Laboratory testing and microanalysis of colloidal mobilization from a glacial till

2011 ◽  
Vol 48 (7) ◽  
pp. 1116-1124
Author(s):  
T. Kunberger ◽  
M.A. Gabr
Keyword(s):  
Colloidal Particles ◽  
Microscopic Analysis ◽  
Clay Content ◽  
Exchange Capacity ◽  
Glacial Till ◽  
Contaminated Site ◽  
Radioactive Cesium ◽  
Average Pore ◽  
Beneficial Effects ◽  
Colloid Mobilization

The effect of the dispersion and piping of clay fines — colloid mobilization — as a means of remediating subsurface contamination was investigated. Prior colloid mobility research has focused on mitigating colloidal movement to reduce contaminant transport or monitoring colloids to determine the extent of mobility and contamination transport. To date, limited work has been performed to evaluate remediation efficiency associated with the removal of clay-sized (colloidal) particles and related sorbed contamination. Laboratory flow-through tests were performed on a glacial till from a radioactive cesium contaminated site. Post-testing analysis comprised mass balance checks, grain-size distribution testing, and microscopic analysis of removed particles. Results showed the potential of initiating and maintaining clay dispersion and piping, thus establishing a means to mobilize colloids and subsequently remove them from the subsurface environment. Beneficial effects of hydraulic gradient and ionic strength manipulations were influenced by soil properties, such as cation exchange capacity, clay content, and average pore diameter. In general, colloid mobilization testing results found that extreme levels of mobilization typically resulted in particle trapping and an overall reduction in colloidal removal, while the effect of more moderate levels was mobilization with increased rates of removal.

Ratio of plant to soil concentrations of strontium-85 and its relation to properties of Greek soils

1991 ◽  
Vol 116 (2) ◽  
pp. 275-279 ◽  
Author(s):  
E. P. Papanicolaou ◽  
C. G. Apostolakis ◽  
V. Skarlou ◽  
C. Nobeli ◽  
P. Kritidis
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Plant Material ◽  
Clay Content ◽  
Exchange Capacity ◽  
Absolute Value ◽  
Plant Parts ◽  
Stems And Leaves ◽  
Lower Variability ◽  
Edible Parts

SUMMARYPlant:soil ratios (CRs) of 85Sr concentration were studied in wheat, lucerne, lettuce, radish, string bean (Phaseolus vulgaris), and cucumber grown in pots in eight Greek soil types in a glasshouse pot experiment in 1989.The CRs of the crops and of the plant parts studied differed according to soil type. They ranged from 0·034–1·39 for wheat grains to 7·6–36·5 for cucumber stems and leaves. The CRs of the edible parts were much lower than those of the other plant material.The correlation between CRs and clay content was negative and, in most cases, significant (P = 0·05–0·01) or highly significant (P < 0·01). The negative correlation improved (higher absolute value of r, lower variability) if clay plus silt content or cation exchange capacity was used instead of clay content.The correlation between CRs and soil properties was greatest for soil pH (r = –0·89) and decreased in the order: pH > total clay plus silt ≃ cation exchange capacity > total clay.

The Pressure Dependence of the Archie Cementation Exponent for Samples from the Ordovician Goldwyer Shale Formation in Australia

SPE Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Zhiqi Zhong ◽  
Lionel Esteban ◽  
Reza Rezaee ◽  
Matthew Josh ◽  
Runhua Feng
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Complex Impedance ◽  
Clay Content ◽  
Exchange Capacity ◽  
Shale Formations ◽  
Fluid Saturation ◽  
Confining Pressures ◽  
Log Interpretation

