Influence of changes in methanol concentration on clay particle interactions

1989 ◽  
Vol 26 (1) ◽  
pp. 57-63 ◽  
Author(s):  
John M. E. Storey ◽  
J. Jeffrey Peirce
Keyword(s):  
Hydraulic Conductivity ◽  
Clay Particle ◽  
Methanol Concentration ◽  
Atterberg Limits ◽  
Organic Liquids ◽  
Compacted Clay ◽  
Particle Settling ◽  
Liner Material ◽  
Clay Particles ◽  
Alcohol Water

The interactions of clay particles with alcohol–water mixtures are investigated with hydraulic conductivity measurements, the electrophoretic mobilities of the suspended particles are measured, particle settling tests are carried out, and Atterberg limits are determined. Organic liquids frequently interact with clay particles in the clay liners of surface impoundments. Such fluids can cause changes in hydraulic conductivity of the liner material. This study looks at the effects of dilution of a liquid hydrocarbon with water on the properties of a clay soil. Tests with 20, 40, 60, 80, and 100% (by volume) methanol concentrations are used to investigate the changes in hydraulic conductivity of water-compacted clay samples. Particle settling tests, Atterberg limits, and electrophoretic mobility studies are used with the same concentrations to determine the effects of changing methanol concentration on clay particle behavior. The results indicate that higher concentrations of methanol cause an increase in the attraction between the clay particles, and the same concentrations also cause an increase in hydraulic conductivity. Key words: Atterberg limits, clay, electrophoresis, hydraulic conductivity, methanol, settling tests, zeta potential.

The use of Ankara Clay as a compacted clay liner for landfill sites

Clay Minerals ◽  
2017 ◽  
Vol 52 (3) ◽  
pp. 391-412 ◽  
Author(s):  
H. Akgün ◽  
A.G. Türkmenoğlu ◽  
İ. Met ◽  
G.P. Yal ◽  
M.K. Koçkar
Keyword(s):  
Hydraulic Conductivity ◽  
Liquid Limit ◽  
Plasticity Index ◽  
Dry Density ◽  
Compacted Clay ◽  
Maximum Dry Density ◽  
Liner Material ◽  
Landfill Liner ◽  
Ankara Clay ◽  
Landfill Sites

AbstractBecause of the current need for new landfill sites in Ankara, the suitability of Ankara Clay as a liner material for landfill sites was investigated. A mineralogical and geotechnical database was created by compiling the results of previous tests by the present authors as well as those of tests performed in the present study. The mineralogical properties of the samples were investigated by X-ray diffraction, scanning electron microscopy and methylene blue adsorption. The cation exchange capacities (CEC) of the samples vary from 12 to 35 meq/100 g soil and the dominant clay minerals are illite, smectite and kaolinite. The geotechnical properties of the Ankara Clay samples that were assessed included specific gravity, the Atterberg limits (plastic limit, liquid limit, plasticity index), particle-size distribution, compaction properties (i.e.maximum dry density and optimum water content) and hydraulic conductivity. Because the hydraulic conductivity of the samples was lower than the acceptable limit of 1 × 10−9 m/s, it follows that, from a geotechnical perspective, Ankara Clay is a suitable material for use as a compacted clay landfill liner. The relationships between the mineralogical and geotechnical parameters that were investigated by regression analysis indicated that the hydraulic conductivity of the compacted soil samples decreased with increasing plasticity index, clay content, CEC, smectite content, smectite to illite ratio and decreasing illite content. According to the specifications for field construction of compacted clay liners, Ankara Clay is suitable for compaction in the field.

Viscosity and dielectric constant controls on the hydraulic conductivity of clayey soils permeated with water-soluble organics

1988 ◽  
Vol 25 (3) ◽  
pp. 582-589 ◽  
Author(s):  
F. Fernandez ◽  
R. M. Quigley
Keyword(s):  
Dielectric Constant ◽  
Hydraulic Conductivity ◽  
Double Layer ◽  
Pore Space ◽  
Water Soluble ◽  
Organic Liquids ◽  
Clayey Soils ◽  
Compacted Clay ◽  
High Concentrations ◽  
Water Saturated

