Calculation from sediment organic carbon concentr

APEO concentrations in suspended matter samples were similar to the sediment concentrations. From these values, in situ organic carbon corrected suspended matter/water distribution coefficients (log Koc) were calculated. For the separate ethoxymers NP, A9PE0i, A9PE02,... 

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... 

Plots of the concentrations of any pair of the three oxidation product groups in Table 5.3 can be made.That of syringyl versus vanillyl generally allows differentiation of the four types of vascular plant tissue and non-vascular plant material (Fig. 5.4a). It is not always simple to determine concentrations relative to the total contribution of organic carbon from vascular plants in a sediment. It is simpler to calculate ratios of the amounts of pairs of oxidation product groups, and the most useful plot of this type in distinguishing the four main types of vascular plant tissues is cinnamyl vanillyl versus syringyl vanillyl (Fig. 5.4b). 

Moreover, this calculated inorganic carbon concentration does not incorporate the fact that carbon is continuously supplied into the atmosphere and oceans by degassing from metamorphism and magmatism and by the weathering of carbonate minerals and organic carbon, and is continuously consumed by the production of carbonate and organic carbon sediments (Fig. 2.9). Flence, the total DIG load of the ocean can be expected to vary over time. Finally, the uptake of atmospheric GO2 by the sea surface is a dynamic process that depends on oceanic and wind circulation interlinked. Observations suggest that the Southern Ocean sink of GO2 has weakened between 1981 and 2004 by 0.08 10 g decade" relative to the... 

---