Organic compound , elements oxidation level

Conditions such as pH, oxidation-reduction potential, and the presence of metal oxides affect the partitioning of the various compounds of selenium in the environment. In general, elemental selenium is stable in soils and is found at low levels in water because of its ability to coprecipitate with sediments. The soluble selenates are readily taken up by plants and converted to organic compounds such as selenomethionine, selenocysteine, dimethyl selenide, and dimethyl diselenide. Selenium is bioaccumulated by aquatic organisms. Very low levels of selenium are found in ambient air. 

Silica is one of the most common elements, and is present in many natural waters. It is found in waters in the form of (a) reactive silica, (b) colloidal silica, and (c) suspended particles (sand). Reactive silica is called silicon dioxide, and in this form is generally not ionised at normal pH levels of water [33,37]. Colloidal silica is either polymerised silicon with multiple units of silicon dioxide, or silicon that has formed loose bonds with organic compounds or other complex inorganic compounds such as calcium oxide and... 

Organic constituents that may be found in ppb levels in WP/F smoke include methane, ethylene, carbonyl sulfide, acetylene, 1,4-dicyanobenzene, 1,3-dicyanobenzene, 1,2-dicyanobenzene, acetonitrile, and acrylonitrile (Tolle et al. 1988). Since white phosphorus contains boron, silicon, calcium, aluminum, iron, and arsenic in excess of 10 ppm as impurities (Berkowitz et al. 1981), WP/F smoke also contains these elements and possibly their oxidation products. The physical properties of a few major compounds that may be important for determining the fate of WP/F smoke in the environment are given in Table 3-3. 

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