Soil materials

When a soil sample is screened for suspect ACMs, it should be possible to pick out pieces of boarding that are less than 0.1 cm3 in volume or small clumps of loose fibre providing that they are not totally encased in soil. 

If these materials are weighed and were detected from within a 1 kg sample of soil, then it is possible to calculate (using density correction factors) a result that can be expressed as a percentage weight-to-weight of asbestos in soil. Using this method, it is possible to achieve a detection limit of between 0.001 and 0.01% w/w (10-100 mg/kg), depending upon the sample matrix. 

In the case of soil or fill type materials that are submitted for analysis, there is no definitive guidance on what level of asbestos in soil might be considered safe or what usages may be permitted where low quantities of asbestos contamination are determined to be present. 

If the soil material is due to be removed from site for disposal, then the waste disposal carrier and site accepting the waste will require a certificate of analysis determining how much asbestos is present. If the asbestos content is equal to or greater than 0.1% w/w (1000 mg/kg), then the material is classified in the UK as special waste (SI 972 1996) and can therefore only be disposed of 

At present, there is no official guidance defining what percentage of asbestos in soil would constitute a health risk and how this figure might depend upon the asbestos type, product, material, friability or moisture content etc. However, the UK HSE is also reviewing the test methods for asbestos materials in contaminated land and may provide additional guidance as part of this future documentation. 

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Material Acid droplet pitting, nylon hose destruction Rubber cracking, silver tarnishing, paint blackening Corrosion, soiling, materials deterioration... 

Interactions Between Organophosphorus Compounds and Soil Materials I. Adsorption of Ethyl-methylphosphonofluoridate by Clay and Organic Matter Preparations and by Soils," M. H. B. Hayes, P. R. Lundie and M. Stacey, Pestic. Sci., 3 (1972) 619-629. 

Since the majority of the elements in surface dust arise from deposited aerosol and added soil it is not surprising to find strong linear relationships between the concentrations of the elements in an atmospheric dust and street or house dust. This is illustrated by the two examples given in Fig. 8 for remote house dust vs urban atmospheric dust and street dust vs rural atmospheric dust. As discussed above crustal/soil material is a major component of atmospheric dust and the soil based elements in the atmospheric dust are Al, Ca, Fe, Mg, Mn, Ni, K, Si and Ti. The elements As, Br, Cd, Cl, Co, Cu, Pb, Rb, Se, V, and Zn are, on the other hand, enriched in atmospheric dust. The same elemental distribution applies to surface dust, but in this case their concentrations (compared on a mass basis) are reduced presumably due to dilution with soil. However, the elements enriched in the atmosphere remain enriched in the surface dusts. 

Sample preparation for analyses Introduces some possibilities for errors. Vegetation, sod, or other non-soil material must be removed from the sample. This Is followed by grinding or mixing the sample In some way, sieving It, and then drying It when necessary. 

Perhaps the most serious possibility for error at this stage of the sampling process Is In discarding of vegetation, sod, or other non-soil material collected along with the soil sample as well as the discarding of other materials retained on the sieve. It Is recommended that for approximately 10% of all samples where vegetation, sod, or other non-soil material Is discarded, all discarded material... 

Soils Four soil samples (Bowman et al. 1979) were selected to represent major kinds of soil materials and to include a wide range of properties. Bulk materials were taken by soil scientists from four different regions of Canada. For example, the... 

Untreated control samples were fortified with mepronil. The fortification levels were 0.05-0.25 mg kg for plant materials and 0.005-0.05 mg kg for soil. The following recoveries were obtained 93-95% from rice grain 93-99% from rice straw 86-96% from grape 99-103% from leek 90-110% from lettuce 96-106% from sugar beet (root) 92-100% from sugar beet (leaf) 91-96% from kidney beans 96-100% from string beans and 86-98% from soil. The limit of detection is 0.005 mg kg for plant samples, except for rice straw and soil materials, and 0.01 mg kg for rice straw. 

Embankment and fill applications are the biggest end-user of spent foundry sand. Natural soils are often composed primarily of sand, clay, and water. Most spent foundry sands have these same constituents, which suggests spent foundry sand as a good fill material. The immediate benefits include saving virgin soil materials and reduce the bottom line of the foundry industry. It is also reported that foundry sand as a fill material may present better performance then conventional materials, including better resistance to freeze-thaw distress. 

For compacted, low-permeability soil liners, the U.S. EPA draft guidance recommends natural soil materials, such as clays and silts. However, soils amended or blended with different additives (e.g., lime, cement, bentonite clays, and borrow clays) may also meet the current selection criteria of low hydraulic conductivity, or permeability, and sufficient thickness to prevent hazardous constituent migration out of the landfill unit. Therefore, U.S. EPA does not exclude compacted soil liners that contain these amendments. Additional factors affecting the design and construction of CCLs include plasticity index (PI), Atterburg limits, grain sizes, clay mineralogy, and attenuation properties. 

U.S. EPA requires that soil liners be built so that the hydraulic conductivity is equal to or less than 1 x 10 7 cm/s. To meet this requirement, certain characteristics of soil materials should be met. First, the soil should have at least 20% fines (fine silt and clay-sized particles). Some soils with less than 20% fines will have hydraulic conductivities below 10-7 cm/s, but at such low fines content, the required hydraulic conductivity value is much harder to meet.5... 