Summary Applying the realistic cementation exponent (m) in Archie’s equation is critical for reliable fluid-saturation calculation from well logs in shale formations. In this study, the cementation exponent was determined under different confining pressures using a high-salinity brine to suppress the surface conductivity related to the cation-exchange capacity of clay particles. A total of five Ordovician shale samples from the Canning Basin, Australia, were used for this study. The shale samples are all illite-rich with up to 60% clay content. Resistivity and porosity measurements were performed under a series of confining pressures (from 500 to 8,500 psi). Nuclear magnetic resonance (NMR) was used to obtain porosity and pore-size distribution and to detect the presence of residual oil. The complex impedance of samples was determined at 1 kHz to verify the change in pore-size distribution using the POLARIS model (Revil and Florsch 2010). The variation of shale resistivity and the Archie exponent m at different pressures is caused by the closure of microfractures at 500 psi, the narrowing of mesopores/macropores between 500 and 3,500 psi, and the pore-throat reduction beyond 3,500 psi. This study indicates that unlike typical reservoirs, the Archie exponent m for shale is sensitive to depth of burial because of the soft nature of the shale pore system. An equation is developed to predict m under different pressures after microfracture closure. Our study provides recommended experimental procedures for the calculation of the Archie exponent m for shales, leading to improved accuracy for well-log interpretation within shale formations when using Archie-basedequations.

scholarly journals Effect of termite activity on soil under different land management strategies

2017 ◽  
Vol 38 (1) ◽  
pp. 143
Author(s):  
Liane Barreto Alves Pinheiro ◽  
Rodrigo Camara ◽  
Marcos Gervasio Pereira ◽  
Eduardo Lima ◽  
Maria Elizabeth Fernandes Correia ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Management Strategies ◽  
Chemical Properties ◽  
Clay Content ◽  
Exchange Capacity ◽  
Termite Mounds ◽  
Eucalyptus Plantation ◽  
Exchangeable Acidity ◽  
Calcium And Magnesium ◽  
Surrounding Soil

Mound-building termites are important agents of soil bioperturbation, but these species have not been extensively studied thus far. The present study aimed to evaluate the soil particle-size and the chemical attributes of termite mounds and the surrounding soil under different land use strategies. A one-hectare plot was defined for an unmanaged degraded pasture, planted pasture, and for a eucalyptus Corymbia citriodora plantation. In each plot, the top, center, and base sections of five Cornitermes cumulans mounds, and the surrounding soil at the depths of 0-5; 5-10; 10-20 cm, were sampled in the Pinheiral, Rio de Janeiro state. In the three areas, the center of the mounds contained higher clay content, organic carbon, phosphorous, calcium and magnesium, total bases, and cation exchangeable capacity, when compared to the top, base, and the surrounding soils. However, the center had lower values of exchangeable acidity and potassium, of the three areas. In the eucalyptus plantation, the values of pH, total bases, calcium, and magnesium were lower, whereas aluminum, exchangeable acidity, sodium, and cation exchange capacity were higher both in the mounds and in the surrounding soil, in relation to the pastures. There were no differences among the three areas in terms of organic carbon, potassium, phosphorous, and total bases, in the mounds and adjacent soil. Thus, the termite activity altered the clay content and most of the soil chemical properties in all of the studied areas, but only for the center of the mounds. However, the effect of these organisms was different in the eucalyptus plantation in relation to the pasture areas.

scholarly journals Combining ground-based and airborne EM through Artificial Neural Networks for modelling glacial till under saline groundwater conditions

2012 ◽  
Vol 16 (8) ◽  
pp. 3061-3074 ◽  
Author(s):  
J. L. Gunnink ◽  
J. H. A. Bosch ◽  
B. Siemon ◽  
B. Roth ◽  
E. Auken
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Clay Content ◽  
Cost Effective ◽  
Glacial Till ◽  
Saline Groundwater ◽  
Cone Penetration Tests ◽  
Artificial Neural ◽  
Groundwater Quantity ◽  
Airborne Em

Abstract. Airborne electromagnetic (AEM) methods supply data over large areas in a cost-effective way. We used Artificial Neural Networks (ANN) to classify the geophysical signal into a meaningful geological parameter. By using examples of known relations between ground-based geophysical data (in this case electrical conductivity, EC, from electrical cone penetration tests) and geological parameters (presence of glacial till), we extracted learning rules that could be applied to map the presence of a glacial till using the EC profiles from the airborne EM data. The saline groundwater in the area was obscuring the EC signal from the till but by using ANN we were able to extract subtle and often non-linear, relations in EC that were representative of the presence of the till. The ANN results were interpreted as the probability of having till and showed a good agreement with drilling data. The glacial till is acting as a layer that inhibits groundwater flow, due to its high clay-content, and is therefore an important layer in hydrogeological modelling and for predicting the effects of climate change on groundwater quantity and quality.