Water-soluble organic liquids may, under some circumstances, dramatically increase the hydraulic conductivity, k, of water-saturated clayey soils, thus destroying their effectiveness as barriers for contaminants. Double-layer contraction at constant void ratio with resultant increases in the pore space available for flow has been identified as a primary mechanism for such increases in k. This paper shows, however, that the increased viscosity of solutions of some organics in water results in significant decreases in k.Pure alcohols (ethanol and methanol) and other water solubles (dioxane) when permeated through water-compacted clay samples produce an initial decrease in k, followed by a gradual increase to equilibrium values. The "hydrocarbon" front raises the viscosity of the pore fluid and causes an initial drop in k. Tests using aqueous solutions of ethanol and dioxane show decreases in k at concentrations up to ~70%. Only at high concentrations does the dielectric constant, double-layer effect overcome the viscosity effect and produce net increases in k.Effective stresses σ′vof 160 kPa during permeation with ethanol and dioxane prevent the increases in k. Physicochemically induced consolidation and increased K0-shearing effects that close shrinkage cracks are operative. Key words: hydraulic conductivity, liquid hydrocarbons, clay, viscosity, dielectric constant.

scholarly journals Hydraulic and Swell–Shrink Characteristics of Clay and Recycled Zeolite Mixtures for Liner Construction in Sustainable Waste Landfill

2021 ◽  
Vol 13 (13) ◽  
pp. 7301
Author(s):  
Marcin K. Widomski ◽  
Anna Musz-Pomorska ◽  
Wojciech Franus
Keyword(s):  
Hydraulic Conductivity ◽  
Exchange Capacity ◽  
Saturated Hydraulic Conductivity ◽  
Clay Soils ◽  
Compacted Clay ◽  
Clay Liner ◽  
Compacted Clay Liner ◽  
Drying And Rewetting ◽  
Swelling Characteristics ◽  
Shrinkage And Swelling

This paper presents research considering hydraulic as well as swelling and shrinkage characteristics of potential recycled fine particle materials for compacted clay liner for sustainable landfills. Five locally available clay soils mixed with 10% (by mass) of NaP1 recycled zeolite were tested. The performed analysis was based on determined plasticity, cation exchange capacity, coefficient of saturated hydraulic conductivity after compaction, several shrinkage and swelling characteristics as well as, finally, saturated hydraulic conductivity after three cycles of drying and rewetting of tested specimens and the reference samples. The obtained results showed that addition of zeolite to clay soils allowed reduction in their saturated hydraulic conductivity to meet the required threshold (≤1 × 10−9 m/s) of sealing capabilities for compacted clay liner. On the other hand, an increase in plasticity, swelling, and in several cases in shrinkage, of the clay–zeolite mixture was observed. Finally, none of the tested mixtures was able to sustain its sealing capabilities after three cycles of drying and rewetting. Thus, the studied clayey soils mixed with sustainable recycled zeolite were assessed as promising materials for compacted liner construction. However, the liner should be operated carefully to avoid extensive dissication and cracking.

INFLUENCE OF AMMONIUM ON THE BEHAVIOR OF CLAY PARTICLES IN A SODIC SOIL AND BENTONITE

1974 ◽  
Vol 54 (1) ◽  
pp. 39-44 ◽  
Author(s):  
J. C. VAN SCHAIK ◽  
R. R. CAIRNS
Keyword(s):  
Hydraulic Conductivity ◽  
Beneficial Effect ◽  
Salt Concentration ◽  
Soil Type ◽  
Water Movement ◽  
Ammonium Salts ◽  
Sodic Soil ◽  
Clay Particles ◽  
Mobility Studies ◽  
Solonetz Soil

The addition of ammonium salts increased the hydraulic conductivity of samples taken from the Bnt horizon of a Solonetz soil. The improved conductivity was caused by an increase in the salt concentration in the soil solution and by the ammonium adsorbed on the clay particles. Since the dominant clay mineral in this soil type is montmorillonite, purified bentonite was used for comparative studies. Mobility studies of montmorillonite systems indicated that the adsorbed NH4 ions are tightly bound to the clay particles. The size of the NH4-tactoids was found to be larger than that of the Na-tactoids but less than half that of the Ca-tactoids. It was concluded that the beneficial effect of ammonium on water movement in Solonetz soils will be less than that of calcium, but the transformation of the adsorbed ammonium in the field, followed by replacement of sodium by hydrogen, may result in further improvement of these soils.

