Coefficients with organic carbon

Absorption by organic matter of rock Content of organic matter C or carbon in rock, of component i in water C,. Absorption partition coefficients with organic matter - carbon - Iw - ... 

Kowalczuk, R, Cooper, W.J., Durako, M J., Kahn, A.E., Gonsior, M., andYoung, H. (2010). Characterization of dissolved organic matter fluorescence in the South Atlantic Bight with use of PARAFAC model Relationships between fluorescence and its components, absorption coefficients and organic carbon concentrations. Mar. Chem., 118,... 

Similar results have been obtained by Bonilla and Perry 79>, Insinger and Bliss 801, and others for a number of organic liquids such as benzene, alcohols, acetone, and carbon tetrachloride. The data in Table 9.9 for liquids boiling at atmospheric pressure show that tile maximum heat flux is much smaller with organic liquids than with water and the temperature difference at this condition is rather higher. In practice the critical value of AT may be exceeded. Sauer et al.m] found that the overall transfer coefficient U for boiling ethyl acetate with steam at 377 kN/m2 was only 14 per cent of that when the steam pressure was reduced to 115 kN/m2. 

The Level I calculation suggests that if 100,000 kg (100 tonnes) of benzene are introduced into the 100,000 km2 environment, 99% will partition into air at a concentration of 9.9 x 10-7 g/m3 or about 1 pg/rn3. The water will contain nearly 1% at a low concentration of 4 pg/rn3 or equivalently 4 ng/L. Soils would contain 5 x 10-6 pg/g and sediments about 9.7 x 10 6 pg/g. These values would normally be undetectable as a result of the very low tendency of benzene to sorb to organic matter in these media. The fugacity is calculated to be 3.14 x 10-5 Pa. The dimensionless soil-water and sediment-water partition coefficients or ratios of Z values are 2.6 and 5.3 as a result of a Koc of about 55 and a few percent organic carbon in these media. There is little evidence of bioconcentration with a very low fish concentration of 3.0 x FT5 pg/g. The pie chart in Figure 1.7.6 clearly shows that air is the primary medium of accumulation. 

Holten Liitzhoft, H.-C., Yaes, W. H. J., Freidig, A. P., Halling-Sorensen, B. and Hermens, J. L. M. (2000). 1-Octanol/water distribution coefficient of oxolinic acid influence of pH and its relation to the interaction with dissolved organic carbon, Chemosphere, 40, 711-714. 

This is a fully automated system capable of determining between lpg L 1 and 300pg L 1 total organic carbon. It is equipped with a 36-place autosampler, microprocessor and printer. Total organic carbon measurements down to 40pg L 1 have been achieved at a coefficient of variation of 16.3%. 

The persulphate oxidation technique [25] has been applied to estuarine sediments. Organic carbon was determined at lOg kg-1 in bay and estuarine sediments with a coefficient of variation of about 10%. 

The most notable correlation found for the organic carbon partition coefficient (Koc) of hydrophobic chemicals is that obtained with the octanol/water partition coefficient (Kow). Recently, a single correlation has been proposed for all these compounds based on previous data (log(Koc/Kow) versus logAow) the specific approximation proposed was Koc = 0.35 Kow, but this could vary by a factor of 2.5 in either direction [39]. 

Kd is difficult to define when dealing with actual field conditions. Laboratory studies have demonstrated that an approximation of Kd can be made based on the more easily determined factors such as organic carbon content of the soil and the octanol-water partitioning coefficient of the compound. For sediment particles <50 pm ... 

In early work with sorption of aromatic hydrocarbons by sediments, it was reported by Karickhoff et al. [76] that the ratio of individual partition coefficients (Kd) for the sorption of the organic compounds to the organic carbon contents of the sediments (%OC) yields a unique constant (Koc) (Eq. 1), which was independent of sediment properties and dependent only upon the nature of the organic analytes ... 

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