Li4Mn5O12 Lithium Ion Sieve Preparation and Adsorption Properties

2014 ◽  
Vol 1004-1005 ◽  
pp. 670-674 ◽  
Author(s):  
Dian Quan Dong ◽  
Hong Bo Dai ◽  
Jian Guo Zheng
Keyword(s):  
High Selectivity ◽  
Colloidal Crystal ◽  
Average Pore Size ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Precursor Solution ◽  
Exchange Capacity ◽  
Average Pore ◽  
Exchange Performance ◽  
Roasting Condition

Polystyrene microspheres with 120nm diameter were synthesized by emulsion polymerization and three-dimensionally ordered colloidal crystal templates were obtained by centrifugal sedimentation.Three dimensionally ordered nanopore (3DON) manganese oxide lithium ion-sieve was prepared after filtration, two heated roasting and acid modified by using precursor solution filling the colloidal crystal templates, which was prepared by Lithium salt, manganese salt and citric acid. SEM, XRD, and saturated exchange capacity test were used to characterize the roasting condition, appearance, structure, and ion exchange performance of the oxide. The results showed that, the optimum roasting condition of preparing lithium ion-sieve precursors were found as follows: heating rate at 2°C/min, 300 °C roasting 4h and 800 °C roasting 8h, The 3DON Li4Mn5O12lithium ion sieve precursor has the shape of three-dimensional cross-linked connected into the network structure. Li4Mn5O12was regularly arranged and the hole wall was integrity,average pore size of approximately 90nm.3DON Li4Mn5O12 showed good stability for acid and the retrofit of lithium ion-sieve showed a high selectivity for Li+. The saturated exchange capacity of Li+is 51.98mgLi+/g.

scholarly journals The development of technology for production of zeolites from fly-ash from Troitskaya power plant

2021 ◽  
Vol 8 (1) ◽  
pp. 20218111
Author(s):  
V. A. Snegirev ◽  
V. M. Yurk
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Pore Diameter ◽  
Silicon Oxide ◽  
Exchange Capacity ◽  
Static Exchange Capacity ◽  
Average Pore ◽  
Hydrochemical Synthesis ◽  
Bet Method ◽  
Zeolite Production

The study examines the technology of processing fly ash from Troitskaya power plant for the production of zeolite. The paper presents the results of laboratory studies evaluating the suitability of fly ash from Troitskaya power plant for the production of zeolites and the development of the zeolite production process. Fly ash contains a small amount of heavy metals that can complicate processing, but contains a large amount of silicon oxide. The technology consists of high-temperature alkaline activation of fly ash and hydrochemical synthesis. The resulting powder has a specific surface area of 89.7 m2/g, determined by the BET method, and an average pore diameter of 0.345 μm. The static exchange capacity was 220 mg/g.

scholarly journals Combining ground-based and airborne EM through Artificial Neural Networks for modelling hydrogeological units under saline groundwater conditions

2012 ◽  
Vol 9 (3) ◽  
pp. 3269-3309 ◽  
Author(s):  
J. L. Gunnink ◽  
J. H. A. Bosch ◽  
B. Siemon ◽  
B. Roth ◽  
E. Auken
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Clay Content ◽  
Cost Effective ◽  
Glacial Till ◽  
Saline Groundwater ◽  
Artificial Neural ◽  
Electro Magnetic ◽  
Groundwater Quantity ◽  
Airborne Em

