anaerobic sludges from various origins

2020 ◽  
Vol 81 (3) ◽  
pp. 544-549
Author(s):  
A. M. Wang ◽  
C. S. Hwu ◽  
C. H. Wu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Physical Factor ◽  
Anaerobic Treatment ◽  
Contaminated Groundwater ◽  
Biological Factors ◽  
Methanogenic Activity ◽  
Surface Areas ◽  
Specific Surface Areas

Abstract Nine anaerobic sludges were screened to obtain the most effective methanogenic inoculum for the anaerobic treatment of groundwater that is contaminated with tetrachloroethene (PCE) or trichloroethene (TCE). The selection was based on the toxicity of PCE or TCE to acetoclastic methanogens in different sludges. The effects of two biological factors, sludge origin and specific acetoclastic methanogenic activity, and a physical factor, specific surface area of sludge, on the degree of inhibition were examined and compared. The fifty percent inhibition concentrations (IC50) of PCE and TCE that were obtained from 30 °C batch inhibition tests ranged from 0.18 to 0.41 and 1.71 to 3.31 mM, respectively, for the examined sludges. The toxicity of the contaminants to anaerobic sludges did not depend on the two biological factors but was closely correlated with the specific surface area of sludge. Suspended sludges, which have higher specific surface areas than granular sludges, suffered much greater inhibition. This paper suggests the use of anaerobic granular sludges as inocula in bioreactors for treating PCE- and TCE-contaminated groundwater to reduce the effect of their inhibition.

Organometallic precursor induced defect-enriched mesoporous CeO2 with high specific surface area: preparation and catalytic performance

2020 ◽  
Vol 8 (28) ◽  
pp. 14006-14014 ◽  
Author(s):  
Shaowei Yang ◽  
Haidong Shen ◽  
Fang Cheng ◽  
Chen Wu ◽  
Yueling Cao ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Specific Surface ◽  
Porous Structure ◽  
Surface Area ◽  
Catalytic Performance ◽  
High Specific Surface Area ◽  
Surface Areas ◽  
Organometallic Precursor ◽  
Specific Surface Areas ◽  
Mesoporous Ceo2

CeO2 with special physicochemical properties including high specific surface areas, suitable porous structure and surface enriched defects has been prepared by an organometallic precursor induced method.

scholarly journals Towards Macroporous α-Al2O3—Routes, Possibilities and Limitations

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1787
Author(s):  
Simon Carstens ◽  
Ralf Meyer ◽  
Dirk Enke
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Surface Areas ◽  
Alumina Membranes ◽  
Sol Gel Process ◽  
Specific Surface Areas ◽  
Α Al2o3 ◽  
Sol Gel Synthesis

This article combines a systematic literature review on the fabrication of macroporous α-Al2O3 with increased specific surface area with recent results from our group. Publications claiming the fabrication of α-Al2O3 with high specific surface areas (HSSA) are comprehensively assessed and critically reviewed. An account of all major routes towards HSSA α-Al2O3 is given, including hydrothermal methods, pore protection approaches, dopants, anodically oxidized alumina membranes, and sol-gel syntheses. Furthermore, limitations of these routes are disclosed, as thermodynamic calculations suggest that γ-Al2O3 may be the more stable alumina modification for ABET > 175 m2/g. In fact, the highest specific surface area unobjectionably reported to date for α-Al2O3 amounts to 16–24 m2/g and was attained via a sol-gel process. In a second part, we report on some of our own results, including a novel sol-gel synthesis, designated as mutual cross-hydrolysis. Besides, the Mn-assisted α-transition appears to be a promising approach for some alumina materials, whereas pore protection by carbon filling kinetically inhibits the formation of α-Al2O3 seeds. These experimental results are substantiated by attempts to theoretically calculate and predict the specific surface areas of both porous materials and nanopowders.

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