Hydrogenation from subsurface hydrogen

FIGURE 2.27 Two possible mechanisms to explain deuterium distributions resulting from deuteriumation and exchange of methyl vinyl ketone. Deuterium is assumed to move subsurface and to attack adsorbed carbons from threefold hollows. Path A multiple exchange by repeated addition-rotation-abstraction at the [3-carbon (classic mechanism) path B I -A hydrogen shift followed by desorption as enol. 

Retention of organic contaminants on subsurface solid phase constituents in general is not completely reversible, so that release isotherms differ from retention isotherms. As a consequence, the extent of sorption depends on the nature of the sorbent. Subsurface constituents as well as the types of bonding mechanisms between contaminants and the sohd phase are factors that control the release of adsorbed organic contaminants. Saltzman et al. (1972) demonstrated the influence of soil organic matter on the extent of hysteresis. Adsorption isotherms of parathion showed hysteresis (or apparent hysteresis) in its adsorption and desorption in a water solution. In contrast, smaller differences between the two processes were observed when the soils were pretreated with hydrogen peroxide (oxidized subsamples) to reduce initial organic matter content. The parathion content of the natural... 

Oxygen and hydrogen isotopes are a powerful tool in the study of the origin of subsurface waters. Prior to the use of isotopes, it was generally assumed that most of the formation waters in marine sedimentary rocks were of connate marine origin. This widely held view was challenged by Clayton et al. (1966), who demonstrated that waters from several sedimentary basins were predominantly of local meteoric origin. 

Battelle Pacific Northwest Laboratory Researchers discovered microbial communities in deep crystalline rock aquifers within the Columbia River Basalt (CRB) Group at a U.S. Department of Energy site in Hanford, Washington. While most subsurface microbial communities depend upon photosynthesis for energy (directly or indirectly), SLiME was found to derive energy from hydrogen that comes from reactions between water and basalt. SLiME could potentially be used in deep strata because they are preadapted to these conditions. 

If the supply is a subsurface water, such as that from a borehole or well, it may contain substantial levels of carbon dioxide (CO2), methane (CH4), and hydrogen sulfide (H2S) as a result of the breakdown of organic matter. 

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