Carbon content reflectance

Fig. 1. The relationship between carbon content and maximum ( ) and minimum (o) reflectances of viitrinite (11).

Volatilization of trichloroethylene from soil is slower than it is from water but more rapid than that of many other volatile organic compounds (Park et al. 1988). This study found that an average of 37% of the applied trichloroethylene was volatilized 168 hours after treatment at 12°C, and 45% was volatilized at 21°C. This study also concluded that soil t> pe had no effect on rate of volatilization, although this may simply be a reflection of the fact that the differences between soils used in the study, particularly in organic carbon content, were not very great. 

The above discussion has assumed that the rank of a coal can be adequately measured by a single parameter, such as the reflectance, the volatile matter yield or the organic carbon content. This assumption is commonly made, but it has for a long time appeared a pretty improbable proposition. The discussion also was restricted to bivariate correlations, that is, plots of a single variable against another. 

The atmospheric height is selected as an arbitrary 1000 m reflecting that region of the troposphere which is most affected by local air emissions. A water surface area of 10% or 10,000 km2 is used, with a water depth of 20 m. The water volume is thus 2 x 10n m3. The soil is viewed as being well mixed to a depth of 10 cm and is considered to be 2% organic carbon. It has a volume of 9 x 109 m3. The bottom sediment has the same area as the water, a depth of 1 cm and an organic carbon content of 4%. It thus has a volume of 10s m3. 

If the blackness of the particulate matter collected on a filter is due to the graphitic carbon content of the sample, then the Km unit should convert to ambient elemental carbon concentrations. The form of that translation is apparent from the definition of the Km unit. Elemental carbon concentration measurements made by laboratory reflactometers calibrated against heated butane soot standards show that elemental carbon concentrations are linearly related to the log of the reflectance ratio R /R. Aerosol loadings stated in Km units should be directly proportional to elemental carbon concentrations sampled. 

As in many other anthracitic substances, diffuse bands also appear near 43° and 80° 26. These represent two-dimensional (hk) reflections only since the turbostratic disorder of graphitic layers which characterizes amorphous carbons does not permit (hkl) three-dimensional atomic planes other than (001). Hirsch (19) proposed that the position of the (11) band was a function of carbon content of the sample, related to the crystallite layer diameter (L ). With increasing rank, the (11) reflection shifts towards smaller 26 values, representing greater bond lengths and larger crystallite size. Using values... 

FIGURE 6.6 Variation of reflectance with carbon content. (Adapted from Dorman et al 1957.)... 

Some FTIR bands can be used to represent existing parameters of coalification because of their interdependent relationships. They are (a) aliphatic CH3 at 2956 cm-1 (and CH at 2891 cm-1) for calorific value and moisture content, and (b) aromatic CH at 750 cm-1 (also 884, 815, and 801 cm-1 bands and total aromatic content) for reflectance and carbon content. 

The results of leaching ground raw coals with HN03 alone are indicated in Table I. The sulfur content of the acid-leached coal is indicative of the organically bound sulfur, while the ash content reflects the removal of iron pyrite and other minerals such as carbonates which are soluble in nitric acid. It can be seen that acid leaching alone reduced the sulfur content of Cherokee coal by 57%,... 

---