Fractionated organics

Gregorich EG, Drury CF, Ellert BH, Liang BC (1997b) Fertilization effects on physically protected light fraction organic matter. Soil Sci Soc Am J... 

Janzen HH, Campbell CA, Brandt SA, Lafond GP, Townley-Smith L (1992) Light-fraction organic matter in soils from long-term crop rotations. Soil Sci Soc Am J 56 1799-1806... 

The selected factors are either mixture-related, quantitative (continuous), or qualitative (discrete).A mixture-related factor is, for instance, the fraction organic solvent in the buffer system. Examples of quantitative factors are the electrolyte concentration, the buffer pH, the capillary temperature, and the voltage, and of qualitative factors the manufacturer or the batch number of a reagent, solvent, or capillary. Sample concentration (see Table 1) is a factor sometimes included. However, the aim of the method tested is to determine this concentration through the measured signal, from a calibration procedure. Thus, one evaluates the influence of the sample concentration on the sample concentration, which we do not consider a good idea. 

Onken, B.M. and Traina, S.J. The sorption of p3U ene and anthracene to humic acid-mineral complexes effect of fractional organic carbon content. J. Environ. Qual, 26(1) 126-132,1997. 

The quasi-linear relationship between the logarithm of the retention factor and volume fraction organic cosolvent in the mobile lase seems to be the general rule in RPC. However, special effects can ur to cause this rule to be violated. Marked deviation from linearity was observed by Melander et al. (158) with retention data o poiy(ethylene glycol) derive-... 

The measured TBT-Sn concentrations were used as a basis for a probabilistic risk assessment. In those samples where the fraction organic carbon (f ) was reported, the sediment and... 

The partition coefficient (K ) was used for the conversion of TBT concentrations in sediment and SPM to TBT concentrations in water. This Kp for TBT was calculated by multiplying the organic carbon partition coefficient (K ) with the measured fraction organic carbon (f ). Consequently, the K value has a strong impact on the final results of the risk prognosis. Generally, in risk predictions the lowest K value is applied to calculate concentrations in water (EC, 2003). This results in a worst-case water concentration, in accordance with the precautionary principle. However, with literature values for the K of TBT ranging from 3.0 - 6.2 (Lepper, 2002), it is more appropriate to base an assessment on local measured values. In this study the... 

The eoneentration in the water eolumn ean be derived from the eorresponding concentration in the sediment, assuming thermo-dynamie partitioning equilibrium. This ean only be done for the loeations were the fraction organic carbon was measured. For the harmonisation of exposure data to water eoneentrations the formulas 1 and 2 taken from the European Commission Techni-eal Guidanee Doeument on Risk Assessment (EC, 2003) were applied. 

Presence of Solid Solid Liquid substrate product fraction Organic solvent or aqueous media Characteristic of the system... 

Contaminants in soil can partition between the soil and air, soil and water, and soil and solids however, the physical structure and chemical composition of surface and subsurface soil are highly variable. Compared to aqueous systems, soil is a complex heterogeneous media composed of solid, liquid, and gaseous phases. The four major components of soil are the inorganic (mineral) fraction, organic matter, water, and air. Soil consists of 50% pore space, which is occupied by air and water 45% minerals and 5% organic matter. Figure 2.5 illustrates a typical soil structure that is important to consider for remediation. 

Soil Fraction % Organic Matter PZC Pore Diameter (nm) % Surface Area in <10-nm Pores Fractal Dimension"6 ... 

Strickland, T. C. (1987). Improved method for separating light and heavy-fraction organic material from soil. Soil Sci. Soc. Am. J. 51(5), 1391-1392. 

Figure 1. Distribution of SDS or APU between soil and aqueous phase. (K gf= [Surf],/([Surf w fx ) = ([mg of surfactant sorbed in soil/g of soil])/([mg of surfactant in aqueous solution/inL] fractional organic carbon content of the soil)...

There is also evidence for the presence of methanotrophs in the 2.8 Ga old Mount Roe palaeosol. This contains highly fractionated organic carbon, probably recording the activity of methanotrophs living near ephemeral ponds this implies that significant biological methane sources existed in the late Archean (Rye and Holland, 2000). Oil is also present in some Archean sandstone (Dutkeiwicz et al, 1998, Rasmussen and Buick, 2000). 

Figure 4. CIR spectra of size-fractionated organics from Volo Bog at pH=8 (top spectra) and pH=2.5 (bottom spectra). Size ranges are A) 0.1 am to 100,000 nominal molecular weight, B) 100,000-30,000 nominal molecular weight, C) 30,000-3,000 nominal molecular weight, and D) 3,000-500 nominal molecular weight.

Phenanthrene Solubilization. A model characterizing the distribution of HOC in systems of soil and micellar nonionic surfactant solution was described previously (7). In this model HOC is assumed to partition among three distinct compartments the soil, the micellar pseudophase, and the aqueous pseudophase. The solubilization model accounts for the partitioning of HOC between the micellar pseudophase and the aqueous pseudophase, the increase in apparent HOC solubility associated with nonionic surfactant monomers in the aqueous pseudophase, the sorption of surfactant onto soil, and the increase in fractional organic carbon content of a soil as a result of surfactant sorption. Evaluation of the model with experimental data was described by Edwards et al. (12). 

In partnership with the clay fraction, organic matter has an extremely important influence on the chemical and physical properties of soils. Critical and beneficial functions of organic matter include ... 

Retardation Parameters Soil fraction organic carbon (foe) content. Soil-water partitioning coefficient (k ). For organic constituents, estimate k,/ = K0Cxfoc. Measure foe on representative background soil samples or use conservative default value per soil type. For metals, run soil leaching test (SPLP) to estimate kj. 

Dzou, L. I. P. Hughes, W. B. 1993. Geochemistry of oils and condensates, K Field, offshore Taiwan a case history in migration fractionation. Organic Geochemistry, 20, 437-462. 

The data in Table XXV-11, plus additional data in the publications cited, indicate that the structural components as well as other components and fractions (organic solvent-soluble... 

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