Dispersive soil

Table 3.1. The major ion composition of dispersed soil solutions and saturation extracts from selected soils in California, U.S. 

The major ion composition of dispersed soil solutions and saturation extracts from selected soils in California, U.S. Concentrations of trace elements in soil solutions of the California soils that received sludge applications. Concentrations of trace elements in soil solutions extracted by saturated paste from two metal salt-spiked Israeli soils incubated at saturated regime. 

In the Mixed Forest ecosystems a soil fraction less than 1 pm contains most of the elements previously confined in the forest litter and gradually involved in the biogeochemical cycle. In this fraction Cu and Mo forms account for 60-70% of the total soil content. The metals, poorly absorbable by plants, for example, Cr and V, occur in finely dispersed soil fraction in smaller amounts, about 20-30%. 

Water samples contain dispersed soil particles and colloids. These can be removed by filtration, either in the field or in the laboratory. Some workers carefully filter every sample in the field others argue that the water emerges with particles that are part of the hydrological system under study and therefore their filtration can be postponed until arrival at the laboratory or skipped altogether. 

Sodium adsorbs more water molecules per unit (mole) of charge than most other metal ions (K+, Mg2+, Ca2+) commonly found in the soil-water environment. Hence, when brine (NaCl) is discharged in the soil-water environment, clay and organic particles tend to adsorb fully hydrated Na ions. This causes the particles to become waterborne, a process also known as dispersion. Under dispersion, soils become impermeable to water lakes, streams, and rivers experience large increases in suspended solids (clays and organics). Most soil clays undergo dispersion at an ESP of around 15. At this ESP level, soils appear to be toxic because they lose the potential to function as porous media (water infiltration and gas exchange are restricted). 

Hybrid fluorocarbons (dual action block copolymers), or polyacrylic acid esters or polyethylene terephthalate block copolymers Anionic polymers such as polyacrylates and CMC in alkaline washing liquors or sulfonates repulse partly negatively charged soil particles or micelles, including dispersed soil particles PVA, CMC, starch... 

Kasolv . [PQCotp.] Hydrous potassium silicate powders adhesives, binders, surfactants, coagulants, flocculants, emulsifiers, dispersants, soil antiredeposition agents, corrosion inhibitors. 

Permalose. [IQ Surf. UK] Hydrophilic cqpolymer aq. dispersion soil-release/ antistatic agent for polyester fabric treatment... 

Restoration of the protective properties of artificial sorption screens created on the ways of radioactive nuclide naigration from accumulating ponds is no less an important problem. Usually, clay soils with high sorption ability and containing such minerals as smectite and illite are applied for constructing such screens. In addition, artificial protective screens made of other disperse soils (from sand to loam) are applied the sorption ability of such soils is artificially enhanced beforehand with strengthening compoundssuch as oxalic silica-alumina gel. These compounds decrease the filtration ability of the screen and raise its sorption characteristics. 

Disodium stearyl sulfosuccinamate PEG-40 lanolin PEG-50 lanolin PEG-85 lanolin dispersant, soil suspending Laureth-6 Laureth-14 Laureth-30 dispersant, soil detergents Sodium polyaspartate dispersant, soil hard-surface cleaners Sodium polyaspartate dispersant, solid particles Diethylene triamine pentamethylene phosphonic acid dispersant, solids... 

Failure of a small dam constructed of dispersive soil, near Ramsgate, Natal, South Africa. 

Bell, F.G. and Maud, R.R. 1994. Dispersive soils and earth dams a South African view. Bulletin Association Engineering Geologists, 31, 433-446. 

Bell, F.G. and Walker, D.J.FI. 2000. A further examination of the nature of dispersive soils in Nafal, South Africa. Quarterly Journal Engineering Geology and Hydrogeology, 33, 187-199. 

Gerber. A. and ttamnse. FI.J. von M. 1987. Proposed procedure for identification of dispersive soils by chemical testing. The Civil Engineer in South Africa, 29. 397-399. 

Sherard, J.L, Dunnigan, L.P. and Decker R.S. 1976. Identification and nature of dispersive soils. 

The polycarboxylate builders inhibit the growth of inorganic crystals, which would be formed in their absence during the washing process when phosphate-free or low-phosphate detergents are used. Another function of the polycarboxylates is their ability to disperse soil as well as prevent redeposition of the soil and minimize incrustations of insoluble salts on the fabric. Polycarboxylates are also used as dispersants and to provide shine in formulations for automatic dishwashing machines. 

The transformation of sand-clay thickness at the expense of the destruction of cementating bonds, accumulation of different protein compounds which are actively sorbing on dispersed soils and furthering their transition into unstable drifting state, the formation of thixotropy and high sensitivity to dynamic and also seismic influences. 

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