Dissolved organic carbon in natural water

Figure 1. Allochthonous and autochthonous sources of dissolved organic carbon in natural waters. (Reproduced with permission from reference 1. Copyright 1985 Kluwer Academic Publishers.)...

Landrum, P. F., S. R. Nihart, B. J. Eadie, and W. S. Gardner. 1984. Reverse-phase separation method for determining pollutant binding to Aldrich humic acid and dissolved organic carbon in natural waters. Environmental Science Technology 18 187. 

Valentine, R. L., and R. G. Zepp. 1993. Formation of carbon monoxide from the photodegradation of terrestrial dissolved organic carbon in natural waters. Environmental Science and Technology 27 409—412. 

The presence of organic solvents in the sample suppresses the analyte absorption onto the fibre. Thus, for benzene is decreased by 20% in the presence of 3% methanol [214]. Other well-sorbing hydrophobic substances such as dissolved organic carbon in natural water can have a similar effect. 

Cai, Y., Size distribution measurements of dissolved organic carbon in natural waters using ultrafiltration technique, Water Res., 33, 3056-3060, 1999. 

The immunoassay also was examined for interference by naturally occurring humic and fulvic acids (14), which account for the majority of dissolved organic carbon in natural waters (15). Atrazine was measured in water samples that contained from 5 to 100 mg/L of humic and fulvic acid from the Suwannee River (standard-reference surface-water sample) (16) and humic and fulvic acids from Biscayne aquifer near Miami, Florida (17). For all samples, there was no difference between the immunoassay response in the presence and absence of the humic material. These data indicate... 

In the real world, levels higher than these would likely be required to produce toxicity since factors such as dissolved organic carbon in natural waters serve to attenuate possible... 

Particle size distributions of natural sediments and soils are undoubtedly continuous and do not drop to zero abundance in the region of typical centrifugation or filtration capabilities. Additionally, there is some evidence to indicate that dissolved and particulate organic carbon in natural waters are in dynamic equilibrium, causing new particles or newly dissolved molecules to be formed when others are removed. Experiments with soil columns have shown that natural soils can release large quantities of DOC into percolating fluids [109]. 

Dissolved organic carbon in natural seawater (>10 L and <10 L) (A) rinse XAD-2 with water until free of chloride (B) sequential Soxhlet extraction with acetone, methanol, and water (24 h each) (1) ammonium hydroxide solution (2) methanol, then ammonium hydroxide in methanol... 

Ogawa, H., and Ogura, N. (1992). Comparison of two methods for measuring dissolved organic carbon in sea water. Nature 356, 696-698. 

The terms DOM, DOC, and CDOM can be confusing and are sometimes used interchangeably. DOM describes the uncharacterized dissolved organic matter in natural waters. While DOM concentration could be quantified on a dry-mass basis (g m ) and values are found in the older literature, current analytical techniques (e.g., high temperature oxidation [40]), are calibrated in terms of the concentration of carbon atoms. The term DOC is now used when specific concentrations are reported. A molar or mass-based carbon concentration (e.g., g C m ) is thus the preferred unit of measure for either DOM or DOC. In... 

Figure 2.7 Dissolved and particulate organic carbon in natural waters. [Reproduced from...

R.T. Edwards, I.D. McKelvie, P.C. Ferret, B.T. Hart, J.B. Bapat, and K. Koshy. Sensitive flow-injection technique for the determination of dissolved organic carbon in natural waste waters. Anal. Chim. Acta, 261 287-294,1992. 

Aluwihare, L. I., D. J. Repeta, and R. F. Chen, A major biopolymeric component to dissolved organic carbon in surface sea water , Nature, 387,166-169 (1997). 

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. 

Stefansson, A., I. Gunnarsson, and N. Giroud. 2007. New methods for the direct determination of dissolved inorganic, organic and total carbon in natural waters by reagent-free ion chromatography and inductively coupled plasma atomic emission spectrometry. Anal. Chim. Acta 582 69-74. 

Anaerobic decomposition of organic matter in natural waters Dissolved organic matter will decompose in water under anaerobic (oxygen-free) conditions if appropriate bacteria are present. Anaerobic conditions occur naturally in stagnant water such as swamps and at the bottom of deep lakes. The bacteria operate on carbon so as to disproportionate it. In other words, some carbon is oxidized to carbon dioxide and the rest is reduced to methane (reaction (8))... 

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