Elemental composition of organic matter

Changes in elemental composition of organic matter during coalification... 

Table I. Average Element Composition of Organic Matter in Mahogany Zone Composites...

This mode of deposition over a wide area explains the lateral uniformity observed in element composition of organic matter in Mahogany zone oil shale (16), and the similarity in properties of the oil-shale organic matter over the entire deposit. The paucity of macrofossils in the oil shale, limited largely to an occasional gar scale and the like, illustrates the power of the lake s lower layer to digest organic matter. 

Pasturable trophic chain removes from the enclosing medixim and first of all from the sxirface of ground water substantial amoxmts of biogenic elements and concentrates them in the biomass, i.e., in the composition of organic matter. This effect is noticeable in the redistribution of C, Si, S, and also K, Ca, Mg and is especially significant with respect to N and P, whose sources are quite limited. 

Cell growth and metabolic activities are similarly described as a simple chemical reaction. It is also necessary to establish a definite formula for dry cell matter. The elemental composition of certain strains of microorganism is defined by an empirical formula CHaO/3Ns. The general biochemical reaction for biomass production is based on consumption of organic substrate, as shown below. Substrate oxidation is simplified in the following biochemical oxidation ... 

Fig. 5. Elemental composition of humic substances representing various solid phase organic matter (SP0M> number of samples = 52)...

In some sediments, downcore variations in the bulk chemical composition are interpretable as records of temporal shifts in the elemental composition of the sinking POM. Such shifts are caused by changes in the production of sinking POM, which are in turn the result of fluctuations in the abundance and diversity of the overlying plankton community. In nearshore sediments, fluctuations in river runoff and lateral transport can lead to shifts in the supply rate of terrigenous organic matter. An example of a nearshore sediment core in which such fluctuations have been recorded is shown in Figure 23.18. 

Elemental Analysis. The elemental analyses are presented in Table IV. The atomic ratios H/C for all drinking water samples (nos. 1-10) were between 1.28 and 1.39. These values were comparable to humic acid derived from lake sediments. However, H/C ratios were much lower when compared to the chlorinated model humic substances (e.g., 1.04-1.08 for CFH-1 and CFH-2). Bromine was present in almost negligible quantities, whereas Cl varied between 0.3 and 2.4, and S varied between 0.9 and 2.7 in the drinking water organic matter. All fractions from drinking water showed similar elemental composition. However, they differed from the elemental composition of the CFH samples in all respects, especially in chlorine content. 

Moisture and ash (Chapter 3) are not determined as a part of the data presented for ultimate analysis but must be determined so that the analytical values obtained can be converted to comparable bases other than that of the analysis sample. In other words, analytical values may need to be converted to an as-received basis, a dry basis, or a dry, ash-free basis. When suitable corrections are made for any carbon, hydrogen, and sulfur derived from the inorganic material, and for conversion of ash to mineral matter, the ultimate analysis represents the elemental composition of the organic material in coal in terms of carbon, hydrogen, nitrogen, sulfur, and oxygen. 

Sun, L., E. M. Perdue, J. L. Meyer, and J. Weis. 1997. Use of the elemental composition to predict bioavailability of organic matter in a Georgia river. Limnology and Oceanography 42 714-727. 

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