It is possible to make soils more resistant to chemical attack. Many of the same methods used to lower hydraulic conductivity can stabilize materials against leachate attack, including greater compaction, an increase in overburden stress, and the mixing of additives such as lime cement or sodium silicate with the natural soil materials.25... 

Farmer (6) reviewed the various diffusion models for soil and developed solutions for several of these models. An appropriate model for field studies is a nonsteady state model that assumes that material is mixed into the soil to a depth L and then allowed to diffuse both to the surface and more deeply into the soil. Material diffusing to the surface is immediately removed by diffusion and convection in the air above the soil. The effect of this assumption is to make the concentration of a diffusing compound zero at the soil surface. With these boundary conditions the solution to Equation 8 can be converted to the useful form ... 

Pedoturbation is the constant internal turnover of soil material. Vertisols are churning heavy clay soils with a high proportion of swelling 2 1 clay minerals (FAO, 2001). These soils form deep wide cracks from the surface downward when they are desiccated, which happens at least once in each year. 

Normally, clay in soil is not present as individual particles but is clustered to aggregates that consist wholly of clay or of a mixture of clay and other mineral and/or organic soil material. Mass transport of soil material along cracks and pores, common in cracking soils in regions with alternating wet and dry periods, does not necessarily enrich the subsoil horizons with clay. 

Roy WR, Griffin RA. 1985. Mobility of organic solvents in water-saturated soil materials. Environ Geol Water Sci 7 241-247. 

Aromatic carbon content for the soil materials was calculated from the CP/MAS 13C NMR spectra using the ratio of peak area of 106-165 ppm to the total area of 0-230 ppm. 

Based on calculated soil adsorption factors (log Koc of 2.24, 2.98, and 4.3), hexachloroethane is expected to have medium to low mobility in soil (Howard 1989). Thus, leaching to groundwater could occur. Results of studies with low organic carbon (0.02%) soil material indicate that sorption to aquifer materials retards hexachloroethane migration in groundwater (Curtis et al. 1986). In aquatic environments, moderate to slight adsorption to suspended solids and partitioning to sediments is likely (Howard 1989). 

Knowing the particle size distribution for soils provides information about many of the soil properties, such as how much heat, water, and nutrients the soil will hold, how fast they will move through the soil, and what kind of structure, bulk density, and consistency the soil will have. The texture of the soil, how it feels, is based on the relative amounts of sand, silt, and clay present. Particles larger than 2.0 mm are called stones or gravels and are not considered soil material. Sand varies in size from 2.0 to 0.05 mm. Silt varies from 0.05 to 0.002 mm. Clays are less than 0.002 mm. 

At locations where aboveground blending takes place, the resulting soil material can be placed back in the original excavation (or selected location) and compacted to the desired density. If the solidified material is to have a desired structural strength (i.e, subbase, pavement, controlled fill, etc.) it can be compacted by conventional construction equipment (vibrating or sheeps-foot rollers). 

Table 4.6 gives a few representative values for Kow and Kp for non-polar organic substances on typical soil material and Table 4.7 gives estimates on typical retardation factors estimated for an aquifer. The data show that many non-polar organic substances, with the possible exception of very lipophilic substances such as hexachlorobenzene, are not markedly retarded in aquifers that contain little organic material (foe = 0.001 - 0.005). On the other hand, such substances are effectively retained in soils rich in organic carbon. 

Table 4.6 Octanol-water Coefficients and Partition Coefficients of Organic Substances on Natural Soil Materials (Modified from Schwarzenbach et al., 1983)...

An inexpensive piston-action ball mill for the rapid preparation of plant and soil material for automated 15N and 13 C analysis enables one to process 150 samples per hour to... 

This is especially the case for biopharmaceutical production, because the soiled materials are normally protein based, and, unlike synthetic drugs, biopharmaceutical drugs are not generally subjected to terminal sterilization. 

Preservation, transport and storage of samples Investigation methods for soils, soil material and other materials Selection and pretreatment of samples Extraction and elution techniques (Table 4)... 

Mills, A.C. and Biggar, J.W. Solubility-temperatrrre effect on the adsorption of gamma- and beta-BHC from aqueous and hexane solutions by soil materials, Soil Sci Soc. Am. Proc., 33 210-216, 1969. 

Morris, D.A. and Johnson, A.l. Summary of hydrologic and physical properties of rocks and soil materials as analyzed by the hydrologic laboratory of the U.S. Geological Survey, 1948-1960, U.S. Geological Survey Water-Supply Paper 1839-D, 1967, 42 p. 

Decabromodiphenyl ether (BDE-209) is a major industrial product from the polybrominated diphenyl ethers used as flame retardants derivatives of this product have been detected in the environment. After exposure to the land surface, these contaminants adsorb on soil materials and may reach the atmosphere as particulate matter these particulates are subsequently subject to photolytic reactions. In this context, Ahn et al. (2006) studied photolysis of BDE-209 adsorbed on clay minerals, metal oxides, and sediments, under sunhght and UV dark irradiation. Dark and light control treatments during UV and sunlight irradiation showed no disappearance of BDE-209 during the experiments. Data on half-lives and rate constants of BDE-209 adsorbed on subsurface minerals and sediments, as determined by Ahn et al. (2006) and extracted from the literature, are shown in Table 16.6. 

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