Particle Settling Times in Ethyl Alcohol-Water Mixtures as Affected by Variables in Impinger Sampling

AIHAJ ◽  
1965 ◽  
Vol 26 (5) ◽  
pp. 537-543 ◽  
Author(s):  
Frank E. Hall ◽  
Richard E. Kupel ◽  
Robert L. Harris
Keyword(s):  
Ethyl Alcohol ◽  
Particle Settling ◽  
Alcohol Water

Influence of alkalinity on the hydraulic conductivity of bentonite-sand liners

1998 ◽  
Vol 38 (2) ◽  
pp. 151-157 ◽  
Author(s):  
David G. Wareham ◽  
Arman Farajollahi ◽  
Mark W. Milke
Keyword(s):  
Hydraulic Conductivity ◽  
Charge Density ◽  
Liquid Limit ◽  
Permeability Test ◽  
Clay Particles ◽  
Sand Mixture ◽  
Compacted Bentonite ◽  
Limit Test ◽  
The Impact

The aim of this research is to record the impact of specific changes in the molding water alkalinity on the hydraulic conductivity of a compacted bentonite-sand mixture. Adding alkalinity to the molding water influences the charge density existing on the clay particles. This can increase the amount of separation of the bentonite particles which causes a decrease in the hydraulic conductivity of the compacted mixture. At the optimum alkalinity the mixture possesses the smallest hydraulic conductivity. In this research an optimum alkalinity (pH=10.1) for a compacted bentonite-sand mixture (7.5% bentonite) was derived from the liquid limit test and the falling-head permeability test.

Influence of sodium adsorption ratio on sodium and calcium breakthrough curves and hydraulic conductivity in soil columns

Soil Research ◽  
2007 ◽  
Vol 45 (8) ◽  
pp. 586 ◽  
Author(s):  
Oagile Dikinya ◽  
Christoph Hinz ◽  
Graham Aylmore
Keyword(s):  
Hydraulic Conductivity ◽  
Electrolyte Concentration ◽  
Soil Aggregates ◽  
Breakthrough Curves ◽  
Sodium Adsorption Ratio ◽  
Threshold Concentration ◽  
Critical Threshold ◽  
Soil Columns ◽  
Clay Particles ◽  
The Matrix

The paper examines the effects of electrolyte concentration and sodium adsorption ratio (SAR) on the relative saturated hydraulic conductivity (RHC) and the ionic behaviour of calcium (Ca) and sodium (Na) ions in the Na–Ca exchange complex. Batch binary exchange and saturated column transport experiments were carried out to quantify these effects using an agricultural Balkuling soil and a mining residue. Generally, RHC has been found to decrease with time, with increasing SAR, and with decreasing electrolyte concentration. The more rapid decrease in RHC in the mining residue, particularly at the lowest concentration (1 mmol/L), was consistent at all SAR values. The decreases in RHC were likely to be caused by partial blocking of pores by dispersed clay particles, as evidenced by the appearance of suspended clay particles in the effluent during leaching. Significant differences in RHC were observed in the passage of fronts of decreasing electrolyte concentrations for CaCl2 and SAR 15 solutions through the soil columns. These differences were attributable to structural alterations (slaking) of the media and the nature of the particles released and mobilised within the porous structure at any given point in the column. Measurements at the critical threshold concentration and turbidity concentration at SAR 15 revealed structural breakdown of the pore matrix system as evidenced by decreased RHC. The increase in SAR to 15 is initially accompanied by erratic RHC, presumably due to the break up of soil aggregates under the increased swelling forces. The less coherent mining residue soil was substantially more vulnerable to blockage of pores than the Balkuling soil in which clay particles are likely to be more readily mobilised, and hence available to re-deposit and occlude the matrix pores.

Winter Effects on Hydraulic Conductivity of Compacted Clay

1995 ◽  
Vol 121 (1) ◽  
pp. 69-79 ◽  
Author(s):  
C. H. Benson ◽  
T. H. Abichou ◽  
M. A. Olson ◽  
P. J. Bosscher
Keyword(s):  
Hydraulic Conductivity ◽  
Compacted Clay
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