Dissolved organic content

Hannaker and Buchanan [82] used a method based on wet oxidation with potassium persulfate [83] for the determination of dissolved organic content in concentrated brines following the removal of inorganic carbonates with phosphoric acid. The method involves wet oxidation with potassium persulfate at 130 °C followed by a hot copper oxidation and gravimetric measurement of the carbon dioxide produced. The technique overcomes difficulties of calibration curvature, catalytic clogging, and instrument fouling often encountered with instrumental methods. 

Dissolved organic carbon in soil solution has been shown to increase, decrease, or have little or no measurable effect on the initial binding of triazines to soil. No relationship was found between dissolved organic carbon and sorption of terbuthylazine on two soils however, in a third soil, sorption Kd was inversely correlated to dissolved organic carbon (Zsolnay et al., 1994). Similarly, dissolved organic content from some sources increased atrazine sorption, but from other sources had no effect (Barriuso et al., 1992a). 

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... 

These preliminary investigations on the role of colloids in high-latitude rivers clearly shows differences compared to rivers from the tropics, even if the total dissolved organic content is similar. This observation shows that there is a potential interesting climatic control on the nature and dynamics of colloids. 

If a waste is a mixture of water and organic liquid, you must report it as wastewater unless the organic content exceeds 50 percent. Slurries and sludges containing water must be reported as solid waste if they contain appreciable amounts of dissolved solids, or solids that may settle, such that the viscosity or density of the waste is considerably different from that of process wastewater. 

Discussion. One of the most useful titrations involving iodine is that originally developed by Winkler18 to determine the amount of oxygen in samples of water. The dissolved oxygen content is not only important with respect to the species of aquatic life which can survive in the water, but is also a measure of its ability to oxidise organic impurities in the water (see also Section 10.103). Despite the advent of the oxygen-selective electrode (Section 16.36) direct titrations on water samples are still used extensively.19... 

Marce R, Moreno-Ostos E, Lopez P, Armengol J (2008) The role of allochthonous inputs of dissolved organic carbon on the hypolimnetic oxygen content of reservoirs. Ecosystems 11 1035-1053... 

Figure 9. Variations of uranium (a) and thorium (b) contents in the filtrates of a sample as a function of the filtration size, and relation with the variations of the dissolved organic carbon (DOC). Data sources (1) Viers et al. (1997), (2) Dupre et al. (1999), (3) Porcelh et al. (1997, 2001), (4) Riotte et al. (2003). Filtrates are recovered by tangential ultra-filtration. Low filtration sizes are usually given in Dalton—a molecular weight unit of 1 g/mol—and are ranging between 3 and 300 kD. These filtration sizes have been converted here into an approximate rm pore size.

Contents of Organic Matter and Dissolved Organic Carbon... 

Gershey et al. [58] concluded that a continuous and automated photooxidation procedure of the type described by Collins and Williams [30], with the reported modifications, will probably satisfy most of the needs of the oceanographer concerning measurement of dissolved organic carbon. The convenience and rapidity of the method opens up a new area of research the study of the small-scale temporal and spatial variations of the dissolved organic carbon content of the oceans. 

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