Dissolved organic carbon distribution

Amon, R.M. W. and Budeus, G. (2003). Dissolved organic carbon distribution and origin in the Nordic Seas Exchanges with the Arctic Ocean and the North Atlantic. J.Geophys. Res., 108 (C7) 3221, doi 10.1029/2002JC001594. 

The early field studies revealed that elevated concentrations of fallout plutonium correlated with Increased concentrations of dissolved organic carbon. Experiments at Argonne National Laboratory corroborate this correlation the explanation Is probably that the organic compounds complex Pu(IV), and, hence, decrease the distribution ratio between water and sedlments(27). In these experiments the distribution ratio (Kj) between sediment and natural waters was measured as a function of DOC. Measurements of Kj In both field and laboratory experiments show an unmistakable effect of DOC upon the distribution ratio. Figure 4 shows the Inverse correlation between the K, of plutonium and concentration of DOC. 

Pu distribution ratios and dissolved organic carbon determination... 

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. 

Caron, G., Suffet, I.H., and Belton, T. Effect of dissolved organic carbon on the environmental distribution of nonpolar organic compounds, Chemosphere, 14(8) 993-1000, 1985. 

All water sources may contain natural organic matter, but concentrations (usually measured as dissolved organic carbon, DOC) differ from 0.2 to more than 10 mg L l. NOM is a direct quality problem due to its color and odor, but more important are indirect problems, such as the formation of organic disinfection by-products (DBPs, e. g. M -halomethanes (THMs) due to chlorination), support of bacterial regrowth in the distribution system, disturbances of treatment efficiency in particle separation, elevated requirements for coagulants and oxidants or reductions in the removal of trace organics during adsorption and oxidation, etc. 

A subsurface peak in HgT was evident at 2-4 cm in most cores. A mechanistic explanation for this observation is not clear. Dissolved organic carbon (DOC) concentrations ranged from about 2.5 to 4 mg/L and generally increased with increasing depth of the core. Thus, a clear correlation was not seen between Hg and DOC (38). Similarly, there was no apparent relationship between dissolved Hg and dissolved Fe or Mn. The distribution of Hg in aqueous and solid phases is the net result of many geochemical processes (e.g., redox, complexation, and solubility). Information available to our group thus far cannot explain the observed subsurface peak in the pore-water Hg profile. 

FIGURE I Molecular weight distribution (thousands of daltons) of dissolved organic carbon in wet precipitation, throughfall, A and B horizon soil solution, and stream water at Hubbard Brook, New Hampshire. Source Adapted from McDowell (1982) and Cole et al. (1984). 

Guggenberger, G., and W. Zech. 1993. Dissolved organic carbon control in acid forest soils of the Fichtelgebirge (Germany) as revealed by distribution patterns and structural composition analysis. Geoderma 59 109-129. 

Marmonier, P., D. Fontvieille, J. Gibert, and V. Vanek. 1995. Distribution of dissolved organic carbon and bacteria at the interface between the Rhone River and its alluvial aquifer. Journal of the North American Benthological Society 14 383-393. 

An approach such as that suggested for the re-examination of the molecular weight distribution of dissolved organic carbon in seawater (Carlson et al., 1985) has been successfully adapted to evaluate the performance of ultrafiltration in the study of radionuclide speciation ... 

Kiichler, I.L., N. Miekeley, and B.R. Forsberg. 1994. Molecular mass distributions of dissolved organic carbon and associated metals in waters from Rio Negro and Rio Solimoes. Sci. Total Environ. 156 207-216. 

Burdige, D.J. and K.G. Gardner. 1998. Molecular weight distribution of dissolved organic carbon in marine sediment pore waters. Mar. Chem. 62 45-64. 

For air-water systems, this equation is known as Henry s law. For solids-water systems, the equilibrium constant is known as the partition coefficient (Ky) or distribution constant (KA). Partition coefficients are available for many organic chemicals from laboratory and field measurements. As organic carbon (OC) present in water (dissolved organic carbon, or DOC), sediment, or soil is the main sink for hydrophobic organic contaminants, the partition coefficients for these compounds are often adjusted (normalized) with respect to the organic carbon content of these compartments ... 

Eyrolle, F., Benedetti, M.F., Benaim, J.Y., and Fevrier, D. (1996) The distributions of colloidal and dissolved organic carbon, major elements, and trace elements in small tropical catchments. Geochim. Cosmochim. Acta 60, 3643-3656. 

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