Organic carbon, dissolved, influence

Research into the aquatic chemistry of plutonium has produced information showing how this radioelement is mobilized and transported in the environment. Field studies revealed that the sorption of plutonium onto sediments is an equilibrium process which influences the concentration in natural waters. This equilibrium process is modified by the oxidation state of the soluble plutonium and by the presence of dissolved organic carbon (DOC). Higher concentrations of fallout plutonium in natural waters are associated with higher DOC. Laboratory experiments confirm the correlation. In waters low in DOC oxidized plutonium, Pu(V), is the dominant oxidation state while reduced plutonium, Pu(III+IV), is more prevalent where high concentrations of DOC exist. Laboratory and field experiments have provided some information on the possible chemical processes which lead to changes in the oxidation state of plutonium and to its complexation by natural ligands. 

Houser JN, Bade DL, Cole JJ, Pace ML (2003) The dual influences of dissolved organic carbon on hypolimnetic metabolism organic substrate and photosynthetic reduction. Biogeochemistry 64 247-69... 

Rates of hydrolysis may be influenced by the presence of dissolved organic carbon, or organic components of soil and sediment. The magnitude of the effect is determined by the structure of the compound and by the kinetics of its association with these components. For example, whereas the neutral hydrolysis of chlorpyrifos was unaffected by sorption to sediments, the rate of alkaline hydrolysis was considerably slower (Macalady and Wolf 1985) humic acid also reduced the rate of alkaline hydrolysis of 1-octyl 2,4-dichlo-rophenoxyacetate (Perdue and Wolfe 1982). Conversely, sediment sorption had no effect on the neutral hydrolysis of 4-chlorostilbene oxide, although the rate below pH 5 where acid hydrolysis dominates was reduced (Metwally and Wolfe 1990). 

Torrents A, BG Anderson, S Bilboulian, WE Johnson, CJ Hapeman (1997) Atrazine photolysis mechanistic investigations of direct and nitrate-mediated hydroxyl radical processes and the influence of dissolved organic carbon from the Chesapeake Bay. Environ Sci Technol 31 1476-1482. 

Miskimmin BM, Rudd JWM, Kelly CA. 1992. Influence of dissolved organic carbon, pH, and microbial respiration rates on mercury methylation and demethylation in lake water. Can J Fish Aquat Sci 49 17-22. 

Hapeman, C J., S. Bilboulian, B.G. Anderson, and A. Torrents. 1998. Structural influences of low-molecular weight dissolved organic carbon mimics on the photolytic fate of atrazine. Environ. Toxicol. Chem. 17 975-981. 

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. 

Evans, A., Jr., L. W. Zelazny, and C. E. Zipper. 1988. Solution parameters influencing dissolved organic carbon levels in three forest soils. Soil Science Society of America Journal 52 1789-1792. 

Malcolm, R. K. 1993. Concentration and composition of dissolved organic carbon in soils, streams and groundwaters. In Organic Substances in Soil and Water Natural Constituents and Their Influence on Contaminant Behavior. (A. J. Beck, K. C. Jones, M. H. B. Hayes, and U. Mingelgrin, eds.), pp. 19—30, Royal Society of Chemistry, Cambridge, UK. 

Moore, T. R., and L. Matos. 1999. The influence of source on the sorption of dissolved organic carbon by soils. Canadian Journal of Soil Science 79 321-324. 

Gergel, S. E., M. G. Turner, and T. K. Kratz. 1999. Dissolved organic carbon as an indictor of the scale of watershed influence on lakes and rivers. Ecological Applications 9 1377-1390. 

Gorham, E., J. K. Underwood, J. A. Janssens, B. Freedman, W. Maass, D. H. Waller, and J. G. Ogden. 1998. The chemistry of streams in southwestern and central Nova Scotia, with particular reference to catchment vegetation and the influence of dissolved organic carbon primarily from wetlands. Wetlands 18 115-132. 

Gergel, S. E., M. G. Turner, and T. K. Kratz. 1999. Dissolved organic carbon as an indictor of the scale of watershed influence on lakes and rivers. Ecological Applications 9 1377-1390. Giovannoni, S., and M. Rappe. 2000. Evolution, diversity, and molecular ecology of marine prokarytoes. In Microbial Ecology of the Oceans (D. L. Kirchman, Ed.), pp. 47-84. Wiley-Liss, New York. 

Gamier, C., Mounier, S., and Benaim, J. Y. (2004). Influence of dissolved organic carbon content on modelling natural organic matter acid-base properties. Water Res. 38, 3685-3692. 

Schreiber, B., Brinkmann, T., Schmalz, V., and Worch, E. (2005). Adsorption of dissolved organic matter onto activated carbon—The influence of temperature, absorption wavelength, and molecular size. Water Res. 39, 3449-3456. 

Dissolved organic carbon content does, however, appear to influence the release of atrazine from soil (Clay and Koskinen, 1990a Liu et al., 1995), with more released in the presence of dissolved organic content. Fulvic acid in... 

Unlike the transformation processes that reduce the total amount of triazine present in soil, retention only decreases the amount available for weed control, microbial transformations, or transport. The amount retained or sorbed by soil can range from 0% to 100% of the amount applied, but sorption on silt loam, loam, or clay loam soils typically ranges from 50% to 80%. Triazine retention in soil is influenced primarily by organic carbon content, soil clay content and type, and soil pH. Other factors influencing retention include the amount of triazine applied, the amount of dissolved organic carbon (DOC) in soil solution, soil water content, and triazine to soil contact time (aging). 

McKenna, J.H. and P.H. Doering. 1995. Measurement of dissolved organic carbon by wet chemical oxidation with persulfate Influence of chloride concentration and reagent volume. Mar. Chem. 48 109-114. 

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