Carbon partitioning

A. Hodge and P. Millard, Effect of elevated CO, on carbon partitioning and exudate release from Planta o hmeeolata seedlings. Physiol. Plant. I0J.2W (1998). 

M. A. Acra, and J. D. Goeschl, Carbon partitioning patterns of mycorrhizal versus non-mycorrhizal plants real-time dynamic measurements using "CO2, New Phyiol. //2 489 (1989). 

This equation is widely used to describe adsorption in soil and near-surface aquatic environments. Another widely used linear coefficient is the organic-carbon partition coefficient Koc, which is equal to the distribution coefficient divided by the percentage of organic carbon present in the system as proposed by Flamaker and Thompson.131... 

K°° organic carbon partition coefficient K°w octanol-water partition coefficient L liter... 

Seth, R., Mackay, D., Munthe, J. (1999) Estimation of organic carbon partition coefficient and its variability for hydrophobic chemicals. Environ, Sci. Technol. 33, 2390-2394. 

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]. 

Figure 2. The correlation between the organic carbon partition coefficient and the octanol water partition coefficient.

Generally, it is clear how Kd can be predicted for organic hydrophobic pollutants which obey a linear isotherm relationship. First, the organic carbon partition coefficient (i. e.,K0C) is predicted based on either solubility or the octanol-water partition coefficient (K0Vf). Then based on an estimate of the organic carbon fraction in the fine and coarse sediments/soils, Kd can be estimated from Eqs. (a and b) (Table 1). 

Buikhard, L.P. 2000, Estimating dissolved organic carbon partition coefficients for nonionic organic chemicals. Environ. Sci. Technol. 34 4663-4668. 

Local equilibrium, i.e., both the substitutional elements and carbon partition between austenite and ferrite. This was called the PLE mode and was taken to occur at high temperatures. 

Para-equilibrium, where only carbon partitions between austenite and ferrite and the concentration of the substitutional elements Fe and Mn does not vary. This was called the PARA mode and occurred at low temperatures. 

An intermediate mode between PLE and PARA modes was also taken to occur. In this case only carbon partitions between austenite and ferrite, but there is also a narrow difliision spike of Fe and Mn at the vicinity of the interface. This was called the NPLE mode. 

---