Abstract. Airborne Electro Magnetic (EM) methods supply data over large areas in a cost-effective way. We used Artificial Neural Networks (ANN) to classify the geophysical signal into a meaningful geological parameter. By using examples of known relations between ground-based geophysical data (in this case electrical conductivity, EC, from Electrical Cone Penetration Tests) and geological parameters (presence of glacial till), we extracted learning rules that could be applied to map the presence of a glacial till using the EC profiles from the airborne EM data. The saline groundwater in the area was obscuring the EC signal from the till but by using ANN we were able to extract subtle and often non-linear, relations in EC that were representative for the presence of the till. The ANN results were interpreted as the probability of having till and showed a good agreement with drilling data. The glacial till is acting as a layer that inhibits groundwater flow, due to its high clay-content, and is therefore an important layer in hydrogeological modelling and for predicting the effects of climate change on groundwater quantity and quality.

scholarly journals Relationship of soil properties to fractionation, bioavailability and mobility of lead and zinc in soil

2008 ◽  
Vol 53 (No. 5) ◽  
pp. 225-238 ◽  
Author(s):  
N. Finžgar ◽  
P. Tlustoš ◽  
D. Leštan
Keyword(s):  
Organic Matter ◽  
Regression Analysis ◽  
Soil Organic Matter ◽  
Soil Properties ◽  
Multiple Regression ◽  
Contaminated Soils ◽  
Organic Matter Content ◽  
Clay Content ◽  
Exchange Capacity ◽  
Matter Content

Sequential extractions, metal uptake by <i>Taraxacum officinale</i>, Ruby&rsquo;s physiologically based extraction test (PBET) and toxicity characteristic leaching procedure (TCLP), were used to assess the risk of Pb and Zn in contaminated soils, and to determine relationships among soil characteristics, heavy metals soil fractionation, bioavailability and leachability. Regression analysis using linear and 2nd order polynomial models indicated relationships between Pb and Zn contamination and soil properties, although of small significance (<i>P</i> < 0.05). Statistically highly significant correlations (<i>P</i> < 0.001) were obtained using multiple regression analysis. A correlation between soil cation exchange capacity (CEC) and soil organic matter and clay content was expected. The proportion of Pb in the PBET intestinal phase correlated with total soil Pb and Pb bound to soil oxides and the organic matter fraction. The leachable Pb, extracted with TCLP, correlated with the Pb bound to carbonates and soil organic matter content (<i>R</i><sup>2</sup> = 69%). No highly significant correlations (<i>P</i> < 0.001) for Zn with soil properties or Zn fractionation were obtained using multiple regression.

Sorption of Anionic Pentachlorophenol (PCP) in Aquatic Environments: The Effect of pH

1992 ◽  
Vol 25 (11) ◽  
pp. 41-48 ◽  
Author(s):  
Y. Shimizu ◽  
S. Yamazaki ◽  
Y. Terashima
Keyword(s):  
Organic Carbon ◽  
Aqueous Phase ◽  
Cation Exchange Capacity ◽  
Clay Content ◽  
Exchange Capacity ◽  
Poor Correlation ◽  
Aquatic Environments ◽  
Organic Carbon Content ◽  
Swelling Clay ◽  
Ph Range

The sorption of pentachlorophenol (PCP, pKa’ = 4.75) onto natural solids from aqueous phase was investigated by batch sorption experiments. The experimental aqueous phase was prepared for set values of pH (2 to 12) and ionic strength (0.1 M). Experimental results indicated that the sorption decreased with increasing pH over the entire pH range tested. A simple mathematical model, based on the hypotheses that the sorption coefficients of non-ionized and ionized species are different and the pH has only negligible effect on the natural solid characteristics, was applied to the pH range between 6 and 8, and the sorption coefficients (Kd) of both species were estimated. The Kd of ionized species (phenolate anion) was smaller than that of non-ionized species. The Kd of both species had poor correlation to the organic carbon content of natural solids. The Kd, however, correlated well with the swelling clay content and cation exchange capacity of natural solids. These results indicated that the sorption of PCP was not controlled by the organic carbon referenced hydrophobic sorption. For broader pH range (i.e., below 6 or above 8), the dependence of the natural solid characteristics on pH must be additionally included in the model.

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